Tektronix 2303, 2303B, 2303-PJ Service Manual

Model 2303/2303B/2303-PJ

High Speed Power Supply

Service Manual

Contains Servicing Information

W ARRANTY

Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a
period of 2 years from date of shipment.

Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables,
rechargeable batteries, diskettes, and documentation.

During the warranty period, we will, at our option, either repair or replace any product that proves to be defecti v e.
To exercise this warranty, write or call your local Keithley representative, or contact Keithley headquarters in

Cleveland, Ohio. You will be given prompt assistance and return instructions. Send the product, transportation
prepaid, to the indicated service facility . Repairs will be made and the product returned, transportation prepaid.
Repaired or replaced products are warranted for the balance of the original warranty period, or at least 90 days.

LIMIT A TION OF W ARRANTY

This warranty does not apply to defects resulting from product modification without Keithley’s express written
consent, or misuse of any product or part. This warranty also does not apply to fuses, software, non-recharge­able batteries, damage from battery leakage, or problems arising from normal wear or failure to follow instruc­tions.

THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUD­ING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE.
THE REMEDIES PROVIDED HEREIN ARE BUYER’S SOLE AND EXCLUSIVE REMEDIES.

NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR
ANY DIRECT , INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF
THE USE OF ITS INSTRUMENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS
BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF SUCH DAMAGES. SUCH EXCLUDED DAM­AGES SHALL INCLUDE, BUT ARE NOT LIMITED TO: COSTS OF REMOVAL AND INSTALLATION,
LOSSES SUSTAINED AS THE RESULT OF INJURY T O ANY PERSON, OR DAMAGE TO PROPERTY.

Keithley Instruments, Inc. • 28775 Aurora Road • Cleveland, OH 44139 • 440-248-0400 • Fax: [phone] • http://www.k eithley.com

BELGIUM: Keithley Instruments B.V.
CHINA: Keithley Instruments China
FRANCE: Keithley Instruments Sarl 3, allée des Garays • 91127 Palaiseau Cedex • 01-64 53 20 20 • Fax: [phone]
GERMANY: Keithley Instruments GmbH Landsberger Strasse 65 • 82110 Germering • 089/84 93 07-40 • Fax: [phone]
GREAT BRITAIN: Keithley Instruments Ltd
INDIA: Keithley Instruments GmbH Flat 2B, WILOCRISSA • 14, Rest House Crescent • Bangalore 560 001 • 91-80-509-1320/21 • Fax: [phone]
ITALY: Keithley Instruments s.r.l. Viale S. Gimignano, 38 • 20146 Milano • 02-48 39 16 01 • Fax: [phone]
NETHERLANDS: Keithley Instruments B.V. Postbus 559 • 4200 AN Gorinchem • 0183-635333 • Fax: [phone]
SWITZERLAND: Keithley Instruments SA Kriesbachstrasse 4 • 8600 Dübendorf • 01-821 94 44 • Fax: [phone]
TAIWAN: Keithley Instruments Taiwan 1 Fl. 85 Po Ai Street • Hsinchu, Taiwan, R.O.C. • 886-3572-9077• Fax: [phone]

Bergensesteenweg 709 • B-1600 Sint-Pieters-Leeuw • 02/363 00 40 • Fax: [phone]
Y uan Chen Xin Building, Room 705 • 12 Y umin Road, De wai, Madian • Beijing 100029 • 8610-62022886 • Fax: [phone]

Unit 2 Commerce Park, Brunel Road • Theale • Reading • Berkshire RG7 4AB • 0118 929 7500 • Fax: [phone]

4/01

Model 2303/2303B/2303-PJ High Speed Power Supply

Service Manual

©1998, Keithley Instruments, Inc.

All rights reserved.

Cleveland, Ohio, U.S.A.

Third Printing, November 1999

Document Number: 2303-902-01 Rev. C

ManualPrint History

The print history shown below lists the printing dates of all Revisions and Addenda created
for this manual. The Revision Level letter increases alphabetically as the manual undergoes sub­sequent updates. Addenda, which are released between Revisions, contain important change in­formation that the user should incorporate immediately into the manual. Addenda are numbered
sequentially. When a new Revision is created, all Addenda associated with the previous Revision
of the manual are incorporated into the new Revision of the manual. Each new Revision includes
a revised copy of this print history page.

Revision A (Document Number 2303-902-01)............................................................January 1998

Revision B (Document Number 2303-902-01) .................................................................June 1998

Revision C (Document Number 2303-902-01) ........................................................November 1999

All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc.
Other brand names are trademarks or registered trademarks of their respective holders.

SafetyPrecautions

The following safety precautions should be observed before using this product and any associated in­strumentation. Although some instruments and accessories would normally be used with non-hazardous
voltages, there are situations where hazardous conditions may be present.

This product is intended for use by qualified personnel who recognize shock hazards and are familiar
with the safety precautions required to avoid possible injury. Read the operating information carefully
before using the product.

The types of product users are:
Responsible body is the individual or group responsible for the use and maintenance of equipment, for

ensuring that the equipment is operated within its specifications and operating limits, and for ensuring
that operators are adequately trained.

Operatorsuse the product for its intended function. They must be trained in electrical safety procedures
and proper use of the instrument.They must be protected from electric shock and contact with hazardous
livecircuits.

Maintenance personnel perform routine procedures on the product to keep it operating, for example,
setting the line voltage or replacing consumable materials. Maintenance procedures are described in the
manual. The procedures explicitly state if the operator may perform them. Otherwise, they should be
performed only by service personnel.

Service personnel are trained to work on live circuits, and perform safe installations and repairs of prod­ucts. Only properly trained service personnel may perform installation and service procedures.

Exercise extreme caution when a shock hazard is present. Lethal voltage may be present on cable con­nector jacks or test fixtures. The American National Standards Institute (ANSI) states that a shock haz­ard exists when voltage levels greater than 30V RMS, 42.4V peak, or 60VDC are present. A good safety

practice is to expect that hazardous voltage is present in any unknown circuit before measuring.

Users of this product must be protected from electric shock at all times. The responsible body must en­sure that users are prevented access and/or insulated from every connection point. In some cases, con­nections must be exposed to potential human contact. Product users in these circumstances must be
trained to protect themselves from the risk of electric shock. If the circuit is capable of operating at or
above 1000 volts, no conductive part of the circuit may be exposed.

As described in the International Electrotechnical Commission (IEC) Standard IEC 664, digital multi­meter measuring circuits (e.g., Keithley Models 175A, 199, 2000, 2001, 2002, and 2010) are Installation
Category II. All other instruments’ signal terminals are Installation Category I and must not be connect­ed to mains.

Do not connect switching cards directly to unlimited power circuits. They are intended to be used with
impedance limited sources. NEVER connect switching cards directly to AC mains. When connecting
sources to switching cards, install protective devices to limit fault current and voltage to the card.

Before operating an instrument, make sure the line cord is connected to a properly grounded power re­ceptacle. Inspect the connecting cables, test leads, and jumpers for possible wear, cracks, or breaks be­fore each use.

For maximum safety, do not touch the product, test cables, or any other instruments while power is ap­plied to the circuit under test. ALWAYS remove power from the entire test system and discharge any
capacitors before: connecting or disconnecting cables or jumpers, installing or removing switching
cards, or making internal changes, such as installing or removing jumpers.

Do not touch any object that could provide a current path to the common side of the circuit under test or power
line (earth) ground. Always make measurements with dry hands while standing on a dry, insulated surface ca­pable of withstanding the voltage being measured.

The instrument and accessories must be used in accordance with its specifications and operating instructions
or the safety of the equipment may be impaired.

Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications
and operating information, and as shown on the instrument or test fixture panels, or switching card.

Whenfuses are usedin a product, replacewith same type and rating for continued protectionagainstfire hazard.
Chassis connections must only be used as shield connections for measuring circuits, NOT as safety earth

ground connections.
If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation

requires the use of a lid interlock.

If a screw is present, connect it to safety earth ground using the wire recommended in the user documen­tation.

!

The symbol on an instrument indicates that the user should refer to the operating instructions located in
the manual.

The symbol on an instrument shows that it can source or measure 1000 volts or more, including the com­bined effect of normal and common mode voltages. Use standard safety precautions to avoid personal contact
with these voltages.

The WARNING heading in a manual explains dangers that might result in personal injury or death. Always
read the associated information very carefully before performing the indicated procedure.

The CAUTION heading in a manual explains hazards that could damage the instrument. Such damage may
invalidate the warranty.

Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and all test cables.
To maintain protection from electric shock and fire, replacement components in mains circuits, including the

power transformer, test leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses,
with applicable national safety approvals, may be used if the rating and type are the same. Other components
that are not safety related may be purchased from other suppliers as long as they are equivalent to the original
component. (Note that selected parts should be purchased only through Keithley Instruments to maintain ac­curacy and functionality of the product.) If you are unsure about the applicability of a replacement component,
call a Keithley Instruments office for information.

To clean an instrument, use a damp cloth or mild, water based cleaner. Clean the exterior of the instrument
only. Do not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument. Prod­ucts that consist of a circuit board with no case or chassis (e.g., data acquisition board for installation into a
computer) should never require cleaning if handled according to instructions. If the board becomes contami­nated and operation is affected, the board should be returned to the factory for proper cleaning/servicing.

Rev. 10/99

T able of Contents

1

Performance Verification

Introduction.............................................................................................1-2

Verification test requirements .................................................................1-2

Environmental conditions................................................................1-2

Warm-up period ...............................................................................1-2

Line power.......................................................................................1-3

Recommended test equipment................................................................1-3

Resistor connections ........................................................................1-3

Resistor considerations ....................................................................1-4

Verification limits....................................................................................1-4

Example limits calculation...............................................................1-4

Performing the verification test procedures............................................1-5

Test summary...................................................................................1-5

Test considerations...........................................................................1-5

Instrument programming ........................................................................1-5

Output voltage accuracy..........................................................................1-5

Voltage readback accuracy......................................................................1-7

Compliance current accuracy..................................................................1-7

Current readback accuracy......................................................................1-9

5A range readback accuracy............................................................1-9

Models 2303 and 2303B 5mA range readback accuracy...............1-10

Model 2303-PJ 500mA range readback accuracy .........................1-11

Digital voltmeter input accuracy...........................................................1-13

Calibration

2

Introduction.............................................................................................2-2

Environmental conditions.......................................................................2-2

Temperature and relative humidity..................................................2-2

Warm-up period ...............................................................................2-2

Line power.......................................................................................2-2

Calibration considerations ......................................................................2-2

Calibration cycle..............................................................................2-3

Recommended calibration equipment.....................................................2-3

Resistor connections ........................................................................2-3

Resistor considerations ....................................................................2-4

Front panel calibration............................................................................2-4

Model 2303 front panel calibration..................................................2-4

Model 2303-PJ front panel calibration ..........................................2-10

Remote calibration................................................................................2-14

Remote calibration commands.......................................................2-14

Remote calibration display ............................................................2-15

Models 2303 and 2303B remote calibration procedure.................2-15

Model 2303-PJ remote calibration procedure................................2-18

Changing the calibration code ..............................................................2-21

Changing the code from the front panel.........................................2-21

Changing the code by remote.........................................................2-21

Resetting the calibration code ........................................................2-22

Viewing calibration date and count.......................................................2-22

Viewing date and count from the front panel.................................2-22

Acquiring date and count by remote ..............................................2-22

Disassembly

3

Introduction.............................................................................................3-2

Handling and cleaning.............................................................................3-2

Handling PC boards .........................................................................3-2

Solder repairs....................................................................................3-2

Static sensitive devices.....................................................................3-2

Assembly drawings .................................................................................3-3

Disassembly procedures..........................................................................3-3

Case cover removal ..........................................................................3-3

Analog board removal......................................................................3-4

Digital board removal.......................................................................3-4

Front panel disassembly...................................................................3-4

Removing mechanical components..................................................3-5

Instrument re-assembly ...........................................................................3-5

4

Replaceable Parts

Introduction.............................................................................................4-2

Ordering information...............................................................................4-2

Factory service ........................................................................................4-2

Parts lists and component layouts ...........................................................4-2

Models 2303 and 2303-PJ parts lists................................................4-3

Model 2303B parts lists..................................................................4-14

A

Specifications

Specifications .........................................................................................A-2

Accuracy calculations.............................................................................A-6

Output and compliance accuracy ....................................................A-6

Readback accuracy..........................................................................A-6

Digital voltmeter input accuracy.....................................................A-6

B

Calibration Reference

Introduction............................................................................................B-2

Command summary ........................................................................B-2

Miscellaneous commands ......................................................................B-3

Detecting calibration errors....................................................................B-6

Reading the error queue ..................................................................B-6

Error summary.................................................................................B-6

Status byte EAV (Error Available) bit .............................................B-6

Generating an SRQ on error ........................................................... B-7

Detecting calibration step completion ................................................... B-7

Using the *OPC command.............................................................. B-7

Using the *OPC? query .................................................................. B-7

Generating an SRQ on calibration complete .................................. B-8

C

Calibration Programs

Introduction............................................................................................ C-2

Computer hardware requirements.......................................................... C-2

Software requirements........................................................................... C-2

Calibration equipment............................................................................ C-2

General program instructions................................................................. C-3

Program C-1 Model 2303/2303B calibration program................... C-4

Program C-2 Model 2303-PJ calibration program.......................... C-6

Instrument Control

D

Introduction............................................................................................ D-2

Front panel control.................................................................................D-2

Setting the display mode.................................................................D-2

Selecting the current range..............................................................D-2

Turning on the output......................................................................D-2

IEEE-bus control....................................................................................D-3

Setting output values....................................................................... D-3

Setting the reading mode ................................................................ D-3

Turning on the output......................................................................D-4

Requesting readings........................................................................D-4

Basic control program..................................................................... D-4

Program D-1 Basic control programming.......................................D-4

List of Illustrations

1

Performance Verification

Test resistor connections ..................................................................1-4

Connections for voltage verification tests........................................1-6

Connections for output current and 5A range current verification tests.......1-8

Connections for Model 2303 and 2303B

5mA current verification tests....................................................1-10

Connections for Model 2303-PJ 500mA current verification tests1-12

Connections for DVM accuracy verification..................................1-13

Calibration

2

Test resistor connections ..................................................................2-4

Connections for voltage calibration .................................................2-6

Connections for 5A current calibration............................................2-7

Connections for 5mA range calibration ...........................................2-8

Connections for 500mA range calibration .....................................2-12

List of T ables

1

Performance Verification

Recommended verification equipment ...................................................1-3

Output voltage accuracy limits ...............................................................1-6

Voltage readback accuracy limits............................................................1-7

Compliance current accuracy limits........................................................1-9

5A range current readback accuracy limits...........................................1-10

Model 2303 and 2303B 5mA range current readback accuracy limits.1-11

Model 2303-PJ 500mA range current readback accuracy limits..........1-13

Digital voltmeter input accuracy limits.................................................1-14

2

Calibration

Recommended calibration equipment.....................................................2-3

Front panel calibration summary............................................................2-9

Model 2303-PJ front panel calibration summary..................................2-13

Remote calibration command summary ...............................................2-14

Models 2303 and 2303B remote calibration summary.........................2-17

Model 2303-PJ remote calibration summary........................................2-20

4

Replaceable parts

Models 2303 and 2303-PJ digital board parts list...................................4-3

Models 2303 and 2303-PJ analog board parts list..................................4-8

Models 2303 and 2303-PJ display board parts.....................................4-12

Models 2303 and 2303-PJ mechanical parts list...................................4-13

Model 2303B digital board parts list ....................................................4-14

Model 2303B analog board parts list....................................................4-19

Model 2303B mechanical parts list.......................................................4-23

B

Calibration Reference

Remote calibration command summary ................................................ B-2

Calibration step summary...................................................................... B-5

Calibration errors................................................................................... B-6

Instrument Control

D

Basic remote commands........................................................................D-3

1

Performance

Verification

1-2 Performance Verification

Introduction

Use the procedures in this section to verify that Model 2303, Model 2303B, or Model
2303-PJ accuracy is within the limits stated in the accuracy specifications. You can perform these
verification procedures:

• When you first receive the unit to make sure that it was not damaged during shipment.

• To verify that the unit meets factory specifications.

• To determine if calibration is required.

• Following calibration to make sure it was performed properly.

WARNING The information in this section is intended only for qualified service per-

sonnel. Do not attempt these procedures unless you are qualified to do so.

NOTE If the power supply is still under warranty, and its performance is outside specified

limits, contact your Keithley representative or the factory to determine the correct
course of action.

Verificationtestrequirements

Be sure that you perform the verification tests:

• Under the proper environmental conditions.

• After the specified warm-up period.

• Using the correct line voltage.

• Using the proper test equipment.

• Using the specified output signals and reading limits.

Environmental conditions

Conduct your performance verification procedures in a test environment with:

• An ambient temperature of 18-28°C (65-82°F).

• A relative humidity of less than 70% unless otherwise noted.

Warm-upperiod

Allow the Model 2303 to warm up for at least one hour before conducting the verification
procedures.

If the unit has been subjected to temperature extremes (those outside the ranges stated above),
allow additional time for the instrument’s internal temperature to stabilize. Typically, allow one
extra hour to stabilize a unit that is 10°C (18°F) outside the specified temperature range.

Also,allowthe test equipment to warmup for theminimumtimespecifiedbythe manufacturer.

Line power

The Model 2303 requires a line voltage of 100 to 240V and a line frequency of 50 to 60Hz.

Verification tests must be performed within this range.

Recommended testequipment

Table 1-1 summarizes recommended verification equipment. You can use alternate equip­ment as long as that equipment has specifications at least four times better than corresponding
Model 2303, 2303B, or 2303-PJ specifications. Keep in mind, however, that test equipment
accuracy will add to the uncertainty of each measurement.

Table 1-1

Recommended verification equipment

Description Manufacturer/Model Specifications

Digital Multimeter Keithley 2001 DC Voltage1 20V: ±22ppm

Precision Resistor 1Ω, 0.1%, 100W
Precision Resistor 30Ω, 0.1%, 50W
Precision Resistor 3kΩ, 0.1%, 0.25W

Performance Verification 1-3

Resistance1 20Ω: ±59ppm

200Ω: ±43ppm
20kΩ: ±36ppm

2
3

4

1. Full-range, 90-day, 23˚C various measurement points.

2. Characterize resistor using 4-wire ohms function and 20Ω range of DMM before use.

3. Used only for Model 2303-PJ. Characterize resistor using 4-wire ohms function and 200Ω range of DMM

before use. See Resistor considerations for temperature coefficient.

4. Used only for Models 2303 and 2303B. Characterize resistor using 4-wire ohms function and 20kΩ range of

DMM before use.

Resistorconnections

When performing the verification tests, make connections to the test resistors as shown in
Figure 1-1. Be sure to connect the Model 2303 SENSE leads and DMM test leads as close to the
resistor body as possible.

1-4 Performance Verification

Figure 1-1

Test resistor connections

Resistorconsiderations

The test resistors should be characterized using the lowest possible range and the 4-wire ohms
function of the DMM recommended in Table 1-1 to measure the resistance values. Use the mea­sured resistance values to calculate the actual currents during the test procedures.

NOTE The temperature coefficient and temperature change of the 1Ω and 30Ω resistors

when passing current at full load must be low enough so that the change in resistance
does not cause incorrect readings as follows:

V

OUT

voltage, and ∆R is the change in resistance caused by heating.)

Verificationlimits

The verification limits stated in this section have been calculated using only the Model 2303
accuracy specifications, and they do not include test equipment uncertainty . If a particular mea-
surement falls outside the allowable range, recalculate new limits based both on Model 2303
specifications and corresponding test equipment specifications.

Examplelimitscalculation

As an example of how verification limits are calculated, assume you are testing the power
supply using a 10V output value. Using the Model 2303 voltage output accuracy specification
of ±(0.05% of output + 10mV offset), the calculated output limits are:

Output limits = 10V ± [(10V X 0.05%) + 10mV]
Output limits = 10V ± (0.005 + 0.01)
Output limits = 10V ± 0.015V
Output limits = 9.985V to 10.015V

/∆R <25% of Model 2303 amps specification. (V

is the Model 2303 output

OUT

Performance Verification 1-5

Performingtheverificationtestprocedures

Testsummary

• DC voltage output accuracy

• DC voltage readback accuracy

• DC current output accuracy

• DC current readback accuracy

• Digital voltmeter input accuracy

If the Model 2303 is not within specifications and not under warranty, see the calibration pro-

cedures in Section 2 for information on calibrating the unit.

Testconsiderations

When performing the verification procedures:

• Make sure that the test equipment is properly warmed up and connected to the correct
Model 2303 terminals on the rear panel. Also be sure the test equipment is set up for the
proper function and range.

• Do not connect test equipment to the Model 2303 through a scanner, multiplexer, or
other switching equipment.

• Be sure that the power supply output is turned on before making measurements.

• Allow the power supply output signal to settle before making a measurement.

Instrumentprogramming

Refer to Appendix D for basic information on programming the Model 2303, 2303B, or

2303-PJ from the front panel or over the bus.

Outputvoltageaccuracy

Follow the steps below to verify that Model 2303, 2303B, or 2303-PJ output voltage accuracy
is within specified limits. This test involves setting the output voltage to specific values and mea­suring the voltages with a precision digital multimeter.

1. With the power off, connect the digital multimeter to the Model 2303 OUTPUT
SOURCE terminals, as shown in Figure 1-2. Be sure to observe proper polarity
(SOURCE + to INPUT HI; SOURCE - to INPUT LO).

1-6 Performance Verification

PREV

DCV ACV DCI ACI Ω2 Ω4

DISPLAY

NEXT

REL TRIG

POWER

INFO LOCAL EXIT ENTER

Figure 1-2

Connections for voltage verification tests

STORE RECALL

FILTER MATH

CHAN SCAN

CONFIGMENU

Model 2001 DMM

2001 MULTIMETER

FREQ TEMP

RANGE

RANGE

AUTO

Input HI

SENSE

Ω 4 WIRE

350V
PEAK

INPUTS

F R

FRONT/REAR

CAL

Input LO

INPUT

HI

1100V

!

PEAK

LO

500V
PEAK

2A 250V

AMPS

Source + Source -

WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.

ISOLATION FROM EARTH:

22 VOLTS MAX.

_ _ _ _

+ + +

SOURCE SENSE D VM INSOURCE

(CHANGE IEEE ADDRESS

WITH FRONT PANEL MENU)

MADE IN

U.S.A.

CAUTION: FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.CAUTION:FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.

OUTPUT

IEEE-488

0-20V, 0-5A

+

Model 2303

LINE FUSE

SLOWBLOW

2.5A, 250V

LINE RATING

100-240VAC

50, 60 HZ

185VA MAX

REMOTE
DISPLAY

OPTION

2. Select the multimeter DC volts measuring function, and enable auto-ranging.

3. Make sure the Model 2303 output is turned on.

4. Verify output voltage accuracy for each of the voltages listed in Table 1-2. For each test
point:

• Set the Model 2303 output voltage to the indicated value. When setting the voltage,

set the compliance current to 3A.

• Allow the reading to settle.

• Verify that the multimeter reading is within the limits given in the table.

Table 1-2

Output voltage accuracy limits

Model 2303 output

voltage setting

Output voltage limits
(1 Year, 18°C-28°C)

5.00V 4.9875 to 5.0125V

10.00V 9.985 to 10.015V

15.00V 14.9825 to 15.0175V

Voltagereadbackaccuracy

Follow the steps below to verify that Model 2303, 2303B, or 2303-PJ voltage readback accu­racy is within specified limits. The test involves setting the source voltage to specific values, as
measured by a digital multimeter, and then verifying that voltage readback readings are within
required limits.

1. With the power off, connect the digital multimeter to the Model 2303 OUTPUT
SOURCE terminals, as shown in Figure 1-3. Be sure to observe proper polarity
(SOURCE + to INPUT HI; SOURCE - to INPUT LO).

2. Select the multimeter DC volts function, and enable auto-ranging.

3. Make sure actual voltage readings are being displayed (use DISPLAY), and turn on the
Model 2303 output.

4. Verify voltage readback accuracy for each of the voltages listed in Table 1-3. For each
test point:

• Set the Model 2303 output voltage to the indicated value as measured by the digital

multimeter. Note that it may not be possible to set the voltage source precisely to the
specified value. Use the closest possible setting, and modify reading limits accord­ingly. When setting the voltage, set the compliance current to 3A.

• Allow the reading to settle.

• Verify that the actualModel 2303 voltagereading is withinthe limits givenin the table.

Performance Verification 1-7

Table 1-3

Voltage readback accuracy limits

Model 2303 output
voltage setting*

5.00V 4.995 to 5.005V

10.00V 9.992 to 10.008V

14.00V 13.990 to 14.010V

* As measured by digital multimeter. See procedure.

Voltage readback limits
(1 Year, 18°C-28°C)

Compliancecurrentaccuracy

Follow the steps below to verify that Model 2303, 2303B, or 2303-PJ compliance current

accuracy is within specified limits. The test involves setting the compliance current to specific
values and determining the actual current by measuring the voltages across a characterized 1Ω
resistor with a precision digital multimeter.

1. With the power off, connect the digital multimeter and characterized 1Ω resistor to the
Model 2303 OUTPUT SOURCE terminals, as shown in Figure 1-3. Be sure to observe

1-8 Performance Verification

proper polarity (SOURCE + to INPUT HI; SOURCE - to INPUT LO). Also be sure to
use 4-wire connections to the resistor terminals.

PREV

DISPLAY

NEXT

POWER

2001 MULTIMETER

DCV ACV DCI ACI Ω2 Ω4

REL TRIG

STORE RECALL

INFO LOCAL EXIT ENTER

CHAN SCAN

FREQ TEMP

FILTER MATH

CONFIGMENU

RANGE

RANGE

AUTO

Input HI

SENSE

Ω 4 WIRE

350V
PEAK

INPUTS

F R

FRONT/REAR

CAL

INPUT

HI

!

LO

Input LO

1100V
PEAK

500V
PEAK

2A 250V

AMPS

1 Ω Resistor

Model 2001 DMM

22 VOLTS MAX.

_ _ _ _

Sense -

+

LINE FUSE

SLOWBLOW

2.5A, 250V

LINE RATING

100-240VAC

50, 60 HZ

185VA MAX

Note: Use 4-wire connections
to resistor terminals.

Sense +

Source + Source -

WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.

ISOLATION FROM EARTH:

+ + +

SOURCE SENSE DVM INSOURCE

OUTPUT

0-20V, 0-5A

IEEE-488

(CHANGE IEEE ADDRESS

WITH FRONT PANEL MENU)

MADE IN

U.S.A.

CAUTION: FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.CAUTION:FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.

Model 2303

Figure 1-3

Connections for output current and 5A range current verification tests

2. Select the multimeter DC voltage measuring function, and enable auto-ranging.

3. Turn on the Model 2303 output.

4. Verify compliance current accuracy for the currents listed in Table 1-4. For each test
point:

• Set the Model 2303 output voltage to 9V, and set the compliance current to the value

being tested.

• Note and record the digital multimeter voltage reading.

• Calculate the current from the voltage reading and actual 1Ω resistor value: I = V/R

• Verify that the current is within the limits given in the table.

REMOTE
DISPLAY

OPTION

Table 1-4

Compliance current accuracy limits

Performance Verification 1-9

Model 2303 compliance
current setting

1.000A 0.993 to 1.007A

2.000A 1.992 to 2.008A

3.000A 2.990 to 3.010A

4.000A 3.989 to 4.011A

5.000A 4.987 to 5.013A

Compliance current limits
(1 Year, 18°C-28°C)

Current readbackaccuracy

Follow the steps below to verify that Model 2303, 2303B, or 2303-PJ current readback accu­racy is within specified limits. The test involves setting the output current to specific values as
measured with a resistor and precision digital multimeter.

5Arangereadbackaccuracy

1. With the power off, connect the digital multimeter and characterized 1Ω resistor to the

Model 2303 OUTPUT SOURCE terminals, as shown in Figure 1-3. Be sure to observe
proper polarity (SOURCE + to INPUT HI; SOURCE - to INPUT LO). Also be sure to
use 4-wire connections to the resistor terminals.

2. Select the multimeter DC volts measuring function, and enable auto-ranging.

3. Select the 5A readback range. Also make sure actual current readings are displayed.

4. Turn on the Model 2303 output.

5. Verify 5A range current readback accuracy for the currents listed in Table 1-5. For each
test point:

• By changing the output voltage, adjust the current to the correct value, as determined

from the multimeter voltage reading and characterized resistance value. When setting
the voltage, be sure to set the compliance current to 5A.

• Notethat it may not be possibleto set the outputcurrent to the exactvalue.In that case,

set the current to the closest possible value, and modify readinglimits accordingly.

• Allow the reading to settle.

• Verify that the actual Model2303 current reading is withinthe limits givenin the table.

1-10 Performance Verification

Table 1-5

5A range current readback accuracy limits

Nominal output
Voltage

Model 2303
Output current*

Current readback limits
(1 Year, 18°C-28°C)

1V 1.000A 0.9976 to 1.0024A
2V 2.000A 1.9956 to 2.0044A
3V 3.000A 2.9936 to 3.0064A
4V 4.000A 3.9916 to 4.0084A

4.9V 4.900A 4.8898 to 4.9102A

* As determined from digital multimeter and 1Ω resistor. See procedure.

Models 2303and2303B5mArange readbackaccuracy

The following test applies only to the Models 2303 and 2303B:

1. With the power off, connect the digital multimeter and characterized 3kΩ resistor to the

Model 2303 or 2303B OUTPUT SOURCE terminals, as shown in Figure 1-4. Be sure
to observe proper polarity and connections (3kΩ resistor between SOURCE + and DMM
INPUT HI; SOURCE - to DMM INPUT LO).

Input HI

Input LO

1100V
PEAK

500V
PEAK

2A 250V

AMPS

PREV

DCV ACV DCI ACI Ω2 Ω4

DISPLAY

NEXT

REL TRIG

POWER

STORE RECALL

INFO LOCAL EXIT ENTER

CHAN SCAN

FILTER MATH

CONFIGMENU

2001 MULTIMETER

FREQ TEMP

RANGE

RANGE

SENSE

INPUT

Ω 4 WIRE

HI

350V

!

PEAK

LO

INPUTS

F R

FRONT/REAR

AUTO

CAL

3kΩ Resistor

Model 2001 DMM

Sense +

Source + Source -

WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.

ISOLATION FROM EARTH:

22 VOLTS MAX.

_ _ _ _

+ + +

SOURCE SENSE DVM INSOURCE

OUTPUT

0-20V, 0-5A

IEEE-488

(CHANGE IEEE ADDRESS

WITH FRONT PANEL MENU)

MADE IN

Note: Use 4-wire connections
to resistor terminals.

U.S.A.

CAUTION: FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.CAUTION:FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.

Model 2303

Figure 1-4

Connections for Model 2303 and 2303B 5mA current verification tests

+

Sense -

SLOWBLOW

LINE RATING

LINE FUSE

2.5A, 250V

100-240VAC
50, 60 HZ
185VA MAX

REMOTE
DISPLAY
OPTION

Performance Verification 1-11

2. Select the multimeter DC volts measuring function, and enable auto-range.

3. Select the 5mA readback range and actual current reading data.

4. Turn on the Model 2303 output.

5. Verify 5mA range current readback accuracy for the currents listed in Table 1-6. For each
test point:

• Set the Model 2303 output current to the correct value, as determined from the digital

multimeter voltage reading and 3kΩ resistance value. Note that it may not be possible
to set the output current to the exact value. In that case, set the current to the closest
possible value, and modify reading limits accordingly.

• Allow the reading to settle.

• Verify that the actual Model2303 current reading is withinthe limits givenin the table.

Table 1-6

Model 2303 and 2303B 5mA range current readback accuracy limits

Nominal output
Voltage

3V 1.0000mA 0.9970 to 1.0030mA
6V 2.0000mA 1.9950 to 2.0050mA
9V 3.0000mA 2.9930 to 3.0070mA
12V 4.0000mA 3.9910 to 4.0090mA

14.7V 4.9000mA 4.8892 to 4.9108mA

* As determined from digital multimeter voltage reading and 3kΩ resistance
value. See procedure.

Model 2303
output current*

Current readback limits
(1 Year, 18°C-28°C)

Model2303-PJ500mArangereadback accuracy

The following tests apply only to the Model 2303-PJ:

1. With the power off, connect the digital multimeter and characterized 30Ω resistor to the
Model 2303-PJ OUTPUT SOURCE terminals, as shown in Figure 1-5. Be sure to
observe proper polarity and connections (30Ω resistor between SOURCE + and DMM
INPUT HI; SOURCE - to DMM INPUT LO).

1-12 Performance Verification

DCV ACV DCI ACI Ω2 Ω4

PREV

DISPLAY

NEXT

REL TRIG

POWER

INFO LOCAL EXIT ENTER

Note: Use 4-wire connections
to resistor terminals.

STORE RECALL

FILTER MATH

CHAN SCAN

CONFIGMENU

Model 2001 DMM

2001 MULTIMETER

FREQ TEMP

RANGE

AUTO

RANGE

Input HI

SENSE

Ω 4 WIRE

350V
PEAK

INPUTS

F R

FRONT/REAR

CAL

INPUT

HI

!

LO

2A 250V

AMPS

Input LO

1100V
PEAK

500V
PEAK

Sense +

Source + Source -

WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.

ISOLATION FROM EARTH:

22 VOL TS MAX.

_ _ _ _

+ + +

SOURCE SENSE DVM INSOURCE

(CHANGE IEEE ADDRESS

WITH FRONT PANEL MENU)

MADE IN

U.S.A.

CAUTION: FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.CAUTION:FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.

OUTPUT

IEEE-488

+

0-20V, 0-5A

Model 2303

Sense -

SLOWBLOW

LINE RATING

3kΩ Resistor

LINE FUSE

2.5A, 250V

100-240VAC

50, 60 HZ

185VA MAX

REMOTE
DISPLAY

OPTION

Figure 1-5

Connections for Model 2303-PJ 500mA current verification tests

2. Select the multimeter DC volts measuring function, and enable auto-range.

3. Select the 500mA readback range and actual current reading data.

4. Turn on the Model 2303-PJ output.

5. Verify 500mA range current readback accuracy for the currents listed in Table 1-7. For
each test point:

• Set the Model 2303-PJ output current to the correct value, as determined from the dig-

ital multimeter voltage reading and 30Ω resistance value. Note that it may not be pos-
sible to set the output current to the exact value. In that case, set the current to the
closest possible value, and modify reading limits accordingly.

• Allow the reading to settle.

• Verify that the actual Model 2303-PJ current reading is within the limits given in the

table.

Table 1-7

Model 2303-PJ 500mA range current readback accuracy limits

Performance Verification 1-13

Nominal output
voltage

Model 2303-PJ
output current*

Current readback limits (1 Year,
18˚C-28˚C)

3V 100.00mA 99.76 to 100.24mA
6V 200.00mA 199.56 to 200.44mA
9V 300.00mA 299.36 to 300.64mA
12V 400.00mA 399.16 to 400.84mA

14.7V 490.00mA 488.98 to 491.02mA

Digital voltmeter input accuracy

Follow the steps below to verify that Model 2303, 2303B, and 2303-PJ digital voltmeter input
accuracy is within specified limits. The test involves setting the voltage applied to the DVM
input to accurate values and then verifying that the Model 2303 digital voltmeter input readings
are within required limits.

1. With the power off, connect the Model 2303 DVM IN terminals to OUTPUT SOURCE
terminals and the digital multimeter, as shown in Figure 1-6. Be sure to observe proper
polarity (DVM IN + to SOURCE + and DMM INPUT HI; DVM IN - to SOURCE - and
DMM INPUT LO).

Input HI

SENSE

Ω 4 WIRE

350V

PREV

DCV ACV DCI ACI Ω2 Ω4

DISPLAY

NEXT

REL TRIG

POWER

STORE RECALL

INFO LOCAL EXIT ENTER

CHAN SCAN

2001 MULTIMETER

FREQ TEMP

FILTER MATH

CONFIGMENU

RANGE

AUTO

RANGE

PEAK

F R

INPUTS

FRONT/REAR

CAL

INPUT

HI

!

LO

Input LO

1100V
PEAK

500V
PEAK

2A 250V

AMPS

DVM IN ­DVM IN +

Model 2001 DMM

Figure 1-6

Connections for DVM accuracy verification

Source +
Source -

WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.

ISOLATION FROM EARTH:

22 VOLTS MAX.

_ _ _ _

+ + +

SOURCE SENSE DVM INSOURCE

OUTPUT

0-20V, 0-5A

IEEE-488

(CHANGE IEEE ADDRESS
WITH FRONT PANEL MENU)

MADE IN

U.S.A.

CAUTION: FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.CAUTION:FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.

LINE FUSE

SLOWBLOW

2.5A, 250V

LINE RATING

100-240VAC

50, 60 HZ

+

185VA MAX

Model 2303

REMOTE
DISPLAY

OPTION

1-14 Performance Verification

2. Select the DMM DC volts function, and enable auto-ranging.

3. Enable the Model 2303 DVM input.

4. Turn on the Model 2303 source output.

5. Verify digital voltmeter input accuracy for each of the voltages listed in Table 1-8. For
each test point:

• Set the voltage to the indicated value as measured by the digital multimeter.

• Set compliance to 3A.

• Allow the reading to settle.

• Verify that the Model 2303 voltage reading is within the limits given in the table.

Table 1-8

Digital voltmeter input accuracy limits

Model 2303 output
voltage setting*

Digital voltmeter input reading limits
(1 Year, 18°C-28°C)

14.00V 13.990 to 14.010V

3.00V 2.996V to 3.004V

* As measured by digital multimeter. See procedure.

2

Calibration

2-2 Calibration

Introduction

Use the procedures in this section to calibrate the Model 2303, 2303B, or 2303-PJ. These pro­cedures require accurate test equipment to measure precise DC voltages and currents. Calibra­tion can be performed either from the front panel (Models 2303 and 2303-PJ only), or by
sending SCPI calibration commands over the IEEE-488 b us with the aid of a computer (Models
2303, 2303B, and 2303-PJ).

WARNING The information in this section is intended only for qualified service person-

nel. Do not attempt these procedures unless you are qualified to do so.

Environmental conditions

T emperature and relative humidity

Conduct the calibration procedures at an ambient temperature of 18-28°C (65-82°F) with a
relative humidity of less than 70% unless otherwise noted.

W arm-up period

Allow the Model 2303 to warm up for at least one hour before performing calibration.

If the instrument has been subjected to temperature extremes (those outside the ranges stated
above), allow additional time for the instrument’s internal temperature to stabilize. Typically,
allow one extra hour to stabilize a unit that is 10°C (18°F) outside the specified temperature
range.

Also, allow the test equipment to warm up for the minimum time specified by the
manufacturer.

Line power

The Model 2303 requires a line voltage of 100 to 240V at line frequency of 50 to 60Hz. The
instrument must be calibrated while operating from a line voltage within this range.

Calibration considerations

When performing the calibration procedures:

• Make sure that the test equipment is properly warmed up and connected to the appropri­ate Model 2303 terminals.

• Always allow the source signal to settle before calibrating each point.

• Do not connect test equipment to the Model 2303 through a scanner or other switching
equipment.

20 Ω

Ω

Ω

Ω

Calibration 2-3

• Calibration must be performed in the sequence outlined in this manual, or an error will
occur.

• If an error occurs during calibration, the Model 2303 will generate an appropriate error
message. See Appendix B for more information.

WARNING The maximum common-mode voltage (voltage between LO and chassis

ground) is 22VDC. Exceeding this value may cause a breakdown in insu­lation, creating a shock hazard.

Calibration cycle

Perform calibration at least once a year to ensure the unit meets or exceeds its specifications.

Recommended calibration equipment

Table 2-1 lists the recommended equipment for the calibration procedures. You can use
alternate equipment as long as that equipment has specifications at least four times better than
corresponding Model 2303 specifications. See also Resistor considerations for important tem­perature coefficient information.

Table 2-1

Recommended calibration equipment

Description Manufacturer/Model Specifications

Digital Multimeter Keithley 2001 DC Voltage

Resistance

Precision Resistor 4
Precision Resistor 30 Ω , 0.1%, 50W
Precision Resistor 3k Ω , 0.1%, 0.125W

1. Full-range, 90-day, 23˚C ±5˚C accuracy specifications of ranges required for various measurement points.

2. Characterize resistor using 4-wire ohms function and 20 Ω range of DMM before use.

3. Required only for Model 2303-PJ. Characterize resistor using 4-wire ohms function and 200 Ω range of DMM

before use. See Resistor considerations for temperature coefficient.

4. Required only for Models 2303 and 2303B. Characterize resistor using 4-wire ohms function and 20k Ω range

of DMM before use. See Resistor considerations for temperature coefficient.

, 0.1%, 100W

1

20V: ±22ppm

1

200
20k

2
3

: ±59ppm

: ±43ppm
: ±36ppm

4

Resistor connections

When performing calibration, make connections to the test resistors as shown in Figure 2-1.
Be sure to connect the Model 2303 SENSE leads and DMM test leads as close to the resistor
body as possible.

2-4 Calibration

2303 Source +

2303 Sense +

2303 Sense -

2303 Source -

Figure 2-1

Test resistor connections

Resistor considerations

The test resistors should be characterized using the 4-wire ohms function of the DMM rec­ommended in Table 2-1 to measure the resistance values. Use the measured resistance values to
calculate the actual currents during the calibration procedures.

NOTE The temperature coefficient and temperature change of the 4

when passing current at full load must be low enough so that the c hange in r esistance
does not cause incorrect readings as follows:

/

∆

R <25% of Model 2303 amps specification. (V

V

OUT

voltage, and

DMM Input HI

Test Resistor

DMM Input LO

OUT

∆

R is the change in resistance caused by heating.)

Ω

and 30

Ω

resistors

is the Model 2303 output

Front panel calibration

Model 2303 and Model 2303-PJ front panel calibration are covered separately below.

Model 2303 front panel calibration

Use the following procedure to calibrate the Model 2303 from the front panel. T able 2-2 sum­marizes calibration steps.

NOTE Calibration must be performed in the following sequence, or an error will occur. To

abort calibration and re vert to previous calibration constants at any time during the
procedure, press the MENU key.

Calibration 2-5

Step 1: Prepare the Model 2303 for calibration

1. Turn on the Model 2303 and the digital multimeter, and allow them to warm up for at
least one hour before performing calibration.

2. Press the MENU key, then choose CALIBRATE UNIT, and press ENTER. The instru­ment will display the date last calibrated:

CALIBRATE UNIT

LAST ON 02/01/98

3. Press the up arrow key. The instrument will display the number of times it was
calibrated:

CALIBRATE UNIT

TIMES= 01

4. Press the up arrow key. The unit will then prompt you to run calibration:

CALIBRATE UNIT

RUN

5. Press ENTER. The unit will then prompt for the calibration code:

CALIBRATE UNIT

Cal Code KI002303

6. Using the edit keys, set the display to the current calibration code, then press ENTER.
(Default: KI002303.) The unit will then prompt you as to whether or not to change the
code:

CALIBRATE UNIT

Change Code NO

7. Be sure NO is selected (use the up and down arrow k eys), press ENTER, then follo w the
steps below to calibrate the unit. (See Changing the calibration code at the end of this
section if you wish to change the code.)

Step 2: Perform calibration steps

NOTE The unit will display the most recently calibrated values. Factory defaults are shown

in this manual.

1. Connect both the OUTPUT SOURCE and DVM IN terminals to the digital multimeter,
as shown in Figure 2-2. (Connect SOURCE + and D VM IN + to DMM INPUT HI; con­nect SOURCE - and DVM IN - to DMM INPUT LO.)