®
5700A/5720A Series II
Multi-Function Calibrator
Service Manual
PN 601630
June 1996 Rev. 1, 3/02
©1996, 2002 Fluke Corporation, All rights reserved. Printed in U.S.A.
All product names are trademarks of their respective companies.
LIMITED WARRANTY & LIMITATI O N OF LIABILITY
Each Fluke product is warranted to be free fr om defects in material and workmanship
under normal use and service. The warranty period is one year and begins on the date
of shipment. Parts, product repairs and services are warranted for 90 days. This
warranty extends only to the original buyer or end- user customer of a Fluke authorized
reseller, and does not apply to fuses, disposable batt er ies or to any product which, in
Fluke’s opinion, has been misused, altered, neglected or damaged by accident or
abnormal conditions of operation or handling. Fluke warr ant s t hat software will operate
substantially in accordance with its functional specifications for 90 days and that it has
been properly recorded on non-defective media. Fluke does not war r ant that software
will be error free or operate without interruption.
Fluke authorized resellers shall extend this warranty on new and unused products to
end-user customers only but have no authority t o extend a greater or different warr anty
on behalf of Fluke. Warranty support is available if product is purchased through a Fluke
authorized sales outlet or Buyer has paid the applicable international price. Fluke
reserves the right to invoice Buyer for im por tation costs of repair/replacement par t s
when product purchased in one country is submitted f or r epair in another country.
Fluke’s warranty obligation is limited, at Fluke’s option, to refund of the purchase pr ice,
free of charge repair, or replacem ent of a defective product which is returned to a Fluke
authorized service center within the warranty period.
To obtain warranty service, contact your near est Fluke authorized service center or
send the product, with a description of the dif ficulty, postage and insurance prepaid
(FOB Destination), to the nearest Fluke authorized service center. Fluke assumes no
risk for damage in transit. Following warr ant y r epair , the product will be returned to
Buyer, transportation prepaid (FO B Dest inat ion) . If Fluke determines that the failur e
was caused by misuse, alteration, accident or abnormal condition of operation or
handling, Fluke will provide an estimate of repair costs and obt ain aut horization before
commencing the work. Following repair, t he pr oduct will be returned to the Buyer
transportation prepaid and the Buyer will be billed for t he r epair and return transportation
charges (FOB Shipping Point).
THIS WARRANTY IS BUYER’S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU O F
ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIM ITED
TO ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE. FLUKE SHALL NOT BE LIABLE FOR ANY SPECI AL,
INDIRECT, INCIDENTAL OR CO NSEQUENTIAL DAMAGES OR LOSSES,
INCLUDING LOSS OF DATA, W HETHER ARI SING FROM BREACH OF WARRANTY
OR BASED ON CONTRACT, TORT, RELI ANCE O R ANY OTHER THEORY.
Since some countries or states do not allow limitat ion of the term of an implied warranty,
or exclusion or limitation of incidental or consequential damages, the limitations and
exclusions of this warranty may not apply to every buyer . If any provision of this
Warranty is held invalid or unenforceable by a court of com petent jurisdiction, such
holding will not affect the validity or enfor ceabilit y of any other provision.
Fluke Corporation Fluke Europe B.V.
P.O. Box 9090 P.O. Box 1186
Everett, WA 98206-9090 5602 BD Eindhoven
U.S.A. The Netherlands
5/94
Interference Information
This equipment generates and uses radio frequency energy and if not installed and used in strict
accordance with the manufacturer’s instructions, may cause interference to radio and television
reception. It has been type tested and found to comply with the limits for a Class B computing
device in accordance with the specifications of Part 15 of FCC Rules, which are designed to
provide reasonable protection against such interference in a residential installation.
Operation is subject to the following two conditions:
This device may not cause harmful interference.
•
This device must accept any interference received, including interference that may cause
•
undesired operation.
There is no guarantee that interference will not occur in a particular installation. If this equipment
does cause interference to radio or television reception, which can be determined by turning the
equipment off and on, the user is encouraged to try to correct the interference by one of more of
the following measures:
Reorient the receiving antenna
•
Relocate the equipment with respect to the receiver
•
Move the equipment away from the receiver
•
Plug the equipment into a different outlet so that the computer and receiver are on different
•
branch circuits
If necessary, the user should consult the dealer or an experienced radio/television technician for
additional suggestions. The user may find the following booklet prepared by the Federal
Communications Commission helpful: How to Identify and Resolve Radio-TV Interference
Problems. This booklet is available from the U.S. Government Printing Office, Washington, D.C.
20402. Stock No. 004-000-00345-4.
Declaration of the Manufacturer or Importer
We hereby certify that the Fluke Model 5700A/5720A Series II Calibrator is in compliance with
BMPT Vfg 243/1991 and is RFI suppressed. The normal operation of some equipment (e.g. signal
generators) may be subject to specific restrictions. Please observe the notices in the users
manual. The marketing and sales of the equipment was reported to the Central Office for
Telecommunication Permits (BZT). The right to retest this equipment to verify compliance with the
regulation was given to the BZT.
Bescheinigung des Herstellers/Importeurs
Hiermit wird bescheinigt, daβ Fluke Models 5700A/5720A Series II Calibrator in Übereinstimung
mit den Bestimmungen der BMPT-AmtsblVfg 243/1991 funk-entstört ist. Der vorschriftsmäßige
Betrieb mancher Geräte (z.B. Meßsender) kann allerdings gewissen Einschränkungen
unterliegen. Beachten Sie deshalb die Hinweise in der Bedienungsanleitung. Dem Bundesamt für
Zulassungen in der Telekcommunikation wurde das Inverkehrbringen dieses Gerätes angezeigt
und die Berechtigung zur Überprüfung der Seire auf Einhaltung der Bestimmungen eingeräumt.
Fluke Corporation
OPERATOR SAFETY
SUMMARY
WARNING
HIGH VOLTAGE
is used in the operation of this equipment
LETHAL VOLTAGE
may be present on the terminals, observe all safety precautions!
To avoid electrical shock hazard, the operator should not electrically
contact the output hi or sense hi binding posts. During operation, lethal
voltages of up to 1100V ac or dc may be present on these terminals.
Whenever the nature of the operation permits, keep one hand away from
equipment to reduce the hazard of current flowing thought vital organs of
the body.
Terms in this Manual
This instrument has been designed and tested in accordance with IEC Publication 348,
Safety Requirements for Electronic Measuring Apparatus. This manual contains information
and warnings which have to be followed by the user to ensure safe operation and to retain
the instrument in safe condition.
Warning statements identify conditions or practices that could result in personal injury or
loss of life.
Caution statements identify conditions or practices that could result in damage to the
equipment or other property.
Symbols Marked on Equipment
DANGER — High Voltage
Protective ground (earth) terminal
Attention — refer to the manual. This symbol indicates that information about
the usage of a feature is contained in the manua
Power Source
The 5700A/5720A Series II is intended to operate from a power source that will not
apply more than 264V ac rms between the supply conductors or between either supply
conductor and ground. A protective ground connection by way of the grounding
conductor in the power cord is essential for safe operation.
Use the Proper Fuse
To avoid fire hazard, use only the fuse specified on the line voltage selection switch
label, and which is identical in type voltage rating, and current rating.
Grounding the 5700A/5720A Series II
The 5700A/5720A Series II is Safety Class I (grounded enclosure) instruments as
defined in IEC 348. The enclosure is grounded through the grounding conductor of the
power cord. To avoid electrical shock, plug the power cord into a properly wired earth
grounded receptacle before connecting anything to any of the 5700A/5720A Series II
terminals. A protective ground connection by way of the grounding conductor in the
power cord is essential for safe operation.
l.
Use the Proper Power Cord
Use only the power cord and connector appropriate for proper operation of a
5700A/5720A Series II in your country.
Use only a power cord that is in good condition.
Refer cord and connector changes to qualified service personnel.
Do Not Operate in Explosive Atmospheres
To avoid explosion, do not operate the 5700A/5720A Series II in an atmosphere of
explosive gas.
Do Not Remove Cover
To avoid personal injury or death, do not remove the 5700A/5720A Series II cover. Do
not operate the 5700A/5720A Series II without the cover properly installed. There are no
user-serviceable parts inside the 5700A/5720A Series II, so there is no need for the
operator to ever remove the cover.
Do Not Attempt to Operate if Protection May be Impaired
If the 5700A/5720A Series II appears damaged or operates abnormally, protection may
be impaired. Do not attempt to operate it. When in doubt, have the instrument serviced.
SERVICING SAFETY
SUMMARY
FOR QUALIFIED SERVICE
PERSONNEL ONLY
Also refer to the preceding Operator Safety Summary
Do Not Service Alone
Do not perform internal service or adjustment of this product unless another person
capable of rendering first aid and resuscitation is present.
Use Care When Servicing With Power On
Dangerous voltage exist at many points inside this product. To avoid personal injury, do
not touch exposed connections and components while power is on.
Whenever the nature of the operation permits, keep one hand away from equipment to
reduce the hazard of current flowing through vital organs of the body.
Do not wear a grounded wrist strap while working on this product. A grounded wrist strap
increase the risk of current flowing through the body.
Disconnect power before removing protective panels, soldering, or replacing components.
High voltage may still be present even after disconnecting power.
FIRST AID FOR ELECTRIC SHOCK
Free the Victim From the Live Conductor
Shut off high voltage at once and ground the circuit. If high voltage cannot be turned off
quickly, ground the circuit.
If the circuit cannot be broken or grounded, use a board, dry clothing, or other
nonconductor to free the victim.
Get Help!
Yell for help. Call an emergency number. Request medical assistance.
Never Accept Ordinary and General Tests for Death
Symptoms of electric shock may include unconsciousness, failure to breathe, absence of
pulse, pallor, and stiffness, and severe burns.
Treat the Victim
If the victim is not breathing, begin CPR or mouth-to-mouth resuscitation if you are
certified.
Table of Contents
Chapter Title Page
1 Introduction and Specifications........................................................ 1-1
1-1. Introduction.......................................................................................... 1-3
1-2. Contacting Fluke .................................................................................. 1-4
1-3. About this Manual................................................................................ 1-4
1-4. How to Use this Manual....................................................................... 1-4
1-5. Additional Instruction Manuals............................................................ 1-5
1-6. Wideband AC Voltage Module (Option 5700A-03)............................ 1-5
1-7. Auxiliary Amplifiers............................................................................ 1-6
1-8. 5725A Amplifier.............................................................................. 1-6
1-9. Support Equipment and Services ......................................................... 1-6
1-10. 732B Direct Voltage Reference Standard........................................ 1-7
1-11. 732B-200 Direct Volt Maintenance Program (U.S.A. Only) .......... 1-7
1-12. 742A Series Resistance Standards................................................... 1-7
1-13. Wideband AC Module (Option 5700A-03) Calibration Support .... 1-7
1-14. Service Centers ................................................................................ 1-8
1-15. The Components of the 5700A/5720A Series II Calibrator................. 1-8
1-16. Calibrating the 5700A/5720A Series II Calibrator............................... 1-9
1-17. The Calibration Process................................................................... 1-10
1-18. Establishing Traceability ................................................................. 1-10
1-19. Calibration Reports.......................................................................... 1-11
1-20. Calibration Check................................................................................. 1-11
1-21. Developing a Performance History...................................................... 1-11
1-22. Range Calibration................................................................................. 1-12
1-23. DC Zeros Calibration ........................................................................... 1-12
1-24. Specifications....................................................................................... 1-12
1-25. Specification Confidence Levels ..................................................... 1-12
1-26. Using Absolute and Relative Uncertainty Specifications................ 1-12
1-27. Using Secondary Performance Specifications................................. 1-13
1-28. DC Voltage Specifications................................................................... 1-14
1-29. AC Voltage Specifications................................................................... 1-17
1-30. Resistance Specifications..................................................................... 1-23
1-31. DC Current Specifications ................................................................... 1-27
1-32. AC Current Specifications ................................................................... 1-30
1-33. Wideband AC Voltage (Option 5700-03) Specifications .................... 1-35
i
5700A/5720A Series II
Service Manual
2 Theory of Operation........................................................................... 2-1
1-34. General Specifications.......................................................................... 1-36
1-35. Auxiliary Amplifier Specifications...................................................... 1-37
2-1. Introduction.......................................................................................... 2-5
2-2. Calibrator Overview............................................................................. 2-5
2-3. Internal References .......................................................................... 2-5
2-4. Hybrid Reference Amplifiers ...................................................... 2-5
2-5. Fluke Thermal Sensor (FTS)....................................................... 2-5
2-6. Digital-to-Analog Converter (DAC)............................................ 2-6
2-7. Digital Section Overview..................................................................... 2-6
2-8. Analog Section Overview..................................................................... 2-6
2-9. Functional Description Presented by Output Function........................ 2-8
2-10. DC Voltage Functional Description................................................. 2-8
2-11. AC Voltage Functional Description................................................. 2-11
2-12. Wideband AC V Functional Description (Option -03).................... 2-12
2-13. DC Current Functional Description................................................. 2-12
2-14. AC Current Functional Description................................................. 2-12
2-15. Ohms Functional Description.......................................................... 2-13
2-16. System Interconnect Detailed Circuit Description............................... 2-13
2-17. Digital Motherboard Assembly (A4)............................................... 2-13
2-18. Transformer Assembly (A22).......................................................... 2-14
2-19. Analog Motherboard Assembly (A3) .............................................. 2-14
2-20. Front/Rear Binding Posts................................................................. 2-18
2-21. Rear Panel Assembly (A21)............................................................. 2-18
2-22. Filter PA Supply Assembly (A18)................................................... 2-18
2-23. Digital Section Detailed Circuit Description....................................... 2-18
2-24. Digital Power Supply Assembly (A19)............................................ 2-18
2-25. +5V Power Supply....................................................................... 2-19
2-26. ±12V Power Supplies.................................................................. 2-19
2-27. +35V Power Supply..................................................................... 2-19
2-28. +75V Power Supply..................................................................... 2-20
2-29. +35V and +75V Shut-Down Circuit............................................ 2-20
2-30. CPU (Central Processing Unit) Assembly (A20) ............................ 2-21
2-31. Power-Up and Reset Circuit........................................................ 2-21
2-32. Clock Generation......................................................................... 2-21
2-33. Watchdog Timer.......................................................................... 2-24
2-34. Address Decoding and DTACK (Data Acknowledge)................ 2-24
2-35. Interrupt Controller...................................................................... 2-25
2-36. Glue Logic................................................................................... 2-25
2-37. RAM (Random-Access Memory)................................................ 2-25
2-38. ROM (Read-Only Memory) ........................................................ 2-25
2-39. Electrically-Erasable Programmable Read-Only Memory
(EEPROM) .................................................................................. 2-26
2-40. DUART (Dual Universal Asynchronous Receiver/transmitter)
Circuit.......................................................................................... 2-26
2-41. Clock/Calendar Circuit................................................................ 2-26
2-42. Clock Filter Circuit...................................................................... 2-27
2-43. CPU to Rear Panel Interface........................................................ 2-27
2-44. CPU to Front Panel Interface....................................................... 2-27
2-45. Fan Monitor................................................................................. 2-27
2-46. Front Panel Assembly (A2).............................................................. 2-28
2-47. Clock Regeneration Circuitry...................................................... 2-28
2-48. Refresh Failure Detect Circuitry ................................................. 2-28
ii
Contents
2-49. Decoding and Timing Circuitry................................................... 2-28
2-50. Control Display Circuitry............................................................ 2-29
2-51. Output Display Circuitry............................................................. 2-30
2-52. Keyboard Scanner Circuitry........................................................ 2-31
2-53. Knob Encoder Circuitry............................................................... 2-31
2-54. Led Circuitry................................................................................ 2-32
2-55. Keyboard Assembly (A1)................................................................ 2-32
2-56. Analog Section Detailed Circuit Description....................................... 2-33
2-57. Filter/PA Supply (A18), Low-voltage Filter/Regulator Section...... 2-33
2-58. Unregulated OSC Supplies.......................................................... 2-34
2-59. Unregulated LH Supplies ............................................................ 2-34
2-60. Unregulated S Supplies ............................................................... 2-34
2-61. Triac Circuit................................................................................. 2-34
2-62. FR1 Supplies................................................................................ 2-34
2-63. Unregulated FR1 Supply ............................................................. 2-34
2-64. FR2 Supplies................................................................................ 2-35
2-65. Filter/PA Supply (A18), Power Amplifier Output Supply Section . 2-35
2-66. ±PA Supplies Digital Control...................................................... 2-35
2-67. ±250V and ±500V Supplies ........................................................ 2-37
2-68. +PA and -PA Supplies................................................................. 2-37
2-69. ±PA Supply Current Limit........................................................... 2-37
2-70. Regulator/Guard Crossing Assembly (A17).................................... 2-38
2-71. Voltage Regulator Circuitry........................................................ 2-38
2-72. Regulated OSC Supplies.............................................................. 2-38
2-73. Regulated LH Supplies................................................................ 2-39
2-74. Regulated S Supplies................................................................... 2-39
2-75. FR1 Supply.................................................................................. 2-40
2-76. FR2 Supply.................................................................................. 2-40
2-77. Guarded Digital Control Circuitry............................................... 2-41
2-87. Switch Matrix Assembly (A8)......................................................... 2-43
2-88. Switch Matrix Digital Control..................................................... 2-44
2-89. Switch Matrix Operation: 11V DC and 22V DC Ranges............ 2-46
2-90. Switch Matrix Operation: 2.2V AC and 22V AC Ranges........... 2-48
2-91. Switch Matrix Operation: 220V AC and DC Ranges.................. 2-48
2-92. Switch Matrix Operation: 2.2V DC Range ................................. 2-51
2-93. Calibration of the 2.2V Range..................................................... 2-53
2-94. Switch Matrix Operation: 220 mV DC Range ............................ 2-53
2-95. Switch Matrix Operation: 220 mV AC Range ............................ 2-56
2-96. Switch Matrix Operation: 2.2 mV and 22 mV AC Ranges......... 2-56
2-97. Calibration of the mV Ranges..................................................... 2-56
2-98. Internal CAL Zero Amplifier....................................................... 2-59
2-99. Switch Matrix 5725A Amplifier Interface.................................. 2-61
2-100. DAC Assembly (A11)...................................................................... 2-61
2-101. Basic DAC Theory of Operation................................................. 2-61
2-102. DAC Assembly Digital Control................................................... 2-64
2-103. DAC Assembly Reference Circuitry........................................... 2-64
2-104. Duty-Cycle Control Circuit......................................................... 2-65
2-105. DAC Filter Circuit....................................................................... 2-66
2-106. DAC Output Stage....................................................................... 2-66
2-107. Sense Current Cancellation Circuit............................................. 2-67
2-108. Linearity Control Circuit............................................................. 2-67
2-109. Negative Offset Circuit................................................................ 2-68
2-110. DAC Output Switching................................................................ 2-68
2-111. DAC Buffered Reference Sip...................................................... 2-68
2-112. Calibration Hardware .................................................................. 2-69
(continued)
iii
5700A/5720A Series II
Service Manual
2-113. ADC Amplifier............................................................................ 2-69
2-114. ADC Input Selection.................................................................... 2-69
2-115. ADC Circuit................................................................................. 2-70
2-116. How the DAC is Used in Calibration.......................................... 2-72
2-117. DAC Assembly Calibration......................................................... 2-72
2-118. Oscillator Section Overview............................................................ 2-73
2-119. Oscillator Control Assembly (A12)................................................. 2-73
2-120. Oscillator Control Digital Control............................................... 2-74
2-121. Oscillator Input Switching........................................................... 2-74
2-122. Sense Current Cancellation ......................................................... 2-74
2-123. Averaging Converter.................................................................... 2-75
2-124. Error Integrator............................................................................ 2-75
2-125. Three-Pole Filter.......................................................................... 2-75
2-126. Analog Amplitude Control Loop................................................. 2-75
2-127. AC/DC Thermal Transfer Circuit................................................ 2-77
2-128. Oscillator Calibration .................................................................. 2-79
2-129. AC/DC Frequency Response Characterization ........................... 2-80
2-130. Oscillator Output Assembly (A13).................................................. 2-80
2-131. Oscillator Output Digital Control................................................ 2-82
2-132. Quadrature RC Oscillator............................................................ 2-82
2-133. Oscillator Amplitude Control...................................................... 2-83
2-134. Phase−locked Loop...................................................................... 2-83
2-135. 2.2V and 22V Range Output Amplifier....................................... 2-84
2-136. Oscillator Wideband Smd Assembly (A13A1) ........................... 2-84
2-137. Output Stage ................................................................................ 2-85
2-138. Phase Shifter................................................................................ 2-85
2-139. Power Amplifier Assembly (A16)................................................... 2-85
2-140. Power Amplifier Digital Control Sip Assembly (A16A1).......... 2-86
2-141. PA Common Circuitry................................................................. 2-87
2-142. +PA and -PA Supplies................................................................. 2-87
2-143. PA Input Stage............................................................................. 2-87
2-144. PA Mid Stage............................................................................... 2-88
2-145. PA Output Stage.......................................................................... 2-88
2-146. PA Sense Current Cancellation Circuitry.................................... 2-89
2-147. PA in Standby.............................................................................. 2-89
2-148. PA Operation: 220V DC Range .................................................. 2-89
2-149. PA Operation: 220V AC Range .................................................. 2-91
2-150. High Voltage Assembly Support Mode....................................... 2-91
2-153. 220V DC Internal Calibration Network ...................................... 2-92
2-154. PA Calibration............................................................................. 2-92
2-155. High Voltage Assemblies (A14 and A15) ....................................... 2-96
2-156. 1100V AC Range......................................................................... 2-96
2-157. 1100V DC Range......................................................................... 2-98
2-158. HVDC Power Supply Filter Circuit............................................. 2-98
2-159. HV DC Output Series Pass and Current Limit Circuit................ 2-98
2-160. DC HV Amplifier/AC Sense Buffer............................................ 2-100
2-161. 2.2A Range.................................................................................. 2-100
2-162. 2.2A Power Supply Filter Circuit................................................ 2-102
2-163. High Voltage Digital Control...................................................... 2-103
2-164. High Voltage Calibration............................................................. 2-104
2-165. Calibration of the AC Function................................................... 2-104
2-166. Calibration of the Current Function. ........................................... 2-106
2-167. High Voltage Magnitude Control................................................ 2-106
2-168. Ohms Overview ............................................................................... 2-108
iv
Contents
2-169. Ohms Main Assembly (A10)........................................................... 2-109
2-170. Selection of Resistance Values.................................................... 2-109
2-171. Ohms Main Assembly Support of Current Function Calibration 2-112
2-172. Ohms Digital Control .................................................................. 2-112
2-173. Ohms Cal Assembly (A9)................................................................ 2-112
2-174. Ohms CAL Digital Control ......................................................... 2-112
2-175. 1, 1.9, and Short Resistance......................................................... 2-113
2-176. Two-Wire Ohmmeter Compensation Circuit. ............................. 2-113
2-180. Ohms Calibration......................................................................... 2-115
2-186. Current/High Resolution Oscillator Assembly Overview (A7)....... 2-121
2-187. Current Section............................................................................ 2-122
2-199. High-Resolution Oscillator Section............................................. 2-128
2-204. Rear Panel Assembly (A21)............................................................. 2-130
2-205. Rear Panel Power Supplies.......................................................... 2-131
2-206. Rear Panel Address Mapping...................................................... 2-131
2-207. Clock Regeneration Circuit......................................................... 2-132
2-208. IEEE-488 (GPIB) Interface.......................................................... 2-132
2-209. RS-232C Interface....................................................................... 2-132
2-210. Auxiliary Amplifier Interface...................................................... 2-133
2-211. 5725A Interface........................................................................... 2-133
2-212. Phase Lock In/Variable Phase out............................................... 2-133
2-213. Rear Panel Relay Control............................................................ 2-134
2-214. Rear Panel CPU Interface............................................................ 2-134
2-215. Wideband AC Module (Option -03)................................................ 2-135
2-216. Wideband Oscillator Assembly (A6) .......................................... 2-135
2-222. Wideband Output Assembly (A5)............................................... 2-138
(continued)
3 Calibration and Verification .............................................................. 3-1
3-1. Introduction.......................................................................................... 3-3
3-2. Accessing the Fuse............................................................................... 3-4
3-3. Cleaning the Air Filter.......................................................................... 3-5
3-4. Cleaning the Exterior ........................................................................... 3-6
3-5. Calibration............................................................................................ 3-6
3-6. Calibrating the 5700A/5720A Series II to External Standards............ 3-6
3-7. Calibration Requirements ................................................................ 3-7
3-8. When to Adjust the Calibrator’s Uncertainty Specifications .......... 3-7
3-9. Calibration Procedure ...................................................................... 3-8
3-10. Range Calibration................................................................................. 3-14
3-11. Calibrating the Wideband AC Module (Option 5700A-03)................. 3-17
3-12. Performing a Calibration Check........................................................... 3-20
3-13. Full Verification................................................................................... 3-22
3-14. Required Equipment for All Tests................................................... 3-23
3-15. Warm-up Procedure for All Verification Tests ............................... 3-23
3-16. Resistance Verification Test............................................................ 3-25
3-17. Two-Wire Compensation Verification ............................................ 3-27
3-18. DC Voltage Verification Test.......................................................... 3-28
3-19. DC Voltage One-Tenth Scale Linearity Test................................... 3-29
3-20. Direct Current Accuracy Verification Test...................................... 3-30
3-21. AC Voltage Frequency Accuracy Test ............................................ 3-31
3-22. Output Level Tests For AC V Ranges............................................. 3-31
3-23. AC Current Test, 22 mA to 11A Ranges......................................... 3-33
3-24. AC Current Test, 2 mA and 200 µA Ranges ................................... 3-36
3-25. Rationale for Using Metal-Film Resistors to Measure AC Current 3-37
3-26. Wideband Frequency Accuracy Test............................................... 3-38
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5700A/5720A Series II
Service Manual
4 Maintenance....................................................................................... 4-1
3-27. Wideband AC Voltage Module Output Verification....................... 3-38
3-28. Wideband Output Accuracy at 1 kHz Test........................................... 3-39
3-29. Wideband Output Flatness Test ........................................................... 3-40
3-30. Wideband Flatness Calibration Procedure....................................... 3-41
3-31. Optional Tests ...................................................................................... 3-42
3-32. DC Voltage Load Regulation Test................................................... 3-42
3-33. DC Voltage Linearity Test............................................................... 3-43
3-34. DC Voltage Output Noise (10 Hz to 10 kHz) Test.......................... 3-43
3-35. DC Voltage Output Noise (0.1 to 10 Hz) Test................................. 3-45
3-36. AC Voltage Distortion Test............................................................. 3-45
3-37. Wideband Distortion Testing........................................................... 3-45
3-38. AC Voltage Overshoot Test............................................................. 3-46
3-39. Minimum Use Requirements................................................................ 3-46
3-40. Determining Test Limits for Other Calibration Intervals..................... 3-48
4-1. Introduction.......................................................................................... 4-3
4-2. Cleaning the Air Filter.......................................................................... 4-3
4-3. General Cleaning.................................................................................. 4-4
4-4. Cleaning PCA’s..................................................................................... 4-4
4-5. Access Procedures................................................................................ 4-4
4-6. Top and Bottom Covers................................................................... 4-4
4-7. Digital Section Cover....................................................................... 4-4
4-8. Analog Section Covers..................................................................... 4-4
4-9. Rear Panel Removal and Installation............................................... 4-4
4-10. Rear Panel Assembly Access........................................................... 4-5
4-11. Front Panel Removal and Installation.............................................. 4-6
4-12. Display Assembly Removal and Installation............................... 4-6
4-13. Keyboard Assembly Removal and Installation ........................... 4-7
4-14. Analog Assembly Removal and Installation.................................... 4-7
4-15. Digital Assembly Removal and Installation .................................... 4-9
4-16. Power Transformer Removal and Installation................................. 4-9
4-17. Hybrid Cover Removal.................................................................... 4-9
4-18. Front/Rear Binding Post Reconfiguration............................................ 4-9
4-19. Installing a Wideband AC Module (Option -03).................................. 4-11
4-20. Clearing Ghost Images from the Control Display................................ 4-11
4-21. Replacing the Clock/Calendar Backup Battery.................................... 4-11
4-22. Using Remote Commands Reserved for Servicing.............................. 4-12
4-23. Using the ETIME Command............................................................ 4-12
5 Troubleshooting................................................................................. 5-1
5-1. Introduction.......................................................................................... 5-3
5-2. Interpreting Diagnostic Fault Codes..................................................... 5-3
5-3. Component-level Troubleshooting....................................................... 5-40
5-4. Troubleshooting the Wideband Output Assembly (A5).................. 5-40
5-5. Troubleshooting the Wideband Oscillator Assembly (A6)............. 5-42
5-6. Troubleshooting the Current/Hi-Res Assembly (A7)...................... 5-47
5-7. Current Section............................................................................ 5-47
5-8. Hi-Res Oscillator Section............................................................ 5-52
5-9. Troubleshooting the Switch Matrix Assembly (A8)........................ 5-54
5-10. Troubleshooting the Ohms Cal Assembly (A9)............................... 5-56
5-11. Two-wire Compensation Circuit................................................. 5-56
5-12. Troubleshooting the Ohms Main Assembly (A10).......................... 5-57
vi
Contents
5-13. Troubleshooting the DAC Assembly (A11).................................... 5-58
5-14. Duty-cycle Control Circuit.......................................................... 5-63
5-15. ADC Circuit................................................................................. 5-67
5-16. Buffered Reference SIP Assembly (A11A2):.............................. 5-68
5-17. Troubleshooting the Oscillator Control Assembly (A12)................ 5-69
5-18. Troubleshooting the Oscillator Output Assembly (A13)................. 5-72
5-19. Troubleshooting the High Voltage Control Assembly (A14).......... 5-74
5-20. Magnitude Control Circuit........................................................... 5-76
5-21. Troubleshooting the High Voltage/High Current Assembly (A15). 5-77
5-22. Troubleshooting the Power Amplifier Assembly (A16).................. 5-79
5-23. Troubleshooting the Filter/PA Supply Assembly (A18) ................. 5-82
6 List of Replaceable Parts .................................................................. 6-1
6-1. Introduction.......................................................................................... 6-3
6-2. How to Obtain Parts............................................................................. 6-3
6-3. Manual Status Information................................................................... 6-3
6-4. Newer Instruments................................................................................ 6-3
6-5. Service Centers..................................................................................... 6-4
7 Schematic Diagrams.......................................................................... 7-1
(continued)
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5700A/5720A Series II
Service Manual
viii
List of Tables
Table Title Page
1-1. Auxiliary Amplifier Data....................................................................................... 1-6
1-2. 5720A Series II DC Voltage Specifications: 99 % and 95 % Confidence Levels 1-14
1-3. 5700A Series II DC Voltage Specifications: 99 % and 95 % Confidence Levels 1-15
1-4. DC Voltage Secondary Performance Specifications and Operating
Characteristics ....................................................................................................... 1-16
1-5. 5720A Series II AC Voltage Specifications: 99 % Confidence Level.................. 1-17
1-6. 5720A Series II AC Voltage Specifications: 95 % Confidence Level.................. 1-18
1-7. 5700A Series II AC Voltage Specifications: 99 % Confidence Level.................. 1-19
1-8. 5700A Series II AC Voltage Specifications: 95 % Confidence Level.................. 1-20
1-9. AC Voltage Secondary Performance Specifications and Operating
Characteristics ....................................................................................................... 1-21
1-10. 5720A Series II Resistance Specifications: 99 % and 95 % Confidence Levels.. 1-23
1-11. 5700A Series II Resistance Specifications: 99 % and 95 % Confidence Levels.. 1-24
1-12. Resistance Secondary Performance Specifications and Operating
Characteristics ....................................................................................................... 1-25
1-13. Current Derating Factors....................................................................................... 1-26
1-14. 5720A Series II DC Current Specifications: 99 % and 95 % Confidence Levels. 1-27
1-15. 5700A Series II DC Current Specifications: 99 % and 95 % Confidence Levels. 1-28
1-16. DC Current Secondary Performance Specifications and Operating
Characteristics ....................................................................................................... 1-29
1-17. 5720A Series II AC Current Specifications: 99 % Confidence Level .................. 1-30
1-18. 5720A Series II AC Current Specifications: 95 % Confidence Level .................. 1-31
1-19. 5700A Series II AC Current Specifications: 99 % Confidence Level .................. 1-32
1-20. 5700A Series II AC Current Specifications: 95 % Confidence Level .................. 1-33
1-21. AC Current Secondary Performance Specifications and Operating
Characteristics ....................................................................................................... 1-34
1-22. Wideband AC Voltage (Option 5700-03) Specifications...................................... 1-35
2-1. Analog Motherboard Connectors .......................................................................... 2-17
2-2. Supplies Generated by the Digital Power Supply ................................................. 2-19
2-3. CPU Acronym Glossary ........................................................................................ 2-23
2-4. CPU Memory Map ................................................................................................ 2-24
2-5. CPU Interrupts, Priorities, and Vectors................................................................. 2-25
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5700A/5720A Series II
Service Manual
2-6. Front Panel Memory Map...................................................................................... 2-29
2-7. Control Lines for the Keyboard LEDs................................................................... 2-32
2-8. Unregulated Supplies from the Filter Assembly................................................... 2-33
2-9. Regulated Supplies from the Filter/PA Supply..................................................... 2-33
2-10. Regulated Outputs from the Regulator/Guard Crossing Assembly ...................... 2-39
2-11. Inguard CPU Memory Map................................................................................... 2-41
2-12. Inguard CPU Interrupts.......................................................................................... 2-43
2-13. PA and -PA Supply Settings at Different Outputs ................................................ 2-87
2-14. AC and DC Current Ranges................................................................................... 2-122
2-15. Relay Settings for Current Range Selection.......................................................... 2-125
2-16. Divider Settings and VCO Frequencies................................................................. 2-131
3-1. Standards for Calibrating 5700A/5720A Series II................................................ 3-7
3-2. List of Required Equipment for Main Output....................................................... 3-24
3-3. Equipment Required for Resistance Testing......................................................... 3-25
3-4. Low Value Resistance Calibration Using a Current Source.................................. 3-27
3-5. Equipment Required for DC Voltage Testing....................................................... 3-28
3-6. Equipment Required for Direct Current Test........................................................ 3-30
3-7. Equipment Required for AC V Output Level Tests.............................................. 3-31
3-8. 5790A Adjustment Counts .................................................................................... 3-33
3-9. Equipment Required for 22 mA to 11A Alternating Current Test Using
the 5790A Input 1.................................................................................................. 3-33
3-10. Equipment Required for Alternating Current Accuracy Test for the 2 mA
and 200 uA Ranges................................................................................................ 3-36
3-11. Equipment Required for Testing and Calibrating the Wideband Option.............. 3-39
3-12. Wideband Adjustment Tolerance.......................................................................... 3-40
3-13. Equipment Required For DC V Optional Tests..................................................... 3-42
3-14. Equipment Required for Distortion Test............................................................... 3-45
3-15. Minimum Use Requirements................................................................................. 3-47
3-16. 5720A Resistance Test Record.............................................................................. 3-50
3-17. 5700A Resistance Test Record.............................................................................. 3-52
3-18. DC Voltage Test Record for 5720A...................................................................... 3-54
3-19. DC Voltage Test Record for 5700A...................................................................... 3-55
3-20. Direct Current Accuracy Test Record (5720A)..................................................... 3-56
3-21. Direct Current Accuracy Test Record (5700A)..................................................... 3-57
3-22. AC Voltage Frequency Accuracy Test Record ..................................................... 3-57
3-23. 5720A AC Voltage Output Test Record................................................................ 3-58
3-24. 5700A AC Voltage Output Test Record................................................................ 3-60
3-25. AC Voltage 2 mV Range Test Record .................................................................. 3-61
3-26. 5720A AC Current 20 mA to 10A Accuracy Test Record.................................... 3-62
3-27. 5700A AC Current 20 mA to 10A Accuracy Test Record.................................... 3-63
3-28. 5720A AC Current 2 mA and 200 mA Accuracy Test Record............................. 3-64
3-29. 5700A AC Current 2 mA and 200µA Accuracy Test Record............................... 3-64
3-30. Wideband Frequency Accuracy Testi Record....................................................... 3-65
3-31. Wideband Accuracy at 1 kHz Test Record............................................................ 3-66
3-32. Wideband Flatness Test Record............................................................................ 3-66
3-33. Wideband Absolute Error 10 Hz to 500 kHz......................................................... 3-68
3-34. Load Regulation Test Record................................................................................ 3-69
3-35. DC Voltage Linearity Test Record....................................................................... 3-69
3-36. DC Voltage Output Noise Test.............................................................................. 3-69
3-37. AC V Distortion Test Summary............................................................................ 3-70
x
Contents
3-38. Test Record for Flatness Check of the AC 2 mV Range....................................... 3-70
5-1. Verifying Multiplexer U 6..................................................................................... 5-46
5-2. Ohms Main Resistance Tolerance ......................................................................... 5-58
6-1. Front Panel Final Assembly .................................................................................. 6-5
6-2. A1 Keyboard PCA................................................................................................. 6-12
6-3. A2 Front Panel PCA.............................................................................................. 6-14
6-4. A3 Analog Motherboard PCA............................................................................... 6-17
6-5. A4 Digital Motherboard PCA................................................................................ 6-19
6-6. A5 Wideband Output PCA, Option -03................................................................ 6-21
6-7. A6 Wideband Ocillator PCA, Option -03.............................................................. 6-25
6-8. A7 Current/High-Res Oscillator PCA................................................................... 6-29
6-9. A8 Switch Matrix PCA.......................................................................................... 6-33
6-10. A9 Ohms Cal PCA................................................................................................. 6-36
6-11. A10 Ohms Main PCA............................................................................................ 6-39
6-12. A11 DAC PCA ...................................................................................................... 6-41
6-13. A11A1 DAC Filter SIP PCA................................................................................. 6-46
6-14. A11A2 DAC Buffered Reference SIP PCA.......................................................... 6-48
6-15. A12 Oscillator Control PCA.................................................................................. 6-50
6-16. A13 Oscillator Output PCA................................................................................... 6-54
6-17. A13A1 Oscillator Wideband SMD PCA.............................................................. 6-58
6-18. A14 High Voltage Control PCA............................................................................ 6-60
6-19. A15 High Voltage/High Current PCA................................................................... 6-63
6-20. A16 Power Amplifier PCA.................................................................................... 6-66
6-21. A16A1 Power Amplifier Digital Control SIP PCA............................................... 6-70
6-22. A17 Regulator/Guard Crossing PCA..................................................................... 6-72
6-23. A18 Filter/PA Supply PCA ................................................................................... 6-75
6-24. A19 Digital Power Supply PCA............................................................................ 6-79
6-25. A20 CPU PCA....................................................................................................... 6-82
6-26. A20 CPU PCA....................................................................................................... 6-83
6-27. A21 Rear Panel PCA............................................................................................. 6-85
(continued)
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5700A/5720A Series II
Service Manual
xii
List of Figures
Figure Title Page
1-1. Time and Costs: Calibrator Calibration................................................................. 1-10
1-2. Volt-Hertz Capability ............................................................................................ 1-22
2-1. Digital Section Block Diagram.............................................................................. 2-7
2-2. Analog Section Block Diagram, Part .................................................................... 2-9
2-3. Analog Section Block Diagram, Part .................................................................... 2-10
2-4. System Interconnections........................................................................................ 2-15
2-5. CPU Assembly Block Diagram............................................................................. 2-22
2-6. Power Amplifier Output Supply Simplified Schematic ........................................ 2-36
2-7. Switch Matrix Assembly Simplified Schematic.................................................... 2-45
2-8. Switch Matrix Configuration for 11V DC and 22V DC Ranges........................... 2-47
2-9. Switch Matrix Configuration for 2.2V and 22V AC Ranges ................................ 2-50
2-10. Switch Matrix Configuration for 220V DC and AC Ranges................................. 2-50
2-11. Switch Matrix Configuration for 2.2V DC Range ................................................ 2-52
2-12. Calibration of the 2.2V DC Range ........................................................................ 2-54
2-13. Switch Matrix Configuration for 220 mV DC Range ........................................... 2-56
2-14. V AC, 2.2 mV AC, and 22 mV AC Range............................................................ 2-57
2-15. Divider Calibration................................................................................................ 2-58
2-16. Divider Gain Calibration ....................................................................................... 2-60
2-17. DAC Assembly Simplified Schematic.................................................................. 2-63
2-18. ADC Circuit Measurement Functions................................................................... 2-71
2-19. Oscillator Control Analog Control Loop............................................................... 2-76
2-20. AC/DC Thermal Transfer Circuit.......................................................................... 2-78
2-21. Quadrature RC Oscillator Circuit.......................................................................... 2-81
2-22. Power Amplifier Simplified Schematic................................................................. 2-90
2-23. Power Amplifier DC Calibration Network............................................................ 2-93
2-24. Power Amplifier Calibration AC Attenuator......................................................... 2-95
2-25. High Voltage/High Current Assembly 1100V AC Range..................................... 2-97
2-26. High Voltage/High Current Assembly 1100V DC Range..................................... 2-99
2-27. High Voltage/High Current Assembly 2.2A AC and DC Ranges......................... 2-102
2-28. High Voltage/High Current Assembly Calibration............................................... 2-106
2-29. High Voltage/High Current Assembly 2.2A Range Calibration........................... 2-107
2-30. Ohms Assemblies Simplified Schematic............................................................... 2-111
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Service Manual
2-31. Ohms Main Assembly Simplified Schematic........................................................ 2-111
2-32. Two-Wire Lead Drop Compensatin Circuit.......................................................... 2-114
2-33. Calibration to an External 10 kΩ Standard ........................................................... 2-116
2-34. Ratio Calibration, 10Ω From 100Ω....................................................................... 2-120
2-35. Current Output Simplified Schematic ................................................................... 2-123
2-36. Current Assembly Calibration............................................................................... 2-128
2-37. Wideband Output Assembly Simplified Schematic.............................................. 2-139
3-1. Accessing the Fuse................................................................................................ 3-4
3-2. Accessing the Air Filter......................................................................................... 3-5
3-3. 732B External Calibration Connections................................................................ 3-9
3-4. 742A-1 and 742A-10k External Calibration Connections .................................... 3-12
3-5. 220V DC Range Calibration Connections............................................................. 3-17
3-6. Wideband Module Calibration Connection........................................................... 3-19
3-7. Overview of Verification Tests............................................................................. 3-22
3-8. 1 Ohm and 10 Ohm Resistor Verification............................................................. 3-26
3-9. Direct Current Accuracy Test Setup...................................................................... 3-30
3-10. 1 MHz Low Pass Filter.......................................................................................... 3-31
3-11. AC Voltage Test Setup.......................................................................................... 3-32
3-12. Alternating Current Test Setup.............................................................................. 3-35
3-13. Alternating Current Test Setup2 mA and 200 µA................................................. 3-36
3-14. Metal Film Resistor Equivalent Circuit................................................................. 3-37
3-15. Metal Film Resistor in Test Circuit....................................................................... 3-37
3-16. Wideband Accuracy at 1 kHz Test Setup.............................................................. 3-39
3-17. Wideband Flatness Test Setup............................................................................... 3-40
3-18. DC Voltage Linearity Test..................................................................................... 3-43
3-19. DC Voltage Output Noise Test Setup.................................................................... 3-44
3-20. Determining Other Test Limits.............................................................................. 3-49
4-1. Air Filter ................................................................................................................ 4-3
4-2. Rear Panel Removal .............................................................................................. 4-5
4-3. Rear Panel Assembly Access................................................................................. 4-5
4-4. Front Panel Removal ............................................................................................. 4-6
4-5. Analog and Digital Assemblies ............................................................................. 4-8
5-1. Waveform at TP10................................................................................................. 5-42
5-2. Waveform at TP1................................................................................................... 5-43
5-3. Waveform at TP15................................................................................................. 5-44
5-4. Waveform at Pins 14 and 15 of U1 ....................................................................... 5-45
5-5. Waveform at Pin 6 of U9....................................................................................... 5-46
5-6. Waveform at Pin 11 of K2..................................................................................... 5-48
5-7. Waveform at Pin 6 of K2....................................................................................... 5-49
5-8. Verifying the 220 uA Range of the 220 µA/2.2 mA Amp Circuit........................ 5-49
5-9. Verifying the 2.2 mA Range of the 220 µA/2.2 mA Amp Circuit........................ 5-50
5-10. Verifying the 22 mA Range of the 22 mA/220 mA Amp Circuit......................... 5-50
5-11. Verifying the 220 mA Range of the 22 mA/220 mA Amp Circuit....................... 5-51
5-12. Waveform at Pin 4 of U13..................................................................................... 5-52
5-13. Waveform at TP12................................................................................................. 5-53
5-14. Waveform at TP13................................................................................................. 5-54
5-15. Waveform at TP16................................................................................................. 5-55
5-16. Waveform at Pin 13 of U6..................................................................................... 5-57
5-17. Waveform at TP6................................................................................................... 5-59
xiv
Contents
5-18. Waveform at TP4, Calibrator Set to 0V................................................................ 5-59
5-19. Waveform at TP4, Calibrator Set to 6.5V............................................................. 5-60
5-20. Waveform at TP7................................................................................................... 5-61
5-21. Waveform at TP5................................................................................................... 5-62
5-22. Waveform at Pin 10 of U6..................................................................................... 5-64
5-23. Waveform at Pin 6 of U13..................................................................................... 5-65
5-24. Waveform at Pin 4 of U10..................................................................................... 5-65
5-25. Waveform at TP6................................................................................................... 5-66
5-26. Waveform at Pin 7 of U12..................................................................................... 5-67
5-27. Waveform at Anode of CR4.................................................................................. 5-70
5-28. Waveform at Pin 6 of U11..................................................................................... 5-70
5-29. DC Sense Buffer Waveform TP6.......................................................................... 5-71
5-30. AC Sense Buffer Waveform at TP6 ...................................................................... 5-72
5-31. Waveform at TP 3.................................................................................................. 5-75
5-32. Waveform at Pin 18 of Hybrid H4 ........................................................................ 5-79
5-33. Power Amplifier with Calibrator Set to 22V at 1 kHz.......................................... 5-80
6-1. Front Panel Final Assembly .................................................................................. 6-6
6-2. Chassis Final Assembly......................................................................................... 6-8
6-3. Rear Panel Final Assembly................................................................................... 6-11
6-4. A1 Keyboard PCA................................................................................................. 6-13
6-5. A2 Front Panel PCA.............................................................................................. 6-16
6-6. A3 Analog Motherboard PCA............................................................................... 6-18
6-7. A4 Digital Motherboard PCA................................................................................ 6-20
6-8. A5 Wideband Output PCA, Option -03................................................................. 6-24
6-9. A6 Wideband Oscillator PCA, Option -03............................................................ 6-28
6-10. A7 Current/HIgh-Res Oscillator PCA................................................................... 6-32
6-11. A8 Switch Matrix PCA.......................................................................................... 6-35
6-12. A9 Ohms Cal PCA................................................................................................. 6-38
6-13. A10 Ohms Main PCA............................................................................................ 6-40
6-14. A11 DAC PCA ...................................................................................................... 6-45
6-15. A11A1 DAC Filter SIP PCA................................................................................. 6-47
6-16. A11A2 DAC Buffered Reference SIP PCA.......................................................... 6-49
6-17. A12 Oscillator Control PCA.................................................................................. 6-53
6-18. A13 Oscillator Output PCA................................................................................... 6-57
6-19. A13A1 Oscillator Wideband SMD PCA.............................................................. 6-59
6-20. A14 High Voltage Control PCA............................................................................ 6-62
6-21. A15 High Voltage/High Current PCA................................................................... 6-65
6-22. A16 Power Amplifier PCA.................................................................................... 6-69
6-23. A16A1 Power Amplifier Digital Control SIP PCA............................................... 6-71
6-24. A17 Regulator/Guard Crossing PCA..................................................................... 6-74
6-25. A18 Filter/PA Supply PCA ................................................................................... 6-78
6-26. A19 Digital Power Supply PCA............................................................................ 6-81
6-27. A20 CPU PCA....................................................................................................... 6-84
6-28. A21 Rear Panel PCA............................................................................................. 6-87
(continued)
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5700A/5720A Series II
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xvi
Chapter 1
Introduction and Specifications
Title Page
1-1. Introduction.......................................................................................... 1-3
1-2. Contacting Fluke .................................................................................. 1-4
1-3. About this Manual................................................................................ 1-4
1-4. How to Use this Manual....................................................................... 1-4
1-5. Additional Instruction Manuals............................................................ 1-5
1-6. Wideband AC Voltage Module (Option 5700A-03)............................ 1-5
1-7. Auxiliary Amplifiers............................................................................ 1-6
1-8. 5725A Amplifier.............................................................................. 1-6
1-9. Support Equipment and Services ......................................................... 1-6
1-10. 732B Direct Voltage Reference Standard........................................ 1-7
1-11. 732B-200 Direct Volt Maintenance Program (U.S.A. Only) .......... 1-7
1-12. 742A Series Resistance Standards................................................... 1-7
1-13. Wideband AC Module (Option 5700A-03) Calibration Support .... 1-7
1-14. Service Centers ................................................................................ 1-8
1-15. The Components of the 5700A/5720A Series II Calibrator................. 1-8
1-16. Calibrating the 5700A/5720A Series II Calibrator............................... 1-9
1-17. The Calibration Process................................................................... 1-10
1-18. Establishing Traceability ................................................................. 1-10
1-19. Calibration Reports.......................................................................... 1-11
1-20. Calibration Check................................................................................. 1-11
1-21. Developing a Performance History...................................................... 1-11
1-22. Range Calibration................................................................................. 1-12
1-23. DC Zeros Calibration ........................................................................... 1-12
1-24. Specifications....................................................................................... 1-12
1-25. Specification Confidence Levels ..................................................... 1-12
1-26. Using Absolute and Relative Uncertainty Specifications................ 1-12
1-27. Using Secondary Performance Specifications................................. 1-13
1-28. DC Voltage Specifications................................................................... 1-14
1-29. AC Voltage Specifications................................................................... 1-17
1-1
5700A/5720A Series II Calibrator
Service Manual
1-30. Resistance Specifications..................................................................... 1-23
1-31. DC Current Specifications ................................................................... 1-27
1-32. AC Current Specifications ................................................................... 1-30
1-33. Wideband AC Voltage (Option 5700-03) Specifications .................... 1-35
1-34. General Specifications.......................................................................... 1-36
1-35. Auxiliary Amplifier Specifications...................................................... 1-37
1-2
1-1. Introduction
The Fluke Model 5700A/5720A Series II calibrators are precise instruments that
calibrate a wide variety of electrical measuring instruments. These calibrators maintain
high accuracy over a wide ambient temperature range, allowing them to test instruments
in any environment, eliminating the restrictions to calibrate only in a temperaturecontrolled standards laboratory. With a 5700A/5720A Series II, you can calibrate
precision multimeters that measure ac or dc voltage, ac or dc current, and resistance. The
5720A Series II operates in a similar manner to the 5700A Series II, the difference is that
the 5720A Series II has a considerably higher specified accuracy. Option 5700A-03
Wideband AC Voltage, which is available for both the 5700A Series II and the 5720A
Series II, extends this workload to include rf voltmeters.
Specifications are provided at the end of this chapter. The calibrator is a fullyprogrammable precision source of the following:
• DC voltage to 1100V
• AC voltage to 1100V, with output available from 10 Hz to 1.2 MHz.
• AC and DC current to 2.2A, with output available from 10 Hz to 10 kHz
• Resistance in values of 1x10
Introduction and Specifications
n
and 1.9x10n from 1Ω to 100 MΩ, plus a short.
Introduction
1
• Optional wideband ac voltage from 300 µV to 3.5V into 50Ω (-57 dBm to
+24 dBm), 10 Hz to 30 MHz.
Features of the calibrator include the following:
• Internal environmentally-controlled references allowing the calibrator to maintain
full performance over a wide ambient temperature range.
• Automatic meter error calculation obtained through using a simple output adjust
knob; the display shows linearity, offset, and scale errors.
• Keys that multiply and divide the output value by 10 to simplify work on meters
with calibration points at decade multiples of a fraction of full-scale.
• Programmable entry limits used for restricting the levels that can be keyed into the
calibrator, preventing access to levels that may be harmful to equipment or
personnel.
• A s key that provides the capability of displaying the instrument’s specification at
the selected operating point, calibration interval, and specification confidence level.
• An auxiliary current binding post that allows you to calibrate meters with separate
current inputs without moving cables.
• Real-time clock and calendar for date stamping reports.
• Offset and scaling modes that simplify linearity testing of multimeters.
• Variable phase reference signal output and phase-lock input.
• Interface for the Fluke 5725 Amplifier.
• Standard IEEE-488 (GPIB) interface, complying with ANSI/IEEE Standards 488.1-
1987 and 488.2-1987.
• Selectable normal remote mode or emulation of the Fluke 5100B and 5200A Series
calibrators in functions and response to system controller software
• EIA Standard RS-232C serial data interface for printing, displaying, or transferring
internally-stored calibration constants, and for remote control of the calibrator.
1-3
5700A/5720A Series II Calibrator
Service Manual
• Extensive internal self testing and diagnostics of analog and digital functions.
• A traceable calibration procedure for all modes and ranges that requires only 10V,
1Ω, and 10 kΩ external standards, with only occasional independent verification.
• Fast, simple, automated calibration check providing added confidence between
calibration recalls, and data that can be used to document and characterize the
calibrator’s performance between calibration recalls.
1-2. Contacting Fluke
To order accessories, receive operating assistance, or get the location of the nearest
Fluke distributor or Service Center, call:
USA: 1-888-99-FLUKE (1-888-993-5853)
Canada: 1-800-36-FLUKE (1-800-363-5853)
Europe: +31 402-678-200
Japan: +81-3-3434-0181
Singapore: +65-738-5655
Anywhere in the world: +1-425-446-5500
Or, visit Fluke's Web site at
www.fluke.com.
1-3. About this Manual
This manual provides complete information for installing the calibrator and operating it
from the front panel keys and in remote. It also provides a glossary of calibration-related
terms as well as general items such as specifications and error code information. The
following topics are covered in this manual:
• Installation
• Operating controls and features
• Front panel operation
• Remote operation (IEEE-488 bus or serial port remote control)
• Serial port operation (printing, displaying, or transferring data, and setting up for
serial port remote control)
• Operator maintenance, including how to calibrate the 5700A/5720A Series II
• Options and accessories
1-4. How to Use this Manual
Use the following list to find the location of specific information.
• Quick setup procedure: 5700A/5720A Series II Operators Reference Guide
1-4
• Unpacking and setup: Chapter 2.
• Installation and rack mounting: Chapter 2; also the rack mount kit instruction sheet
• AC line power and interface cabling: Chapter 2
• Controls, indicators, and displays: Chapter 3
• Front panel operation: Chapter 4
• Cabling to a UUT (Unit Under Test): Chapter 4
• Using auxiliary amplifiers: Chapter 4
• Self calibration: Chapters 1 and 7
• Remote operation (IEEE-488 or serial): Chapter 5
• Options and accessories: Chapters 2 and 8
• Instrument specifications: The end of this Chapter
• Theory of operation: Chapter 2 of the 5700A/5720A Series II Service Manual
1-5. Additional Instruction Manuals
The 5700A/5720A Series II Calibrators ship with a complete manual set that contains
information for the operator and service or maintenance technicians. The set includes:
• 5700A/5720A Series II Getting Started Manual (PN 1668111)
• 5700A/5720A Series II Operator Reference Guide (PN 601648)
• 5700A/5720A Series II Remote Programming Reference Guide (PN 601655)
• 5700A/5720A Series II Operator Manual (provided on CD-ROM, PN 1668127, or a
printed copy is available for purchase through the Fluke Service Department under
PN 601622)
Introduction and Specifications
Additional Instruction Manuals
1
• 5700A/5720A Series II Service Manual (provided on CD-ROM, PN 1668127, or a
printed copy is available for purchase through the Fluke Service Department under
PN 105798)
Order additional copies of these instruction manuals separately using the part numbers
provided. For ordering instructions, refer to the Fluke Catalog or contact a Fluke sales
representative.
1-6. Wideband AC Voltage Module (Option 5700A-03)
The Wideband AC Voltage Module (Option 5700A-03) can be installed in both the
5700A and 5720A Series II Calibrators. The module is a high-accuracy, low-noise,
extremely flat ac voltage source for calibrating rf voltmeters, with a frequency range of
10 Hz to 30 MHz. Output is in seven ranges from 300 µV (-57 dBm) to 3.5 V (+24 dBm)
through a Type-N coaxial connector into a 50 Ω load. The output level is selected in
volts or dBm through either the front panel controls or under remote control.
The wideband module also functions with the calibrator’s output adjust controls that let
display the error of a wideband meter in either percentage of output or in decibels.
Included with the wideband module is a Type-N output cable and a 50 Ω terminator. The
wideband module is calibrated to the end of its standard-equipment output cable.
1-5
5700A/5720A Series II Calibrator
Service Manual
1-7. Auxiliary Amplifiers
The Fluke Model 5725A Amplifier is available to extend the high voltage performance
and current range of the calibrator:
Interface connectors on the calibrator’s rear panel accept cables to directly operate a
5725A. Three amplifiers can be connected to the calibrator at the same time, but only
one output can be active at a time. Once you have connected the amplifiers and
configured the calibrator in a setup menu, amplifier operation is controlled by the
calibrator.
Chapter 4 provides instructions for operating the 5725A. The general specifications at
the end of this chapter include specifications for operating the calibrator with the 5725A.
For other amplifier specifications, refer to their instruction manuals. Table 1-1
summarizes the extended capabilities offered by the 5725A. Brief descriptions of the
extended capabilities follow.
Model Mode Range
5725A Amplifier AC V 220 to 1100V rms up to 70 mA, 40 Hz to 30 kHz
Table 1-1. Auxiliary Amplifier Data
(50 mA < 5 kHz)
1-8. 5725A Amplifier
The Fluke 5725A Amplifier is an external unit operating under calibrator control to
extend ac voltage drive capabilities and both ac and dc current output range. The
amplifier adds the following capabilities to the calibrator’s 1100V ac range with no
compromise in accuracy:
• Frequency limits at higher voltage increase to 100 kHz at 750V, 30 kHz at 1100V.
• Load limit increases to 70 mA for frequencies above 5 kHz.
• Capacitive drive increases to 1000 pF, subject to the maximum output current.
Extended-performance voltage is available at the calibrator’s front or rear binding posts,
eliminating the need to change cables during a procedure.
A separate set of binding posts on the front panel of the 5725A supplies extended-range
ac and dc current outputs. Since most meters have a separate input terminal for the high
current ranges, this eliminates the need to change cables during a procedure. The 5725A
can also be configured to source all current (both standard calibrator-generated current
and its own current) through the 5725A binding posts.
220 to 750V rms up to 70 mA, 30 kHz to 100 kHz
DC Amps 0 to ±11A
AC Amps 1 to 11A rms, 40 Hz to 10 kHz
1-6
1-9. Support Equipment and Services
Fluke supports your calibration needs with precision, high-quality equipment and a wide
range of services. Depending on your needs, location, and capabilities, you may decide
to support your 5700A/5720A Series II calibrator independently or use Fluke services
for part, or all, of your support needs. The following paragraphs describe the support
equipment and services offered by Fluke for the calibrator. For specifications and
Introduction and Specifications
Support Equipment and Services
ordering instructions for this support equipment and other Fluke instruments, refer to the
Fluke catalog, or contact a representative at a Fluke Sales and Service Center.
1-10. 732B Direct Voltage Reference Standard
The Fluke 732B is a rugged, easily transported solid state direct voltage reference
standard with a highly predictable 10V output. This predictability allows the Fluke
Standards Laboratory, as well as many Fluke customers, to completely eliminate fragile,
saturated standard cells. Laboratories still maintain standard cells using the 732A and
732B as a transportable voltage standard, eliminating the need to transport their standard
cells. The 732B can be short-circuited, even for extended periods of time, without
damage or loss of stability. It maintains full specified stability over a temperature span
of 18 to 28 °C.
The calibrator uses a 10V reference standard such as the Fluke 732B in its semi-
automated calibration procedure to establish external voltage traceability. Chapter 7
describes this procedure.
1-11. 732B-200 Direct Volt Maintenance Program (U.S.A. Only)
The Fluke 732B-200 Direct Volt Maintenance Program provides your laboratory with
NIST-traceable 10V calibration uncertainty as low as 0.6 parts per million.
1
The program maintains the 732B that you keep in your laboratory. To accomplish this,
the following occurs:
1. Fluke sends you a calibrated Fluke-owned 732B standard, together with all
necessary connecting cables and instructions for comparison with your 10V
reference standard.
2. You take a series of readings over a five-day period, and return the results to the
Fluke Standards Laboratory.
3. The Fluke Standards Laboratory assigns a value to your 10V standard relative to the
NIST legal volt and sends you a report of calibration.
1-12. 742A Series Resistance Standards
The calibrator uses 1Ω and 10 kΩ resistor standards such as the 742A Series in its semiautomated calibration procedure to establish external traceability of resistance and
current. Chapter 7 describes this procedure.
The 742A Resistance Standards, which are constructed of arrays of Fluke wirewound
precision resistors, are ideally suited as support standards for the calibrator. Stability of
the resistance transfer standards and their temperature coefficients make them ideal for
easy transport to and operation in the calibrator's working environment.
1-13. Wideband AC Module (Option 5700A-03) Calibration Support
The Wideband AC Module (Option 5700A-03) requires two kinds of calibration: gain
and flatness. Gain constants are checked and recalibrated as a part of the normal
calibrator semi-automated calibration process.
Since frequency flatness is determined by such stable parameters as circuit geometry and
dielectric constants, flatness of the Wideband AC module has excellent long-term
stability. This stability gives the Wideband AC Module a two-year calibration cycle for
flatness calibration. Flatness calibration is required only infrequently, and can be done
1-7
5700A/5720A Series II Calibrator
Service Manual
when the calibrator is returned to a standards laboratory for periodic verification. The
5700A/5720A Series II Service Manual contains the wideband flatness calibration
procedure. Chapter 7 of this manual contains the wideband gain calibration procedure.
1-14. Service Centers
A worldwide network of Fluke service centers supports Fluke instruments and assists
customers in many ways. Most service centers have standards and calibration
laboratories certified by local national standards organizations. The following is a partial
list of the services provided by most service centers:
• Repair and certified traceable calibration of all Fluke products.
• Certified traceable calibration of many non-Fluke standards and calibrators.
• Worldwide exchange of calibrator internal modules. Delivery inside the U.S.A. is
typically within 48 hours.
• Service agreements with the flexibility to suit your needs. These can be a simple
warranty extension or an agreement that includes on-site support. Calibration service
agreements are also available in many areas.
• Training programs and seminars, including laboratory metrology, system
applications, and product maintenance.
• Application help and consulting, including system design, hardware selection,
custom software, site evaluation and installation.
• Replacement parts inventory, including recommended spare parts and module kits.
• Visit www.fluke.com for locations and phone numbers of authorized Fluke service
centers.
1-15. The Components of the 5700A/5720A Series II Calibrator
The calibrator is configured internally as an automated calibration system, with process
controls and consistent procedures. Internal microprocessors control all functions and
monitor performance, using a switching matrix to route signals between modules.
Complete automatic internal diagnostics, both analog and digital, confirm operational
integrity.
Reference amplifiers maintain dc accuracy and stability. Of all technologies available,
reference amplifiers have the lowest noise and best stability. Reference amplifiers in the
calibrator go through special selection processes including long-term aging to ensure
high reliability and performance well within specifications.
The calibrator achieves its exceptional ac voltage accuracy by using a patented Fluke
rms sensor to make real-time ac/dc comparison measurements. The Fluke rms sensor is
similar in principle to the traditional thermal voltage converter, but has a shorter time
constant, virtually no reversal error, higher signal-to-noise ratio, and better frequency
response. In the calibrator, one Fluke rms sensor serves as an ac/dc transfer standard to
develop gain and flatness correction constants during calibration. The second Fluke rms
sensor continuously monitors and corrects output voltage during operation.
1-8
A patented 26-bit digital-to-analog converter (dac) provides the calibrator with the
ability to precisely vary its output. This is a pulse-width modulated dac with linearity
typically better than 0.2 ppm of full scale. As with the other internal functions, the
linearity of the dac is automatically checked during calibration and analog diagnostics.
Introduction and Specifications
Calibrating the 5700A/5720A Series II Calibrator
1-16. Calibrating the 5700A/5720A Series II Calibrator
The traditional practice of returning a calibrator to a standards laboratory at regular
intervals for a full calibration is time consuming, expensive, and disruptive to the task to
which the calibrator is being applied. Moreover, it leaves gaps in confidence. You must
rely on manufacturer’s specifications to determine if a calibrator will perform acceptably
in an operating environment outside the lab. Also, you must assume that drift is
predictable enough so that performance is within limits between recalls.
The 5700A/5720A Series II Calibrator makes use of Fluke design breakthroughs in the
use of internal check standards and measurement systems. As a result, it can be
completely calibrated in place to full specifications using a small number of convenient,
portable, environmentally tolerant standards available from Fluke. As you will see
below, this procedure is traceable to military standard requirements.
When manufactured, each calibrator is calibrated and thoroughly verified with process
metrology and calibration standards traceable to the U.S. National Bureau of Standards.
A certificate of calibration is included.
A calibration verification procedure described in the 5700A/5720A Series II Service
Manual is recommended every two years, or as required by your established policies.
This procedure involves no adjustments. It simply ensures internal processes are in
control, and establishes parallel external traceability paths for internal functions such as
ac transfers that are never adjusted or corrected.
1
Figure 1-1 illustrates the time and money that can be saved by using the 5700A/5720A
Series II calibration support plan recommended by Fluke. Depending on your policies,
you may initially decide to perform calibration verification more often. The calibrator
makes this unnecessary and offers you a practical way to collect data unavailable with a
traditional calibrator design about performance between calibrations.
1-9
5700A/5720A Series II Calibrator
Service Manual
COST $
TRADITIONAL CALIBRATOR CALIBRATION
CALIBRATION CYCLE
TIME
5700A/5720A SERIES II CALIBRATION
CALIBRATION CYCLE
COST $
Figure 1-1. Time and Costs: Calibrator Calibration
1-17. The Calibration Process
Calibration requires only three external standards: 10V, 1Ω, and 10 kΩ.
Environmentally-controlled internal check standards provide the primary reference
points. A stored table of calibration constants defines additional reference points for
controlling the output. Traceable calibration and adjustment to the specified level of
performance is accomplished in a semi-automated process that revises this table.
When you finish calibration, but before you save the new constants, the calibrator
presents you with the proposed adjustments as +/- ppm of range and percentage change
in specification for each range and function. You can print a list of changes through the
serial (RS-232C) port, or send them to a computer through either the serial port or the
IEEE-488 port. Also on completion of calibration, the calibrator displays the largest
proposed change.
Calibration can be completed as far as deriving and printing the proposed adjustments
without changing the setting of the rear panel CALIBRATION switch; however, the
switch must be set to ENABLE to store the changes in nonvolatile memory and make
them effective. The switch is recessed to allow the metrologist to cover it with a
calibration sticker to guarantee calibrator integrity.
TIME
f1-1.eps
1-10
1-18. Establishing Traceability
Traceability to national standards is established as follows:
• Except for the internal ac/dc transfer standard, the internal check standards are
directly calibrated by traceable external standards every time the 5700A/5720A
Series II is calibrated.
• The internal ac/dc transfer standard is never adjusted, so its traceability is not
disturbed by calibration. Infrequent verification is done in the traditional way, by
comparing selected ac voltage outputs with an external dc voltage standard through
an external ac/dc transfer standard. Fluke recommends this be done every two years,
or as determined by the policy of your organization.
• Infrequent independent verification is also performed on stable parameters, such as
frequency flatness, determined more by circuit geometry and dielectric constants
than time.
1-19. Calibration Reports
The calibrator stores two sets of calibration constants: the set currently in use and the old
set from the previous calibration. This gives the calibrator the ability at any time to
produce a calibration report of the differences between the present settings and the
settings that were in effect before the last calibration. The report shows changes for each
range and function in +/- ppm of range and in percentage of specification limit. You can
print the report or send it to a host computer through either the RS-232-C or IEEE-488
interface.
Introduction and Specifications
Calibration Check
1
If you request a calibration report after doing calibration but before saving the new
constants, the report shows proposed changes to the calibration constants relative to the
previously stored settings.
1-20. Calibration Check
Checking the calibration takes about an hour, and provides you with a means of
documenting the calibrator’s performance of a between calibrations. Calibration
checking is similar to calibration, except internal check standards are used as primary
references (no external standards are needed), and changes cannot be stored. The process
produces a report similar to normal calibration, showing drift relative to internal check
standards. Because cal check does not change stored calibration constants, there is no
need to enable the rear panel CALIBRATION switch. Therefore, an external computer
can do the procedure unattended.
1-21. Developing a Performance History
A Fluke specification is a set of performance limits that all products must meet. To
maintain consistent quality, Fluke calibrators are specified with enough margin to
include temperature, line, and load extremes, plus additional margin for production. This
means that a typical 5700A/5720A Series II calibrator in a typical environment operates
inside 50% of specification limits. For some exacting applications, it can be helpful to
know just how accurately a particular calibrator operates. The proper way to do this is to
accumulate a performance history by calibrating regularly and recording results on a
control chart.
Calibrating regularly and recording the results on a control chart is tedious and requires a
large array of equipment. The calibrator’s calibration check feature is an alternative with
some distinct advantages:
• Calibrated check standards are already programmed into the unit. You do not have to
use external standards.
1-11
5700A/5720A Series II Calibrator
Service Manual
• The process is consistent and automatic: it does not require an operator’s assistance.
Each calibration check produces a new set of data points for accumulating a historical
record. When this process is externally automated, significant history can be
accumulated much faster than with a manual calibration.
1-22. Range Calibration
After calibration, you can make further fine adjustments to each range. Range
adjustments are optional; they are not necessary to meet total uncertainty specifications.
However, they do allow you to align your calibrator closer to your standards.
Before you do range calibration, you must first use the calibrator’s semi-automated
calibration procedure. This is to calibrate the ranges that will not be adjusted. It also
performs an initial adjustment for each range, and supplies flatness corrections for ac
functions.
1-23. DC Zeros Calibration
To ensure the validity of the specifications, a dc zeros calibration must be performed at
least every 30 days. If more than 30 days elapse without a dc zeros calibraiton a warning
message appears. This procedure does not require any external equipment or connections
and takes approximately 2.5 minutes to complete.
1-24. Specifications
The 5700A/5720A Series II calibrators are verified and calibrated at the factory prior to
shipment to ensure they meet the accuracy standards required for all certified calibration
laboratories. By calibrating to the specifications in this chapter, you can maintain the
high performance level throughout the life of your calibrator.
Specifications are valid after a warm-up period of twice the time the calibrator has been
turned off, up to a maximum of 30 minutes. For example, if the calibrator has been
turned off for five minutes, the warm-up period is ten minutes.
1-25. Specification Confidence Levels
You calibrator’s performance level is ensured by regular calibration to the primary
performance specifications, which are provided at both the 99% and 95% confidence
levels. The 95% confidence level will provide an accuracy that surpasses the accuracy
requirements for meeting Tag 4 standards, or a coverage factor of 2. Calibration at the
99% confidence level is also available for those applications that require a confidence
factor for the specifications that is higher than 95%. For information on selecting the
confidence level, refer to Chapter 4.
The tables in this chapter provide specifications at both the 95% and 99% confidence
levels for the 5700A/5720A Series II calibrators. Included with these tables are operating
specifications for using the calibrator with the Wideband AC Module (Option 5700A-03)
and the 5725A Amplifier.
1-12
1-26. Using Absolute and Relative Uncertainty Specifications
To evaluate the 5700A/5720A Series II coverage of your calibration workload, use the
Absolute Uncertainty specifications. Absolute uncertainty includes stability, temperature
coefficient, linearity, line and load regulation, and the traceability to external standards.
You do not need to add anything to absolute uncertainty to determine the ratios between
the calibrator’s uncertainties and the uncertainties of your calibration workload.
Relative uncertainty specifications are provided for enhanced accuracy applications.
These specifications apply when range constants are adjusted (see “Range Calibration”).
To calculate absolute uncertainty, you must combine the uncertainties of your external
standards and techniques with relative uncertainty.
1-27. Using Secondary Performance Specifications
Secondary performance specifications and operating characteristics are included in
uncertainty specifications. They are provided for special calibration requirements such as
stability or linearity testing.
Introduction and Specifications
Specifications
1
1-13
5700A/5720A Series II Calibrator
Service Manual
1-28. DC Voltage Specifications
Table 1-2. 5720A Series II DC Voltage Specifications: 99 % and 95 % Confidence Levels
5720A
99%
99 % Confidence Level
Absolute Uncertainty
± 5 °C from calibration temperature
Range Resolution
220 mV 10 nV 0 5 + 0.5 7 + 0.5 0 8 + 0.5 0 9 + 0.5 0 2 + 0.4 2.5 + 0.4
2.2 V 100 nV 3.5 + 0.8 4 + 0.8 4.5 + 0.8 0 6 + 0.8 0 2 + 0.8 2.5 + 0.8
11 V 1 µV 2.5 + 3 3 + 3 3.5 + 3 0 4 + 3 0 1 + 3 1.5 + 3
22 V 1 µV 2.5 + 5 3 + 5 3.5 + 5 0 4 + 5 0 1 + 5 1.5 + 5
220 V 10 µV 3.5 + 50 4 + 50 0 5 + 50 06 + 50 02 + 50 2.5 + 50
1100 V 100 µV 0 5 + 500 6 + 500 0 7 + 500 08 + 500 2.5 + 400 03 + 400
For fields strengths >1 V/m but ≤3 V/m,
add 0.01% of range.
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
± (ppm output + µV) ± (ppm output + µV)
Relative Uncertainty
± 1 °C
5720A
95%
95% Confidence Level
Relative Uncertainty
± 1 °C
Range Resolution
Absolute Uncertainty
± 5 °C from calibration temperature
For fields strengths >1 V/m but ≤3 V/m,
add 0.01 % of range.
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
± (ppm output + µV) ± (ppm output + µV)
1-14
220 mV 10 nV 4 + 0.4 0 6 + 0.4 6.5 + 0.4 7.5 + 0.4 1.6 + 0.4 02 + 0.4
2.2 V 100 nV 3 + 0.7 3.5 + 0.7 0 4 + 0.7 05 + 0.7 1.6 + 0.7 02 + 0.7
11 V 1 µV 2 + 2.5 2.5 + 2.5 03 + 2.5 3.5 + 2.5 0.8 + 2.5 1.2 + 2.5
22 V 1 µV 2 + 4 2.5 + 4 03 + 4 3.5 + 4 0.8 + 4 1.2 + 4
220 V 10 µV 3 + 40 3.5 + 40 04 + 40 0 5 + 40 1.6 + 40 02 + 40
1100 V 100 µV 4 + 400 4.5 + 400 06 + 400 6.5 + 400 02 + 400 2.4 + 400
Introduction and Specifications
Table 1-3. 5700A Series II DC Voltage Specifications: 99 % and 95 % Confidence Levels
5700A
99%
99 % Confidence Level
DC Voltage Specifications
1
Absolute Uncertainty
± 5 °C from calibration temperature
Range Resolution
220 mV 10 nV 6.5 + .75 7 + .75 08 + .75 09 + .8 2.5 + .5 04 + .5
2.2 V 100 nV 3.5 + 1.2 6 + 1.2 07 + 1.2 08 + 1.2 2.5 + 1.2 04 + 1.2
11 V 1 µV 3.5 + 3 5 + 4 07 + 4 08 + 4 1.5 + 3 3.5 + 4
22 V 1 µV 3.5 + 6 5 + 8 07 + 8 08 + 8 1.5 + 6 3.5 + 8
220 V 10 µV 05 + 100 6 + 100 08 + 100 09 + 100 2.5 + 100 04 + 100
1100 V 100 µV 07 + 600 8 + 600 10 + 600 11 + 600 03 + 600 4.5 + 600
For fields strengths >1 V/m but ≤3 V/m,
add 0.01 % of range.
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
± (ppm output + µV) ± (ppm output + µV)
Relative Uncertainty
± 1 °C
5700A
95%
95 % Confidence Level
Relative Uncertainty
± 1 °C
Range Resolution
Absolute Uncertainty
± 5 °C from calibration temperature
For fields strengths >1 V/m but ≤3 V/m,
add 0.01 % of range.
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
± (ppm output + µV) ± (ppm output + µV)
220 mV 10 nV 5.5 + 0.6 6 + 0.6 7 + 0.6 8 + 0.6 02 + 0.4 3.5 + 0.4
2.2 V 100 nV 3.5 + 1 5 + 1 6 + 1 7 + 1 02 + 1 3.5 + 1
11 V 1 mV 03 + 3.5 4 + 3.5 6 + 3.5 7 + 3.5 1.2 + 3 03 + 3.5
22 V 1 mV 03 + 6.5 4 + 6.5 6 + 6.5 7 + 6.5 1.2 + 6 03 + 7
220 V 10 mV 04 + 80 5 + 80 7 + 80 8 + 80 02 + 80 3.5 + 80
1100 V 100 mV 06 + 500 7 + 500 8 + 500 9 + 500 2.4 + 500 04 + 500
1-15
5700A/5720A Series II Calibrator
Service Manual
Table 1-4. DC Voltage Secondary Performance Specifications and Operating Characteristics
Range Stability [Note 1]
220 mV
2.2 V
11 V
22 V
220 V
1100 V
± 1 °C
24 Hours 40°-50 °C pk-pk RMS
± (ppm output + µV) ± (ppm output + µV)/°C ± (ppm output + µV) µV
0.3 + 0.3
0.3 + 1
0.3 + 2.5
0.4 + 5
0.5 + 40
0.5 + 200
Temperature Coefficient
Adder [Note 2]
10 °-40 °C 0 °-10 °C
00.4 + 0.1
00.3 + 0.1
0.15 + 0.2
00.2 + 0.4
00.3 + 5
00.5 + 10
and
1.5 + 0.5
1.5 + 2
0 1 + 1.5
1.5 + 3
1.5 + 40
0 3 + 200
Linearity
± 1 °C
0 1 + 0.2
0 1 + 0.6
0.3 + 2
0.3 + 4
0 1 + 40
0 1 + 200
Bandwidth
0.1-10 Hz
0.15 + 0.1
0.15 + 0.4
0.15 + 2
0.15 + 4
0.15 + 60
0.15 + 300
Noise
Bandwidth
10 Hz-10 kHz
5
15
50
50
150
500
Notes:
1. Stability specifications are included in the Absolute Uncertainty values in the primary specification
tables.
2. Temperature coefficient is an adder to uncertainty specifications that does
not
apply unless operating
more than ±5 °C from calibration temperature.
Minimum output: 0 V for all ranges, except 100 V for 1100 V range
Maximum load: 50 mA for 2.2 V through 220 V ranges; 20 mA for 1100 V range; 50 Ω output impedance
on 220 mV range; all ranges <1000 pF, >25 Ω
Load regulation: <(0.2 ppm of output + 0.1ppm of range), full load to no load
Line regulation: <0.1 ppm change, ± 10 % of selected nominal line
Settling time: 3 seconds to full accuracy; + 1 second for range or polarity change; + 1 second for 1100 V
range
Overshoot: <5 %
Common mode rejection: 140 dB, DC to 400 Hz
1-16
Remote sensing: Available 0 V to ±1100 V, on 2.2 V through 1100 V ranges
1-29. AC Voltage Specifications
Table 1-5. 5720A Series II AC Voltage Specifications: 99 % Confidence Level
5720A
99%
99 % Confidence Level
Range Resolution Frequency
Hz ± (ppm output + µV) ± (ppm output + µV)
2.2 mV 1 nV
22 mV 10 nV
220 mV 100 nV
2.2 V 1 mV
22 V 10 mV
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0250 + 5
0100 + 5
0085 + 5
0220 + 5
0500 + 6
1000 + 12
1400 + 25
2900 + 25
0250 + 5
0100 + 5
0085 + 5
0220 + 5
0500 + 6
1000 + 12
1400 + 25
2900 + 25
0250 + 15
0100 + 8
0085 + 8
0220 + 8
0500 + 20
0850 + 25
1400 + 30
2700 + 60
0250 + 50
0095 + 20
0045 + 10
0080 + 12
0120 + 40
0380 + 100
1000 + 250
1600 + 400
0250 + 500
0095 + 200
0045 + 70
0080 + 120
0110 + 250
0300 + 800
1000 + 2500
1500 + 4000
± (ppm output + mV) ± (ppm output + mV)
220 V
[Note 2]
1100 V
100 mV
1 mV
[Note 1]
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0015 - 50
0050 - 1 k
0250 + 5
0095 + 2
0057 + 0.7
0090 + 1.2
0160 + 3
0900 + 20
5000 + 50
8000 + 100
0300 + 20
0070 + 4
5725A Amplifier:
0040 - 1 k
1100 V
1 mV
750 V
Notes: 1. Maximum output 250V from 15-50 Hz.
2. See Volt-Hertz capability in Figure 1-2.
001 k - 20 k
020 k - 30 k
030 k - 50 k
050 k - 100k
0075 + 4
0105 + 6
0230 + 11
0230 + 11
0600 + 45
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
± 5 °C from calibration temperature
0270 + 5
0105 + 5
0090 + 5
0230 + 5
0540 + 6
1200 + 12
1500 + 25
3100 + 25
0270 + 5
0105 + 5
0090 + 5
0230 + 5
0540 + 6
1200 + 12
1500 + 25
3100 + 25
0270 + 15
0105 + 8
0090 + 8
0230 + 8
0540 + 20
0900 + 25
1500 + 30
2900 + 60
0270 + 50
0100 + 20
0047 + 10
0085 + 12
0125 + 40
0420 + 100
1100 + 250
1800 + 600
0270 + 500
0100 + 200
0047 + 70
0085 + 120
0115 + 250
0310 + 800
1100 + 2500
1600 + 4000
0270 + 5
0100 + 2
0060 + 0.7
0095 + 1.2
0170 + 3
1000 + 20
5200 + 50
9000 + 100
0320 + 20
0075 + 4
0080 + 4
0125 + 6
0360 + 11
0360 + 11
1300 + 45
Absolute Uncertainty
0290 + 5
0110 + 5
0095 + 5
0240 + 5
0570 + 6
1250 + 12
1600 + 25
3250 + 25
0290 + 5
0110 + 5
0095 + 5
0240 + 5
0570 + 6
1250 + 12
1600 + 25
3250 + 25
0290 + 15
0110 + 8
0095 + 8
0240 + 8
0570 + 20
1000 + 25
1600 + 30
3100 + 60
0290 + 50
0105 + 20
0050 + 10
0087 + 12
0127 + 40
0460 + 100
1150 + 250
1900 + 400
0290 + 500
0105 + 200
0050 + 70
0087 + 120
0117 + 250
0320 + 800
1150 + 2500
1700 + 4000
0290 + 5
0105 + 2
0062 + 0.7
0097 + 1.2
0175 + 3
1050 + 20
5300 + 50
9500 + 100
0340 + 20
0080 + 4
0085 + 4
0135 + 6
0440 + 11
0440 + 11
1600 + 45
Introduction and Specifications
AC Voltage Specifications
Relative Uncertainty
± 1 °C
00300 + 5
00115 + 5
00100 + 5
00250 + 5
00600 + 6
01300 + 12
01700 + 25
03400 + 25
00300 + 5
00115 + 5
00100 + 5
00250 + 5
00600 + 6
01300 + 12
01700 + 25
03400 + 25
00300 + 15
00115 + 8
00100 + 8
00250 + 8
00600 + 20
01100 + 25
01700 + 30
03300 + 60
00300 + 50
00110 + 20
00052 + 10
00090 + 12
00130 + 40
00500 + 100
01200 + 250
02000 + 400
00300 + 500
00110 + 200
00052 + 70
00090 + 120
00120 + 250
00325 + 800
01200 + 2500
01800 + 4000
00300 + 5
00110 + 2
00065 + 0.7
00100 + 1.2
00 180 + 3
0 1100 + 20
0 5400 + 50
10,000 + 100
00 360 + 20
00085 + 4
000 90 + 4
00 165 + 6
00 600 + 11
00600 + 11
02300 + 45
0250 + 5
0100 + 5
0060 + 5
0085 + 5
0200 + 6
0350 + 12
0800 + 25
2700 + 25
0250 + 5
0100 + 5
0060 + 5
0085 + 5
0200 + 6
0350 + 12
0800 + 25
2700 + 25
0250 + 15
0100 + 8
0060 + 8
0085 + 8
0200 + 20
0350 + 25
0800 + 30
2600 + 60
0250 + 50
0095 + 20
0030 + 10
0070 + 12
0100 + 40
0270 + 100
0900 + 250
1200 + 400
0250 + 500
0095 + 200
0030 + 70
0070 + 120
0100 + 250
0270 + 800
0900 + 2500
1300 + 4000
0250 + 5
0095 + 2
0045 + 0.7
0075 + 1.2
0140 + 3
0600 + 20
4500 + 50
8000 + 100
0300 + 20
0050 + 4
0050 + 4
0085 + 6
0160 + 11
0160 + 11
0380 + 45
1
0270 + 5
0105 + 5
0065 + 5
0095 + 5
0220 + 6
0400 + 12
1000 + 25
3000 + 25
0270 + 5
0105 + 5
0065 + 5
0095 + 5
0220 + 6
0400 + 12
1000 + 25
3000 + 25
0270 + 15
0105 + 8
0065 + 8
0095 + 8
0220 + 20
0400 + 25
1000 + 30
2800 + 60
0270 + 50
0100 + 20
0040 + 10
0075 + 12
0105 + 40
0290 + 100
1000 + 250
1300 + 400
0270 + 500
0100 + 200
0040 + 70
0075 + 120
0105 + 250
0290 + 800
1000 + 2500
1400 + 4000
0270 + 5
0100 + 2
0050 + 0.7
0080 + 1.2
0150 + 3
0700 + 20
4700 + 50
8500 + 100
0320 + 20
0055 + 4
0055 + 4
0105 + 6
0320 + 11
0320 + 11
1200 + 45
1-17
5700A/5720A Series II Calibrator
Service Manual
Table 1-6. 5720A Series II AC Voltage Specifications: 95 % Confidence Level
5720A
95%
95 % Confidence Level
Range Resolution Frequency
Hz ± (ppm output + µV) ± (ppm output + µV)
0010 - 20
0020 - 40
0040 - 20 k
2.2 mV 1 nV
22 mV 10 nV
220 mV 100 nV
2.2 V 1 mV
22V 10 mV
220 V
[Note 2]
1100 V
1100 V
750 V
Notes: 1. Maximum output 250V from 15-50 Hz.
100 mV
1 mV
[Note 1]
1 mV
2. See Volt-Hertz capability in Figure 1-2.
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
00010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20k
020k - 50k
050k - 100k
100k - 300k
300k - 500k
500k - 1M
± (ppm output + mV) ± (ppm output + mV)
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0015 - 50
0050 - 1 k
0040 - 1 k
001 k - 20 k
020 k - 30 k
030 k - 50 k
050 k - 100 k
Absolute Uncertainty
± 5 °C from calibration temperature
Relative Uncertainty
± 1 °C
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
0200 + 4
0080 + 4
0070 + 4
0170 + 4
0400 + 5
0300 + 10
1100 + 20
2400 + 20
0200 + 4
0080 + 4
0070 + 4
0170 + 4
0400 + 5
0300 + 10
1100 + 20
2400 + 20
0200 + 12
0080 + 7
0070 + 7
0170 + 7
0400 + 17
0700 + 20
1100 + 25
2400 + 45
0200 + 40
0075 + 15
0037 + 8
0065 + 10
0100 + 30
0300 + 80
0800 + 200
1300 + 300
0200 + 400
0075 + 150
0037 + 50
0065 + 100
0090 + 200
0250 + 600
0800 + 2000
1200 + 3200
0200 +4
0075 + 1.5
0045 + 0.6
0070 + 1
0120 + 2.5
0700 + 16
4000 + 40
6000 + 80
0240 + 16
0055 + 3.5
0220 + 4
0085 + 4
0075 + 4
0180 + 4
0460 + 5
0900 + 10
1200 + 20
2500 + 20
0220 + 4
0085 + 4
0075 + 4
0180 + 4
0460 + 5
0900 + 10
1200 + 20
2500 + 20
0220 + 12
0085 + 7
0075 + 7
0180 + 7
0420 + 17
0750 + 20
1200 +25
2500 + 45
0220 + 40
0080 + 15
0040 + 8
0070 + 10
0105 + 30
0340 + 80
0900 + 200
1500 + 300
0220 + 400
0080 + 150
0040 + 50
0070 + 100
0095 + 200
0260 + 600
0900 + 2000
1300 + 3200
0220 + 4
0080 + 1.5
0047 + 0.6
0075 + 1
0130 + 2.5
0800 + 16
4200 + 40
7000 + 80
0260 + 16
0060 + 3.5
0230 + 4
0087 + 4
0077 + 4
0190 + 4
0480 + 5
1000 + 10
1300 + 20
2600 + 20
0230 + 4
0087 + 4
0077 + 4
0190 + 4
0480 + 5
1000 + 10
1300 + 20
2600 + 20
0230 + 12
0087 + 7
0077 + 7
0190 + 7
0440 + 17
0800 + 20
1300 + 25
2600 + 45
0230 + 40
0085 + 15
0042 + 8
0073 + 10
0107 + 30
0380 + 80
0950 + 200
1600 + 300
0230 + 400
0085 + 150
0042 + 50
0073 + 100
0097 + 200
0270 + 600
0900 + 2000
1400 + 3200
0230 + 4
0085 + 1.5
0050 + 0.6
0077 + 1
0140 + 2.5
0850 + 16
4300 + 40
7500 + 80
0280 + 16
0065 + 3.5
0240 + 4
0090 + 4
0080 + 4
0200 + 4
0500 + 5
1050 + 10
1400 + 20
2700 + 20
0240 + 4
0090 + 4
0080 + 4
0200 + 4
0500 + 5
1050 + 10
1400 + 20
2700 + 20
0240 + 12
0090 + 7
0080 + 7
0200 + 7
0460 + 17
0900 + 20
1400 + 25
2700 + 45
0240 + 40
0090 + 15
0045 + 8
0075 + 10
0110 + 30
0420 + 80
1000 + 200
1700 + 300
0240 + 400
0090 + 150
0045 + 50
0075 + 100
0100 + 200
0275 + 600
1000 + 2000
1500 + 3200
0240 + 4
0090 + 1.5
0052 + 0.6
0080 + 1
0150 + 2.5
0900 + 16
4400 + 40
8000 + 80
0300 + 16
0070 + 3.5
0200 + 4
0080 + 4
0050 + 4
0070 + 4
0160 + 5
0280 + 10
0650 + 20
2100 + 20
0200 + 4
0080 + 4
0050 + 4
0070 + 4
0160 + 5
0280 + 10
0650 + 20
2100 + 20
0200 + 12
0080 + 7
0050 + 7
0070 + 7
0160 + 17
0280 + 20
0650 + 25
2100 + 45
0200 + 40
0075 + 15
0025 + 8
0055 + 10
0080 + 30
0230 + 80
0700 + 200
1000 + 300
0200 + 400
0075 + 150
0025 + 50
0055 + 100
0080 + 200
0250 + 600
0700 + 2000
1100 + 3200
0200 + 4
0075 + 1.5
0035 + 0.6
0060 + 1
0110 + 2.5
0500 + 16
3600 + 40
6500 + 80
0240 + 16
0040 + 3.5
5725A Amplifier:
0075 + 4
0105 + 6
0230 + 11
0230 + 11
0600 + 45
0080 + 4
0125 + 6
0360 + 11
0360 + 11
1300 + 45
0085 + 4
0135 + 6
0440 + 11
0440 + 11
1600 + 45
0090 + 4
0165 + 6
0600 + 11
0600 + 11
2300 + 45
0050 + 4
0085 + 6
0160 + 11
0160 + 11
0380 + 45
0220 + 4
0085 + 4
0055 + 4
0080 + 4
0180 + 5
0320 + 10
0800 + 20
2400 + 20
0220 + 4
0085 + 4
0055 + 4
0080 + 4
0180 + 5
0320 + 10
0800 + 20
2400 + 20
0220 + 12
0085 + 7
0055 + 7
0080 + 7
0180 + 17
0320 + 20
0800 + 25
2400 + 45
0220 + 40
0080 + 15
0035 + 8
0060 + 10
0085 + 30
0250 + 80
0800 + 200
1100 + 300
0220 + 400
0080 + 150
0035 + 50
0060 + 100
0085 + 200
0270 + 600
0800 + 2000
1200 + 3200
0220 + 4
0080 + 1.5
0040 + 0.6
0065 + 1
0120 + 2.5
0600 + 16
3800 + 40
7000 + 80
0260 + 16
0045 + 3.5
0055 + 4
0105 + 6
0320 + 11
0320 + 11
1200 + 45
1-18
Table 1-7. 5700A Series II AC Voltage Specifications: 99 % Confidence Level
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
12,500 + 220
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
5700A
99%
99 % Confidence Level
Range Resolution Frequency
Hz ± (ppm output + µV) ± (ppm output + µV)
2.2 mV 1 nV
22 mV 10 nV
220 mV 100 nV
2.2 V 1 mV
22 V 10 mV
220 V
[Note 2]
1100 V 1 mV
100 mV
[Note 1]
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
00015 - 50
00050 - 1 k
5725A Amplifier:
1100 V 1 mV 00040 - 1 k
750 V 0030 k - 50 k
Notes: 1. Maximum output 250V from 15-50 Hz.
2. See Volt-Hertz capability in Figure 1-2.
0001 k - 20 k
0020 k - 30 k
0050 k - 100 k
0 500 + 5
00200 + 5
0 100 + 5
0 340 + 5
0 800 + 8
01100 + 15
01500 + 30
4000 + 40
0 500 + 6
0 200 + 6
0100 + 6
0340 + 6
0800 + 8
1100 + 15
01500 + 30
04000 + 40
0500 + 16
0 200 + 10
0 095 + 10
0 300 + 10
0 750 + 30
0 940 + 30
1500 + 40
3000 + 100
0 500 + 100
0 150 + 30
00 70 + 7
0 120 + 20
0 230 + 80
0 400 + 150
1000 + 400
2000 + 1000
0 500 + 1000
0 150 + 300
00 70 + 70
0 120 + 200
0 230 + 400
0 500 + 1700
1200 + 5000
2600 + 9000
± (ppm output + mV) ± (ppm output + mV)
0 500 + 10
0 150 + 3
00 75 + 1
0 200 + 4
0 500 + 10
1500 + 110
5000 + 110
12,000 + 220
0 400 + 20
00 75 + 4
00 75 + 4
0 105 + 6
0 230 + 11
0 230 + 11
0 600 + 45
Introduction and Specifications
AC Voltage Specifications
Absolute Uncertainty
± 5 °C from calibration temperature
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
0 550 + 5
0 220 + 5
0 110 + 5
0 370 + 5
0 900 + 8
01200 + 15
01700 + 30
04400 + 40
0 550 + 6
0 220 + 6
0 110 + 6
0 370 + 6
0 900 + 8
01200 + 15
01700 + 30
04400 + 40
0 550 + 16
0 220 + 10
0 100 + 10
0 330 + 10
0 800 + 30
1000 + 30
01700 + 40
03300 + 100
0 550 + 100
0 170 + 30
00 75 + 7
0 130 + 20
0 250 + 80
0 440 + 150
1100 + 400
2200 + 1000
0 550 + 1000
0 170 + 300
00 75 + 70
0 130 + 200
0 250 + 400
0 550 + 1700
1300 + 5000
2800 + 9000
0 550 + 10
0 170 + 3
00 80 + 1
0 220 + 4
0 550 + 10
1500 + 110
5200 + 110
12,500 + 220
00420 + 20
00 80 + 4
00 80 + 4
0 125 + 6
0 360 + 11
0 360 + 11
1300 + 45
0 600 + 5
0 230 + 5
0 120 + 5
0 390 + 5
0 950 + 8
1300 + 15
01700 + 30
4700 + 40
00600 + 6
0 230 + 6
0 120 + 6
0 390 + 6
0 950 + 8
1300 + 15
1700 + 30
4700 + 40
0 600 + 16
0 230 + 10
0 110 + 10
0 350 + 10
0 850 + 30
01100 + 30
1700 + 40
3500 + 100
0 600 + 100
0 170 + 30
00 80 + 7
0 140 + 20
0 270 + 80
0 470 + 150
1200 + 400
2300 + 1000
0 600 + 1000
0 170 + 300
00 80 + 70
0 140 + 200
0 270 + 400
0 550 + 1700
1300 + 5000
2900 + 9000
0600 + 10
0 170 + 3
00 85 + 1
0 240 + 4
0 600 + 10
1600 + 110
5300 + 110
00440 + 20
00 85 + 4
00 85 + 4
0 135 + 6
0 440 + 11
0 440 + 11
1600 + 45
0 600 + 5
0 240 + 5
0 120 + 5
0 410 + 5
0950 + 8
1300 + 15
1800 + 30
4800 + 40
0600 + 6
0 240 + 6
0 120 + 6
0 410 + 6
0 950 + 8
1300 + 15
1800 + 30
4800 + 40
0 600 + 16
00240 + 10
00110 + 10
00360 + 10
0900 + 30
01100 + 30
01800 + 40
03600 + 100
0 600 + 100
0 180 + 30
00 85 + 7
0 140 + 20
0 280 + 80
0 480 + 150
1200 + 400
2400 + 1000
0 600 + 1000
0 180 + 300
00 85 + 70
0 140 + 200
0 280 + 400
0 600 + 1700
1400 + 5000
3000 + 9000
0 600 + 10
0 180 + 3
00 90 + 1
0 250 + 4
0 600 + 10
1600 + 110
5400 + 110
13,000 + 220
00460 + 20
00 90 + 4
00 90 + 4
0 165 + 6
0 600 + 11
0 600 + 11
2300 + 45
Relative Uncertainty
± 1 °C
00 500 + 5
00 200 + 5
000 60 + 5
00 100 + 5
00 220 + 8
00 400 + 15
01000 + 30
00 400 + 30
00 500 + 6
00 200 + 6
000 60 + 6
00 100 + 6
00 220 + 8
00 400 + 15
01000 + 30
0 4000 + 30
00 500 + 16
00200 + 10
00060 + 10
00100 + 10
00220 + 30
00400 + 30
01000 + 40
03000 + 100
00 500 + 100
00 150 + 30
000 40 + 7
00 100 + 20
00 200 + 80
00 400 + 150
0 1000 + 400
0 2000 + 1000
00 500 + 1000
00 150 + 300
000 40 + 70
00 100 + 200
00 200 + 400
00500 + 1700
01200 + 5000
02600 + 9000
00 500 + 10
00 150 + 3
000 45 + 1
00 100 + 1
00 300 + 10
01500 + 110
0 5000 + 110
12,000 + 220
00400 + 20
000 50 + 4
000 50 + 4
000 85 + 6
00 160 + 11
00 160 + 11
00 380 + 45
12,000 + 220
0 550 + 5
0220 + 5
0 065 + 5
0 110 + 5
0 240 + 8
0 440 + 15
1100 + 30
4400 + 30
0 550 + 6
0 220 + 6
00 65 + 6
0 110 + 6
0 240 + 8
0 440 + 15
1100 + 30
4400 + 30
00550 + 16
00220 + 10
00065 + 10
00110 + 10
00240 + 30
00440 + 30
01100 + 40
03300 + 100
0 550 + 100
0 170 + 30
00 45 + 7
0 110 + 20
0 220 + 80
0 440 + 150
1100 + 400
2200 + 1000
0 550 + 1000
0 170 + 300
00 45 + 70
0 110 + 200
0 220 + 400
0 550 + 1700
1300 + 5000
2800 + 9000
0 550 + 10
0 170 + 3
00 50 + 1
0 110 + 1
0 330 + 10
1500 + 100
5200 + 110
00420 + 20
00 55 + 4
00 55 + 4
0 105 + 6
0 320 + 11
0 320 + 11
1200 + 45
1
1-19
5700A/5720A Series II Calibrator
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
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0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
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0
0
0
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0
0
0
0
0
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0
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0
0
0
0
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0
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0
0
0
0
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0
0
0
0
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0
0
0
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0
0
0
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0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
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0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
11,500 + 190
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
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0
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0
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0
Service Manual
Table 1-8. 5700A Series II AC Voltage Specifications: 95 % Confidence Level
5700A
95%
95% Confidence Level
Range Resolution Frequency
Hz ± (ppm output + µV) ± (ppm output + µV)
0010 - 20
0020 - 40
2.2 mV 1 nV
22 mV 10 nV
220 mV 100 nV
2.2 V 1 mV
22 V 10 mV
220 V
[Note 2]
1100 V
1100 V
750 V
Notes: 1. Maximum output 250V from 15-50 Hz.
100 mV
1 mV
[Note 1]
1 mV
2. See Volt-Hertz capability in Figure 1-2.
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0015 - 50
0050 - 1 k
0040 - 1 k
001 k - 20 k
020 k - 30 k
030 k - 50 k
050 k - 100 k
Absolute Uncertainty
± 5 °C from calibration temperature
Relative Uncertainty
± 1 °C
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
0 400 + 4.5
0 170 + 4.5
00 85 + 4.5
0 300 + 4.5
0 700 + 7
0 900 + 13
1300 + 25
2800 + 25
0 400 + 5
0 170 + 5
00 85 + 5
0 300 + 5
0 700 + 7
0 900 + 12
1300 + 25
2800 + 25
0 400 + 13
0 170 + 8
00 85 + 8
0 250 + 8
0 700 + 25
0 900 + 25
1300 + 35
2800 + 80
0 400 + 80
0 130 + 25
00 60 + 6
0 105 + 16
0 190 + 70
0 350 + 130
0 850 + 350
1700 + 850
0 400 + 800
0 130 + 250
00 60 + 60
0 105 + 160
0 190 + 350
0 400 + 1500
1050 + 4300
2300 + 8500
0 500 + 4.5
0 190 + 4.5
00 95 + 4.5
0 330 + 4.5
0750 + 7
1000 + 13
1500 + 25
3100 + 25
0 500 + 5
0 190 + 5
00 95 + 5
0 330 + 5
0 750 + 7
1000 + 12
1500 + 25
3100 + 25
0 500 + 13
0 190 + 8
00 95 + 8
0 280 + 8
0 750 + 25
1000 + 25
1500 + 35
3100 + 80
0 450 + 80
0 140 + 25
00 65 + 6
0 110 + 16
0 210 + 70
0 390 + 130
0950 + 350
1900 + 850
0 450 + 800
0 140 + 250
00 65 + 60
0 110 + 160
0 210 + 350
0 450 + 1500
1150 + 4300
2500 + 8500
0 530 + 4.5
0 200 + 4.5
0 100 + 4.5
0 350 + 4.5
0 800 + 7
1050 + 13
1600 + 25
3300 + 25
0 530 + 5
0 200 + 5
0 100 + 5
0 350 + 5
0 800 + 7
1050 + 12
1600 + 25
3300 + 25
0 530 + 13
0 200 + 8
0 100 + 8
0 300 + 8
0 800 + 25
1050 + 25
1600 + 35
3300 + 80
0 480 + 80
0 150 + 25
00 70 + 6
0 115 + 16
0 230 + 70
0 420 + 130
1000 + 350
2100 + 850
0 480 + 800
0 150 + 250
00 70 + 60
0 115 + 160
0 230 + 350
0 470 + 1500
1200 + 4300
2600 + 8500
0 550 + 4.5
0 210 + 4.5
0 105 + 4.5
0 370 + 4.5
0 850 + 7
1100 + 13
1700 + 25
3400 + 25
0 550 + 5
0 210 + 5
0 105 + 5
0 370 + 5
0 850 + 7
1100 + 12
1700 + 25
3400 + 25
0 550 + 13
0 210 + 8
0 105 + 8
0 320 + 8
0 850 + 25
1100 + 25
1700 + 35
3400 + 80
0 500 + 80
0 160 + 25
00 75 + 6
0 120 + 16
0 250 + 70
0 430 + 130
1050 + 350
2200 + 850
0 500 + 800
0 160 + 250
00 75 + 60
0 120 + 160
0 250 + 350
0 500 + 1500
1250 + 4300
2700 + 8500
00 400 + 4.5
00 170 + 4.5
000 55 + 4.5
000 90 + 4.5
00 210 + 7
00 380 + 13
00 900 + 25
0 2900 + 25
00 400 + 5
00 170 + 5
000 55 + 5
000 90 + 5
00 210 + 7
00 380 + 12
00900 + 25
0 2900 + 25
00 400 + 13
00 170 + 8
000 55 + 8
000 90 + 8
00 210 + 25
00 380 + 25
00 900 + 35
0 2900 + 80
00 400 + 80
00 130 + 25
000 35 + 6
000 85 + 16
00 170 + 70
00 340 + 130
00 850 + 350
0 1700 + 850
00 400 + 800
00 130 + 250
000 35 + 60
000 85 + 160
00 170 + 350
00 400 + 1500
0 1000 + 4300
0 2200 + 8500
0 500 + 4.5
0 190 + 4.5
00 60 + 4.5
0 100 + 4.5
0 230 + 7
0 420 + 13
1000 + 25
3200 + 25
0 500 + 5
0 190 + 5
00 60 + 5
0 100 + 5
0 230 + 7
0 420 + 12
1000 + 25
3200 + 25
0 500 + 13
0 190 + 8
00 60 + 8
0 100 + 8
0 230 + 25
0 420 + 25
1000 + 35
3200 + 80
0 450 + 80
0 140 + 25
00 40 + 6
00 95 + 16
0 190 + 70
0 380 + 130
0 950 + 350
1900 + 850
0 450 + 800
0 140 + 250
00 40 + 60
00 95 + 160
0 190 + 350
0 450 + 1500
1100 + 4300
2400 + 8500
± (ppm output + mV) ± (ppm output + mV)
0 400 + 8
0 130 + 2.5
00 65 + 0.8
0 170 + 3.5
0 400 + 8
1300 + 90
4300 + 90
10,500 + 190
0 340 + 16
00 65 + 3.5
0 450 + 8
0 140 + 2.5
00 70 + 0.8
0 190 + 3.5
0 450 + 8
1400 + 90
4500 + 90
11,000 + 190
00360 + 16
00 70 + 3.5
0 480 + 8
0 150 + 2.5
00 75 + 0.8
0 210 + 3.5
0 480 + 8
1450 + 90
4600 + 90
11,300 + 190
00380 + 16
00 75 + 3.5
0 500 + 8
0 160 + 2.5
00 80 + 0.8
0 220 + 3.5
0 500 + 8
1500 + 90
4700 + 90
00400 + 16
00 80 + 3.5
00 400 + 8
00 130 + 2.5
000 40 + 0.8
000 85 + 3.5
00 270 + 8
0 1200 + 90
0 4200 + 90
10,500 + 190
00340 + 16
000 45 + 3.5
0 450 + 8
0 140 + 2.5
00 45 + 0.8
00 95 + 3.5
0 300 + 8
1300 + 90
4500 + 90
11,000 + 190
00360 + 16
00 50 + 3.5
5725A Amplifier:
00 75 + 4
0 105 + 6
0 230 + 11
0 230 + 11
0 600 + 45
00 80 + 4
0 125 + 6
0 360 + 11
0 360 + 11
1300 + 45
00 85 + 4
0 135 + 6
0 440 + 11
0 440 + 11
1600 + 45
00 90 + 4
0 165 + 6
0 600 + 11
0 600 + 11
2300 + 45
000 50 + 4
000 85 + 6
00 160 + 11
00 160 + 11
00 380 + 45
00 55 + 4
0 105 + 6
0 320 + 11
0 320 + 11
1200 + 45
1-20
Introduction and Specifications
AC Voltage Specifications
Table 1-9. AC Voltage Secondary Performance Specifications and Operating Characteristics
Stability
± 1 °C [Note 1]
Range Frequency 24 Hours 10°-40 °C 0°-10 °C and
Hz ± µV ±µV/°C Ω± (% output + µV)
5
5
2
2
3
3
5
5
5
5
2
2
3
5
10
15
2.2 mV
22 mV
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
± (ppm output + µV) ± (ppm output µV)/°C
150 + 20
080 + 15
012 + 2
010 + 2
010 + 2
020 + 4
100 + 10
200 + 20
150 + 20
080 + 15
012 + 4
015 + 5
015 + 5
030 + 10
070 + 20
150 + 50
150 + 20
080 + 15
012 + 8
015 + 10
015 + 10
030 + 15
070 + 100
150 + 100
150 + 200
080 + 150
012 + 80
015 + 100
015 + 100
030 + 400
100 + 10,000
200 + 20,000
220 mV
2.2 V
22 V
220 V
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
0010 - 20
0020 - 40
0040 - 20 k
020 k - 50 k
050 k - 100 k
100 k - 300 k
300 k - 500 k
500 k - 1 M
±(ppm output + mV) ±(ppm output)/°C ±(% output)
1100 V
Note: 1. Stability specifications are included in Absolut e Uncert aint y v alues f or t he primary s pec if ic at ions .
0015 - 50
0050 - 1 k
150 + 0.5
020 + 0.5
Temperature Coefficient Maximum
Output Impedance Bandwidth
40°-50 °C
0.05
0.05
0.05
0.1
0.2
0.3
0.4
0.5
0.2
0.2
0.2
0.4
0.5
0.6
1
1
002 + 1
002 + 1
002 + 1
015 + 2
015 + 4
080 + 5
080 + 5
080 + 5
0.05
0.05
0.05
0.1
0.2
0.3
0.4
0.5
0.3
0.3
0.3
0.5
0.5
0.6
1
1
02 + 1
02 + 1
02 + 1
15 + 2
15 + 4
80 + 5
80 + 5
80 + 5
50
50
50
Load Regulation
±(ppm output+ µV)
050 + 10
015 + 5
002 + 1
010 + 2
010 + 4
080 + 15
080 + 40
080 + 100
050 + 100
015 + 30
002 + 10
010 + 20
010 + 40
080 + 150
080 + 300
080 + 500
0 50 + 1000
0 15 + 300
00 2 + 80
0 10 + 100
0 10 + 500
0 80 + 600
0 80 + 800
0 80 + 1000
50
2
50 + 10
15 + 5
05 + 2
15 + 4
20 + 4
80 + 15
80 + 40
80 + 100
50 + 100
15 + 40
04 + 15
20 + 20
20 + 40
80 + 150
80 + 300
80 + 500
50 + 1000
15 + 300
04 + 80
20 + 100
20 + 500
80 + 600
80 + 800
80 + 1000
50
5
0010 + 2
0010 + 2
0010 + 4
0030 + 10
0120 + 16
0300 ppm
0600 ppm
01200 ppm
0010 + 20
0010 + 20
0010 + 30
0030 + 50
0080 + 80
0100 + 700
0200 + 1100
0600 + 3000
0010 + 200
0010 + 200
0010 + 300
0030 + .600
0080 + 3,000
0250 + 25,000
0500 + 50,000
1000 + 110,000
0010 + 2
0010 + 1
1
Distortion
10 Hz-10 MHz
00.05 + 10
0.035 + 10
0.035 + 10
0.035 + 10
0.035 + 10
000.3 + 30
000.3 + 30
000 1 + 30
00.05 + 11
0.035 + 11
0.035 + 11
0.035 + 11
0.035 + 11
000.3 + 30
000.3 + 30
000 1 + 30
00.05 + 16
0.035 + 16
0.035 + 16
0.035 + 16
0.035 + 16
000.3 + 30
000.3 + 30
000 1 + 30
00.05 + 80
0.035 + 80
0.035 + 80
0.035 + 80
0.035 + 80
000.3 + 110
000.3 + 110
000 1 + 110
00.05 + 700
0.035 + 700
0.035 + 700
0.035 + 700
0.035 + 700
000.3 + 800
000.3 + 800
000 2 + 800
00.05 + 10,000
00.05 + 10,000
00.05 + 10,000
00.05 + 10,000
000.1 + 13,000
001.5 + 50,000
001.5 + 50,000
003.5 + 100,000
0.15
0.07
1-21
5700A/5720A Series II Calibrator
Service Manual
Table 1-9. AC Voltage Secondary Performance and Operating Characteristics (continued)
5725A Amplifier:
±1 °C [Note 1]
Range Frequency
Hz ±(ppm output + mV) ±(ppm output)/°C
1100 V
040 - 1 k
01 k - 20 k
20 k - 50 k
50 k - 100 k
010 + .5
015 + 2
040 + 2
130 + 2
Stability
Temperature Coefficient
24 Hours 10°-40 °C
5
5
10
30
Adder
0°-10 °C
and
40°-50 °C
5
5
10
30
Load Regulation
[Note 2]
(ppm output + mV)
010 + 1
090 + 6
275 + 11
500 + 30
Distortion
Bandwidth
10 Hz-10 MHz
±(% output)
150 pF 1000 pF
0.10
0.10
0.30
0.40
0.10
0.15
0.30
0.40
Voltage Range Maximum Current Limits Load Limits
2.2 V [Note 3]
22 V
220 V
1100 V 6 mA 600 pF
50 mA, 0 °C-40 °C
20 mA, 40 °C-50 °C
>50 Ω,
1000 pF
5725A Amplifier: 1000 pF [Note 2]
040 Hz-5 kHz 50 mA
1100 V 05 kHz-30 kHz 70 mA 300 pF
30 kHz-100 kHz 70 mA
[Note 4]
150 pF
Notes:
1 Stability specifications are included in Absolut e Uncert aint y v alues
for the primary specifications.
2. The 5725A will drive up to 1000 pF of load capacitance.
Uncertainty specifications include loads t o 300 pF and 150 pF as
shown under "Load Limits." For capacitances up to the maximum of
1000 pF, add "Load Regulation."
3. 2.2 V Range, 100 kHz-1.2 MHz only: uncertainty specif ic at ions
cover loads to 10 mA or 1000 pF. For higher loads, load regulation
is added.
4. Applies from 0 °C to 40 °C
10000
5700A/5720A
5725A
2.2 x 107 V-Hz
5700A-03
ahp160f.eps
1000
100
Voltage
10
3.5 V
0
40 Hz 30 Hz
15 Hz
Volt-Hertz Capability
50 Hz10 Hz 1 kHz 100 kHz 1 MHz 30 MHz
Frequency
Figure 1-2. Volt-Hertz Capability
Output display formats: Voltage or dBm,
dBm reference 600 Ω.
Minimum output:: 10 % on eac h range
External sense: Selectable for 2.2 V, 22 V, 220 V, and
1100 V ranges; 5700A/5720A <100 kHz, 5725A <30 kHz
Settling time to full accuracy:
Frequency (Hz) Settling time (seconds)
<20 7
120-120 k 5
>120 k 2
+ 1 second for amplitude or frequency range change;
+ 2 seconds for 5700A/5720A 1100 V range;
+ 4 seconds for 5725A 1100 V range
Overshoot:: <10%
Common mode rejection: 140 dB, DC to 400 Hz
Frequency:
Ranges (Hz):
10.000-119.99
0.1200 k-1.1999 k, 1.200 k-11.999 k
12.00 k-119.99 k,120.0 k-1.1999
Uncertainty: ±0.01 %
Resolution: 11.999 counts
Phase lock: Selectable rear panel BNC input
Phase uncertainty (except 1100 V range):
>30 Hz: ±1° + 0.05°/kHz), <30 Hz: ±3°
Input voltage: 1 V to 10 V rms sine wave (do not exceed
1 V for mV ranges)
Frequency range: 10 Hz to 1.1999 MHz
Lock range: ±2 % of frequency
Lock-in time: Larger of 10/frequency or 10 msec
Phase reference: Selectable, rear panel BNC output
Range: ±180°
Phase Uncertainty (except 1100 V range):
±1° at quadrature points (0°, ±90°, ±180°) elsewhere
±2°
Stability: ±0.1°
Resolution: 1°
Output level: 2.5 V rms ±0.2 V
Frequency range:
50 kHz to 1 kHz, usable 10 Hz to 1.1999 MHz
1-22
Introduction and Specifications
1-30. Resistance Specifications
Table 1-10. 5720A Series II Resistance Specifications: 99 % and 95 % Confidence Levels
5720A
99%
99% Confidence Level
Nominal
Value
Ω
0
1
1.9
10
19
100
190
1 k
1.9 k
10 k
19 k
100 k
190 k
1 M
1.9 M
10 M
19 M
100 M
Absolute Uncertainty of Characterized Value
±5 °C from calibration temperature [Note 1]
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
±ppm ±ppm
50 µΩ
85
85
23
23
10
10
8
8
8
9
9
9
16
17
33
43
100
50 µΩ
95
95
25
25
11
11
9
9
9
9
11
11
18
19
37
47
110
50 µΩ
100
100
26
26
11.5
11.5
9.5
9.5
9.5
9.5
12
12
20
21
40
50
115
50 µΩ
110
110
27
27
12
12
10
10
10
10
13
13
23
24
46
55
120
Relative Uncertainty
50 µΩ
32
25
5
4
2
2
2
2
2
2
2
2
2.5
3
10
20
50
Resistance Specifications
±1 °C
50 µΩ
40
33
8
7
4
4
3
3
3
3
3
3
5
6
14
24
60
1
5720A
95%
95 % Confidence Level
Nominal
Value
Ω
0
1
1.9
10
19
100
190
1 k
1.9 k
10 k
19 k
100 k
190 k
1 M
1.9 M
10 M
19 M
100 M
Note: 1. Specificati ons apply to displayed value. 4-wi re connections, except 100 MΩ.
Absolute Uncertainty of Characterized Value
±5 °C from calibration temperature [Note 1]
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
±ppm ±ppm
40 µΩ
70
70
20
20
8
8
6.5
6.5
6.5
7.5
7.5
7.5
13
14
27
35
85
40 µΩ
80
80
21
21
9
9
7.5
7.5
7.5
7.5
9
9
15
16
31
39
95
40 µΩ
85
85
22
22
9.5
9.5
8
8
8
8
10
10
17
18
34
42
100
40 µΩ
95
95
23
23
10
10
8.5
8.5
8.5
8.5
11
11
20
21
40
57
100
Relative Uncertainty
±1 °C
40 µΩ
27
20
4
3.5
1.6
1.6
1.6
1.6
1.6
1.6
1.6
1.6
2
2.5
8
16
40
40 µΩ
35
26
7
6
3.5
3.5
2.5
2.5
2.5
2.5
2.5
2.5
4
4
12
20
50
1-23
5700A/5720A Series II Calibrator
Service Manual
Table 1-11. 5700A Series II Resistance Specifications: 99 % and 95 % Confidence Levels
5700A
99%
99 % Confidence Level
Nominal
Value
Ω
0
1
1.9
10
19
100
190
1 k
1.9 k
10 k
19 k
100 k
190 k
1 M
1.9 M
10 M
19 M
100 M
Absolute Uncertainty of Characterized Value
±5 °C from calibration temperature [Note 1]
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
50 µΩ
85
85
26
24
15
15
11
11
9
9
11
11
16
17
33
43
110
±ppm ±ppm
50 µΩ
95
95
28
26
17
17
12
12
11
11
13
13
18
19
37
47
120
50 µΩ
100
100
30
28
18
18
13
13
12
12
14
14
20
21
40
50
125
50 µΩ
110
110
33
31
20
20
15
15
14
14
16
16
23
24
46
55
130
Relative Uncertainty
±1 °C
50 µΩ
32
25
5
4
2
2
2
2
2
2
2
2
2.5
3.5
10
20
50
50 µΩ
40
33
8
7
4
4
3.5
3.5
3.5
3.5
3.5
3.5
5
6
14
24
60
5700A
95%
95 % Confidence Level
Nominal
Value
Ω
0
1
1.9
10
19
100
190
1 k
1.9 k
10 k
19 k
100 k
190 k
1 M
1.9 M
10 M
19 M
100 M
Note: 1. Specificati ons apply to displayed value. 4-wi re connections, except 100 MΩ.
Absolute Uncertainty of Characterized Value
±5 °C from calibration temperature [Note 1]
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
±ppm ±ppm
50 µΩ
70
70
21
20
13
13
9
9
7.5
7.5
9
9
13
14
27
35
90
50 µΩ
80
80
23
22
14
14
10
10
9.5
9.5
11
11
15
16
31
39
100
50 µΩ
85
85
27
24
15
15
11
11
10.5
10.5
12
12
17
18
34
42
105
50 µΩ
95
95
28
27
17
17
13
13
12
12
14
14
20
21
40
47
110
Relative Uncertainty
±1 °C
50 µΩ
32
25
5
4
2
2
2
2
2
2
2
2
2.5
3
10
20
50
50 µΩ
40
33
8
7
4
4
3.5
3.5
3.5
3.5
3.5
3.5
5
6
14
24
60
1-24
Introduction and Specifications
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
Resistance Specifications
Table 1-12. Resistance Secondary Performance Specifications and Operating Characteristics
Nominal
Value
Ω±ppm ±ppm/°C mA mA ±ppm ±mΩ
0 008 - 500 500
13245008 - 100 700 500
1.9 25 6 7
10 5 2 3
19 4 2 3
100 2 2 3
190 2 2 3
1 k 2 2 3
1.9 k 2 2 3
Stability
±1 °C
[Note 1]
24 Hours 40°-50 °C 0.1Ω 1Ω
Temperature
Coefficient Adder
[Note 2]
10°-40 °C 0° -10 ° C
and
Full Spec
Load Range
[Note 3] to Nominal
00
8 - 100 500 500
00
8 - 11
00
8 - 11 160 300
00
8 - 11 70 150
00
8 - 11 50 150
00
1 - 2 22 150
00
1 - 1.5 16 150
Maximum
Peak
Current
Characterized
220 300
Maximum
Difference
Value
Two-Wire Adder
of
compensation
Lead Resistance
2 +
2 +
2 +
2 +
2 +
2 +
2 +
10 15
10 15
active
[Note 4]
µ
4 V
Im
4 V
Im
4 V
Im
4 V
Im
4 V
Im
4 V
Im
4 V
Im
4 +
4 +
4 +
4 +
4 +
4 +
4 +
1
4 V
Im
4 V
Im
4 V
Im
4 V
Im
4 V
Im
4 V
Im
4 V
Im
10 k 2 2 3 100 - 500 µA 7 150
19 k 2 2 3
100 k 2 2 3 10 - 100 µA 1 150 Im= Current
190 k 2 2 3 00 5 - 50 µA 500 µA 150
1 M 2.5 2.5 6 00 5 - 20 µA 100 µA 200
1.9 M 3.5 3 10 02.5 - 10 µA 50 µA 200
10 M 10 5 20 00.5 - 2 µA 10 µA 300
19 M 20 8 40 0.25 - 1 µA5 µA 300
100 M 50 12 100 0 50 - 200 nA 1 µA 500
0
50 - 250 µA 5 150
50 60
100 120
produced by
Ohmmeter
Notes:
1. Stability specifications are included in the Absolute Uncertainty values in the primary specification tables.
2. Temperature coefficient is an adder to uncertainty specifications that does not apply unless operated
more than 5 °C from calibration temperature, or calibrated outside the range 19 °C to 24 °C. Two
examples:
• Calibrate at 20 °C: Temperature coefficient adder is not required unless operated below 15 °C or
above 25 °C.
• Calibrate at 26 °C: Add 2 °C temperature coefficient adder. Additional temperature coefficient adder is
not required unless operated below 21 °C or above 31 °C.
3. Refer to current derating factors table for loads outside of this range.
4. Active two-wire compensation may be selected for values less than 100 kΩ, with either the front panel or
the meter input terminals as reference plane. Active compensation is limited to 11 mA load, and to 2 V
burden. Two-wire compensation can be used only with Ω-meters that source continuous (not pulsed) dc
current.
1-25
5700A/5720A Series II Calibrator
Service Manual
Nominal Value Value of Derating Factor K for Over or Under Current
Ω
SHORT
1
1.9
10
19
100
190
1 k
1.9 k
10 k
19 k
100 k
190 k
1 M
1.9 M
10 M
19 M
100 M
Notes:
Table 1-13. Current Derating Factors
Two-Wire Comp
I < I
L
[Note 1]
4.4
4.4
4.4
4.4
4.4
4.4
4.4
4.4
4.4
5000
5000
Four-Wire
I < I
[Note 1]
0.3
300
160
30
16
3.5
2.5
0.4
0.4
50
50
7.5
4.0
1.0
0.53
0.2
0.53
0.1
Four-Wire
I
L
< I < I
U
[Note 2]
4 x10
1.5 x 10
1.6 x 10
3 x 10
1 x 10
1.9 x 10
0.1
0.19
2.0
3.8
2 x 10
3.8 x 10
1.5 x 10
2.9 x 10
1 x 10
1.9 x 10
max
-5
-4
-3
-3
-2
-2
-5
-5
-4
-4
-3
-3
I < I
1. For
equat
spec
Error = K(
Where: Error
four-w
, errors occur due to thermally generated voltages within the 5720A. Use the following
L
ion to determine the error, and add this error to the corresponding uncertainty or stability
ification.
I
- I)/( I
L
L
x I)
is in mΩ for all two-wire comp values and four-wire short, and in ppm for the remaining
ire values.
K is the constant from the above table;
2. For
equat
spec
Error
I and I
I and I
I
U
ion to determine the error in ppm and add this error to the corresponding uncertainty or stability
ification.
in ppm = K(I
are expressed in mA for short to 1.9 kΩ;
L
are expressed in µA for 10 kΩ to 100 MΩ
L
< I < I
errors occur due to self-heating of the resistors in the calibrator. Use the following
MAX
2
2
-I
)
U
Where: K is the constant from the above table;
I and I
I and I
are expressed in mA for short to 19 kΩ;
U
are expressed in µA for 100 kΩ to 100 MΩ
U
1-26
Introduction and Specifications
DC Current Specifications
1-31. DC Current Specifications
Table 1-14. 5720A Series II DC Current Specifications: 99 % and 95 % Confidence Levels
5720A
99%
99 % Confidence Level
Range Resolution
For fields strengths >0.4 V/m but ≤3 V/m,
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
nA ± (ppm output + nA) ± (ppm output + nA)
220 µA
2.2 mA
22 mA
220 mA
2.2 A
[Note 1]
11 A 10 330 + 470 340 + 480 350 + 480 360 + 480 100 + 130 110 + 130
0.1
1
10
µA ± (ppm output + µA) ± (ppm output + µA)
0.1
1
040 + 7
030 + 8
030 + 50
040 + 0.8
060 + 15
5725A Amplifier:
Absolute Uncertainty
±5 °C from calibration temperature.
add 1 % of range.
042 + 7
035 + 8
035 + 50
045 + 0.8
070 + 15
045 + 7
037 + 8
037 + 50
047 + 0.8
080 + 15
050 + 7
040 + 8
040 + 50
050 + 0.8
090 + 15
Relative Uncertainty ±1 °C
024 + 7
024 + 8
024 + 50
026 + 0.5
040 + 12
026 + 7
026 + 8
026 + 50
030 + 0.5
045 + 12
1
5720A
95%
95 % Confidence Level
Range Resolution
For fields strengths >0.4 V/m but ≤3 V/m,
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
nA ± (ppm output + nA) ± (ppm output + nA)
220 µA
2.2 mA
22 mA
220 mA
2.2 A
[Note 1]
11 A 10 330 + 470 340 + 480 350 + 480 360 + 480 100 + 130 110 + 130
Note: Maximum output from calibrator terminals is 2.2 A. Uncertainty specifications for 220 mA and 2.2 mA
0.1
1
10
µA ± (ppm output + µA) ± (ppm output + µA)
0.1
1
032 + 6
025 + 7
025 + 40
035 + 0.7
050 + 12
5725A Amplifier:
ranges are increased by a factor of 1.3 when supplied through 5725A terminals.
Specifications are otherwise identical for all output locations.
1. Add to uncertainty specifications:
±200 x
2
I
ppm for >100 mA on 220 mA range
±10 x I2 ppm for >1 A on 2.2 A range
Absolute Uncertainty
±5 °C from calibration temperature
add 1 % of range.
035 + 6
030 + 7
030 + 40
040 + 0.7
060 + 12
037 + 6
033 + 7
033 + 40
042 + 0.7
070 + 12
040 + 6
035 + 7
035 + 40
045 + 0.7
080 + 12
Relative Uncertainty ±1 °C
020 + 6
020 + 7
020 + 40
020 + 0.7
032 + 12
022 + 6
022 + 7
022 + 40
025 + 0.7
040 + 12
1-27
5700A/5720A Series II Calibrator
Service Manual
Table 1-15. 5700A Series II DC Current Specifications: 99 % and 95 % Confidence Levels
5700A
99%
99 % Confidence Level
Range Resolution
nA ± (ppm output + nA) ± (ppm output + nA)
220 µA
2.2 mA
22 mA
220 mA
2.2 A
[Note 1]
5725A Amplifier:
11 A 10 330 + 470 340 + 480 350 + 480 360 + 480 100 + 130 110 + 130
0.1
1
10
µA ± (ppm output + µA) ± (ppm output + µA)
0.1
1
Absolute Uncertainty
±5 °C from calibration temperature
For fields strengths >0.4 V/m but ≤3 V/m,
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
045 + 10
045 + 10
045 + 100
055 + 1
075 + 30
add 1% of range.
050 + 10
050 + 10
050 + 100
060 + 1
080 + 30
055 + 10
055 + 10
055 + 100
065 + 1
090 + 30
060 + 10
060 + 10
060 + 100
070 + 1
095 + 30
Relative Uncertainty ±1 °C
024 + 2
024 + 5
024 + 50
026 + .3
040 + 7
026 + 2
026 + 5
026 + 50
030 + .3
045 + 7
5700A
95%
95 % Confidence Level
Absolute Uncertainty
±5 °C from calibration temperature
Range Resolution
nA ± (ppm output + nA) ± (ppm output + nA)
220 µA
2.2 mA
22 mA
220 mA
2.2 A
[Note 1]
5725A Amplifier:
11 A 10 330 + 470 340 + 480 350 + 480 360 + 480 100 + 130 110 + 130
Note: Maximum output from the calibrator’s terminals is 2.2 A. Uncertainty specifications for 220 mA and
0.1
1
10
µA ± (ppm output + µA) ± (ppm output + µA)
0.1
1
For fields strengths >0.4 V/m but ≤3 V/m,
add 1 % of range.
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
035 + 8
035 + 8
035 + 80
045 + 0.8
060 + 25
040 + 8
040 + 8
040 + 80
050 + 0.8
065 + 25
045 + 8
045 + 8
045 + 80
055 + 0.8
075 + 25
050 + 8
050 + 8
050 + 80
060 + 0.8
080 + 25
2.2 mA ranges are increased by a factor of 1.3 when supplied through 5725A terminals.
Specifications are otherwise identical for all output locations.
1. Add to uncertainty specifications:
±200 x
2
I
ppm for >100 mA on 220 mA range
±10 x I2 ppm for >1A on 2.2A range
Relative Uncertainty ±1 °C
020 + 1.6
020 + 4
020 + 80
022 + 0.25
035 + 6
022 + 1.6
022 + 4
022 + 80
025 + 0.25
040 + 6
1-28
Introduction and Specifications
0
0
0
0
0
0
0
0
0
0
DC Current Specifications
Table 1-16. DC Current Secondary Performance Specifications and Operating Characteristics
Temperature
Coefficient [Note 2]
Range Stability
220 µA
2.2 mA
22 mA
220 mA
2.2 A
5725A ± (ppm output
11 A
±1 °C [Note 1]
24 Hours 40 °-50 °C [Note 4] pk-pk RMS
± (ppm output
+ nA)
05 + 1
05 + 5
05 + 50
08 + 300
09 + 7 µA
+ µA)
25 + 100 20 + 75 30 + 120
10 °-40 °C 0 °-10 °C
and
± (ppm output + nA)/ °C ±nA/V Ω ppm output
1 + 0.40
1 + 2
1 + 20
1 + 200
1 + 2.5 µΑ
± (ppm output + µA)/
3 + 1
3 + 10
3 + 100
3 + 1 µA
3 + 10 µA
°C
Compliance
Limits
10
10
10
10
3 [Note 5]
4
Burden
Voltage
Adder
[Note 3]
0.2
0.2
10
100
2 µA
Maximum
Load for
Full
Accuracy
20k
2k
200
20
2
4 15 + 70 175
Bandwidth
0.1-10 Hz
06 + .9
06 + 5
06 + 50
09 + 300
12 + 1.5 µA
ppm output
Notes:
Maximum output from the calibrator’s terminals is 2.2 A. Uncertainty specifications for 220 mA and 2.2 mA
ranges are increased by a factor of 1.3 when supplied through 5725A terminals.
Noise
Bandwidth
0 Hz-10 kHz
+ nA
10
10
50
500
20 µA
+ µA
1
nA
µA
1. Stability specifications are included in the Absolute Uncertainty values for the primary specifications.
2. Temperature coefficient is an adder to uncertainty specifications. It does not apply unless operating more
than ±5 °C from calibration temperature.
3. Burden voltage adder is an adder to uncertainty specifications that does not apply unless burden voltage is
greater than 0.5 V.
4. For higher loads, multiply uncertainty specification by:
1
+
0.1 x actual load
maximum load for full accuracy
5. The calibrator’s compliance limit is 2 V for outputs from 1 A to 2.2 A. 5725A Amplifier may be used in rangelock mode down to 0 A.
Minimum output: 0 for all ranges, including 5725A.
Settling time to full accuracy: 1 second for mA and mA ranges; 3 seconds for 2.2 A range; 6 seconds for 11 A
range; + 1 second for range or polarity change
Overshoot: <5 %
1-29
5700A/5720A Series II Calibrator
Service Manual
1-32. AC Current Specifications
Table 1-17. 5720A Series II AC Current Specifications: 99 % Confidence Level
5720A
99%
99 % Confidence Level
Range Resolution Frequency
Hz ± (ppm output + nA) ± (ppm output + nA)
010 - 20
220 µA1 nA
2.2 mA 10 nA
22 mA 100 nA
220 mA 1 µA
2.2 A 10 µA
11 A 100 µA
020 - 40
040 - 1 k
01k - 5 k
05k - 10 k
010 - 20
020 - 40
040 - 1 k
01k - 5 k
05k - 10 k
010 - 20
020 - 40
040 - 1 k
01k - 5 k
05k - 10 k
010 - 20
020 - 40
040 - 1 k
01k - 5 k
05k - 10 k
020 - 1 k
01 k - 5 k
05 k - 10 k
040 - 1 k
01 k - 5 k
05 k - 10 k
Absolute Uncertainty
±5 °C from calibration temperature
Relative Uncertainty
±1 °C
For fields strengths >0.4 V/m but ≤3 V/m,
add 1 % of range.
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
0260 + 20
0170 + 12
0120 + 10
0300 + 15
1000 + 80
0260 + 50
0170 + 40
0120 + 40
0210 + 130
1000 + 800
0260 + 500
0170 + 400
0120 + 400
0210 + 700
1000 + 6000
0280 + 20
0180 + 12
0130 + 10
0320 + 15
1100 + 80
0280 + 50
0180 + 40
0130 + 40
0220 + 130
1100 + 800
0280 + 500
0180 + 400
0130 + 400
0220 + 700
1100 + 6000
0290 + 20
0190 + 12
0135 + 10
0340 + 15
1200 + 80
0290 + 50
0190 + 40
0135 + 40
0230 + 130
1200 + 800
0290 + 500
0190 + 400
0135 + 400
0230 + 700
1200 + 6000
0300 + 20
0200 + 12
0140 + 10
0350 + 15
1300 + 80
0300 + 50
0200 + 40
0140 + 40
0240 + 130
1300 + 800
0300 + 500
0200 + 400
0140 + 400
0240 + 700
1300 + 6000
0260 + 20
0130 + 12
0100 + 10
0250 + 15
0900 + 80
0260 + 50
0130 + 40
0100 + 40
0250 + 130
0900 + 800
0260 + 500
0130 + 400
0100 + 400
0250 + 700
0900 + 6000
0280 + 20
0150 + 12
0110 + 10
0280 + 15
01000 + 80
0280 + 50
0150 + 40
0110 + 40
0280 + 130
1000 + 800
0280 + 500
0150 + 400
0110 + 400
0280 + 700
1000 + 6000
Hz ± (ppm output + µA) ± (ppm output + µA)
0260 + 5
0170 + 4
0120 + 3
0210 + 4
1000 + 12
0290 + 40
0440 + 100
6000 + 200
0280 + 5
0180 + 4
0130 + 3
0220 + 4
1100 + 12
0300 + 40
0460 + 100
7000 + 200
0290 + 5
0190 + 4
0135 + 3
0230 + 4
1200 + 12
0310 + 40
0480 + 100
7500 + 200
0300 + 5
0200 + 4
0140 + 3
0240 + 4
1300 + 12
0320 + 40
0500 + 100
8000 + 200
0260 + 5
0130 + 4
0100 + 3
0250 + 4
0900 + 12
0300 + 40
0500 + 100
6000 + 200
0280 + 5
0150 + 4
0110 + 3
0280 + 4
1000 + 12
0350 + 40
0520 + 100
7000 + 200
5725A Amplifier:
0370 + 170
0800 + 380
3000 + 750
0400 + 170
0850 + 380
3300 + 750
0440 + 170
0900 + 380
3500 + 750
0460 + 170
0950 + 380
3600 + 750
0300 + 170
0700 + 380
2800 + 750
0330 + 170
0800 + 380
3200 + 750
Note: Maximum output from the calibrator’s terminals is 2.2 A. Uncertainty specifications for 220 µA and 2.2 mA
ranges are increased by a factor of 1.3 plus 2 µA when supplied through 5725A terminals. Specifications are
otherwise identical for all output locations.
1-30
Introduction and Specifications
AC Current Specifications
Table 1-18. 5720A Series II AC Current Specifications: 95 % Confidence Level
5720A
95%
95 % Confidence Level
Range Resolution Frequency
±5 °C from calibration temperature
For fields strengths >0.4 V/m but ≤3 V/m,
add 1 % of range.
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
Hz ± (ppm output + nA) ± (ppm output + nA)
Absolute Uncertainty
0250 + 16
0160 + 10
0120 + 8
0280 + 12
1100 + 65
0250 + 40
0160 + 35
0120 + 35
0200 + 110
1100 + 650
0250 + 400
0160 + 350
0120 + 350
0200 + 550
1100 + 5000
220 µA1 nA
2.2 mA 10 nA
22 mA 100 nA
010 - 20
020 - 40
040 - 1 k
01k - 5 k
05k - 10 k
010 - 20
020 - 40
040 - 1 k
01k - 5 k
05k - 10 k
010 - 20
020 - 40
040 - 1 k
01k - 5 k
05k - 10 k
0210 + 16
0130 + 10
0100 + 8
0240 + 12
0800 + 65
0210 + 40
0140 + 35
0100 + 35
0170 + 110
0800 + 650
0210 + 400
0130 + 350
0100 + 350
0170 + 550
0800 + 5000
0230 + 16
0140 + 10
0110 + 8
0250 + 12
0900 + 65
0230 + 40
0140 + 35
0110 + 35
0180 + 110
0900 + 650
0230 + 400
0140 + 350
0110 + 350
0180 + 550
0900 + 5000
0240 + 16
0150 + 10
0115 + 8
0270 + 12
1000 + 65
0240 + 40
0150 + 35
0115 + 35
0190 + 110
1000 + 650
0240 + 400
0150 + 350
0115 + 350
0190 + 550
1000 + 5000
Hz ± (ppm output + µA) ± (ppm output + µA)
220 mA 1 µA
2.2 A 10 µA
010 - 20
020 - 40
040 - 1 k
01k - 5 k
05k - 10 k
020 - 1 k
01 k - 5 k
05 k - 10 k
0210 + 4
0130 + 3.5
0100 + 2.5
0170 + 3.5
0800 + 10
0230 + 35
0350 + 80
5000 + 160
0230 + 4
0140 + 3.5
0110 + 2.5
0180 + 3.5
0900 + 10
0240 + 35
0390 + 80
6000 + 160
0240 + 4
0150 + 3.5
0115 + 2.5
0190 + 3.5
1000 + 10
0250 + 35
0420 + 80
6500 + 160
0250 + 4
0160 + 3.5
0120 + 2.5
0200 + 3.5
1100 + 10
0260 + 35
0450 + 80
7000 + 160
5725A Amplifier:
11 A 100 µA
040 - 1 k
01 k - 5 k
05 k - 10 k
0370 + 170
0800 + 380
3000 + 750
0400 + 170
0850 + 380
3300 + 750
0440 + 170
0900 + 380
3500 + 750
0460 + 170
0950 + 380
3600 + 750
Note: Maximum output from the calibrator’s terminals is 2.2 A. Uncertainty specifications for 220 µA and
2.2 mA ranges are increased by 1.3 x plus 2 µA when supplied through 5725A terminals. Specifications are
otherwise identical for all output locations.
Relative Uncertainty
±1 °C
0210 + 16
0110 + 10
0080 + 8
0200 + 12
0700 + 65
0210 + 40
0110 + 35
0080 + 35
0200 + 110
0700 + 650
0210 + 400
0110 + 350
0080 + 350
0200 + 550
0700 + 5000
0210 + 4
0110 + 3.5
0080 + 2.5
0200 + 3.5
0700 + 10
0250 + 35
0400 + 80
5000 + 160
0300 + 170
0700 + 380
2800 + 750
0230 + 16
0130 + 10
0090 + 8
0230 + 12
0800 + 65
0230 + 40
0130 + 35
0090 + 35
0230 + 110
0800 + 650
0230 + 400
0130 + 350
0090 + 350
0230 + 550
0800 + 5000
0230 + 4
0130 + 3.5
090 + 2.5
0230 + 3.5
0800 + 10
0300 + 35
0440 + 80
6000 + 160
0330 + 170
0800 + 380
3200 + 750
1
1-31
5700A/5720A Series II Calibrator
0
0
0
0
0
0
0
0
0
0
Service Manual
Table 1-19. 5700A Series II AC Current Specifications: 99 % Confidence Level
5700A
99%
99 % Confidence Level
Absolute Uncertainty
Range Resolution Frequency
±5 °C from calibration temperature
Relative Uncertainty
±1 °C
For fields strengths >0.4 V/m but ≤3 V/m,
add 1 % of range.
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
Hz ± (ppm output + nA) ± (ppm output + nA)
220 µA1 nA
2.2 mA 10 nA
22 mA 100 nA
010 - 20
020 - 40
040 - 1 k
01k - 5 k
5k - 10 k
010 - 20
020 - 40
040 - 1 k
01k - 5 k
5k - 10 k
010 - 20
020 - 40
040 - 1 k
01k - 5 k
5k - 10 k
0650 + 30
0350 + 25
0120 + 20
0500 + 50
1500 + 100
0650 + 50
0350 + 40
0120 + 40
0500 + 500
1500 + 1000
0650 + 500
0350 + 400
0120 + 400
0500 + 5000
1500 + 10,000
0700 + 30
0380 + 25
0140 + 20
0600 + 50
1600 + 100
0700 + 50
0380 + 40
0140 + 40
0600 + 500
1600 + 1000
0700 + 500
0380 + 400
0140 + 400
0600 + 5000
1600 + 10,000
0750 + 30
0410 + 25
0150 + 20
0650 + 50
1700 + 100
0750 + 50
0410 + 40
0150 + 40
0650 + 500
1700 + 1000
0750 + 500
0410 + 400
0150 + 400
0650 + 5000
1700 + 10,000
00 800 + 30
00 420 + 25
00 160 + 20
00 700 + 50
0 1800 + 100
00 800 + 50
0 0420 + 40
00 160 + 40
00 700 + 500
0 1800 + 1000
00 800 + 500
00 420 + 400
00 160 + 400
00 700 + 5000
0 1800 + 10,000
0450 + 30
0270 + 25
0110 + 20
0450 + 50
1400 + 100
0450 + 50
0270 + 40
0110 + 40
0450 + 500
1400 + 1000
0450 + 500
0270 + 400
0110 + 400
0450 + 5000
1400 + 10,000
0500 + 30
0300 + 25
0120 + 20
0500 + 50
1500 + 100
0500 + 50
0300 + 40
0120 + 40
0500 + 500
1500 + 1000
0500 + 500
0300 + 400
0120 + 400
0500 + 5000
1500 +
10,000
Hz ± (ppm output + µA) ± (ppm output + µA)
220 mA 1 µA
2.2 A 10 µA
010 - 20
020 - 40
040 - 1 k
01k - 5 k
5k - 10 k
20 - 1 k
1 k - 5 k
5 k - 10 k
0650 + 5
0350 + 4
0120 + 4
0500 + 50
1500 + 100
0600 + 40
0700 + 100
8000 + 200
0700 + 5
0380 + 4
0150 + 4
0600 + 50
1600 + 100
0650 + 40
0750 + 100
9000 + 200
0750 + 5
0410 + 4
0170 + 4
0650 + 50
1700 + 100
0700 + 40
0800 + 100
9500 + 200
00 800 + 5
00 420 + 4
00 180 + 4
0 700 + 50
0 1800 + 100
0 750 + 40
00 850 + 100
10,000 + 200
0450 + 5
0280 + 4
0110 + 4
0450 + 50
1400 + 100
0600 + 40
0650 + 100
7500 + 200
0500 + 5
0300 + 4
0130 + 4
0500 + 50
1500 + 100
0650 + 40
0750 + 100
8500 + 200
5725A Amplifier:
11 A 100 µA
40 - 1 k
1 k - 5 k
5 k - 10 k
0370 + 170
0800 + 380
3000 + 750
400 + 170
850 + 380
3300 + 750
0440 + 170
0900 + 380
3500 + 750
00 460 + 170
00 950 + 380
0 3600 + 750
0300 + 170
0700 + 380
2800 + 750
0330 + 170
0800 + 380
3200 + 750
Note: Maximum output from the calibrator’s terminals is 2.2 A. Uncertainty specifications for 220 µA and 2.2 mA
ranges are increased by 1.3 x plus 2 µA when supplied through 5725A terminals. Specifications are otherwise
identical for all output locations.
1-32
5700A
0
0
0
0
0
0
0
0
0
0
95%
Introduction and Specifications
Table 1-20. 5700A Series II AC Current Specifications: 95 % Confidence Level
95 % Confidence Level
AC Current Specifications
1
Absolute Uncertainty
Range Resolution Frequency
±5 °C from calibration temperature
For fields strengths >0.4 V/m but ≤3 V/m,
Relative Uncertainty
±1 °C
add 1 % of range.
24 Hours 90 Days 180 Days 1 Year 24 Hours 90 Days
Hz ± (ppm output + nA) ± (ppm output + nA)
220 µA1 nA
2.2 mA 10 nA
22 mA 100 nA
010 - 20
020 - 40
040 - 1 k
01k - 5 k
5k - 10 k
010 - 20
020 - 40
040 - 1 k
01k - 5 k
5k - 10 k
010 - 20
020 - 40
040 - 1 k
01k - 5 k
5k - 10 k
0550 + 25
0280 + 20
0100 + 16
0400 + 40
1300 + 80
0550 + 40
0280 + 35
0100 + 35
0400 + 400
1300 + 800
0550 + 400
0280 + 350
0100 + 350
0400 + 4000
1300 + 8000
0600 + 25
0310 + 20
0120 + 16
0500 + 40
1400 + 80
0600 + 40
0310 + 35
0120 + 35
0500 + 400
1400 + 800
0600 + 400
0310 + 350
0120 + 350
0500 + 4000
1400 + 8000
0650 + 25
0330 + 20
0130 + 16
0550 + 40
1500 + 80
0650 + 40
0330 + 35
0130 + 35
0550 + 400
1500 + 800
0650 + 400
0330 + 350
0130 + 350
0550 + 4000
1500 + 8000
0700 + 25
0350 + 20
0140 + 16
0600 + 40
1600 + 80
0700 + 40
0350 + 35
0140 + 35
0600 + 400
1600 + 800
0700 + 400
0350 + 350
0140 + 350
0600 + 4000
1600 + 8000
0375 + 25
0220 + 20
090 + 16
0375 + 40
1200 + 80
0375 + 40
0220 + 35
0090 + 35
0375 + 400
1200 + 800
0375 + 400
0220 + 350
0090 + 350
0375 + 4000
1200 + 8000
Hz ± (ppm output + µA) ± (ppm output + µA)
220 mA 1 µA
2.2 A 10 µA
010 - 20
020 - 40
040 - 1 k
01k - 5 k
5k - 10 k
20 - 1 k
1 k - 5 k
5 k - 10 k
0550 + 4
0280 + 3.5
0100 + 3.5
0400 + 40
1300 + 80
0500 + 35
0600 + 80
6500 + 160
0600 + 4
0310 + 3.5
0120 + 3.5
0500 + 40
1400 + 80
0550 + 35
0650 + 80
7500 + 160
0650 + 4
0330 + 3.5
0130 + 3.5
0550 + 40
1500 + 80
0600 + 35
0700 + 80
8000 + 1600
0700 + 4
0350 + 3.5
0140 + 3.5
0600 + 40
1600 + 80
0650 + 35
0750 + 80
8500 + 160
0375 + 4
0220 + 3.5
0090 + 3.5
0375 + 40
1200 + 80
0500 + 35
0550 + 80
6000 + 160
5725A Amplifier:
11 A 100 µA
40 - 1 k
1 k - 5 k
5 k - 10 k
0370 + 170
0800 + 380
3000 + 750
0400 + 170
0850 + 380
3300 + 750
0440 + 170
0900 + 380
3500 + 750
0460 + 170
0950 + 380
3600 + 750
0300 + 170
0700 + 380
2800 + 750
Note: Maximum output from the calibrator’s terminals is 2.2 A. Uncertainty specifications for 220 µA and
2.2 mA ranges are increased by a factor of 1.3 plus 2 µA when supplied through 5725A terminals.
Specifications are otherwise identical for all output locations.
0400 + 25
0250 + 20
0100 + 16
0400 + 40
1200 +80
0400 + 40
0250 + 35
0100 + 35
0400 + 400
1200 + 800
0400 + 400
0250 + 350
0100 + 350
0400 + 4000
1200 + 8000
0400 + 4
0250 + 3.5
0100 + 3.5
0400 + 40
1200 + 80
0550 + 35
0650 + 80
7000 + 160
0330 + 170
0800 + 380
3200 + 750
1-33
5700A/5720A Series II Calibrator
Service Manual
Table 1-21. AC Current Secondary Performance Specifications and Operating Characteristics
Stability
±1 °C [Note 1]
Range Frequency 24 Hours 10°-40 °C 0°-10 °C and
Hz ± (ppm output + nA) ± (ppm output + nA)/°C V rms Ω± (% output + µA)
220 µA 010 - 20
020 - 40
040 - 1 k
01k - 5 k
05k - 10 k
2.2 mA 010 - 20
020 - 40
040 - 1 k
01k - 5 k
05k - 10 k
22 mA 010 - 20
020 - 40
040 - 1 k
01k - 5 k
05k - 10 k
Hz ± (ppmutput + µA) ± (ppm output + µA)/°C
220 mA 010 - 20
020 - 40
040 - 1 k
01k - 5 k
05k - 10 k
2.2 A 20 - 1 k
1 k - 5 k
5 k - 10 k
5725A Amplifier: ± (% output)
11 A 40 - 1 k
1 k - 5 k
5 k - 10 k
Notes:
Maximum output from 5720A t erm i nal s is 2.2 A. Uncertaint y specifications for 220 µA and 2.2 mA ranges are increased by a
factor of 1.3, plus 2 µA when supplied through 5725A terminals. Speci f i cations are otherwise identical for all output locations.
1. Stabilit y specifications are included in the Absolut e Unc ert aint y values for the primary specifications.
2. Temperature coefficient is an adder to uncertainty specifications that does not apply unl ess operating more than ±5 °C from
calibration temperature.
3. For larger res i stive loads multiply uncertainty specif i cations by:
4. 1.5 V compliance limi t above 1 A. 5725A Amplifier m ay be used in range-lock mode down to 1 A.
5. For resistive loads wit hi n rated compliance voltage lim i ts.
6. For outputs from the Aux Current terminals, the maximum resistive load for full accuracy is 1 kΩ. For larger resistive loads ,
multiply the uncertai nt y as described in Note 3.
Minimum output: 9 µA for 220 µA range, 10 % on all other ranges. 1 A minimum for 5725A.
Inductive load limits: 400 µH (5700A/5720A, or 5725A). 20 µH for 5700A/5720A output >1 A.
Power factors: 5700A/5720A, 0.9 to 1; 5725A, 0.1 to 1. Subject t o compliance voltage limits.
Frequency:
Range (Hz): 10.000-11.999, 12.00-119.99, 120.0-1199.9, 1.200 k-10.000 k
Uncertainty: ±0.01 %
Resolution: 11,999 counts
Settling time to full accuracy: 5 sec onds for 5700A/5720A ranges; 6 seconds for 5725A 11 A range; +1 second for ampl i tude
or frequency range change.
Overshoot: <10 %
150 + 5
080 + 5
030 + 3
050 + 20
400 + 100
150 + 5
080 + 5
030 + 3
050 + 20
400 + 100
150 + 50
080 + 50
030 + 30
050 + 500
400 + 1000
150 + 0.5
080 + 0.5
030 + 0.3
050 + 3
400 + 5
050 + 5
080 + 20
800 + 50
075 + 100
100 + 150
200 + 300
Temperature Coefficient
[Note 2]
40°-50 °C
050 + 5
020 + 5
004 + 0.5
010 + 1
020 + 100
050 + 5
020 + 4
004 + 1
010 + 100
050 + 400
050 + 10
020 + 10
004 + 10
010 + 500
050 + 1000
050 + 0.05
020 + 0.05
004 + 0.1
010 + 2
050 + 5
004 + 1
010 + 5
050 + 10
020 + 75
040 + 75
100 + 75
050 + 5
020 + 5
010 + 0.5
020 + 1
020 + 100
050 + 5
020 + 4
010 + 2
020 + 100
050 + 400
050 + 10
020 + 10
010 + 20
020 + 400
050 + 1000
050 + 0.05
020 + 0.05
010 + 0.1
020 + 2
050 + 5
010 + 1
020 + 5
050 + 10
030 + 75
050 + 75
100 + 75
(
maximum load for full accuracy
Compliance
Limits
72k
7 500 0.05 + 0.1
7 150 0.05 + 0.1
7 15 0.05 + 10
1.4
[Note 4]
3 3 0.05
actual load
Maximum
Resistive
Load
For Full
Accuracy
[Note 3]
[Note 6]
0.5 0.5 + 100
2
)
Noise and
Distortion
Bandwidth
10 Hz-50 kHz
<0.5V Burden
0.05 + 0.1
0.05 + 0.1
0.05 + 0.1
0.25 + 0.5
00.5 + 1
0.05 + 0.1
0.05 + 0.1
0.25 + 0.5
00.5 + 1
0.05 + 0.1
0.05 + 0.1
0.25 + 0.5
00.5 + 1
0.05 + 10
0.05 + 10
0.25 + 50
00.5 + 100
0.3 + 500
0 1 + 1 mA
0.12
0.5
[Note 5]
1-34
Introduction and Specifications
Wideband AC Voltage (Option 5700-03) Specifications
1-33. Wideband AC Voltage (Option 5700-03) Specifications
Table 1-22. Wideband AC Voltage (Option 5700-03) Specifications
Specifications apply to the end of the cable and 50 Ω termination used for calibration
Range Resolution
Volts dBm 24 Hours 90 Days 180 Days 1 Year
1.1 mV -46 10 nV 0.4 + 0.4 00.5 + 0.4 00.6 + 0.4 0.8 + 2
3 mV -37 10 nV 0. 4 + 1 0.45 + 1 00.5 + 1 0.7 + 3
11 mV -26 100 nV 0.2 + 4 0.35 + 4 00.5 + 4 0.7 + 8
33 mV -17 100 nV 0.2 + 10 00.3 + 10 0. 45 + 10 0.6 + 16
110 mV -6.2 1 µV 0.2 + 40 00.3 + 40 0.45 + 40 0.6 + 40
330 mV +3.4 1 µV 0.2 + 100 0 2.5 + 100 0.35 + 100 0.5 + 100
1.1 V +14 10 µV 0.2 + 400 0.25 + 400 0.35 + 400 0.5 + 400
3.5 V +24 10 µV 0.15 + 500 00.2 + 500 00.3 + 500 0.4 + 500
Absolute Uncertainty
±5 °C from calibration temperature
30 Hz-500 kHz
± (% output + µV)
1
Frequency Frequency
Hz Hz ± (% output + floor indicat ed) ±ppm/°C Seconds dB
00 10 - 30 0.01 0.3 0.3 0.3 100 7 -40
00 30 - 120 0.01 0.1 0.1 0.1 100 7 -40
0 120 - 1.2 k 0.1 0.1 0.1 0.1 100 5 -40
01.2 k - 12 k 1 0.1 0.1 0.1 100 5 -40
0 12 k - 120 k 10 0.1 0.1 0.1 100 5 -40
120 k - 1.2 M 100 00.2 + 3 µV 00.1 + 3 µV 0.1 + 3 µV 100 5 -40
1.2 M - 2 M 100 k 00. 2 + 3 µV 00.1 + 3 µV 0.1 + 3 µV 100 0.5 -40
0 2 M - 10 M 100 k 00.4 + 3 µV 00.3 + 3 µV 0.2 + 3 µV 100 0.5 -40
10 M - 20 M 1 M 00.6 + 3 µV 00.5 + 3 µV 0.4 + 3 µV 150 0.5 -34
20 M - 30 M 1 M 10.5 + 15 µV 10.5 + 3 µV 0 1 + 3 µV 300 0.5 -34
Additional Operating Information:
dBm reference = 50 Ω
Range boundaries are at voltage points, dBm levels are approximat e.
dBm = 10 log
Minimum output: 300 µV (-57 dBm)
Frequency uncertainty: ±0.01 %
Frequency resolution: 11,999 counts to 1.1999 MHz, 119 counts to 30 MHz.
Overload protection: A short circuit on t he wideband out put will not result in damage. After sett ling time, normal operation is
restored upon removal.
Resolution
Power
(
1 mW
) ; 0.22361 V across 50 Ω = 1 m W or 0 dBm
Amplitude Flatness, 1 kHz Reference
Voltage Range
1.1 mV 3 mV >3 mV
Temperature
Coefficient
Settling
Time To
Full
Accuracy
Harmonic
Distortion
1-35
5700A/5720A Series II Calibrator
Service Manual
1-34. General Specifications
Warm-Up Time: Twice the time since last warmed up, to a maximum of 30 minutes.
System installation: Rear output configuration and rack- mount kit available.
Standard interfaces: IEEE-488, RS-232, 5725A, 5205A or 5215A, 5220A, phase lock in (BNC), phase
reference out (BNC).
Temperature performance: Operating: 0 °C to 50 °C. Calibration: 15 °C to 35 °C. Storage: -40 °C to
75 °C; DC Zeros calibration required every 30 days.
Relative humidity: Operating: <80 % to 30 °C, <70 % to 40 °C, <40 % to 50 °C. Storage: <95 %, noncondensing. A power stabilization period of four days may be required after extended storage at high
temperature and humidity.
Safety: Designed to comply with UL3111; EN61010; CSA C22.2 No. 1010; ANSI/ISA S82.01-1994
Guard isolation: 20 V
EMI/RFI: Designed to comply with FCC Rules Part 15, Subpart B, Class B; EN50081-1, EN50082-1
Electro Static Discharge: This instrument meets criteria C for ESD requirements per EN61326
Line Power: 47 to 63 Hz; ±10 % allowed about selectable nominal line voltage: 100 V, 110 V, 115 V,
120 V, 200 V, 220 V, 230 V, 240 V. Maximum power: 5700A/5720A, 300 VA; 5725A, 750 VA.
Size:
5700A/5720A: Height 17.8 cm (7 in), standard rack increment, plus 1.5 cm (0.6 in) for feet; Width 43.2 cm
(17 in), standard rack width; Depth 63.0 cm (24.8 in), overall; 57.8 cm (22.7 in), rack depth.
5725A: Height 13.3 cm, (5.25 in); Width and depth same as 5700A/5720A. Both units project 5.1 cm, (2 in)
from rack front.
Weight: 5700A/5720A: 27kg (62 lbs); 5725A: 32kg (70 lbs).
43.2 cm (17 in)
17.8 cm (7 in)
63 cm (24.8 in)
6.35 cm (2.5 in)
FOR CABLE
ACCESS
1-36
1-35. Auxiliary Amplifier Specifications
For complete specifications, see the 5205A and 5220A Operators Manuals.
5205A (220V - 1100 V ac, 0 V - 1100 V dc)
Overshoot: < 10 %
Distortion (bandwidth 10 Hz - 1 MHz):
10 Hz - 20 kHz
20 kHz - 50 kHz
50 kHz - 100 kHz
Frequency
(Hz)
0.07 %
0.2 %
0.25 %
90 Day Accuracy
at 23° ±5 °C
± (% output + % range)
Introduction and Specifications
Auxiliary Amplifier Specifications
Temperature Coefficient for
0°-18 °C and 28°-50 °C
± (ppm output + ppm range)/ °C
1
00 dc
010 - 40
040 - 20 k
20 k - 50 k
50 k - 100 k
0.05 + 0.005
0.15 + 0.005
0.04 + 0.004
0.08 + 0.006
00.1 + 0.01
5220A (AC Current, 180-day specifications):
Accuracy:
20 Hz - 1 kHz
1 kHz - 5 kHz
Temperature Coefficient (0° - 18 °C and 28° - 50 °C): (0.003 % + 100 µA)/°C
Distortion (bandwidth 300 kHz):
20 Hz - 1 kHz
1 kHz - 5 kHz
Note: 5700A/5720A combined with 5220A is not specified for inductive loads.
0.07% + 1 mA
(0.07% + 1mA) x frequency in kHz
0.1% + 1 mA
(0.1% + 1 mA) x frequency in kHz
15 + 3
45 + 3
15 + 3
50 + 10
70 + 20
1-37
5700A/5720A Series II Calibrator
Service Manual
1-38
Chapter 2
Theory of Operation
Title Page
2-1. Introduction.......................................................................................... 2-5
2-2. Calibrator Overview............................................................................. 2-5
2-3. Internal References .......................................................................... 2-5
2-4. Hybrid Reference Amplifiers ...................................................... 2-5
2-5. Fluke Thermal Sensor (FTS)....................................................... 2-5
2-6. Digital-to-Analog Converter (DAC)............................................ 2-6
2-7. Digital Section Overview..................................................................... 2-6
2-8. Analog Section Overview..................................................................... 2-6
2-9. Functional Description Presented by Output Function........................ 2-8
2-10. DC Voltage Functional Description................................................. 2-8
2-11. AC Voltage Functional Description................................................. 2-11
2-12. Wideband AC V Functional Description (Option -03).................... 2-12
2-13. DC Current Functional Description................................................. 2-12
2-14. AC Current Functional Description................................................. 2-12
2-15. Ohms Functional Description.......................................................... 2-13
2-16. System Interconnect Detailed Circuit Description............................... 2-13
2-17. Digital Motherboard Assembly (A4)............................................... 2-13
2-18. Transformer Assembly (A22).......................................................... 2-14
2-19. Analog Motherboard Assembly (A3) .............................................. 2-14
2-20. Front/Rear Binding Po sts................................................................ 2-18
2-21. Rear Panel Assembly (A21)............................................................. 2-18
2-22. Filter PA Supply Assembly (A18)................................................... 2-18
2-23. Digital Section Detailed Circuit Description....................................... 2-18
2-24. Digital Power Supply Assembly (A19)............................................ 2-18
2-25. +5V Power Supply....................................................................... 2-19
2-26. ±12V Power Supplies.................................................................. 2-19
2-27. +35V Power Supply..................................................................... 2-19
2-28. +75V Power Supply..................................................................... 2-20
2-29. +35V and +75V Shut-Down Circuit............................................ 2-20
2-30. CPU (Central Processing Unit) Assembly (A20) ............................ 2-20
2-31. Power-Up and Reset Circuit........................................................ 2-21
2-32. Clock Generation......................................................................... 2-21
2-33. Watchdog Timer.......................................................................... 2-24
2-34. Address Decoding and DTACK (Data Acknowledge)................ 2-24
2-35. Interrupt Controller...................................................................... 2-25
2-1
5700A/5720A Series II Calibrator
Service Manual
2-36. Glue Logic................................................................................... 2-25
2-37. RAM (Random-Access Memory)................................................ 2-25
2-38. ROM (Read-Only Memory) ........................................................ 2-25
2-39. Electrically-Erasable Programmable Read-Only
Memory (EEPROM) .................................................................... 2-26
2-40. DUART (Dual Universal Asynchronous Receiver/transmitter)
Circuit........................................................................................... 2-26
2-41. Clock/Calendar Circuit................................................................ 2-26
2-42. Clock Filter Circuit...................................................................... 2-27
2-43. CPU to Rear Panel Interface........................................................ 2-27
2-44. CPU to Front Panel Interface....................................................... 2-27
2-45. Fan Monitor................................................................................. 2-27
2-46. Front Panel Assembly (A2).............................................................. 2-28
2-47. Clock Regeneration Circuitry...................................................... 2-28
2-48. Refresh Failure Detect Circuitry ................................................. 2-28
2-49. Decoding and Timing Circuitry................................................... 2-28
2-50. Control Display Circuitry............................................................ 2-29
2-51. Output Display Circuitry............................................................. 2-30
2-52. Keyboard Scanner Circuitry........................................................ 2-31
2-53. Knob Encoder Circuitry............................................................... 2-31
2-54. Led Circuitry................................................................................ 2-32
2-55. Keyboard Assembly (A1)................................................................ 2-32
2-56. Analog Section Detailed Circuit Description....................................... 2-33
2-57. Filter/PA Supply (A18), Low-voltage Filter/Regulator Section...... 2-33
2-58. Unregulated OSC Supplies.......................................................... 2-34
2-59. Unregulated LH Supplies ............................................................ 2-34
2-60. Unregulated S Supplies ............................................................... 2-34
2-61. Triac Circuit................................................................................. 2-34
2-62. FR1 Supplies................................................................................ 2-34
2-63. Unregulated FR1 Supply ............................................................. 2-34
2-64. FR2 Supplies................................................................................ 2-35
2-65. Filter/PA Supply (A18), Power Amplifier Output Supply Section . 2-35
2-66. ±PA Supplies Digital Control...................................................... 2-35
2-67. ±250V and ±500V Supplies ........................................................ 2-37
2-68. +PA and -PA Supplies................................................................. 2-37
2-69. ±PA Supply Current Limit........................................................... 2-37
2-70. Regulator/Guard Crossing Assembly (A17).................................... 2-38
2-71. Voltage Regulator Circuitry........................................................ 2-38
2-72. Regulated OSC Supplies.............................................................. 2-38
2-73. Regulated LH Supplies................................................................ 2-39
2-74. Regulated S Supplies................................................................... 2-39
2-75. FR1 Supply.................................................................................. 2-40
2-76. FR2 Supply.................................................................................. 2-40
2-77. Guarded Digital Control Circuitry............................................... 2-41
2-87. Switch Matrix Assembly (A8)......................................................... 2-43
2-88. Switch Matrix Digital Control..................................................... 2-44
2-89. Switch Matrix Operation: 11V DC and 22V DC Ranges............ 2-46
2-90. Switch Matrix Operation: 2.2V AC and 22V AC Ranges........... 2-48
2-91. Switch Matrix Operation: 220V AC and DC Ranges.................. 2-48
2-92. Switch Matrix Operation: 2.2V DC Range ................................. 2-51
2-93. Calibration of the 2.2V Range..................................................... 2-53
2-94. Switch Matrix Operation: 220 mV DC Range ............................ 2-53
2-95. Switch Matrix Operation: 220 mV AC Range ............................ 2-56
2-96. Switch Matrix Operation: 2.2 mV and 22 mV AC Ranges......... 2-56
2-97. Calibration of the mV Ranges..................................................... 2-56
2-2
Theory of Operation
Introduction
2-98. Internal CAL Zero Amplifier....................................................... 2-59
2-99. Switch Matrix 5725A Amplifier Interface.................................. 2-61
2-100. DAC Assembly (A11)...................................................................... 2-61
2-101. Basic DAC Theory of Operation................................................. 2-61
2-102. DAC Assembly Digital Control................................................... 2-64
2-103. DAC Assembly Reference Circuitry........................................... 2-64
2-104. Duty-Cycle Control Circuit......................................................... 2-65
2-105. DAC Filter Circuit....................................................................... 2-66
2-106. DAC Output Stage....................................................................... 2-66
2-107. Sense Current Cancellation Circuit............................................. 2-67
2-108. Linearity Control Circuit............................................................. 2-67
2-109. Negative Offset Circuit................................................................ 2-68
2-110. DAC Output Switching................................................................ 2-68
2-111. DAC Buffered Reference Sip...................................................... 2-68
2-112. Calibration Hardware .................................................................. 2-69
2-113. ADC Amplifier............................................................................ 2-69
2-114. ADC Input Selection.................................................................... 2-69
2-115. ADC Circuit................................................................................. 2-70
2-116. How the DAC is Used in Calibration.......................................... 2-72
2-117. DAC Assembly Calibration......................................................... 2-72
2-118. Oscillator Section Overview............................................................ 2-73
2-119. Oscillator Control Assembly (A12)................................................. 2-73
2-120. Oscillator Control Digital Control............................................... 2-74
2-121. Oscillator Input Switching........................................................... 2-74
2-122. Sense Current Cancellation ......................................................... 2-74
2-123. Averaging Converter.................................................................... 2-75
2-124. Error Integrator............................................................................ 2-75
2-125. Three-Pole Filter.......................................................................... 2-75
2-126. Analog Amplitude Control Loop................................................. 2-75
2-127. AC/DC Thermal Transfer Circuit................................................ 2-77
2-128. Oscillator Calibration .................................................................. 2-79
2-129. AC/DC Frequency Response Characterization ........................... 2-80
2-130. Oscillator Output Assembly (A13).................................................. 2-80
2-131. Oscillator Output Digital Control................................................ 2-82
2-132. Quadrature RC Oscillator............................................................ 2-82
2-133. Oscillator Amplitude Control...................................................... 2-83
2-134. Phase−locked Loop...................................................................... 2-83
2-135. 2.2V and 22V Range Output Amplifier....................................... 2-84
2-136. Oscillator Wideband Smd Assembly (A13A1) ........................... 2-84
2-137. Output Stage ................................................................................ 2-85
2-138. Phase Shifter................................................................................ 2-85
2-139. Power Amplifier Assembly (A16)................................................... 2-85
2-140. Power Amplifier Digital Control Sip Assembly (A16A1).......... 2-86
2-141. PA Common Circuitry................................................................. 2-87
2-142. +PA and -PA Supplies................................................................. 2-87
2-143. PA Input Stage............................................................................. 2-87
2-144. PA Mid Stage............................................................................... 2-88
2-145. PA Output Stage.......................................................................... 2-88
2-146. PA Sense Current Cancellation Circuitry.................................... 2-89
2-147. PA in Standby.............................................................................. 2-89
2-148. PA Operation: 220V DC Range .................................................. 2-89
2-149. PA Operation: 220V AC Range .................................................. 2-91
2-150. High Voltage Assembly Support Mode....................................... 2-91
2-153. 220V DC Internal Calibration Network ...................................... 2-92
2-154. PA Calibration............................................................................. 2-92
2
2-3
5700A/5720A Series II Calibrator
Service Manual
2-155. High Voltage Assemblies (A14 and A15) ....................................... 2-96
2-156. 1100V AC Range......................................................................... 2-96
2-157. 1100V DC Range......................................................................... 2-98
2-158. HVDC Power Supply Filter Circuit............................................. 2-98
2-159. HV DC Output Series Pass and Current Limit Circuit................ 2-98
2-160. DC HV Amplifier/AC Sense Buffer............................................ 2-100
2-161. 2.2A Range.................................................................................. 2-100
2-162. 2.2A Power Supply Filter Circuit................................................ 2-102
2-163. High Voltage Digital Control...................................................... 2-103
2-164. High Voltage Calibration............................................................. 2-104
2-165. Calibration of the AC Function................................................... 2-104
2-166. Calibration of the Current Function. ........................................... 2-106
2-167. High Voltage Magnitude Control................................................ 2-106
2-168. Ohms Overview ............................................................................... 2-108
2-169. Ohms Main Assembly (A10)........................................................... 2-109
2-170. Selection of Resistance Values.................................................... 2-109
2-171. Ohms Main Assembly Support of Current Function Calibration 2-112
2-172. Ohms Digital Control .................................................................. 2-112
2-173. Ohms Cal Assembly (A9)................................................................ 2-112
2-174. Ohms CAL Digital Control ......................................................... 2-112
2-175. 1, 1.9, and Short Resistance......................................................... 2-113
2-176. Two-Wire Ohmmeter Compensation Circuit. ............................. 2-113
2-180. Ohms Calibration......................................................................... 2-115
2-186. Current/High Resolution Oscillator Assembly Overview (A7)....... 2-121
2-187. Current Section............................................................................ 2-122
2-199. High-Resolution Oscillator Section............................................. 2-128
2-204. Rear Panel Assembly (A21)............................................................. 2-130
2-205. Rear Panel Power Supplies.......................................................... 2-131
2-206. Rear Panel Address Mapping...................................................... 2-131
2-207. Clock Regeneration Circuit......................................................... 2-132
2-208. IEEE-488 (GPIB) Interface.......................................................... 2-132
2-209. RS-232C Interface....................................................................... 2-132
2-210. Auxiliary Amplifier Interface...................................................... 2-133
2-211. 5725A Interface........................................................................... 2-133
2-212. Phase Lock In/Variable Phase out............................................... 2-133
2-213. Rear Panel Relay Control............................................................ 2-134
2-214. Rear Panel CPU Interface............................................................ 2-134
2-215. Wideband AC Module (Option -03)................................................ 2-135
2-216. Wideband Oscillator Assembly (A6) .......................................... 2-135
2-222. Wideband Output Assembly (A5)............................................... 2-138
2-4
2-1. Introduction
This section provides theory of operation in increasing level of detail. The calibrator is
first broadly defined in terms of digital functions (relating to the Digital Motherboard
assembly) and analog functions (relating to the Analog Motherboard assembly). The
interrelationship of these two areas is then explored in discussions of each output
function. Finally, the overall picture is rounded out with a discussion of system
interconnections.
Most of this section is devoted to detailed circuit descriptions, first of in the digital
(unguarded) section, then in the analog (guarded) section.
2-2. Calibrator Overview
Figures 2-1, 2-2, and 2-3 comprise the block diagram of the Calibrator. These figures are
presented further on in the Analog Section Overview and the Digital Section Overview.
The Calibrator is configured internally as an automated calibration system with process
controls and consistent procedures. Internal microprocessors control all functions and
monitor performance, using a switching matrix to route signals between modules.
Complete automatic internal diagnostics, both analog and digital, confirm operational
integrity.
Theory of Operation
Introduction
2
The heart of the measurement system is a 5 1/2-digit adc (analog-to-digital converter),
which is used in a differential mode with the Calibrator dac. (The dac is described next
under "Internal References.")
2-3. Internal References
The major references that form the basis of the Calibrator’s accuracy are the hybrid
reference amplifiers, patented Fluke solid-state thermal rms sensors, an extremely linear
dac, and two internal precision resistors.
2-4. Hybrid Reference Amplifiers
A precision source can only be as accurate as its internal references, so the dc voltage
reference for the Calibrator was chosen with extreme care. Years of data collection have
proven the ovenized reference amplifier to be the best reference device available for
modern, ultra-stable voltage standards.
In a microprocessor-controlled precision instrument such as the 5700A/5720A Series II,
the important characteristics of its dc voltage references are not the accuracy of the value
of the references, but rather their freedom from drift and hysteresis. (Hysteresis is the
condition of stabilizing at a different value after being turned off then on again.) The
5700A/5720A Series II hybrid reference amplifiers excel in both freedom from drift and
absence of hysteresis.
2-5. Fluke Thermal Sensor (FTS).
Thermal rms sensors, or ac converters, convert ac voltage to dc voltage with great
accuracy. These devices sense true rms voltage by measuring the heat generated by a
voltage through a known resistance.
Conventional thermal voltage converters suffer from two main sources of error. First,
they exhibit frequency response errors caused by component reactance. Second, they
have a poor signal-to-noise ratio because they operate at the millivolt level. The FTS has
a full-scale input and output of 2V and a flat frequency response.
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After initial functional verification of the Fluke Thermal Sensors, their characteristics
only change by less than 1/10th of the allowed ac/dc error per year. External calibration
of the ac voltage function of the Calibrator consists of verifying that the Calibrator meets
its specifications.
2-6. Digital-to-Analog Converter (DAC).
A patented 26-bit dac is used in the calibrator as a programmable voltage divider. The
dac is a pulse-width modulated (pwm) type with linearity better than 1 ppm (part-permillion) from 1/10th scale to full scale.
2-7. Digital Section Overview
The unguarded Digital Section contains the CPU assembly (A20), Digital Power Supply
assembly (A19), Front Panel assembly (A2), Keyboard assembly (A1), and the
unguarded portion of the Rear Panel assembly (A21). Figure 2-1 is a block diagram of
the digital section of the Calibrator.
Power for the digital assemblies and the cooling fans is supplied by the Digital Power
Supply assembly.
The CPU (central processing unit) assembly is a single-board computer based on the
68HC000 microprocessor. It controls local and remote interfaces, as well as serial
communications over a fiber-optic link to the crossing portion of the Regulator/Guard
Crossing assembly (A17). The guard crossing controls the guarded analog circuitry.
A Keyboard assembly provides the user with front-panel control of the Calibrator. It
contains four LED’s, a rotary edit knob, and a forty-five key keypad. It connects to the
Front Panel assembly via a cable.
The Front Panel assembly provides information to the user on an Output Display and a
Control Display. The Front Panel also contains circuitry that scans the keyboard and
encodes key data for the CPU.
The Rear Panel assembly includes digital interfaces for the following:
• IEEE-488 bus connection
• RS-232-C DTE serial port
• Auxiliary amplifier: the 5725A
2-8. Analog Section Overview
The guarded analog section contains the following assemblies:
• Wideband Output (A5) (Part of Option -03)
• Wideband Oscillator (A6) (Part of Option -03)
• Current/Hi-Res (A7)
• Switch Matrix (A8)
• Ohms Cal (A9)
• Ohms (A10)
• DAC (A11)
• Oscillator Control (A12)
• Oscillator Output (A13)
• High Voltage Control (A14)
• High Voltage/High Current (A15)
• Power Amplifier (A16)
• Regulator/Guard Crossing (A17)
• Filter/PA Supply (A18)
2-6
Theory of Operation
Analog Section Overview
2
Figure 2-1. Digital Section Block Diagram
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These analog assemblies are interfaced to the Analog Motherboard assembly (A3). The
guarded digital bus generated by the guard crossing portion of the Regulator/Guard
Crossing assembly controls all analog assemblies except the Filter/PA Supply. The
Guard Crossing interfaces with the unguarded CPU assembly via a fiber-optic link. The
Transformer assembly, along with the filter portion of the Filter/PA Supply assembly
and the regulator portion of the Regulator/Guard Crossing assembly, create the system
power supply for all the analog assemblies. The Power Amplifier Supply portion of the
Filter/PA Supply assembly provides the high voltage power supplies required by the
Power Amplifier assembly. The amplitudes of these high voltage supplies are controlled
by circuitry contained on the Power Amplifier assembly.
Figures 2-2 and 2-3 are block diagrams for the analog section of the Calibrator.
2-9. Functional Description Presented by Output Function
This part of the theory section presents Calibrator operation from the perspective of each
output function. It describes which assemblies come into play, and how they interact. It
does not provide a detailed circuit description. Refer to the individual assembly theories
further on in this section for detailed circuit descriptions.
2-10. DC Voltage Functional Description
The DAC assembly (A11) provides a stable dc voltage and is the basic building block of
the Calibrator. DC voltages are generated in six ranges:
• 220 mV
• 2.2V
• 11V
• 22V
• 220V
• 1100V
The 11V and 22V ranges are generated by the DAC assembly, with its output, DAC
OUT HI and DAC SENSE HI routed to the Switch Matrix assembly, where relays
connect it to INT OUT HI and INT SENSE HI. Lines INT OUT HI and INT SENSE HI
connect to the Calibrator binding posts by relays on the Analog Motherboard assembly
(A3).
The 2.2V range is created on the Switch Matrix assembly by resistively dividing by five
the 11V range from the DAC assembly. Relays on the Switch Matrix and Analog
Motherboard route the 2.2V range output to the Calibrator binding posts.
The 220 mV range is an extension of the 2.2V range. The Switch Matrix assembly
resistively divides by ten the 2.2V range to create the 220 mV range. Relays on the
Switch Matrix and Analog Motherboard route the 220 mV range output to the front
panel binding posts.
The 220V range is generated by the DAC and Power Amplifier assemblies. The Power
Amplifier amplifies the 11V range of the DAC assembly by a gain of -20 to create the
220V range. The output of the Power Amplifier is routed to the High Voltage Control
assembly (A14), where a relay connects it to PA OUT DC. Line PA OUT DC is routed
to the binding posts via relays on the Switch Matrix and Analog Motherboard.
2-8
Theory of Operation
Theory of Operation
2
Figure 2-2. Analog Section Block Diagram, Part 1
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2-10
Figure 2-3. Analog Section Block Diagram, Part 2
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The 1100V range is generated by the High Voltage/High Current assembly (A15)
operating in conjunction with the Power Amplifier assembly and the High Voltage
Control assembly. The 11V range of the DAC assembly is routed to the High
Voltage/High Current assembly which amplifies by a gain of -100 to create the 1100V
range. Basically the high voltage output is obtained by rectifying and filtering a high
voltage ac signal generated by the High Voltage Control assembly operating in
conjunction with the Power Amplifier assembly.
2-11. AC Voltage Functional Description
The Oscillator Output assembly (A13) is the ac signal source for the Calibrator. The
Oscillator Control assembly (A12), controls the amplitude of this ac signal by comparing
it with the accurate dc voltage from the DAC assembly and making amplitude
corrections via the OSC CONT line. The frequency of oscillation is phase locked to
either the high resolution oscillator on the Current/Hi-Res (A7) assembly or an external
signal connected to the PHASE LOCK IN connector on the rear panel. AC voltages are
generated in the following ranges:
• 2.2 mV
• 22 mV
• 220 mV
• 2.2V
• 11V
• 22V
• 220V
• 1100V
Theory of Operation
Functional Description Presented by Output Function
2
The 2.2V and 22V ranges are generated by the Oscillator Output assembly and routed to
the Calibrator binding posts via relays on the Switch Matrix (A8) and Analog
Motherboard assemblies.
The 220 mV range is generated on the Switch Matrix assembly, which resistively divides
by ten the 2.2V range of the Oscillator Output assembly. Relays on the Switch Matrix
and Analog Motherboard route the 220 mV range to the Calibrator binding posts.
The 2.2 mV and 22 mV ranges are generated on the Switch Matrix assembly. In this
mode, the Switch Matrix resistively divides the 2.2V range or the 22V range by 1000 to
create the 2.2 mV and 22 mV ranges respectively. Relays on the Switch Matrix and
Analog Motherboard route these ranges to the Calibrator binding posts.
The 220V range is generated on the Power Amplifier assembly. In this mode, the Power
Amplifier is set for a nominal gain of -10 to amplify the 22V range from the Oscillator
Output to the 220V range. The 220V ac range from the Power Amplifier is routed to the
Calibrator binding posts by relays on the High Voltage Control assembly and the Analog
Motherboard.
The 1100V range is generated by the High Voltage Control assembly operating in
conjunction with the Power Amplifier assembly. In this mode, the 22V range from the
Oscillator Output is amplified by the Power Amplifier and High Voltage Control
assemblies, which create an amplifier with a nominal gain of -100. Relays on the High
Voltage Control and Analog Motherboard assemblies route the 1100V ac range to the
Calibrator binding posts.
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2-12. Wideband AC V Functional Description (Option -03)
The Wideband AC Voltage module (Option -03) consists of the Wideband Oscillator
assembly (A6) and the Wideband Output assembly (A5). There are two wideband
frequency ranges:
• 10 Hz to 1.1 MHz
• 1.2 MHz to 30 MHz
During operation between 10 Hz and 1.1 MHz, output from the Oscillator Output
assembly is routed to the Wideband Output assembly where it is amplified and
attenuated to achieve the specified amplitude range. The output is connected to the
Calibrator front panel WIDEBAND connector. Operation between 1.2 MHz and 30 MHz
works the same way, except the input to the Wideband Output assembly is the ac signal
from the Wideband Oscillator assembly.
2-13. DC Current Functional Description
DC current is generated in five ranges:
• 20 µA - 220 µA
• 220 µA - 2.2 mA
• 2.2 mA - 22 mA
• 22 mA - 220 mA
• 2.2A
All current ranges except 2.2A are generated by the current portion of the Current/HiRes assembly. These currents are created by connecting the output of the DAC assembly,
set to the 22V range, to the input of the Current assembly. The Current assembly uses
this dc voltage to create the output current. The current output can be connected to the
AUX CURRENT OUTPUT binding post by relays on the Current assembly, to the
OUTPUT HI binding post by relays on the Current, Switch Matrix, and Analog
Motherboard assemblies, or to the 5725A via the B-CUR line by relays on the Analog
Motherboard assembly and Rear Panel assembly.
The 2.2A range is an extension of the 22 mA range. The 22 mA range output from the
Current assembly is amplified by a gain of 100 by the High Voltage/High Current
assembly operating in conjunction with the Power Amp assembly and the High Voltage
Control assembly. The 2.2A current range is routed back to the Current assembly where
it is connected to either the AUX CURRENT OUTPUT binding post, the OUTPUT HI
binding post, or the 5725A in the same manner as the lower current ranges.
2-14. AC Current Functional Description
AC current is created in the same manner as dc current, except the input to the Current
assembly is the ac voltage from the Oscillator Output assembly set to the 22V range. The
switching between ac and dc is carried out on the Switch Matrix, Oscillator Control,
Oscillator Output, and DAC assemblies.
2-12
Theory of Operation
System Interconnect Detailed Circuit Description
2-15. Ohms Functional Description
Two assemblies function as one to supply the fixed values of resistance:
• Ohms Main assembly (A10)
• Ohms Cal assembly (A9)
All of the resistance values except the 1Ω, 1.9Ω, and short are physically located on the
Ohms Main assembly. The 1Ω, 1.9Ω, and short are physically located on the Ohms Cal
assembly. The desired resistance is selected by relays on these Ohms assemblies and is
connected to the Calibrator binding posts by relays on the Analog Motherboard. The
Ohms Cal assembly also contains the appropriate circuitry to enable the Calibrator to
perform resistance calibration. Once calibrated, the Calibrator output display shows the
true value of the resistance selected, not the nominal (e.g., 10.00031 kΩ, not 10 kΩ).
Four ohms measurement modes are available. For the two-wire configuration,
measurement with or without lead-drop compensation sensed at the binding posts of the
UUT (using the SENSE binding posts and another set of leads), or at the ends of its test
leads is available for 19 kΩ and below. Four-wire configuration is available for all but
the 100 MΩ value.
2-16. System Interconnect Detailed Circuit Description
The motherboard assembly contains the Digital Motherboard assembly (A4), and the
Analog Motherboard assembly (A3). These two Motherboards are mechanically fastened
together with screws. They are electrically connected by connectors P81 and P82 on the
Digital Motherboard and connectors J81 and J82 on the Analog Motherboard. AC
voltage taps from the Transformer assembly (A22) are connected to the Analog
Motherboard through these connectors. Refer to Figure 2-4 for an overview of system
interconnections. Figure 2-4 continues on the reverse side, showing system grounds.
2
2-17. Digital Motherboard Assembly (A4)
The Digital Motherboard contains the line-select switches, line fuse, power switch, a
fiber-optic transmitter (J73), and a fiber-optic receiver (J74). It also contains connectors
for the Transformer assembly (A22), Digital Power Supply assembly (A19), CPU
assembly (A20), Front Panel assembly (A2), Rear Panel assembly (A21), and the two
24V dc fans mounted in the chassis.
The fiber-optic receiver and transmitter provide the serial communication link between
the CPU on the unguarded Digital Motherboard and the Regulator/Guard Crossing on the
guarded Analog Motherboard.
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2-18. Transformer Assembly (A22)
The Transformer assembly receives ac line inputs routed through the A4 Digital
Motherboard. This assembly supplies outputs throughout the Calibrator, all of which are
routed through the A4 Digital Motherboard.
The Transformer assembly, the filter portion of the Filter/PA Supply assembly (A18),
and the regulator portion of the Regulator/Guard Crossing assembly (A17) create the
system power supply for all analog assemblies. The Transformer assembly also supplies
ac voltages to the Digital Power Supply assembly which generates five regulated dc
voltages for use by the CPU, Front Panel assembly, Rear Panel assembly, and the
cooling fans.
2-19. Analog Motherboard Assembly (A3)
The Analog Motherboard contains the connectors for all assemblies in the guarded
section of the calibrator. The Analog Motherboard also contains 13 relays, a fiber-optic
transmitter, a fiber-optic receiver, a cable for binding post connections, and two cables
for the interface to the Rear Panel assembly. Table 2-1 lists Analog Motherboard
The fiber-optic transmitter (J72) and the fiber-optic receiver (J71) provide the serial
communication link between the Regulator/Guard Crossing assembly and the CPU
assembly on the unguarded Digital Motherboard.
Control lines for relays K1-K10 and K13 on the Analog Motherboard assembly are
generated on the Switch Matrix (A8) assembly. Control line RLY11*, which controls
relay K11, is generated on the Current/Hi-Res assembly (A7). Control line RLY12*,
which controls relay K12, is generated on the Rear Panel assembly (A21).
2-14
Theory of Operation
Functional Description Presented by 0utput Function
2
Figure 2-4. System Interconnections
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2-16
ahp35f.eps
Figure 2-4. System Interconnections (cont)
System Interconnect Detailed Circuit Description
Table 2-1. Analog Motherboard Connectors
Motherboard Connector Connected to Assembly
J101 Wideband Oscillator Assembly (A6)
J111 Wideband Output Assembly (A5)
J201 and J202 Switch Matrix Assembly (A8)
J211 and J212 Current/Hi-Res Assembly (A7)
J301 and J302 Ohms Main Assembly (A10)
J311 and J312 Ohms Cal Assembly (A9)
J401 and J402 DAC Assembly (A11)
J501 and J502 Oscillator Control Assembly (A12)
J511 and J512 Oscillator Output Assembly (A13)
J601 and J602 High Voltage/High Current Assembly (A15)
J611 and J612 High Voltage Control Assembly (A14)
J701 and J702 Power Amplifier Assembly (A16)
J801 and J802 Regulator/Guard Crossing Assembly (A17)
J901 and J902 Filter/PA Supply Assembly (A18)
Theory of Operation
2
Line INT OUT HI is the calibrator output for ac voltage operation in the 22V range and
below, dc voltage operation in the 220V range and below, all resistance functions, and
all ac/dc current ranges. Relays on the Current assembly route the current output to the
AUX CURRENT OUTPUT binding post via the I OUT line if so selected by the
operator. INT SENSE HI is the sense high path during these modes of operation. INT
OUT HI is connected to the OUTPUT HI binding post through relay K1. INT SENSE HI
is connected to the SENSE HI or OUTPUT HI binding post through relays K2 and K3.
Line HV OUT is the calibrator output for dc voltage operation in the 1100V range, and
ac voltage operation in the 220V and 1100V ranges. Line HV SENSE is the sense high
path during these modes of operation. HV OUT is connected to the OUT HI binding post
through relays K9 and K1. HV SENSE is connected to the SENSE HI or OUTPUT HI
binding post through relays K10, K2, and K3.
The 5725A Amplifier output is B OUT HI and the sense high path is B SNS HI. When
the 5725A is active, B OUT HI is connected to the OUT HI binding post through relays
K4 and K1. When the 5725A Amplifier is inactive, B OUT HI is connected to GUARD
CHASSIS by relay K12. Line B SNS HI is tied to B OUT HI through diode clamps CR1
and CR2 and is connected to the SENSE HI or OUTPUT HI binding post through relays
K5, K2, and K3.
The cable from the motherboard to the binding posts consists of six insulated wires and
six shields, each with its own drain wire. The OUT HI line, SENSE HI line,
OUT/SENSE HI line and AUX CURRENT line each connect to an insulated wire and
each has a shield around the wire. These shields are connected to OUT LO, SENSE LO,
OUT/SENSE LO, and I/V GUARD, respectively. The I/V GUARD line is connected to I
GUARD during operation in the current mode or V GUARD during operation in the
voltage mode. This selection is done by relay K11.
When the Calibrator is in standby, all binding posts are open-circuited except the
GROUND binding post. In addition, GUARD CHASSIS is connected to S COM by K6.
When in the operate condition, this connection is broken (K6 energized) and GUARD
CHASSIS is connected to V GUARD via K7, which goes to the GUARD binding post,
and to OUT LO via K8. GUARD CHASSIS is also connected to OSC LO GD by K13
except during ac or dc millivolt operation, when instead OSC LO GD is connected to S
COM.
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2-20. Front/Rear Binding Posts
An internal cable can be configured to enable either the front panel or panel binding
posts. When compared to front panel binding posts, the rear panel provides the same
OUTPUT HI, OUTPUT LO, SENSE HI, SENSE LO, AND V GUARD functions. Also,
the rear panel provides an I GUARD (current guard) connection for use when the
Calibrator is supplying low-level ac current through a long cable. Use of the I GUARD
connection removes errors introduced by leakage through such cables. The rear panel
binding posts do not provide an AUX CURRENT OUTPUT connection. The procedure
to disable the front panel binding posts and enable the rear panel binding posts is to be
done at Service Centers, although it is described in this manual in Section 4.
2-21. Rear Panel Assembly (A21)
The Rear Panel assembly provides physical and electrical connections for the auxiliary
amplifiers, along with RS-232-C and IEEE-488 interface connections. Relays on the
Rear Panel assembly are used as the interfaces for the 5725A amplifier, or for switching
the PHASE LOCK IN and VARIABLE PHASE OUT signals.
A 5725A auxiliary amplifier can be physically connected to the Rear Panel assembly of
the 5700A/5720A Series II at J7. Only one amplifier can be in use at one time.
• The Rear Panel assembly provides relay switching for 5725A signals. Voltage
outputs from the 5725A are routed to the binding posts on the Calibrator. Current
outputs are soured at the 5725A OUTPUT binding posts. An alternate configuration
is also available, allowing for routing of Calibrator current outputs to the 5725A
OUTPUT binding posts.
2-22. Filter PA Supply Assembly (A18)
The Filter/PA Supply assembly incorporates two sections. The first section contains
filters and regulators for some of the in-guard low-voltage supplies, and the second
contains the power supply for the Power Amplifier output. Theory for each section is
discussed separately.
2-23. Digital Section Detailed Circuit Description
Detailed descriptions of each assembly in the digital section are provided here.
Simplified schematics and block diagrams are provided to supplement the text.
2-24. Digital Power Supply Assembly (A19)
The Digital Power Supply assembly receives ac voltages from the transformer and
provides five regulated dc voltages for use by the CPU, Front Panel assembly, Rear
Panel assembly, and the cooling fans. All power supply voltages are referenced to
COMMON, which is the transformer center tap for the ±12V supplies. Test points at the
top of the assembly can be used to check unregulated input voltages, and regulated dc
output voltages. Table 2-2 lists the supplies generated by the Digital Power Supply.
2-18
Digital Section Detailed Circuit Description
Table 2-2. Supplies Generated by the Digital Power Supply
Theory of Operation
2
Signal Name Test Point Nominal
Output
+75V OUT TP2 73V +/-8% 121 mA 100 mA
+35V OUT TP5 35V +/-7% 52 mA 40 mA
+12 VOLTS TP8 12V +/-5% 1.5A 700 mA
-12 VOLTS TP10 12V +/-5% 1.5A 450 mA
+5V TP12 5.2V +/-5% 2.4A 2.0A
COMMON TP13
Tolerance Current
Limit
2-25. +5V Power Supply
The unregulated +5V supply uses CR25-CR28 in a full-wave rectifier configuration with
filter capacitors C12, C13, and C14. Capacitors C20 and C21 filter out high-frequency
noise. Inductor L8 is a common-mode choke and C11 is a bypass capacitor. The
regulator is fused by 3.15A slow-blow fuse F5.
The regulated +5V is generated by three-terminal low-dropout +5V regulator U3 with
heat sink. The regulator’s output voltage is increased about 0.2V by CR35, a germanium
diode connected between the regulator’s ground pin and COMMON. Capacitor C14 is
for bypass. Capacitor C23 filters out high-frequency noise. Diode CR29 protects the
regulator against input shorts, and diode CR30 protects the regulator from reverse
voltage. Inductor L7 and C16 further filter the output to P41.
2-26. ±12V Power Supplies
A full-wave rectifier made of diodes CR17-CR20 and filter capacitors C6 and C7
generate the unregulated +12V and -12V supplies. AC inputs are fused by F3 and F4,
both 2A slow blow.
Rated
Output
The regulated +12V supply is generated by a three-terminal +12V regulator U1 with heat
sink. Capacitors C5 and C9 are for bypass. Diode CR21 protects the regulator from input
shorts, and diode CR23 protects the regulator from reverse voltage. Capacitor C22 filters
out high frequency noise.
Three-terminal -12V regulator U2 with heat sink generates the regulated -12V supply.
Capacitors C8, C10, and C19 are for bypass. Diode CR22 protects the regulator from
input shorts, and diode CR24 protects the regulator from reverse voltage.
Inductors L3-L6 filter the regulated outputs. R7 further isolates the ±12V FAN lines
from the ±12V power lines. The +12V FAN and -12V FAN lines power the two 24V dc
fans inside the calibrator.
2-27. +35V Power Supply
The +35V power supply powers the grid drivers and anode drivers on the front panel
output display circuitry.
A full-wave rectifier made of diodes CR9-CR12 and filter capacitor C3 generate the
unregulated +35V supply. Its input is fused by F2, a 0.125A slow-blow. Capacitor C18 is
for bypass. Capacitor C25 filters out high frequency noise.
Zener diodes VR14, VR15 and transistor Q5 generate the +35V regulated output. Zener
diodes VR14 and VR15 (both 18V) make up the control element which sets the output
voltage. Transistor Q5 is used as an emitter follower. CR13 is the constant current source
supplying current to the zener diodes and the base of Q5. Components R5 and Q6 make
up the current-limiting circuit. During an over-current condition, the voltage drop across
R5 turns Q6 on, thus drawing current away from the base of Q5 and limiting current
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flow to the output. Diode CR16 protects this circuit from reverse voltage and C4 is a
bypass capacitor. Inductor L2 filters the regulated output. Resistor R13 is a bleed-off
resistor for C3.
2-28. +75V Power Supply
The +75V power supply powers the grid drivers and anode drivers on the front panel
control display circuitry.
A full-wave rectifier made of diodes CR1-CR4 and filter capacitor C1 generate the
unregulated +75V supply. Its input is fused by F1, a 0.315A slow-blow. Capacitor C17 is
for bypass. Capacitor C24 filters out high frequency noise.
The +75V regulated output is generated by 36V zener diode VR6, 39V zener diode VR7,
and transistors Q1 and Q3. Zener diodes VR6 and VR7 set the output voltage.
Transistors Q1 and Q3, in a Darlington configuration for current gain, are used as an
emitter follower. Transistor Q4, zener diode VR5, and resistors R2 and R3 make up the
constant current source supplying current to the zener diodes and the base of Q3. Current
limiting is performed by R1 and Q2 in the same manner as in the +35V supply. Diode
CR8 protects the circuit from reverse voltage and C2 is a bypass capacitor. Inductor L1
filters the regulated output. Resistor R6 is a bleed-off resistor for C1.
2-29. +35V and +75V Shut-Down Circuit
The +35V and +75V high voltage supplies are shut down when a fault occurs in the
control display refresh circuitry. This shut-down circuit prevents the Control Display and
Output Display from burning out, and also verifies that the master clock is generating
control signals for both displays.
During normal operation, 75VSD is low, turning Q10 off. Line RESETL pulls the base
of Q9 high through R9, turning Q9 on. This action in turn pulls the junctions of CR31CR32 and CR33-CR34 low, turning Q7 and Q8 off. The +75V and +35V constantcurrent sources can then supply the appropriate zener diodes and drive the bases of the
respective emitter followers.
When a display refresh fault occurs, the 75VSD line on P41 pin 5C, coming from the
Front Panel assembly, goes high. this signal, pulled up by R4, drives the base of Q10
through base resistor R11. Transistor Q10 then saturates, pulling the base of Q9 near
ground, turning Q9 off. On power-up or during a CPU reset, the RESETL signal is low,
pulling the base of Q9 near ground through R9, also turning Q9 off. Resistor R12 is a
turn-off resistor for Q9. Diodes CR31 and CR33 are in a wired-OR configuration. When
Q9 is saturated (on), CR31 and CR33 pull their respective junctions to CR32 and CR34
near ground, turning Q7 and Q8 off. When Q9 is off, the junctions are pulled high
through R8 and R10, saturating Q7 and Q8 (on). When on, Q7 removes the base drive
from Q3, shutting down the +75V supply. Similarly, Q8 removes the base drive from
Q5, shutting down the +35V supply.
Diodes CR32 and CR34 simply ensure that Q7 and Q8 are off when Q9 is on. Resistor
R8 guarantees that Q7 will hold the +75V supply off until it drops below 15.6V, and R10
holds the +35V supply off to 7.8V.
2-20
2-30. CPU (Central Processing Unit) Assembly (A20)
The CPU (Central Processing Unit) for the Calibrator is a single-board computer based
on a 68HC000 microprocessor. The CPU assembly communicates with the Guarded
Digital section, the Front Panel assembly, and the Rear Panel assembly. The board can
be divided into three primary areas:
• The microprocessor and its support circuitry
• Memory
• Peripheral chips and I/O interfaces
Microprocessor support circuitry consists of a power-up and reset circuit, clock
generation, a watchdog timer, address decoders and DTACK (data acknowledge)
generator, bus error timeout, and interrupt controller.
Figure 2-5 is a block diagram of the CPU assembly. Table 2-3 is a glossary of the
acronyms used in the text and schematic for the CPU assembly.
2-31. Power-Up and Reset Circuit
The power-up and reset circuitry consists of line monitor chip U1, C5, C6, CR1, R3, Z3,
switch SW1, and inverters on U2. This circuit provides a 195 ms reset pulse at power-up
or upon pressing and releasing SW1, placing the CPU assembly in a known safe
condition. If the power supply glitches or falls below 4.55V ±0.05V, U1 resets the
Calibrator. The reset pulse duration is determined by C5. Note that SW1 performs a
different function than the front panel RESET button. SW1 is a hardware reset that is
hard-wired to and directly read by the microprocessor. The front panel RESET button is
a software reset; it tells the system software to restore the Calibrator configuration to a
default condition.
Theory of Operation
Digital Section Detailed Circuit Description
2
The heart of this circuit is the line monitor chip U1. On power-up or when SW1 is
pushed, U1 forces an active-low reset pulse on RESETL and an active-high pulse on
RESET. RESETL helps to prevent accidental writes to EEPROM and drives an inverter
in U2 to turn off LED CR1. CR1 indicates that the +5V supply is on and that the CPU is
operating, i.e. not reset. RESETL also resets the rear panel assembly. The other output,
RESET, drives two inverters in U2. One of these inverters provides HALT*. The other
generates IORESET*, which drives the processor's RESET, and provides a reset for the
front panel interface and DUARTs (dual universal asynchronous receiver/transmitter)
circuitry.
2-32. Clock Generation
The clock generation circuit uses components Y1, Y2, U3, U4, R4, R5, C8, C9, and E5.
The crystal Y1, along with the resistors, capacitors, and an inverter in U3 generates the
7.3728 MHz primary system clock CLK. This system clock is used by the processor and
is divided down by a binary counter (U4) for clocks of 3.6864 MHz, 28.8 kHz, and 450
Hz. The 450 Hz clock is used by the watchdog timer, the 28.8 kHz is used by U6 in the
decoding circuit, and the 3.6864 MHz is used by the DUARTs, and the clock filter
circuit. Jumper E5 allows for selection of the alternate oscillator (Y2) as the system
clock.
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2-22
Figure 2-5. CPU Assembly Block Diagram
ahp004f.eps
Theory of Operation
Digital Section Detailed Circuit Description
Table 2-3. CPU Acronym Glossary
Signal Name Function
A01-A23 Address lines
ADCLKCS* Clock/calendar (U33) chip select
AS* Address strobe
BERR* Bus error
BGACK* Bus grant acknowledge
BR* Bus request
BRPDRTINT* Rear panel DUART interrupt
BRPDTK* Rear panel data transfer acknowledge
BRPIEEEINT* Rear panel IEEE-488 interrupt
CLKCALINT* Clock/calendar interrupt
D00-D15 Data lines
DOGCLR Dog clear (clears watchdog timer)
DOGINTH Dog interrupt (interrupt from watchdog timer)
DRTDTK* DUART data transfer acknowledge
DTACK* Data transfer acknowledge
E Enable for 6800 family devices (737.28 kHz clock)
EXDUARTINT* External DUART Interru
FAN1 Signal monitoring fan 1
FAN2 Signal monitoring fan 2
FANINT* Fan monitor interrupt
FC0 Function code output 0
FC1 Function code output 1
FC2 Function code output 2
FPDTK* Front panel data transfer acknowledge
FRNTPNLCS* Front panel chip select
FRNTPNLEN* Front panel enable
GCDRTCS* Guard crossing DUART chip se lect
GCDUARTINT* Guard crossing DUART interrupt
INTRCNTL1 Interrupt control 1
INTRCNTL2 Interrupt control 2
IPL0* Interrupt priority level 0
IPL1* Interrupt priority level 1
IPL2* Interrupt priority level 2
KEYBRDINT* Keyboard interrupt
LDS* Lower data strobe
MISCCS* Miscellaneous chip select enable (upper address bits decoder)
NVMCS* Nonvolatile memory chip select
NVMOE* Nonvolatile memory output enable
PROM0CS* PROM 0 chip select (U15 and U16)
PROM1CS* PROM 1 chip select (U17 and U18)
PROM2CS* PROM 2 chip select (U23 and U24)
PSFAILINT* Power supply fail interrupt
RAM0CS* RAM chip select (U19 and U20)
RAM1CS* RAM chip select (U21 and U22)
RAM2CS* RAM chip select (U40 and U41)
R/WR* Read/write
RDINT* Read interrupt
RDL* Read data lower
RDU* Read data upper
RDY/BSYL Ready/busy
RPSEL* Rear panel chip select
RRPNLEN* Rear panel enable
RXDA Receive Data Port A
RCVB Receive Data Port B
SCLK Serial clock
TXDA Transmit Data Port A
TXDB Transmit Data Port B
UDS* Upper data strobe
WRL* Write lower
WRU* Write upper
XDUARTCS* External DUART chip select
2
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2-33. Watchdog Timer
The watchdog timer circuitry uses a 74HC4020 binary counter (U11) to divide the 450
Hz from the clock generation circuit to produce interrupt DOGINTH, signifying that the
system may be locked up. This interrupt is generated 1.14 seconds after the last
DOGCLR2 signal from interrupt controller U10. Therefore, DOGCLR2 must occur more
often then every 1.14 seconds to clear U11 and prevent the watchdog interrupt.
Generation of DOGCLR2 is under software control. The watchdog timer can be disabled
by cutting jumper E1.
2-34. Address Decoding and DTACK (Data Acknowledge)
Two Programmable Logic Devices (PLDs) accomplish address decoding and DTACK
(data acknowledge) generation. ICs U5 and U6 provide chip selects and generate
acknowledgment signals for those devices without DTACK lines. IC U5 receives
DTACK signals from the asynchronous devices and ORs these signals together to form
DTACK*. Table 2-4 is the memory map for the system. It shows the chip select, address
range, and notes whether AS* (address strobe) or LDS* (lower data strobe) is required.
Chip Select Read/Write Address Range AS* or LDS* Required?
PROM0CS* R 0 to 3FFFF no
PROM1CS* R 40000 to 7FFFF no
PROM2CS* R 80000 to BFFFF no
RAM0CS* 600000 to 60FFFF no
RAM1CS* 610000 to 61FFFF no
RAM2CS* 620000 to 623FFF no
NVMCS* R/W C00000 to CFFFFF no
MISCCS* R/W D00000 to DFFFFF no
RPSEL* R/W D00000 to D01FFF LDS*
RPDUARTCS* R/W D00000 to D0001F LDS*
RPIEEECS* R/W D00020 to D0002F LDS*
Y52XXRD* R D00030 to D00031 LDS*
Y5205WR* W D00032 to D00033 LDS*
Y5220WR* W D00034 to D00035 LDS*
FRNTPNLCS* R/W D02000 to D03FFF AS*
OTDCS* R/W D02000 to D027FF AS*
DMDCS* R/W D02800 to D02FFF AS*
ENCODERCSR R D03000 to D033FF AS*
ENCODERRESETW W D03000 to D033FF AS*
LED_OUTPUT_ R R D03400 to D037FF AS
LED_LATCH_EN R/W D03400 to D037FF AS*
KEYBOARDCS R/W D03800 to D038FF AS*
GCDRTCS* D04000 to D05FFF LDS*
XDUARTCS* R/W D06000 to D07FFF LDS*
RDINT* W D08000 to D09FFF AS*
DOGCLR D08000 to D09FFF even only, AS*
ADCLKCS* E00000 to EFFFFF AS*
Table 2-4. CPU Memory Map
2-24
2-35. Interrupt Controller
PLD U10 is the priority interrupt controller. The interrupt controller reads incoming
interrupts and interrupt control lines, then encodes the highest priority interrupt into the
interrupt level for the 68HC000. When the 68HC000 responds to an interrupt request, it
asks the interrupt controller for an 8-bit vector that corresponds to the pending interrupt
of highest priority. The interrupt controller responds with the 4 LSB’s of the vector
according to how it is programmed. The 4 MSB’s are pulled up on resistor network Z1.
Table 2-5 shows the interrupts, their priority levels, and vectors.
Table 2-5. CPU Interrupts, Priorities, and Vectors
Interrupt Priority Level Vector (Hex)
NMI 7 - (not used)
DOGINTH 6 F4
BRPDRTINT* 5 F6
GCDUARTINT* 5 F7
EXDUARTINT* 5 F8
Theory of Operation
Digital Section Detailed Circuit Description
2
CLKCALINT* 4 F5
BRPIEEEINT* 4 F9
KEYBRDINT* 3 FA
BPSFAILINT* 2 FB
FANINT* 0 FF (not used)
RDY/BSYL 0 FF (not used)
No interrupt 0 FF
2-36. Glue Logic
ICs U2, U3, and U9 form the glue logic circuit, which keeps various CPU functions
running properly. The four OR gates in U9 and an inverter in U3 use control signals
UDS*, LDS*, and R/WR* from the microprocessor to generate control signals WRU*,
WRL*, RDL*, and RDU*.
2-37. RAM (Random-Access Memory)
Random-access memory is contained in three pairs of sockets, U19 and U20, U21 and
U22, and U40 and U41. These sockets accommodate either 32K x 8 or 128K x 8 static
CMOS RAM modules (32KB or 128 KB each). The Calibrator is shipped with U19-U22
installed, using 32K x 8 parts and providing 128 KB of static RAM.
2-38. ROM (Read-Only Memory)
Read-only memory is contained in three pairs of sockets, U15-U16, U17-U18, and U23U24. These sockets accommodate 27010 EPROMS, 128K x 8 devices (128 KB each).
Jumpers allow 256 KB devices to be used in their place. The Calibrator is shipped with
U15-U18 installed, providing 512 KB of EPROM.
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2-39. Electrically-Erasable Programmable Read-Only Memory (EEPROM)
IC U13 is an EEPROM. The socket accommodates a 32K x 8 device (32 KB of storage.)
A jumper is provided to allow an 8K x 8 (8 KB) device to be used in place of the 32 KB
device. The Calibrator is shipped with a 32KB EEPROM installed.
The EEPROM requires protection against inadvertent writes during power-up and
power-down sequences, which could corrupt calibration constants stored there by the
68HC000. The 32 KB EEPROM provides for software-controlled protection against
accidental writes.
Hardware is also used to further ensure data integrity. The EEPROMs are designed so
that writes to the device are prevented by holding the output enable line (NVMOE*) low.
Diodes CR5, CR6 and CR8, together with resistor R6, perform a wired-OR function for
three signals that control NVMOE*. Components R6, CR6 and C17 hold NVMOE* to a
valid logic low for typically 37.3 ms during power-up; 26.8 ms minimum, 49.6 ms
maximum. Diode CR7 provides a discharge path for C17 on power-down, allowing the
operator to quickly turn the Calibrator off then on again, without interfering with the
power-up charge time of the capacitor. Diode CR8 allows the normal microprocessor
read of the device to take place. And diode CR5 allows power monitoring IC U1 to hold
NVMOE* low when the +5V power supply drops below 4.5V on power-down or during
power glitches.
2-40. DUART (Dual Universal Asynchronous Receiver/transmitter) Circuit
The 68C681 DUART (U31) has several functions. Its primary function is to provide the
asynchronous serial lines that communicate with the Guarded Digital Controller over the
fiber-optic path off the Digital Motherboard. A 75451 driver chip (U32) drives the fiberoptic transmitter on the digital Motherboard.
The DUART has 8 output lines that perform various functions. INTRCNTL1 and
INTRCNTL2 go to the interrupt controller and are fed back to the DUART inputs. These
are used by the interrupt controller to enable certain interrupts. Line SCLK is a test
output of the channel A serial clock.
The DUART monitors the EEPROM ready signal and the FANINT* signal. It also has a
spare serial channel that goes to connector J5. Components U44 and U43 convert the
TTL-level signals at the DUART to RS-232-C-level signals at J5.
The DUART generates its own DTACK signal, DRTDTK*, which is used by U5 to
generate system DTACK, DTACK*. A second DUART, U42, with associated RS-232-C
drivers and receivers is used only for test purposes. It generates its own DTACK, wireORed to DRTDTK*.
2-41. Clock/Calendar Circuit.
Time and date information is stored in a battery-backed clock/calendar circuit consisting
of 32.768 kHz crystal Y3, 3V lithium battery BT1, clock/calendar IC U33, and
capacitors C10 and C11. The clock/calendar IC has the necessary circuitry internally to
switch operation from the power supply to battery BT1. Pull-up resistors in Z5 off U33
are to ensure low power operation when the +5V supply is off. U33 generates
CLKCALINT* under software control.
2-26
2-42. Clock Filter Circuit
The clock filter circuit generates a 3.6864 MHz 200 mV sine wave for the Rear Panel
and Front Panel assemblies. This circuit buffers the 3.6864 MHz Clock with an inverter
in U3. The circuit contains dc-blocking capacitor C80, two stages of a low pass LC filter
(L80 and C81, L81 and C82), transformer T51, and termination resistor R82.
2-43. CPU to Rear Panel Interface
Components U25, U26, U27, and connector P62 interface the CPU to the rear panel. Bidirectional bus transceiver U26 buffers the data lines. Signal R/WR* controls the
transmission direction of the data lines, and RRPNLEN* is the chip enable. IC U25
buffers control lines BRPDRTINT*, BRPIEEEINT*, and BRPDTK*. U27, enabled by
RRPNLEN*, buffers address line A01-A05 and control lines WRL* and R/WR*.
Control lines RESETL, RPSEL*, TXDB, RCVB, and XMT go directly to connector P62.
2-44. CPU to Front Panel Interface
Components U25, U28, U29, U30 and connector P61 interface the front panel to the
CPU. Bi-directional bus transceiver U30 buffers the data lines. Control signal R/WR*
controls the transmission direction of the data lines, and FRNTPNLEN* is the chip
enable. IC U28, enabled by FRNTPNLEN*, buffers address lines A05-A12. IC U29, also
enabled by FRNTPNLEN*, buffers address lines A01-A04 and control line R/WR*. Two
sections of U25 in parallel buffer IORESET*, providing twice the drive current of a
single section, generating BRESET*. Three other sections of U25 buffer FPINT*,
FPDTK*, and PSFAILINT*. Control line FRNTPNLCS* goes directly to connector P61.
Theory of Operation
Digital Section Detailed Circuit Description
2
2-45. Fan Monitor
The fan monitor circuit detects whether one of the two fans is fully or partially shorted,
open-circuited, or drawing excessive current. Current-sense resistors on the Digital
Motherboard send analog signals FAN1 and FAN2 to the CPU through P61. FAN1 is
subtracted from FAN2 in U52D, and the difference is amplified before being sent to a
window comparator made up of U52B and U52C (plus associated resistors). Capacitors
C12 and C13 act as low-pass filters for the two signals, preventing spurious noise from
interfering with detection circuitry.
When the output of U52D is greater than +5V, the output of U52B goes low (to about 11V); otherwise the output is high (about +11V). U52A takes the +5V and generates a 5V reference for comparator U52C. When the output of U52D is more negative than 5V, the output of U52C goes low (to about -11V); otherwise the output is high (about
+11V). The outputs of U52B and U52C are wire-ORed through CR2 and CR3, using
R52 and R53 to limit current sunk by the comparators when their respective outputs are
low. Schottky barrier diode CR4 converts the -11V outputs of the comparators, when
either is low, to a TTL-level logic low, which is the active (true) level of FANINT*.
When both fans are functioning properly, diodes CR2 and CR3 are reverse-biased,
effectively taking the comparators out of the circuit. At this point, R51 pulls FANINT*
to a valid TTL-level logic high, the inactive state of FANINT*. R51 and CR4 level-shift
the ±11V signal to valid TTL levels.
Signal FANINT* goes to DUART U31 and to the interrupt controller U10 for further
processing. System software monitors FANINT* through U31, and can program the
DUART to generate a GCDUARTINT* interrupt signal on FANINT* going low.
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2-46. Front Panel Assembly (A2)
The Front Panel assembly, operating in conjunction with the Keyboard assembly (linked
by a cable), is the operator interface to the Calibrator. This assembly contains two
separate vacuum-fluorescent displays: the Control Display and the Output Display. Each
display has its own control, high voltage drive, and filament-switching circuits. This
assembly also contains clock regeneration, refresh failure detect, keyboard scanner,
rotary knob encoder, LED drive, and decoding and timing circuitry.
Connector J2 connects this assembly with the Keyboard/Encoder. Connector J1
interfaces with the CPU assembly and the Digital Power Supply assembly via the Digital
Motherboard.
2-47. Clock Regeneration Circuitry
To minimize EMI (electro-magnetic interference), the Front Panel assembly accepts a
low-level sine-wave (approximately 200 mV p-p) 3.6864 MHz clock from the CPU
assembly and converts it to a TTL-acceptable level. This is done by high-speed
differential comparator (U7A), operating on incoming signals 3.6864MHZCLK and
3.6864MHZCLK*. The output of U7A is the input to U8 and is also inverted by U11B to
create the 3.6864 MHz clock signal CLOCK. Twelve-stage binary counter U8 divides
the 3.6864 MHz clock by eight and U11A inverts the signal to create 460.8 kHz. The
master clock is further divided by U8, which outputs a 900 Hz signal on pin 1. These
clocks provide system timing for the other ICs on the assembly. A -5.2V supply for U7
is provided by VR5, with C64 acting as the supply bypass.
2-48. Refresh Failure Detect Circuitry
If a clock failure were to occur, the refresh cycles of the vacuum-fluorescent displays
would be interrupted. This condition could damage the tubes if not immediately
detected. Refresh failure detect circuitry monitors the GRIDDATA output from the last
high voltage driver (U23) for the Control Display. This output (REFRESH) is used to
clear a watchdog timer (U6) every refresh cycle. If the refresh is interrupted and
GRIDDATA does not occur, the watchdog timer times out and latches U12. Flip-flop
U12 generates control lines 75VSD and PSFAILINTR*. Control line 75VSD is routed to
the Digital Power Supply assembly to shut down the +35V and +75V power supplies,
thus preventing damage to the vacuum-fluorescent displays. Interrupt line
PSFAILINTR* is used by PLD U3 to properly blank the Control Display and Output
Display through DMDBLANK and OTDBLANK, and alerts the CPU that this failure
has occurred.
2-49. Decoding and Timing Circuitry
Main decoding and master timing functions for the front panel are accomplished by an
EP900 PLD (Programmable Logic Device), U3. Two state machines control display
refresh and filament switching. Filament switching is handled by two non-overlapping
57.6 kHz signals.
Signals GSTRBE and STROBE are master timing and synchronization signals used by
the other ICs. Signal DMDBLANK controls the Control Display grid drivers, ABCLK
and CDCLK control the Control Display anode drivers, and OTDBLANK controls the
Output Display grid and anode drivers. Front panel DTACK and interrupt functions, and
generation of the various chip select and reset signals are also provided by U3. Table 2-6
is a memory map for the front panel.
2-28
Digital Section Detailed Circuit Description
Table 2-6. Front Panel Memory Map
Name Read/Write Address
OTDCS* R/W D02000 to D027FF
DMDCS* R/W D02800 to D02FFF
ENCODERCS* R D03000 to D033FF
ENCODERRESET* W D03000 to D033FF
LED_OUTPUT_CNTRL R D03400 to D037FF
LED_LATCH_EN W D03400 to D037FF
KEYBOARDCS* R/W D03800 to D03BFF
2-50. Control Display Circuitry
Control display circuitry consists of a 26-row by 256-column vacuum-fluorescent dot
matrix display under the control of PLD U4, four high voltage grid drivers (U20-U23),
four high voltage anode drivers (U16-U19), a filament switching circuit, and 1K x 8 (1
KB) dual-port RAM U1.
This display is divided into 129 grids; alternate grids contain two anode columns lettered
B C or D A. Grid G129 and column C in grid G128 are not used. Each column contains
26 individual anodes.
Theory of Operation
2
IC U4 is an EP900 Programmable Logic Device (PLD). It provides the timing and
control signals for control display circuitry. Display data written by the microprocessor
into the Control Display’s dual port RAM (U1) is read by U4 and sent serially to the high
voltage anode drivers. Both the anode and grid drivers are serial TTL-level input, 32-bit
parallel high voltage output devices. IC U4 also controls the grid timing and display
refresh.
B C
G4
D A
G5
B C
G6
Adjacent columns in adjacent grids are driven, while the opposite columns are turned
off. For instance, grid G4 contains columns B and C, and grid G5 contains columns D
and A. G4 and G5 are driven simultaneously while anode columns G4-C and G5-D are
activated, and G4-B and G5-A are driven off. Next, grids G5 and G6 are driven
simultaneously, while columns G5-A and G6-B are activated, and G5-D and G6-C are
driven off. This pattern is repeated for all 128 grids at a refresh rate of about 75 Hz.
This particular scheme was selected because of the way the anode drivers are loaded
with display data. Both the A and C (U16 and U18), and B and D (U17 and U19) anode
drivers’ input registers are latched with the same data, while the output drivers are
appropriately enabled and displaying the data previously strobed to the driver outputs
from the input registers. The input register data is strobed to the output drivers while all
of the drivers are disabled, or blanked. Following this, either the A and B drivers are
enabled to display the A-B data, when the C and D drivers, latched with A-B data, are
disabled, or the C and D drivers are enabled to display the C-D data, when the A and B
drivers, latched with C-D data, are disabled.
Control display filament driver circuitry consists of transistors Q1 through Q6 and zener
diodes VR1 and VR2, with associated resistors. The transistors are driven by 7406 open
collector drivers U13B and U13A. These drivers are controlled by AOUT and BOUT.
AOUT and BOUT are synchronous, non-overlapping, three-eighths duty cycle, 57.6 kHz
timing signals generated by U3. Each signal is alternately active high for 6.51 us, with a
dead time between active signals of about 2.17 us to allow for turn-off times of the drive
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transistors. When AOUT is high, U13B turns Q2 and Q4 on. Q4 turns Q6 on, providing a
path for the filament current through Q2 and Q6. Zener diode VR2 provides the dc
voltage offset necessary for proper filament operation. Then when BOUT is high, U13A
turns Q1 and Q3 on. Q1 turns Q5 on, providing a path for the filament current through
Q3 and Q5, effectively reversing the direction of the voltage driving the filament. Zener
diode VR1 provides the dc voltage offset necessary for proper filament operation.
PLD U4 also generates the 225 Hz square-wave SCAN signal used by PLD U9 to control
front panel keypad scanning and key debounce.
Dual-port RAM U1 contains all the Control Display data written by the 68HC000
microprocessor on the CPU board. PLD U4 contains a 10-bit address counter which is
used by U4 to read the contents of U1. U1 provides a BUSYD signal to U3, which is
active low whenever the CPU and U4 try to access the same RAM location at the same
time. If the microprocessor attempts to write to the RAM location that U4 is reading (as
it refreshes the DMD), U3 uses BUSYD to hold off DTACK to the microprocessor. This
prevents the written data from being lost. The other busy signal, generated when U4
attempts to read from a location being written to by the microprocessor, is ignored.
Losing display data for one refresh cycle is insignificant.
The Control Display can be blanked to maintain its brightness over years of operation.
The Main CPU pulls U10 pin 12 (SQ) low when the Calibrator has been inactive for at
least 30 minutes. This action results in U13 E&F being driven low to short the bases of
Q5 and Q6 to common, turning off any filament drive to the control display. Since U13
outputs are open-collector, they have no effect on the filament drive circuit when the
Main CPU returns U10 pin 12 high.
2-51. Output Display Circuitry
Output display circuitry consists of a custom 2-row, 22-character vacuum-fluorescent
display under the control of PLD U5. The circuit contains high voltage grid driver U15,
high voltage anode driver U14, a filament switching circuit, and a 1K x 8 (1 KB) dualport RAM, U2.
The custom display is divided into 24 grids. The 22 characters are made up of fourteen
seven-segment digits and eight 14-segment characters.
IC U5 is an EP900 PLD, programmed to provide the timing and control signals for the
output display circuitry. Display data written by the microprocessor into the Output
Display’s dual-port RAM U2, is read by U5 and sent serially to the high voltage anode
driver. Both the anode and grid drivers are serial TTL-level input, 32-bit parallel high
voltage output devices. Only 31 anode driver outputs and 24 grid driver outputs are used,
the remaining high voltage outputs are left unconnected. IC U5 also controls grid timing
and display refresh.
A special refresh scheme is used by the Output Display to intensify a specific digit to be
displayed. This feature is used by the Calibrator when in Error Mode, while editing a
value displayed on the Output Display. The digit selected for editing is brighter than the
other digits. To accomplish this, U5 monitors data it reads from the dual-port RAM.
Following the entry of the fourth data byte to the input registers of the anode driver, the
registers are strobed to the high voltage output drivers, then the drivers are enabled. If
data bit D7 of the fourth byte is low, the state machine in U5 simply goes on to refresh
the next digit at the normal rate of approximately 200 Hz. If, however, bit D7 of the
fourth byte is high, the state machine enters a delay routine that adds about 625 us to the
normal 5 ms anode and grid on-time, thereby intensifying the digit. Unlike the Control
Display, only one grid at a time is turned on.
2-30
Theory of Operation
Digital Section Detailed Circuit Description
Output display filament driver circuitry consists of transistors Q7-Q12 and zener diodes
VR3 and VR4, plus associated resistors. The transistors are driven by 7406 opencollector drivers U13C and U13D. These drivers are controlled by AOUT and BOUT as
in the Control Display. When AOUT is high, U13C turns Q8 and Q10 on. Q10 turns Q12
on, providing a path for the filament current through Q8 and Q12. Zener diode VR4
provides the dc voltage offset necessary for proper filament operation. Then when
BOUT is high, U13D turns Q7 and Q9 on. Q7 turns Q11 on, providing a path for the
filament current through Q9 and Q11, effectively reversing the direction of the voltage
driving the filament. Zener diode VR3 provides the dc voltage offset necessary for
proper filament operation.
Dual-port RAM U2 contains all the Output Display data written by the 68HC000
microprocessor on the CPU board. U5 contains a 7-bit address counter which U5 uses to
read the contents of U2. U2 provides a BUSYO signal to U3, which is active low
whenever the CPU and U5 try to access the same RAM location at the same time. If the
microprocessor attempts to write to the same RAM location U5 is reading as it refreshes
the Control Display, U3 uses BUSYO to hold off DTACK to the microprocessor. This
prevents written data from being lost. The other busy signal, generated when U5
attempts to read from a location being written to by the microprocessor, is ignored.
Losing display data for one refresh cycle is insignificant.
IC U5 also generates the FPINTR* (front panel interrupt, active low) signal sent to the
68HC000 microprocessor, telling it there is an encoder or keyboard interrupt. The
interrupt inputs to U5, ENCODERINTR (encoder interrupt, active high) and
KEYBOARDINTR (keyboard interrupt, active high), are generated by PLDs U24 and
U9 respectively.
2
2-52. Keyboard Scanner Circuitry
The key matrix is scanned by PLD U9. It sequentially drives one of the eight columns
for about 2.2 ms, then reads all six rows of the matrix on each column scan. When a key
is pressed and the column associated with that key is scanned, the row associated with
that key goes low. If the key is still pressed after a 6.6 ms debounce period, U9 generated
signal KEYBOARDINTR. This signal goes to U5 where it generates FPINTR*, which
interrupts the 68HC000 microprocessor. The microprocessor generates
KEYBOARDCS* through PLD U3, causing U9 to output encoded row and column data
on the data bus for the microprocessor to read. This also resets the keyboard interrupt.
The microprocessor controls the speaker, also referred to as the beeper. Writing a logic
high on data line D6 to U9 enables the speaker, writing a logic low on D6 disables the
speaker. When enabled, a 900 Hz square-wave signal generated by U8 is gated out to the
speaker through U9.
2-53. Knob Encoder Circuitry
Knob encoder circuitry consists of PLD U24 and resistors R22, R23, R26, and R27. The
resistors configure the U24 knob inputs as Schmitt trigger inputs, with approximately
400 mV of hysteresis. The Schmitt inputs receive the two quadrature signals from the
optical shaft encoders at the knob, and remove digital bounce that can result from slowly
rotating the knob. The state machine inside U24 uses these signals to determine direction
and amount of rotation.
A feature was incorporated to allow the operator to quickly spin the knob and allow the
Calibrator to properly track it in spite of the inherent delay servicing the interrupt. Every
time the operator moves the knob through a 180º rotation of a single detent, U24
generates ENCODERINTR which is sent to U5. IC U5 then generates FPINTR*,
interrupting the 68HC000 microprocessor. The microprocessor services the encoder
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5700A/5720A Series II Calibrator
Service Manual
interrupt by reading U24. On a read, indicated by a logic low on ENCODERCS*, U24
places the contents of a seven-bit up/down counter on the data bus. The counter keeps
track of the number of 180º rotations that have occurred between the time the interrupt
was first initiated and the counter is read. The counter is incremented or decremented
depending on the direction of rotation. Signal ENCODERRESET*, generated by U3 on a
write to the front panel encoder address space, clears the encoder interrupt.
2-54. Led Circuitry
The LED circuit controls the four light-emitting diodes mounted on the keyboard
assembly. It includes a 74LS373 8-bit latch (U10), and four resistors (R16-R19). The
respective LEDs light when the following states are active: external sense (EX SNS),
external guard (EX GRD), the wideband module is active (WBND), or when an attached
5725A Amplifier is active (BOOST).
Latch (U10) is controlled by the LED_LATCH_EN signal from the decoding PLD U3.
Signal LED_LATCH_EN latches the CPU data bus into the internal latches of U10 on a
write to the front panel LED memory space. This data appears at the output when control
line LEDENABLE* goes low. Control line LED_OUTPUT_CNTRL from U3 is inverted
by U11C to create LEDENABLE*. Table 2-7 shows which line activates each LED.
Table 2-7. Control Lines for the Keyboard LEDs
Keyboard Led Control Lines
EX SNS LED1A
EX GRD LED2A
W BND LED2B
BOOST LED1B
2-55. Keyboard Assembly (A1)
The Keyboard assembly provides the operator with front panel control of the Calibrator.
It connects to the Front Panel assembly (A2) through a cable, and includes an
elastomeric keypad, four LEDs, and a rotary encoder (output adjustment) knob.
The elastomeric keypad and the printed circuit board form a 45-switch keyboard
arranged in eight columns and six rows. The keyboard scanner circuit on the Front Panel
assembly sequentially drives columns one through eight. When a key is pressed, a low
appears on the corresponding row as the key's column is scanned. The keyboard scanner
circuit encodes the key's row and column location, then takes appropriate action.
The four LEDs (CR1-CR4) are controlled by the LED driver circuit on the Front Panel
assembly. LED CR1 is turned on by LED1A when external sensing is selected. LED
CR2 is turned on by LED2A when external guard is selected. LED CR3 is turned on by
LED2B when the wideband module is active. LED CR4 is turned on by LED1B when an
attached 5725A Amplifier is active.
The rotary output adjustment knob activates UUT "Error Mode", allowing the operator
to adjust the Calibrator output. It can also control the phase shift for variable phase
output. The knob assembly consists of two optocouplers (DT1 and DT2) and a
magnetically-detented rotary knob. As the knob is turned, optocoupler DT1 generates a
pulse signal on ENCODERA and optocoupler DT2 generates a pulse signal on
ENCODERB. These signals are routed to the Front Panel assembly where knob encoder
circuitry interprets these signals and takes appropriate action. The current-limiting
resistor for LEDs within DT1 and DT2 is located on the Front Panel assembly.
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Analog Section Detailed Circuit Description
2-56. Analog Section Detailed Circuit Description
Detailed descriptions of each assembly in the analog section are provided here.
Simplified schematics are provided to supplement the text.
2-57. Filter/PA Supply (A18), Low-vol t age Fi lter/Regulator Section
The Filter assembly receives various ac inputs from the main power transformer and
provides unregulated dc to the Regulator/Guard Crossing assembly (A17), and regulated
dc supplies +5FR1, -18FR1, and -5FR2 to the DAC assembly. The unregulated supplies
are listed in Table 2-8 and the regulated supplies are listed in Table 2-9.
Table 2-8. Unregulated Supplies from the Filter Assembly
Theory of Operation
2
Signal Name
+15 OSCR 27V +/-8V 2V 200 mA TP2
-15 OSCR 27V +/-8V 2V 200 mA TP5
OSC COM RETURN TP4
+5 LHR 12V +/-4V 3V 3.5A TP1
-5 LHR 12V +/-4V 2V 400 mA TP6
LH COM RETURN TP3
+44 SR 60V +/-15V 3V 155 mA TP7
-44 SR 60V +/-15V 3V 460 mA TP9
44 S COM* TP22
+17 SR 27V +/-8V 3V 1.3A TP10
-17 SR 27V +/-8V 3V 1.3A TP14
17 S COM* RETURN TP12
+5 FR1R 12V +/-4V 2V 400 mA TP17
-18 FR1R 27V +/-8V 2V 50 mA TP20
FR1 COM RETURN TP19
+30 FR1R 50V +/-15V 3V 85 mA TP15
FR1R COM RETURN TP16
Nominal
Output
Tolerance
Max. P-P
Ripple
Rated Output
Point
Test
+30 FR2R RETURN +/-15V 3V 85 mA TP8
FR2 COM TP11
* 44 S COM and 17 S COM are tied together on the Regulator/Guard Crossing assembly (A17).
Table 2-9. Regulated Supplies from the Filter/PA Supply
Signal Name
-5 FR2 -5V +/-0.3V 0.15A 0.03A TP13
FR2 COM RETURN TP11
+5 FR1 +5V +/-0.3V 2A 0.1A TP18
-18 FR1 -18V +/-0.9V 2A 0.05A TP21
FR1 COM RETURN TP19
Nominal
Output
Tolerance Current Limit Rated Output Test Point
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2-58. Unregulated OSC Supplies
Line OSC COM is the return path for the +15 OSCR and -15 OSCR supplies. These
supplies use a full-wave center-tapped configuration. They consist of bridge rectifier
CR3 and two filter capacitors, C4 and C6, for +15 OSCR and -15 OSCR, respectively.
Inputs are fused with 1.6A slow-blow fuses F1 and F2.
2-59. Unregulated LH Supplies
Line 5 LH COM is the return path for the +5 LHR and -5 LHR supplies. These supplies
use a full-wave center-tapped configuration, and consist of four diodes (CR1, CR2, CR4,
CR5) configured as a bridge rectifier.
Capacitors C2 and C3 filter +5 LHR, and C5 filters -5 LHR. Capacitor C1 reduces the
level of generated transients.
2-60. Unregulated S Supplies
The ±44 SR supplies use full-wave center-tapped rectifiers. Bridge rectifier CR6 is
followed by two filter capacitors C7 and C8 for the +44 SR and -44 SR supplies,
respectively. Inputs are fused by 0.5A slow blow fuses, F3 and F5. The ±17 SR supplies
also are full-wave center-tapped, consisting of four diodes (CR8, CR10, CR12, CR13)
configured as a bridge rectifier. Capacitors C13 and C14 filter the +17 SR supply, while
C15 and C16 filter the -17 SR supply.
2-61. Triac Circuit
The triac circuit protects the Calibrator if it is inadvertently plugged into an excessively
high line voltage. For example, it protects the Calibrator if it is plugged into a 230V line
when the rear panel line voltage select switches are set for 115V operation.
This circuit contains triac CR19, zener diodes VR20, VR21, resistor R1, and capacitor
C23. The zener diodes set a trip voltage of 82V. If the ac voltage across the main
transformer secondary for the ±17V supply exceeds 82V, the triac fires, shorting out the
winding, which causes the main transformer primary fuse to blow.
2-62. FR1 Supplies
Line FR1 COM is the return path for the unregulated +5 FR1R raw supply and the
regulated +5 FR1, and -18 FR1 supplies. Each supply uses a full-wave bridge
configuration.
The unregulated +5 FR1R supply consists of bridge rectifier CR15 and filter capacitor
C19. The input is fused with 1.6A slow-blow fuse F8. The regulated +5 FR1 supply uses
the unregulated +5 FR1R supply and contains regulator U2, filter capacitor C20, and
protection diode CR16.
The -18 FR1 supply consists of bridge rectifier CR17 and filter capacitor C21. Its input
is fused with 0.5A slow-blow fuse F9. The regulated -18 FR1 supply uses the
unregulated -18 FR1 supply and contains regulator U3, filter capacitor C22, and
protection diode CR18.
2-63. Unregulated FR1 Supply
FR1R COM is the return path for the unregulated +30 FR1 supply. This supply uses fullwave bridge rectifier CR14 and filter capacitor C18. Its input is fused with 0.5A slowblow fuse F7.
2-34
Analog Section Detailed Circuit Description
2-64. FR2 Supplies
FR2 COM is the return path for unregulated +30 FR2R supply and regulated -5 FR2
supply. Each supply uses a full-wave, bridge configuration. The unregulated +30 FR2R
supply consists of bridge rectifier CR7 and filter capacitor C9. Its input is fused with
0.5A slow-blow fuse F4. The -5 FR2 supply consists of bridge rectifier CR11, filter
capacitor C11, regulator U1, bypass capacitor C12, and protection diode CR9. The input
is fused with 315 mA slow-blow fuse F6.
2-65. Filter/PA Supply (A18), Power Ampli f ier Output Supply Section
The power amplifier output power supply section of the Filter/PA Supply assembly
(A18) receives ac voltage from the main power transformer to generate power supplies
+PA and -PA for the output stage of the Power Amplifier assembly (A16). These two
power supplies can be switched between the following three modes of operation,
depending on the needs of the Power Amplifier.
• +PA and -PA to ±185V respectively.
• +PA and -PA to ±365V respectively.
• +PA and -PA are both turned off.
Figure 2-6 is a simplified schematic for the Power Amplifier Output Supply section of
this assembly.
Theory of Operation
2
2-66. ±PA Supplies Digital Control
Circuitry to control the three modes of operation of the +PA and -PA supplies is located
on the Power Amplifier Digital Control SIP assembly (A16A1). This SIP assembly is
mounted on the main Power Amplifier assembly (A16). Not on the assembly is the quad
comparator U201.
The main Power Amplifier assembly generates four control lines:
• +HI/LO V
• LO/HI I
• +ON/OFF
• H/LV S
Component Z201 pulls these signals up. At calibrator power up, the ±PA supply is off.
The Power Amplifier Digital Control SIP (A16A1) selectively pulls these control lines
low to achieve the two modes of operation. Pulling control lines +HI/LO V and
+ON/OFF low sets the +PA supply to +365V. Releasing +HI/LO V changes the +PA
supply to 185V.
The comparator (U201) provides level shifting to control the PMOSFETS in the -PA
circuit in a similar way. Signal -ON/OFF is generated from +ON/OFF, and -HI/LO V
from -H/LV. Control line +LO/HI I switches transistor Q217 which controls relay K201.
Relay K201 selects the current limit for both +PA and -PA supplies.
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Service Manual
2-36
Figure 2-6. Power Amplifier Output Supply Simplified Schematic
ahp005f.eps
2-67. ±250V and ±500V Supplies
Input signals PA CT, PA HAC1, PA HAC2, PA LAC1, and PA LAC2 come from the
main transformer.
• PA CT is the center tap.
• PA HAC1 and PA HAC2 are high voltage taps with approximately 400V rms and
are fused by F201 and F204 respectively.
• PA LAC1 and PA LAC2 are lower voltage taps with approximately 200V rms and
are fused by F202 and F203 respectively.
• PA LAC1 and PA LAC2 and bridge rectifier CR222 generate the unregulated ±250V
supplies.
• PA HAC1 and PA HAC2 and diodes CR217, CR218, CR220, CR221, CR223,
CR224, CR227, and CR228 are in a bridge rectifier configuration to generate the
unregulated ±500V supplies.
When the PA supply outputs ±185V, current is drawn only from the lower voltage taps
LAC1 and LAC2.
2-68. +PA and -PA Supplies
Unregulated voltage for +PA is selected between the +250V and +500V unregulated
supplies by control line +HI/LO V and diodes CR201, CR203, CR208, and CR210.
Theory of Operation
Analog Section Detailed Circuit Description
2
Transistor Q204 is a current source that biases VR212 and VR216.
Supply +PA is +185V when the +HI/LO V signal is above 3V. (Transistors Q205 and
Q208 are turned on.) Transistor Q205 shorts VR216, while Q208 places a short across
VR214, VR215, and VR219. A voltage of +185V appears at the gate of Q202 because of
VR212. Approximately 140V appears at the gate of Q201. This 140V and about 250V at
the anode of CR208 reverse biases CR201 and CR210, thereby shutting off Q201.
Current flows out of the 250V unregulated supply through CR203 and Q202. Regulated
supply voltage +PA is determined by the gate voltage of Q202, which is about 190V
when +HI/LO V is above 3V.
When +HI/LO V is close to 0V, both Q208 and Q205 are turned off, and over 400V
appears at the gate of Q201. CR203 and CR208 are reverse biased, and the supply
current flows from the +500V unregulated supply through Q201, CR201, and Q202. The
gate voltage of Q202 is approximately 370V, nearly the same as +PA.
The -PA side works exactly like the +PA side except -PA is switched between -185V
and -365V by control line -HI/LO V.
The ±PA supplies can be replaced by the ±44SR unregulated supplies by moving switch
S201 switched towards the top edge of the board. This feature provides the means to
troubleshoot the Power Amplifier using reduced voltages.
NOTE
Make sure S201 is returned to the ±PA position before resuming normal
operation.
2-69. ±PA Supply Current Limit
The current limit for both the +PA and -PA supplies is set to either about 90 mA (K201
de-energized) or 150 mA (K201 energized) by K201. Control line +LO/HI I controls
relay K201. The high-current mode (150 mA) is used during operation in the 1100V dc
range and the 2.2A range.
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5700A/5720A Series II Calibrator
Service Manual
Output current on the +PA side is sensed between the emitter and base of Q203 by R202
and/or R201. Supply +PA shuts off to near 0V when enough current is flowing through
+PA to forward-bias Q203. Then, current though Q203 charges capacitor C209 through
R214 to a voltage above the threshold voltage at the inverting input of comparator
U201C. The overcurrent condition must persist for about 75 ms for C209 to charge
above the threshold. The output of U201 goes high, turning on Q207. This forces the
zener diode bias current to flow through Q207 instead of VR212 or VR216, leaving only
a few volts at the gate of Q202, thus shutting +PA off. The output of U201C also
saturates Q218 and reduces the comparator threshold voltage to near 0V. This provides
the comparator with hysteresis; C209 has to discharge close to 0V before +PA can turn
on again. The +PA supply cycles on and off as long as the overcurrent condition exists.
Transistor Q206 provides another current limit. While otherwise similar to the Q203
limit, the Q206 current limit turns on at 0.5A and turns off immediately without any
delay. The Q206 limit thereby protects the supply under short circuit conditions.
Current limiting on the -PA side works similarly to the +PA side with one difference.
That is that shutoff of -PA can happen under two circumstances:
• -PA is loaded beyond its current limit.
• +PA is shut off. (Shut off of -PA is slaved to shut off of +PA.)
2-70. Regulator/Guard Crossing Assembly (A17)
The Regulator/Guard Crossing assembly (A17) provides two separate functions: voltage
regulation for the analog power supplies, and digital control of the guard crossing. The
voltage regulation portion is described first followed by the digital control portion. Refer
to the schematic diagrams for the Regulator/Guard Crossing Assembly for this
discussion.
2-71. Voltage Regulator Circuitry
The regulator circuit receives unregulated dc from the regulator filter circuit on the
Filter/PA Supply assembly (A18) and provides 13 regulated dc outputs and 1
unregulated dc output for the various analog assemblies. Table 2-10 lists the regulated
supplies from the Regulator/Guard Crossing Assembly.
2-72. Regulated OSC Supplies
The +15 OSC and -15 OSC supplies are used exclusively by the Oscillator Output (A12)
and Oscillator Control (A13) assemblies. OSC COM is the return path for these supplies.
The +15 OSC uses the unregulated +15 OSCR from the Filter assembly and consists of
three-terminal TO-220 regulator U2 with heat sink, bypass capacitors C1 and C2, and
protection diodes CR2 and CR3. The -15 OSC uses the unregulated -15 OSCR from the
Filter assembly and consists of three-terminal TO-220 regulator U3 with heat sink,
bypass capacitors C4 and C5, and protection diodes CR5 and CR7. Capacitors C2 and
C5 improve the stability of U2 and U3 respectively. Diodes CR3 and CR5 protect U2
and U3 from reverse voltages. Diodes CR2 and CR7 protect U2 and U3 from input
shorts.
2-38
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