Service Manual
For Agilent Technologies
Model 66111A, 66311A/B/D, 66309B/D
Mobile Communications DC Source
For instruments with Serial Numbers:
66111A: US38460101 and up (through-hole)
66311A: US38180101 through US38180408 (through-hole)
66311B: US38440101 through US38442274 (through-hole)
66311B: US38442500 and up (surface-mount)
66311D: US39010101 and up (surface mount
66309B: US39050101 and up (surface mount)
66309D: US39070101 and up (surface mount)
Agilent Part No. 5964-8176 Printed in U.S.A.
Microfiche No 5964-8177 January, 2001
Warranty Information
CERTIFICATION
Agilent Technologies certifies that this product met its published specifications at time of shipment from the factory.
Agilent Technologies further certifies that its calibration measurements are traceable to the United States National
Bureau of Standards, to the extent allowed by the Bureau’s calibration facility, and to the calibration facilities of other
International Standards Organization members.
WARRANTY
This Agilent Technologies hardware product is warranted against defects in material and workmanship for a period
of three years from date of delivery. Agilent Technologies software and firmware products, which are designated by
Agilent Technologies for use with a hardware product and when properly installed on that hardware product, are
warranted not to fail to execute their programming instructions due to defects in material and workmanship for a
period of 90 days from date of delivery. During the warranty period Agilent Technologies will, at its option, either
repair or replace products which prove to be defective. Agilent Technologies does not warrant that the operation for
the software firmware, or hardware shall be uninterrupted or error free.
For warranty service, with the exception of warranty options, this product must be returned to a service facility
designated by Agilent Technologies. Customer shall prepay shipping charges by (and shall pay all duty and taxes)
for products returned to Agilent Technologies for warranty service. Except for products returned to Customer from
another country, Agilent Technologies shall pay for return of products to Customer.
Warranty services outside the country of initial purchase are included in Agilent Technologies’ product price, only if
Customer pays Agilent Technologies international prices (defined as destination local currency price, or U.S. or
Geneva Export price).
If Agilent Technologies is unable, within a reasonable time to repair or replace any product to condition as warranted,
the Customer shall be entitled to a refund of the purchase price upon return of the product to Agilent Technologies.
LIMITATION OF WARRANTY
The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by the
Customer, Customer-supplied software or interfacing, unauthorized modification or misuse, operation outside of the
environmental specifications for the product, or improper site preparation and maintenance. NO OTHER
WARRANTY IS EXPRESSED OR IMPLIED. AGILENT TECHNOLOGIES SPECIFICALLY DISCLAIMS THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
EXCLUSIVE REMEDIES
THE REMEDIES PROVIDED HEREIN ARE THE CUSTOMER’S SOLE AND EXCLUSIVE REMEDIES. AGILENT
TECHNOLOGIES SHALL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR
CONSEQUENTIAL DAMAGES, WHETHER BASED ON CONTRACT, TORT, OR ANY OTHER LEGAL THEORY.
ASSISTANCE
The above statements apply only to the standard product warranty. Warranty options, extended support contacts,
product maintenance agreements and customer assistance agreements are also available. Contact your nearest
Agilent Technologies Sales and Service office for further information on Agilent Technologies’ full line of support
programs.
2
Safety Summary
The following general safety precautions must be observed during all phases of operation of this instrument. Failure to comply
with these precautions or with specific warnings elsewhere in this manual violates safety standards of design, manufacture, and
intended use of the instrument. Agilent Technologies assumes no liability for the customer’s failure to comply with these
requirements.
WARNING
Servicing instructions are for use by service-trained personnel. To avoid dangerous electrical shock, do not perform any servicing
unless you are qualified to do so. Some procedures described in this manual are performed with power supplied to the instrument
while its protective covers are removed. If contacted, the energy available at many points may result in personal injury.
BEFORE APPLYING POWER
Verify that the product is set to match the available line voltage, the correct line fuse is installed, and all safety precautions (see
following warnings) are taken. In addition, note the instrument’s external markings described under "Safety Symbols"
GROUND THE INSTRUMENT
Before switching on the instrument, the protective earth terminal of the instrument must be connected to the protective conductor
of the (mains) power cord. The mains plug shall be inserted only in an outlet socket that is provided with a protective earth
contact. This protective action must not be negated by the use of an extension cord (power cable) that is without a protective
conductor (grounding). Any interruption of the protective (grounding) conductor or disconnection of the protective earth
terminal will cause a potential shock hazard that could result in personal injury.
FUSES
Only fuses with the required rated current, voltage, and specified type (normal blow, time delay, etc.) should be used. Do not use
repaired fuses or short-circuited fuseholders. To do so could cause a shock or fire hazard.
KEEP AWAY FROM LIVE CIRCUITS
Operating personnel must not remove instrument covers. Component replacement and internal adjustments must be made by
qualified service personnel. Do not replace components with power cable connected. Under certain conditions, dangerous
voltages may exist even with the power cable removed. To avoid injuries, always disconnect power, discharge circuits and
remove external voltage sources before touching components.
DO NOT SERVICE OR ADJUST ALONE
Do not attempt internal service or adjustment unless another person, capable of rendering first aid and resuscitation, is present.
Any adjustment, maintenance, and repair of this instrument while it is opened and under voltage should be avoided as much as
possible. When this is unavoidable, such adjustment, maintenance, and repair should be carried out only by a skilled person who
is aware of the hazard involved.
DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT
Because of the danger of introducing additional hazards, do not install substitute parts or perform any unauthorized modification
to the instrument. Return the instrument to a Agilent Technologies Sales and Service Office for service and repair to ensure that
safety features are maintained.
SAFETY SYMBOLS
Refer to the table on the following page
WARNING The WARNING sign denotes a hazard. It calls attention to a procedure, practice, or the like, which, if not
correctly performed or adhered to, could result in personal injury. Do not proceed beyond a WARNING sign
until the indicated conditions are fully understood and met.
Caution The CAUTION sign denotes a hazard. It calls attention to an operating procedure, or the like, which, if not
correctly performed or adhered to, could result in damage to or destruction of part or all of the product. Do
not proceed beyond a CAUTION sign until the indicated conditions are fully understood and met.
3
Safety Symbol Definitions
Symbol Description
Direct current
Alternating current
Both direct and alternating current
Three-phase alternating current
Earth (ground) terminal
Protective earth (ground) terminal
Frame or chassis terminal
Terminal is at earth potential (Used for measurement and control circuits designed to be
operated with one terminal at earth potential.)
Terminal for Neutral conductor on permanently installed equipment
Terminal for Line conductor on permanently installed equipment
On (supply)
Off (supply)
Standby (supply)
Units with this symbol are not completely disconnected from ac mains when this switch
is off. To completely disconnect the unit from ac mains, either disconnect the power
cord or have a qualified electrician install an external switch.
In position of a bi-stable push control
Out position of a bi-stable push control
Caution, risk of electric shock
Caution, hot surface
Caution (refer to accompanying documents)
4
Notice
The information contained in this document is subject to change without notice. Agilent Technologies makes no
warranty of any kind with regard to this material, including but not limited to, the implied warranties of
merchantability, and fitness for a particular purpose.
Agilent Technologies shall not be liable for errors contained herein or for incidental or consequential
damages in connection with the furnishing, performance or use of this material.
This document contains proprietary information which is protected by copyright. All rights are reserved. No part of
this document may be photocopied, reproduced, or translated into another language without the prior written consent
of Agilent Technologies .
Copyright 1999
Agilent Technologies
Printing History
The edition and current revision of this manual are indicated below. Reprints of this manual containing minor
corrections and updates may have the same printing date. Revised editions are identified by a new printing date. A
revised edition incorporates all new or corrected material since the previous printing date.
Changes to the manual occurring between revisions are covered by change sheets shipped with the manual. In some
cases, the manual change applies only to specific instruments. Instructions provided on the change sheet will indicate
if a particular change applies only to certain instruments.
Edition 1............................................................................................................................................ December 1999
Update 1............................................................................................................................................ January 2001
Instrument Identification
The dc source is identified by a unique, two-part serial number, such as, US39450101. The items in this serial
number are explained as follows:
US39450101
The first two letters indicate the country of manufacture. US = United States.
The next four digits are the year and week of manufacture or last significant design change. Add
1960 to the first two digits to determine the year. For example, 39=1999. The third and fourth
digits specify the week of the year (45 = the forty-fifth week).
The last four digits (0101) are a unique sequential number assigned to each unit.
5
Table of Contents
Warranty Information 2
Safety Summary 3
Notice 5
Printing History 5
Instrument Identification 5
Table of Contents 6
1 - INTRODUCTION 9
Organization 9
Safety Considerations 9
Related Documents 9
Revisions 10
Manual Revisions 10
Firmware Revisions 10
Electrostatic Discharge 10
2 - VERIFICATION AND PERFORMANCE TESTS 11
Introduction 11
Test Equipment Required 11
Measurement Techniques 12
Test Setup 12
Electronic Load 13
Current-Monitoring Resistor 13
Operation Verification Tests 13
Performance Tests 13
Programming 13
Constant Voltage (CV) Tests 14
CV Setup 14
Voltage Programming and Readback Accuracy 14
CV Load Effect 14
CV Source Effect 14
CV Noise (PARD) 15
Transient Recovery Time 15
Constant Current (CC) Tests 16
CC Setup 16
Current Programming and Readback Accuracy 16
Current Sink (-CC) Opera tion 16
Low Range Current Readback Accuracy 17
CC Load and Line Regulatio n 17
CC Load Effect 18
CC Source Effect 18
CC Noise (PARD) 18
Performance Test Equipment Form 19
Performance Test Record Form 20
3 - TROUBLESHOOTING 23
Introduction 23
Test Equipment Required 24
Overall Troubleshooting 24
Flow Charts 24
Specific Troubleshooting Procedures 29
6
Power-on Self-test Failures 29
Bias and Reference Supplies 30
CV/CC Status Annunciators Troubleshooting 30
J307 Voltage Measurements 30
Manual Fan Speed Co ntrol 32
Disabling Protection Features 32
Post-repair Calibration 32
Calibration Password 32
Inhibit Calibration Switch 33
Initialization 33
ROM Upgrade 33
Identifying the Firmware 33
Upgrade Procedure 34
Disassembly Procedures 35
List of Required Tools 35
Cover, Removal and Replacement 37
A2 Interface Board, Removal and Replacement 37
Front Panel Assembly, Removal and Replacement 37
A3 Front Panel Board, Removal and Replacement 38
A6 Option 521 Relay Board (not on all models) 38
A7 DVM Board (not on all models) 38
A1 Main Control Board 38
T1 Power Transformer, Removal and Replacement 39
4 - PRINCIPLES OF OPERATION 41
Introduction 41
I/O Interface Signals 41
A3 Front Panel Circuits 42
A2 Interface Circuits 42
Primary Interface 42
Secondary Interface 42
A1 Main Board Circuits 43
Power Circuits 43
Control Circuits 44
Output 2 45
A5 DVM Circuits 46
A6 Option 521 Relay Circuits 46
5 - REPLACEABLE PARTS LIST 47
Introduction 47
6 - DIAGRAMS 53
Introduction 53
INDEX 59
7
1
Introduction
Organization
This manual contains information for troubleshooting and repairing Agilent 66111A, 66311A, 66311B, 66311D,
66309B and 66309D Mobile Communications DC Sources. Hereafter all models will be referred to as the dc source.
This manual is organized as follows:
Chapter 1
Chapter 2
Chapter 3
Chapter 4
Chapter 5
Chapter 6
Organization
Performance tests
Troubleshooting procedures
Principles of operation on a block-diagram level
Replaceable parts
Diagrams
Safety Considerations
WARNING: Hazardous voltages exist within the dc source chassis.
This dc source is a Safety Class I instrument, which means it has a protective earth terminal. This terminal must be
connected to earth ground through a power source equipped with a 3-wire, ground receptacle. Refer to the "Safety
Summary" page at the beginning of this manual for general safety information. Before operation or repair, check the
dc source and review this manual for safety warnings and instructions. Safety warnings for specific procedures are
located at appropriate places in the manual.
Related Documents
The following documents are shipped with your dc source:
ñ a User’s Guide, part number 5964-8125, containing installation, operating, programming, and calibration
information
9
1 - Introduction
Revisions
Manual Revisions
This manual was written for dc sources that have the same manufacturing dates (the first four digits) as those listed
on the title page and whose unique identification number (the last four digits) are equal to or higher than those listed
in the title page.
NOTE: 1) If the first four digits of the serial number of your unit are higher than those shown in the title
page, your unit was made after the publication of this manual and may have hardware or firmware
differences not covered in this manual. If they are significant to the operation and/or servicing of
the dc source, those differences are documented in one or more Manual Change sheets included
with this manual.
2) If the first four digits of the serial number of your unit are lower than those shown on the title
page, your unit was made before the publication of this manual and may be different from that
described here. Such differences, if any, will be covered in a backdating section in chapter 6.
Firmware Revisions
You can obtain the firmware revision number by either reading the integrated circuit label, or query the dc source
using the GPIB *IDN?’ query command (see chapter 3, ROM Upgrade).
Electrostatic Discharge
CAUTION: The dc source has components that can be damaged by ESD (electrostatic discharge). Failure to
observe standard antistatic practices can result in serious degradation of performance, even when
an actual failure does not occur.
When working on the dc source, observe all standard, antistatic work practices. These include, but are not limited to:
ñ Working at a static-free station such as a table covered with static-dissipative laminate or with a conductive
table mat (P/N 9300-0797, or equivalent).
ñ Using a conductive wrist strap, such as P/N 9300-0969 or 9300-0970.
ñ Grounding all metal equipment at the station to a single common ground.
ñ Connecting low-impedance test equipment to static-sensitive components only when those
components have power applied to them.
ñ Removing power from the dc source before removing or installing printed circuit boards.
10
Verification and Performance Tests
Introduction
This document contains test procedures to verify that the dc source is operating no rmally and is within published
specifications. There are three types of tests as follows:
2
Built-in Self Tests
Operation Verification
Performance Tests
NOTE: The dc source must pass the built-in self-tests before calibration or any of the verification or
performance tests can be performed. If the supply fails any of the tests or if abnormal test results
are obtained, refer to the troubleshooting procedures in chapter 3. The troubleshooting procedures
will determine if repair and/or calibration is required.
These tests, run automatically when the dc source is turned on, check most of the
digital circuits and the programming and readback DACs.
These tests verify that the dc source is probably operating normally but do not
check all of the specified operating parameters.
These tests check that the supply meets all of the operating specifications as
listed in the User’s Guide.
Test Equipment Required
Table 2-1 lists the equipment required to perform the verification and performance tests. A test record sheet with
specification limits and measurement uncertainties (when test using the recommended test equipment) may be found
at the back of this section.
Table 2-1. Test Equipment Required for Verification and Performance Tests
Type Specifications Recommended Model
Digital Voltmeter Resolution: 10 nV @ 1V
Readout: 8 1/2 digits
Accuracy: 20 ppm
Current Monitor
Resistor
DC Power Supply
Electronic Load 20 V, 5 A minimum, with transient capability Agilent 6060B or equivalent
15 A (0.1 ohm) 0.04%, TC=5ppm/°C
for power supplies up to 15 A output
8V @ 5A (for current sink veri fic ation/calibration)
25 V source (for DVM verification/calibration)
Agilent 3458A or equivalent
Guildline 9230/15
Agilent 6611C, 6631B
6631C, or 6633B
GPIB Controller Full GPIB capabilities (only required if you are
calibrating the unit over the GPIB)
Load Resistor
(3 W min. TC=20ppm/°C)
Oscilloscope Sensitivity: 1 mV
400Ω (verification)
800Ω (calibration)
Bandwidth Limit: 20 MHz
Probe: 1:1 with RF tip
HP Series 200/300 or
equivalent
p/n 0811-0942
p/n 0811-0600
Agilent 54504A or equivalent
11
2 - Verification and Performance Tests
RC network (for
transient response test)
Capacitor: fixed film 25µF, 50V
Resistor: 0.25Ω, 1W
RMS Voltmeter True RMS
Kit p/n 6950L#T03
Agilent 3400B or equivalent
Bandwidth: 20 MHz
Sensitivity: 100 µV
Variable-Voltage
Transformer
Adjustable to highest rated input voltage range.
Power: 500 VA
Measurement Techniques
Test Setup
All tests are performed at the rear terminals of the supply as shown in Figure 2-1. Measure the dc voltage directly at
the +S and -S terminals. Connect the output for remote sensing. Use adequate wire gauge for the load leads.
+S
++S
+
SENSE
Load
resistor
400 ohm
Local
Remote
Set to Remote
(through-hole
units only)
SENSE
Local
Remote
Set to Remote
(through-hole
units only)
DVM, Scope, or
RMS voltmeter
(for CV tests)
DVM or
RMS voltmeter
(for CC tests)
Notes:
Use dc supply with same polarity
connections for - CC tests.
Replace electronic load with resistors
for CC noise test.
A.
NOTE: Connector
is removable
-
+
-
Current
monitor
+
-S -
++S
+
50VDC MAX TO
-
-+
Electronic
Load
(see note)
-S - +
SENSE
+S
SENSE
Local
Remote
Set to Remote
(through-hole
units only)
Local
Remote
Ammeter
C.
Oscilloscope
DC
-
+
NOTE: Connector
is removable
+
-
-S
-+
+
50VDC MAX TO
-
External
DC supply
-S -
+
50VDC MAX TO
-
12
+
50VDC MAX TO
DC
Ammeter
-
-
+
Set to Remote
Load
resistor
400 ohm
(through-hole
units only)
D.
-+
Electronic
Load
B.
Figure 2-1. Test setup Agilent 66111A, 66311B/D, 66309B/D (surface-mount units)
Verification and Performance Tests -2
Electronic Load
Many of the test procedures require the use of a variable load capable of dissipating the required power. If a variable
resistor is used, switches should be used to either; connect, disconnect, or short the load resistor. For most tests, an
electronic load can be used. The electronic load is considerably easier to use than load resistors, but it may not be
fast enough to test transient recovery time and may be too noisy for the noise (PARD) tests.
Fixed load resistors may be used in place of a variable load, with minor changes to the test procedures. Also, if
computer controlled test setups are used, the relatively slow (compared to computers and system voltmeters) settling
times and slew rates of the dc source may have to be taken into account. "Wait" statements can be used in the test
program if the test system is faster than the dc source.
Current-Monitoring Resistor
To eliminate output-current measurement error caused by voltage drops in the leads and connections, connect the
current monitoring resistor between the -OUT and the load as a four-terminal device. Connect the current-monitoring
leads inside the load-lead connections directly at the monitoring points on the resistor element.
Operation Verification Tests
To assure that the supply is operating properly, without testing all specified parameters, perform the turn-on and
checkout procedures given in the User’s Guide.
Performance Tests
NOTE: A full Performance Test consists of only those items listed as “Specifications” in Table A-1 of the
User’s Guide, and that have a procedure in this document.
The following paragraphs provide test procedures for verifying the supply's compliance with the specifications listed
in Table A-1 of the User’s Guide. All of the performance test specifications and calculated measurement
uncertainties are entered in the appropriate Performance Test Record Card for your specific model. You can record
the actual measured values in the column provided in this card.
If you use equipment other than that recommended in Table 2-1, you must recalculate the measurement uncertainties
for the actual equipment used.
Programming
You can program the supply from the front panel keyboard or from an GPIB controller when performing the tests.
The test procedures are written assuming that you know how to program the supply either; remotely from an GPIB
controller or locally using the control keys and indicators on the supply's front panel. Complete instructions on
remote and local programming are given in the User’s Guide and in the Programming Guide.
Table 2-2. Programming and Output Values
Agilent
Model
66111A 15 15.535 3 3.0712 - 2A 22.0
66311A/B/D 15 15.535 3 3.0712 - 2A 22.0
66309B/D 15 15.535 3 3.0712 - 2A 22.0
Full scale
Voltage
Vmax Full Scale
Current
Imax Isink OV
Max
13
2 - Verification and Performance Tests
Constant Voltage (CV) Tests
CV Setup
If more than one meter or if a meter and an oscilloscope are used, connect each to the terminals by a separate pair of
leads to avoid mutual coupling effects. For constant voltage dc tests, connect only to +S and -S, since the unit
regulates the output voltage that appears between +S and -S, and not between the (+) and (-) output terminals. Use
coaxial cable or shielded two-wire cable to avoid noise pickup on the test leads.
Voltage Programming and Readback Accuracy
This test verifies that the voltage programming, GPIB readback and front panel display functions are within
specifications. Note that values read back over the GPIB should be identical to those displayed on the front panel.
a. Turn off the supply and connect a digital voltmeter between the +S and -S terminals as shown in Figure 2-1a.
b. Turn on the supply and program the supply to zero volts and the maximum programmable current (Imax in
Table 2-2) with the load off.
c. Record the output voltage readings on the digital voltmeter (DVM) and the front panel display. The readings
should be within the limits specified in the performance test record card for the appropriate model under Voltage
Programming and Readback @ 0 Volts. Also, note that the CV annunciator is on. The output current reading
should be approximately zero.
d. Program the output voltage to full-scale (see Table 2-2) .
e. Record the output voltage readings on the DVM and the front panel display. The readings should be within the
limits specified in the performance test record card for the appropriate model under Voltage Programming and
Readback @ Full Scale.
CV Load Effect
This test measures the change in output voltage resulting from a change in output current from full load to no load.
a. Turn off the supply and connect the output as shown in Figure 2-1a with the DVM connected between the +S
and -S terminals.
b. Turn on the supply and program the current to the maximum programmable value (Imax) and the voltage to the
full-scale value in Table 2-2.
c. Adjust the load for the full-scale current in Table 2-2 as indicated on the front panel display. The CV
annunciator on the front panel must be on. If it is not, adjust the load so that the output current drops slightly.
d. Record the output voltage reading on the DVM connected to +S and -S.
e. Open the load and again record the DVM voltage reading. The difference between the DVM readings in steps
(d) and (e) is the load effect voltage, and should not exceed the value listed in the performance test record card
for the appropriate model under CV Load Effect.
CV Source Effect
This test measures the change in output voltage that results from a change in ac line voltage from the minimum to
maximum value within the line voltage specifications.
a. Turn off the supply and connect the ac power line through a variable voltage transformer.
b. Connect the output as shown in Figure 2-1a with the DVM connected between the +S and the -S terminals. Set
the transformer to nominal line voltage.
14
Verification and Performance Tests -2
c. Turn on the supply and program the current to the maximum programmable value (Imax) and the output voltage
to the full-scale value in Table 2-2.
d. Adjust the load for the full-scale current value in Table 2-2 as indicated on the front panel display. The CV
annunciator on the front pa nel must be on. If it is not, adjust the loa d so that the output current d rops slightly.
e. Adjust the transformer to the lowest rated line voltage (e.g., 104 Vac for a 115 Vac nominal line voltage input).
f. Record the output voltage reading on the DVM.
g. Adjust the transformer to the highest rated line voltage (e.g., 127 Vac for 115 Vac nominal line voltage input).
h. Record the output voltage reading on the DVM. The difference between the DVM reading is steps (f) and (h) is
the source effect voltage and should not exceed the value listed in the performance test record card for the
appropriate model under CV Source Effect.
CV Noise (PARD)
Periodic and random deviations (PARD) in the output (ripple and noise) combine to produce a residual ac voltage
superimposed on the dc output voltage. CV PARD is specified as the rms or peak-to-peak output voltage in the
frequency range specified in the User’s Guide.
a. Turn off the supply and connect the output as shown in Figure 2-1a to an oscilloscope (ac coup led) between the
(+) and the (-) terminals. Set the scope's bandwidth limit to 20 MHz and use an RF tip on the scope probe.
b. Turn on the supply and program the current to the maximum programmable value (Imax) and the output voltage
to the full-scale value in Table 2-2.
c. Adjust the load for the full-scale current value in Table –2 as indicated on the front panel display.
d. Note that the waveform on the oscilloscope should not exceed the peak-to-peak limits in the performance test
record card for the appropriate model under CV Noise (PARD).
e. Disconnect the oscilloscope and connect an ac rms voltmeter in its place. The rms voltage reading should not
exceed the RMS limits in the performance test record card for the appropriate model under CV Noise (PARD).
Transient Recovery Time
This test measures the time for the output voltage to recover to within the specified value following a change in the
load current. The focus of the transient is on the initial dip below zero. To recover to within the 20mV band, the
negative portion should be within 35 microseconds to meet the specification.
Figure 2-2. Transient Waveform
15
2 - Verification and Perform ance Tests
a. Turn off the supply and connect the output as in Figure 2-1d with the oscilloscope and the RC network across
the + and - load terminals. Connect everything at the load and keep the load leads as short as possible. To reduce
noise, twist the sense lead pair together. Also twist the load lead pair together.
b. Turn on the supply and program the output current to the maximum programmable value (Imax) and the voltage
to the full-scale value in Table 2-2. Make sure that compensation is set to High capacitance mode.
c. Set the load to the Constant Current mode and program the load current to 0.1 amps.
d. Set the electronic load’s transient generator frequency to 220 Hz and its duty cycle to 50%.
e. Program the load’s transient current level to 1.5 amps and turn the transient generator on.
f. Set the oscilloscope for negative edge triggering and adjust it for a waveform similar to that in Figure 2-2.
g. The output voltage should return to within the specified voltage (v) in less than 35 microseconds. Record the
voltage at time “t” in the performance test record card under CV Transient Response.
Constant Current (CC) Tests
CC Setup
Follow the general setup instructions in the Measurement Techniques paragraph and the specific instructions given in
the following paragraphs.
Current Programming and Readback Accuracy
This test verifies that the current programming and readback are within specification.
a. Turn off the dc source and connect the current monitoring resistor across the dc source output and the DVM
across the resistor. See "Current Monitoring Resistor" for connection information.
b. Turn on the dc source and program the output voltage to 5 V and the current to 20mA (±1mA). The dc source’s
current detecto r must be set to DC and the pro gramming language mode to SCPI. See the specifications for high
range current readback in the User’s Guide if operating with the detector in ACDC or the language in
Compatability mode.
c. Divide the voltage drop (DVM reading) across the current monitoring resistor by its resistance to convert to
amps and record this value (Iout). Also, record the current reading on the front panel display. The readings
should be within the limits specified in the performance test record card for the appropriate model under Current
Programming and Readback @ 0 Amps.
d. Program the output current to the full-scale value in Table 2-2.
e. Divide the voltage drop (DVM reading) across the current monitoring resistor by its resistance to convert to
amps and record this value (Iout). Also, record the current reading that appears on the front panel display. The
readings should be within the limits specified in the performance test record card for the appropriate model
under Current Programming and Readback @ Full Scale.
Current Sink (-CC) Operation
This test verifies current sink operation and readback.
a. Turn off the dc source and connect the output as shown in Figure 2-1a, except connect a dc power supply in
place of the electronic load as indicated. Connect the DMM across the current shunt.
b. Set the power supply to 5 V and the current to the full scale current rating of the dc source as in Table 2-2.
c. Turn on the dc source under test and program the output voltage to zero and the current to full scale as in Table
2-2. The current on the UUT display should be negative and decreases linearly from 2.8A @ 0V to 1.2 A @
15V. The sink current does not track the programmed current.
16
Verification and Performance Tests -2
d. Divide the voltage drop across the current monitoring resistor by its resistance to obtain the current sink value in
amps and subtract this from the current reading on the display. The difference between the readings should be
within the limits specified in the performance test record card under Current Sink Readback.
Low Range Current Readback Accuracy
This test verifies the readback accuracy of the 20 milliampere current range.
a. Turn off the supply and connect the output as shown in Figure 2-1b. Set the DMM to operate in current mode.
b. Turn on the supply under test and set the current range readback to Low or Auto. Program the output voltage to
zero and the current to the full scale value in Table 2-2. The current on the UUT display should be
approximately 0 mA.
c. Record the current reading on the DMM and the reading on the front panel display. The difference between the
two readings should be within the limits specified in the performance test record card under 20mA Range
Current Readback Accuracy @ 0A.
d. Program the output voltage to 8V and record the current reading on the DMM and the reading on the front
panel display. If the meter indicates overrange, lower the 8 volts slightly. The difference between the readings
should be within the limits specified in the performance test record card for the appropriate model under 20mA
Range Current Readback Accuracy @ +20mA
e. Turn off the supply and connect the output and an external supply as shown in Figure 2-1c. Set the DMM to
operate in current mode.
f. Turn on the external supply and program it to 8V and 1 amp. Then program the supply under test to zero volts
and 1 amp. If the meter indicates overrange, lower the voltage of the external supply slightly. The UUT display
should read approximately −20 mA.
g. Record the current reading on the DMM and the reading on the front panel display. The difference between the
two readings should be within the limits specified in the performance test record card under 20mA Range
Current Readback Accuracy @ −20 mA.
CC Load and Line Regulation
These tests (CC Load Effect and CC Source Effect given below) are tests of the dc regulation of the dc source’s
output current. To insure that the values read are not the instantaneous measurement of the ac peaks of the output
current ripple, several dc measurements should be made and the average of these readings calculated. An example of
how to do this is given below using an Agilent 3458A System Voltmeter programmed from the front panel. Set up
the voltmeter and execute the "Average Reading" program follows:
a. Program 10 power line cycles per sample by pressing NPLC 1 0 ENTER .
b. Program 100 samples per trigger by pressing (N Rdgs/Trig) 1 0 0 ENTER .
c. Set up voltmeter to take measurements in the statistical mode as follows:
Press Shift key, f0, Shift key, N
Press ^ (up arrow) until MATH function is selected, then press >.
Press ^ (up arrow until STAT function is selected then press (ENTER).
d. Set up voltmeter to read the average of the measurements as follows:
Press Shift key, f1, Shift key, N.
Press down arrow until RMATH function is selected, then press >.
Press ^ (up arrow) until MEAN function is selected, then press ENTER.
e. Execute the program by pressing f0, ENTER, TRIG, ENTER
f. Wait for 100 readings and then read the average measurement by pressing f1, ENTER.
To repeat the measurement, perform steps (e) and (f).
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2 - Verification and Performance Tests
CC Load Effect
This test measures the change in output current for a change in load from full scale output voltage to short circuit.
a. Turn off the supply and connect the output as shown in Figure 2-1a with the DVM connected across the current
monitoring resistor.
b. Turn on the supply and if it was set to low range readback in the previous test, set it back to high or auto.
Program the current to full scale and the output voltage to the maximum programmable voltage value (Vmax) in
Table 2-2.
c. Adjust the load in the CV mode for the UUT full scale voltage in Table 2-2 as indicated on the front panel
display. Check that the CC annunciator of the UUT is on. If it is not, adjust the load so that the output voltage
drops slightly.
d. Record the output current reading (DVM reading/current monitor resistance value in ohms). You may want to
use the average reading program described under “CC Load and Line Regulation”.
e. Short the load switch and record the output current reading. The difference in the current readings in steps (d)
and (e) is the load effect and should not exceed the limit specified in the performance test record card for the
appropriate model under CC Load Effect.
CC Source Effect
This test measures the change in output current that results when the AC line voltage changes from the minimum to
the maximum value within the specifications.
a. Turn off the supply and connect the ac power line through a variable voltage transformer.
b. Connect the output terminals as shown in Figure 2-1a with the DVM connected across the current monitoring
resistor. Set the transformer to the nominal line voltage.
c. Turn on the supply and program the current to the full scale value and the output voltage to the maximum
programmable value (Vmax) in Table 2-2.
d. Adjust the load in the CV mode for full scale voltage as indicated on the front panel display. Check that the CC
annunciator of the UUT is on. If it is not, adjust the load so that the output voltage drops slightly.
e. Adjust the transformer to the lowest rated line voltage.
f. Record the output current reading (DVM reading/current monitoring resistor in ohms). You may want to use the
average reading program described under “CC Load and Line Regulation”.
g. Adjust the transformer to the highest rated line voltage.
h. Record the output current reading again. The difference in the current readings in steps (f) and (h) is the CC
source effect and should not exceed the values listed in the performance test record card under CC Source
Effect.
CC Noise (PARD)
Periodic and random deviations (PARD) in the output combine to produce a residual ac current, as well, as an ac
voltage superimposed on the dc output. Constant current (CC) PARD is specified as the rms output current in a
frequency range 20 Hz to 20 Mhz with the supply in CC operation.
a. Turn off the supply and connect the load, monitoring resistor, and rms voltmeter as shown in Figure 2-1a. The
Current Monitoring resistor may have to be substituted by one with a higher resistance and power rating, such as
a 1 ohm 50W, to get the RMS voltage drop high enough to measure with the RMS voltmeter. Leads should be as
short as possible to reduce noise pick-up. An electronic load may contribute ripple to the measurement so if the
RMS noise is above the specification a resistive load may have to be substituted for this test.
18
Verification and Performance Tests -2
b. Check the test setup for noise with the supply turned off. Other equipment (e.g. computers, DVMs, etc.) may
affect the reading.
c. Turn on the supply and program the current to full scale and the output voltage to the maximum programmable
value (Vmax) in Table 2-2.
d. The output current should be at the full scale rating with the CC annunciator on.
e. Divide the reading on the rms voltmeter by the current monitor resistance to obtain rms current. It should not
exceed the values listed in the performance test record card under CC Noise (RMS).
Performance Test Equipment Form
Test Facility:_________________________
____________________________________ Date _________________________________
____________________________________ Customer _____________________________
____________________________________ Tested By ____________________________
Model ______________________________ Ambient Temperature (C) ________________
Serial No. ____________________________ Relative Humidity (%) ___________________
Options _____________________________ Nominal Line Frequency __________________
Firmware Revision ____________________
Special Notes:
Test Equipment Used:
Description Model No. Trace No. Cal. Due Date
AC Source
DC Voltmeter
RMS Voltmeter
Oscilloscope
Electronic Load
Current Shunt
_________________ _________________ _________________
_________________ _________________ _________________
_________________ _________________ _________________
_________________ _________________ _________________
_________________ _________________ _________________
_________________ _________________ _________________
_________________ _________________ _________________
Report Number ________________________
19
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