Agilent Technologies 66332A User manual

Service Manual
Agilent Model 66332A
Dynamic Measurement DC Source
and Agilent Model 6632B, 6633B, 6634B
System DC Power Supply
s1
Agilent Part No. 5962-8119 Printed in Malaysia
Microfiche No 6962-8120 October, 2003

2
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 one year 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.

3
Safety Summary
The
f
ollowin
g
g
eneral sa
f
et
y
p
recautions must be observed durin
g
all
p
hases o
f
o
p
eration o
f
this instrument. Failure to com
p
l
y
with these
p
recautions or with s
p
eci
f
ic warnin
g
s elsewhere in this manual violates sa
f
et
y
standards o
f
desi
g
n, manu
f
acture, and
intended use o
f
the instrument. A
g
ilent Technolo
g
ies assumes no liabilit
y
f
or the customer's
f
ailure to com
p
l
y
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 an 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.

4
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)

5
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, Inc.
Copyright 1997, 2000 Agilent Technologies, Inc.
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...............................................................June, 1997
Update 1...............................................................October, 2003
Instrument Identification
Agilent Technologies power supplies are identified by a 10-digit serial number. The format is described as follows:
first two letters indicate the country of manufacture. The next four digits are a code that identify either the date of
manufacture or of a significant design change. The last four digits are a sequential number assigned to each
instrument.
Item Description
US The first two letters indicates the country of manufacture, where US = USA; MY = Malaysia; SG = Singapore.
3631 This is a code that identifies either the date of manufacture or the date of a significant design change.
0101 The last four digits are a unique number assigned to each power supply.
Edition 2...............................................................September, 2000

6
Table of Contents
Warranty Information 2
Safety Summary 3
Notice 4
Printing History 5
Instrument Identification 5
Table of Contents 6
INTRODUCTION 9
Organization 9
Safety Considerations 9
Related Documents 9
Revisions 10
Manual Revisions 10
Firmware Revisions 10
Electrostatic Discharge 10
VERIFICATION AND PERFORMANCE TESTS 11
Introduction 11
Test Equipment Required 11
Measurement Techniques 12
Setup for Most Tests 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 15
CV Noise (PARD) 15
Transient Recovery Time 16
Constant Current (CC) Tests 16
CC Setup 16
Current Programming and Readback Accuracy 16
Current Sink (CC-) Operation 17
CC Load and Line Regulation 17
CC Load Effect 18
CC Source Effect 18
CC Noise (PARD) 19
Performance Test Equipment Form 19
Performance Test Record Form 20
TROUBLESHOOTING 23
Introduction 23
Test Equipment Required 24
Overall Troubleshooting 24
Flow Charts 24
Specific Troubleshooting Procedures 34

7
Power-on Self-test Failures 37
CV/CC Status Annunciators Troubleshooting 38
Bias and Reference Supplies 38
J307 Voltage Measurements 39
Manual Fan Speed Control 40
Disabling Protection Features 40
Post-repair Calibration 41
Inhibit Calibration Switch 41
Calibration Password 41
Initialization 42
ROM Upgrade 42
Identifying the Firmware 42
Upgrade Procedure 42
Disassembly Procedures 43
List of Required Tools 43
Cover, Removal and Replacement 44
A2 Interface Board, Removal and Replacement 44
Front Panel Assembly, Removal and Replacement 44
A3 Front Panel Board, Removal and Replacement 45
A1 Main Control Board 45
T1 Power Transformer, Removal and Replacement 45
Line Voltage Wiring 46
PRINCIPLES OF OPERATION 47
Introduction 47
I/O Interface Signals 47
A3 Front Panel Circuits 48
A2 Interface Circuits 48
Primary Interface 48
Secondary Interface 48
A1 Main Board Circuits 50
Power Circuits 50
Control Circuits 52
REPLACEABLE PARTS LIST 55
Introduction 55
DIAGRAMS 71
Introduction 71
General Schematic Notes 71
Backdating 71
INDEX 81

9
1
Introduction
Organization
This manual contains information for troubleshooting and repairing to the component level the Agilent Model
66332A Dynamic Measurement DC Source and the Agilent Model 6632B, 6633B, 6634B System DC Power
Supplies. Hereafter all models will be referred to as the dc power supply.
This manual is organized as follows:
Chapter 1 Organization
Chapter 2 Performance tests
Chapter 3 Troubleshooting procedures
Chapter 4 Principles of operation on a block-diagram level
Chapter 5 Replaceable parts
Chapter 6 Diagrams
Safety Considerations
WARNING:Hazardous voltages exist within the dc power supply chassis.
This dc power supply; 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 power supply 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 power supply:
aa User’s Guide, containing installation, operating, and calibration information
aa Programming Guide, containing detailed GPIB programming information.

1 -Introduction
10
Revisions
Manual Revisions
If changes have been made to your power supply since the publication of this manual, a yellow Manual Change
sheet may be supplied with the manual. It defines the differences between your power supply and the unit described
in this manual. The yellow change sheet may also contain information for correcting errors in the manual. Note that
because not all changes to the product require changes to the manual, there may be no update information required
for your power supply.
Firmware Revisions
You can obtain the firmware revision number by either reading the integrated circuit label, or query the dc power
supply using the GPIB *IDN?' query command (See Chapter 3, ROM Upgrade).
Electrostatic Discharge
CAUTION: The dc power supply 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 power supply, observe all standard, antistatic work practices. These include, but are not
limited to:
—Working at a static-free station such as a table covered with static-dissipative laminate or with a conductive
table mat (Agilent P/N 9300-0797, or equivalent).
—Using a conductive wrist strap, such as Agilent P/N 9300-0969 or 9300-0970.
—Grounding all metal equipment at the station to a single common ground.
—Connecting low-impedance test equipment to static-sensitive components only when those
components have power applied to them.
—Removing power from the dc power supply before removing or installing printed circuit boards.

11
2
Verification and Performance Tests
Introduction
This document contains test procedures to verify that the dc power supply is operating normally and is within
published specifications. There are three types of tests as follows:
Built-in Self Tests These tests, run automatically when the power supply is turned on, check most
of the digital circuits and the programming and readback DACs.
Operation Verification These tests verify that the power supply is probably operating normally but do
not check all of the specified operating parameters.
Performance Tests These tests check that the supply meets all of the operating specifications as
listed in the Operating Manual.
NOTE: The dc power supply 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.
Test Equipment Required
Table 2-1 lists the equipment required to perform the verification and performance tests. A test record sheet with
specification limits (when test using the recommended test equipment) may be found at the back of this section.
WARNING: SHOCK HAZARD. These tests should only be performed by qualified personnel. During the
performance of these tests, hazardous voltages may be present at the output of the supply.
Table 2-1. Test Equipment Required for Verification and Performance Tests
Type Specifications Recommended Model
Current Monitor
Resistor 15 A (0.1 ohm) 0.04%, for power supplies up to 15 A output Guildline 9230/15
DC Power Supply 5 V, 10 A Agilent 6642A, 6653A
Digital Voltmeter Resolution: 10 nV @ 1V
Readout: 8 1/2 digits
Accuracy: 20 ppm
Agilent 3458A or equivalent
Electronic Load 20 V, 5 A minimum, with transient capability Agilent 6060B or equivalent
GPIB Controller HP Series 300 or other controller with full GPIB
capabilities

2 -Verification and Performance Tests
12
Resistor
(substitute for electronic
load if load is too noisy
for CC PARD test)
1 ohm, 50 W
3 ohm, 100 W (Agilent 66332A/6632B)
24 ohm, 100 W (Agilent 6633B)
99 ohm, 100 W (Agilent 6634B)
1k ohm, 5%, 3W (all models)
Ohmite L50J1R0
Ohmite RLS5R0 (adjustable)
Ohmite RLS25R (adjustable)
Ohmite RLS100 (adjustable)
Agilent 0813-0001
Oscilloscope Sensitivity: 1 mV
Bandwidth Limit: 20 MHz
Probe: 1:1 with RF tip
Agilent 54504A or equivalent
RMS Voltmeter True RMS
Bandwidth: 20 MHz
Sensitivity: 100 µV
Agilent 3400B or equivalent
Variable-Voltage
Transformer Adjustable to highest rated input voltage range. Power: 500 VA
Measurement Techniques
Test Setup
Most tests are performed at the rear terminals of the supply as shown in Figure 2-1a. Measure the dc voltage directly
at the +S and-S terminals.
Figure 2-1. Test Setup
Load
resistor
DC
Ammeter
-
+
Load
resistor
DC
Ammeter
-
+
+
-
External
DCsupply
b.
c.
+S + - -S
+ 240 VDC MAX
-
+S + - -S
+240VDCMAX
-
+S
+ - -S
+240VDCMAX
-
a.
DVM or
Current
monitor
RMSvoltmeter
-
+
Electronic
-
+
DVM,Scope,or
-
+
RMSvoltmeter
Load
(forCVtests)
(for CC tests)
Note: Use dc supply with same polarity
connections for -CC tests.
Replace load wit
h appropriate
resistor for CC noise test.
(see note)
1 k ohm
400 ohm

Verification and Performance Tests -2
13
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 testprocedures. Also, if
computer controlled test setups are used, the relatively slow (compared to computers and system voltmeters) settling
times and slew rates of the power supply may have to be taken into account. "Wait" statements can be used in the
testprogram if the test system is faster than the supply.
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 following test
procedures:
a. Perform the turn-on and checkout procedures given in the Operating Manual.
b. Perform the Voltage Programming and Readback Accuracy test, and the Current Programming and Readback
Accuracy tests from this procedure.
Performance Tests
NOTE: A full Performance Test consists of only those items listed as “Specifications” in Table A-1 of the
Operating Manual, 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 Operating Manual. All of the performance test specificationsare 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.
Programming
You can program the supply from the front panel keyboard or from a GPIB controller when performing the tests. The
test procedures are written assuming that you know how to program the supply either; remotely from a 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 inthe Programming Guide. Programming ratings are
as follows:

2 - Verification and Performance Tests
14
Table 2-2. Programming Ratings
Model Voltage Rating Full Scale Rating Current Rating Full Scale Rating
Agilent
66332A/6632B
Agilent 6633B
Agilent 6634B
20 V
50 V
100 V
20.020 V
50.045 V
100.1 V
5 A
2 A
1 A
5.0045 A
2.002 A
1.001 A
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 the 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 the -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 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 chart for the appropriate model under CV
PROGRAMMING @ 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.
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 chart for the appropriate model under CV PROGRAMMING @
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 and the voltage to the full-
scale value.
c. Adjust the load for the full-scale current 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.

Verification and Performance Tests - 2
15
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 chart
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.
c. Turn on the supply and program the current to the maximum programmable value and the output voltage to the
full-scale value .
d. Adjust the load for the full-scale current value 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.
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 chart 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 coupled) between the
(+) and the (-) terminals. Set the oscilloscope's bandwidth limit to 20 MHz and use an RF tip on the oscilloscope
probe.
b. Turn on the supply and program the current to the maximum programmable value and the output voltage to the
full-scale value.
c. Adjust the load for the full-scale current value 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 chart 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 chart for the appropriate model under CV NOISE
(PARD).

2 -Verification and Performance Tests
16
Transient Recovery Time
This test measures the time for the output voltage to recover to within the specified value following a 50% change in
the load current.
tttt
t
v
Loading
Transient
Unloading
Transient
v
t
Figure 2-2. Transient Waveform
a. Turn off the supply and connect the output as in Figure 2-1a with the oscilloscope across the +S and the -S
terminals.
b. Turn on the supply and program the output voltage to the full-scale value and the current to the maximum
programmable value.
c. Set the load to the Constant Current mode and program the load current to 1/2 the power supply full-scale rated
current.
d. Set the electronic load's transient generator frequency to 100 Hz and its duty cycle to 50%.
e. Program the load's transient current level to the supply's full-scale current value and turn the transient generator
on.
f. Adjust the oscilloscope 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 the specified time (t). Check
both loading and unloading transients by triggering on the positive and negative slope.
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 supply and connect the current monitoring resistor across the power supply output and the DVM
across the resistor as shown in Figure 2-1a. See "Current Monitoring Resistor" for connection information.
b. Turn on the supply and program the output voltage to 5 V and the current to zero.
c. Divide the voltage drop (DVM reading) across the current monitoring resistor by its resistance to convert to
amps and record this value (Iout). The reading should be within the limits specified in the performance test
record card for the appropriate model under CC PROGRAMMING @ 0 AMPS.
d. Set the current readback range to High and program the output current to 20mA. For model 66332A, set the
current detect mode to“DC”. Repeat step C to get the Iout. Record the current reading on the front panel
display. The reading should be within the limits specified in the performance test recordcard for the appropriate
model under Current Readback Accuracy @ 20mA (High Range).

Verification and Performance Tests -2
17
e. Program the output current to full-scale .
f. 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
CC PROGRAMMING @ FULL-SCALE.
Current Sink (-CC) Operation
This test verifies current sink operation and readback.
a. Turn off the supply 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 external power supply to 5 V and the current limit approximately 20% above the full scale current rating
of the supply under test.
c. Turn on the supply under testand program the output voltage to zero and full scale output current. The current
on the UUT display should be approximately full scale current negative.
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 chart 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 program the output voltage to zero and full scale output current. 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 chart under 20mA RANGE
CURRENT READBACK ACCURACY @ 0A.
d. Program the output voltage to 20V and record the current reading on the DMM and the reading on the front
panel display. The difference between the readings should be within the limits specified in the performance test
record chart 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 20 V and 1 amp. Then program the supply under test to zero volts
and 1 amp. The UUT display should read approximately−20 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 chart 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 power supply'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 .

2 - Verification and Performance Tests
18
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).
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 program the current to the full scale current value and the output voltage to the
maximum programmable voltage value.
c. 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.
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 chart 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.
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.

Verification and Performance Tests - 2
19
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 across the monitoring resistor
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 50 W current shunt in series with the appropriate 3, 24, or 99 ohm
resistor, 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.
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.
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 monitor resistor 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:_________________________ Report Number ________________________
____________________________________ 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 _________________ _________________ _________________
_________________ _________________ _________________

2 -Verification and Performance Tests
20
Performance Test Record Forms
Model Agilent 66332A OR Agilent6632B
Report No _______________ Date __________________
Test Description Minimum
Specs. Results* Maximum Specs.
Constant Voltage Tests
Voltage Programming and Readback
Low Voltage (0V) Vout
Front Panel Display Readback
High Voltage (Full Scale) Vout
Front Panel Display Readback
−10 mV
Vout −3 mV
19.980 V
Vout −9 mV
__________
__________
__________
__________
+ 10 mV
Vout + 3 mV
20.020 V
Vout + 9 mV
Load Effect −2 mV __________ + 2 mV
Source Effect −0.5 mV __________ + 0.5 mV
PARD (Ripple and Noise)
Peak-to-Peak
RMS
N/A
N/A
__________
__________
+ 3 mV
+ 0.3 mV
Transient Response
Voltage in 100 µs Vout −20 mV __________ Vout + 20 mV
Constant Current Tests
Current Programming and Readback(High Range)
CC Programming Accuracy @ 0A
Current Readback Accuracy @ 20mA (High Range)
CC Programming @ Full Scale
Current Readback Accuracy @ Full Scale
−3.32mA
Iout −0.54 mA
4.9955 A
Iout −10.5 mA
__________
__________
__________
__________
+ 3.32 mA
Iout + 0.54 mA
5.0045 A
Iout + 10.5 mA
Current Sink Readback Isink −11.1mA __________ Isink + 11.1mA
20 mA Range Current Readback
Readback Accuracy @ 0 A
Readback Accuracy @ + 20 mA
Readback Accuracy @ −20 mA
−2.5 µA
Iout −22.5 µA
Iout −22.5 µA
__________
__________
__________
+ 2.5 µA
Iout + 22.5 µA
Iout + 22.5 µA
PARD (Current Ripple and Noise)
RMS N/A __________ + 2.0 mA
Load Effect −1.0 mA __________ + 1.0 mA
Source Effect −0.5 mA __________ +0.5 mA
* Enter your test results in this column