Guildline 7620 User manual

Technical Manual
For The
Model 7620 Wideband
Transconductance Amplifier
www.guildline.com
NOTICE
The contents and information contained in this manual are proprietary to
Guildline Instruments Limited. They are to be used only as a guide to the
operation and maintenance of the equipment with which this manual was
issued and may not be duplicated or transmitted by any means, either in whole
or in part, without the written permission of Guildline Instruments Limited.
TM7620-G-00
February 04, 2014

Dwg: 30162-08-64, Rev A
Issue Date: 12/09/06
HAZARDS WARNING!
CURRENT AND VOLTAGE SOURCE INSTRUMENTS
READ THESE SAFETY PRECAUTIONS BEFORE
SETTING UP OR USING THIS INSTRUMENT!
IMPROPER SETUP OR OPERATION OF THIS
INSTRUMENT CAN RESULT IN PERSONAL INJURY,
BURNS OR ELECTRICAL SHOCK!
Precautions, Safety and Preparation for Use
1. Thoroughly read the set up and operating procedures in
this manual before installing or using this instrument.
2. Select the proper line voltage on the back panel and use only the
proper fuse type and rating specified for this product.
3. The line power connection must have an earth ground conductor
and must be connected to the instrument only with the line cord
supplied or a proper line cord specified for the country of use.
Operating this instrument without a proper grounded
line connection can result in electrical shock hazard.
4. Observe all connector and terminal markings and ratings to avoid
any possible shock, or other hazard to the user of this instrument.
5. Under no circumstances should unqualified personnel operate or
service this instrument.
6. Do not connect the line power or operate this instrument with the
covers removed.
7. Do not touch exposed terminal connections or make or break
terminal connections with the instrument operating.
8. Operate this instrument only in a well ventilated and dry
environment.
9. Do not touch or make any type of connection to the
CURRENT OR VOLTAGE OUTPUT connections while
the instrument is in operation, to avoid POSSIBLE
ELECTRICAL SHOCK HAZARD.

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TABLE OF CONTENTS
INTRODUCTION................................................................................................................................................................. 1-1
1.1 SCOPE .................................................................................................................................................... 1-1
1.2 GENERAL DESCRIPTION............................................................................................................ 1-1
1.3 GENERAL THEORY OF OPERATION ................................................................................... 1-1
1.3.1 GENERAL DESIGN APPROACH ............................................................................ 1-3
1.3.2 7620 FEATURES............................................................................................................... 1-6
1.3.2.1 COMPLIANCE VOLTAGE DISPLAY .................................................. 1-6
1.3.2.2 FREQUENCY MONITOR......................................................................... 1-6
1.3.2.3 4-WIRE INPUT BUFFER AMPLIFIER ................................................. 1-7
1.3.2.4 OUTPUT CURRENT-CELL ARRAY ..................................................... 1-7
1.3.2.5 IEEE-488 INTERFACE (CPU).................................................................. 1-7
1.3.2.6 OVERLOAD PROTECTION ................................................................... 1-7
SPECIFICATIONS ................................................................................................................................................................ 2-1
OPERATING INSTRUCTIONS....................................................................................................................................... 3-1
3.1 INSTALLATION................................................................................................................................. 3-1
3.1.1 RACKMOUNT FEATURE ........................................................................................... 3-1
3.1.2 RECOMMENDED PRACTICE .................................................................................. 3-1
3.2 FRONT PANEL INDICATORS..................................................................................................... 3-2
3.2.1 DISPLAY WINDOW....................................................................................................... 3-4
3.2.2 20 A 100 kHz INDICATOR........................................................................................... 3-4
3.2.3 10 A 750 kHz INDICATOR........................................................................................... 3-4
3.2.4 8 A 1 MHz INDICATOR................................................................................................ 3-4
3.3 FRONT PANEL CONTROLS ........................................................................................................ 3-4
3.3.1 POWER SWITCH............................................................................................................. 3-4
3.3.2 OVERLOAD SWITCH................................................................................................... 3-4
3.3.3 1 V MOMENTARY SWITCH....................................................................................... 3-5
3.3.4 10 V MOMENTARY SWITCH..................................................................................... 3-5
3.3.5 200 µA MOMENTARY SWITCH................................................................................ 3-5
3.3.6 2 mA MOMENTARY SWITCH ................................................................................... 3-5
3.3.7 20 mA MOMENTARY SWITCH................................................................................. 3-5
3.3.8 200 mA MOMENTARY SWITCH............................................................................... 3-6
3.3.9 2 A MOMENTARY SWITCH....................................................................................... 3-6
3.3.10 20 A MOMENTARY SWITCH..................................................................................... 3-6
3.3.11 REMOTE MOMENTARY SWITCH.......................................................................... 3-6
3.4 REAR PANEL CONTROLS............................................................................................................ 3-6
3.4.1 LINE VOLTAGE SELECTION SWITCH............................................................... 3-7
3.4.2 GPIB ADDRESS SELECTION SWITCH............................................................... 3-10
3.5 FRONT PANEL INPUT CONNECTORS................................................................................ 3-10
3.5.1 HI INPUT TERMINAL................................................................................................ 3-11
3.5.2 LO INPUT TERMINAL............................................................................................... 3-11

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3.5.3 I+ INPUT TERMINAL ................................................................................................ 3-11
3.5.4 I- INPUT TERMINAL.................................................................................................. 3-11
3.5.5 INPUT GUARD TERMINAL .................................................................................... 3-11
3.5.6 GROUND TERMINAL................................................................................................ 3-12
3.6 FRONT PANEL OUTPUT CONNECTORS........................................................................... 3-12
3.6.1 OUTPUT GUARD TERMINAL................................................................................ 3-12
3.6.2 2 A OUTPUT CONNECTOR .................................................................................... 3-12
3.6.3 20 A OUTPUT CONNECTOR .................................................................................. 3-13
3.7 REAR PANEL CONNECTORS................................................................................................... 3-13
3.7.1 GPIB DATA CONNECTOR...................................................................................... 3-13
3.7.2 POWER INLET CONNECTOR ............................................................................... 3-13
REMOTE CONTROL.......................................................................................................................................................... 4-1
4.1 IEEE-488/1978 (GPIB) INTERFACE .......................................................................................... 4-1
4.2 CONTROLLER.................................................................................................................................... 4-1
4.3 GPIB RESPONSES............................................................................................................................. 4-2
4.4 INTERCONNECTING CABLE AND GPIB CONNECTOR ............................................. 4-2
4.5 TYPICAL SYSTEM............................................................................................................................. 4-2
4.6 GPIB INTERFACE............................................................................................................................. 4-2
4.6.1 GPIB INPUT BUFFERING.......................................................................................... 4-5
4.6.2 GPIB OUTPUT BUFFERING..................................................................................... 4-6
4.6.3 GPIB DEADLOCK ......................................................................................................... 4-6
4.6.4 GPIB DEVICE CLEAR.................................................................................................. 4-6
4.7 COMMAND LANGUAGE.............................................................................................................. 4-6
4.7.1 GENERAL SYNTAX FOR COMMANDS............................................................... 4-7
4.7.2 GENERAL SYNTAX FOR NUMBERS.................................................................... 4-7
4.8 REMOTE AND LOCAL OPERATION...................................................................................... 4-8
4.9 GPIB COMMANDS ........................................................................................................................... 4-9
4.9.1 *ESE - SET STATUS ENABLE REGISTER............................................................ 4-9
4.9.2 *ESE? - EVENT STATUS ENABLE QUERY....................................................... 4-11
4.9.3 *ESR? - EVENT STATUS REGISTER QUERY................................................... 4-11
4.9.4 *IDN? - IDENTIFICATION QUERY..................................................................... 4-11
4.9.5 *OPC - OPERATION COMPLETE......................................................................... 4-11
4.9.6 *OPC? - OPERATION COMPLETE QUERY...................................................... 4-11
4.9.7 *OPT? - REPORT AVAILABLE OPTIONS.......................................................... 4-11
4.9.8 *RST - DEVICE RESET............................................................................................... 4-12
4.9.9 *SRE - SERVICE REQUEST ENABLE COMMAND........................................ 4-15
4.9.10 *SRE? - SERVICE REQUEST ENABLE QUERY............................................... 4-15
4.9.11 *STB? - READ STATUS BYTE QUERY................................................................. 4-15
4.9.12 *TRG - GROUP EXECUTE TRIGGER................................................................. 4-15
4.9.13 *TST? - QUERY RESULTS OF SELFTEST........................................................... 4-16
4.9.14 Date - SET THE SYSTEM DATE ............................................................................. 4-16
4.9.15 Date? - DISPLAY THE 7620 INTERNAL DATE ................................................ 4-16
4.9.16 DER? - DEVICE ERROR REGISTER .................................................................... 4-17
4.9.17 DFR? - DEVICE FREQUENCY REGISTER........................................................ 4-17
4.9.18 Key? - REPORT LAST KEY PRESSED .................................................................. 4-19
4.9.19 Key <keyname> - ENTER A KEYSTROKE.......................................................... 4-20

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4.9.20 Range - SELECT OUTPUT CURRENT RANGE................................................. 4-20
4.9.21 Range? - DISPLAY THE CURRENTLY SELECTED RANGE....................... 4-21
4.9.22 RomChecksum? - DISPLAY THE ROM CHECKSUM....................................... 4-21
4.9.23 SInce? - DISPLAY THE TIME THE 7620 WAS LAST RESET........................ 4-22
4.9.24 Serial Number - SET THE 7620 SERIAL NUMBER ............................................ 4-22
4.9.25 TErse - TURN OFF VERBOSE MODE.................................................................. 4-22
4.9.26 TIme - SET THE SYSTEM TIME ............................................................................. 4-23
4.9.27 TIme? - DISPLAY THE SYSTEM TIME................................................................. 4-23
4.9.28 TimeZone - SET THE OPERATIONAL TIME ZONE ..................................... 4-23
4.9.29 UPtime? - DISPLAY HOW LONG THE 7620 HAS BEEN RUNNING
4-24
4.9.30 VErbose - SET VERBOSE MODE............................................................................ 4-24
4.9.31 Voltage - SELECT THE INPUT VOLTAGE RANGE ....................................... 4-25
4.9.32 Voltage? - DISPLAY THE CURRENT INPUT VOLTAGE RANGE............ 4-25
4.10 PROGRAMMING HINTS ............................................................................................................. 4-26
CALIBRATION...................................................................................................................................................................... 5-1
5.1 CALIBRATION EQUIPMENT...................................................................................................... 5-1
5.2 DC CALIBRATION............................................................................................................................ 5-1
5.2.1 EQUIPMENT SET-UP................................................................................................... 5-1
5.2.2 DC OFF-SET CURRENT CHECK............................................................................. 5-2
5.2.2.1 DC OFF-SET CURRENT ADJUSTMENT ........................................... 5-2
5.2.3 DC GAIN CHECK........................................................................................................... 5-3
5.2.3.1 DC GAIN ADJUSTMENT ......................................................................... 5-3
5.2.4 TRANSCONDUCTANCE............................................................................................. 5-4
5.3 FREQUENCY RESPONSE ............................................................................................................. 5-5
5.3.1 EQUIPMENT SET-UP................................................................................................... 5-5
5.3.2 PROCEDURE.................................................................................................................... 5-5
PRINCIPLES OF OPERATION....................................................................................................................................... 6-1
6.1 INTRODUCTION.............................................................................................................................. 6-1
6.2 DUAL LINEAR POWER SUPPLY................................................................................................ 6-1
6.3 DUAL HIGH-CURRENT SWITCHING POWER SUPPLY................................................. 6-2
6.4 CPU ASSEMBLY ................................................................................................................................. 6-2
6.4.1 CENTRAL PROCESSING UNIT ............................................................................... 6-3
6.4.1.1 CLOCK GENERATION ............................................................................ 6-3
6.4.1.2 CONTROL SIGNAL GENERATION................................................... 6-3
6.4.1.3 ADDRESS AND DATA BUFFERS......................................................... 6-3
6.4.1.4 MEMORY AND IO ADDRESS DECODING .................................... 6-3
6.4.1.5 INTERRUPT CONTROLLER.................................................................. 6-4
6.4.1.6 POWER SUPPLIES....................................................................................... 6-4
6.4.2 MEMORY ........................................................................................................................... 6-4
6.4.3 GPIB INTERFACE.......................................................................................................... 6-4
6.4.4 OPTICAL INTERFACE ................................................................................................ 6-5
6.5 FRONT PANEL................................................................................................................................... 6-8
6.5.1 INPUT BUFFER AND DIFFERENTIAL DRIVER............................................. 6-8
6.5.2 INPUT FREQUENCY RANGE DETECTOR ....................................................... 6-9

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6.5.3 OVERLOAD DETECT CIRCUIT.............................................................................. 6-9
6.5.4 POSITIVE 200 µA TO 2 A CURRENT-CELL......................................................... 6-9
6.5.5 NEGATIVE 200 µA TO 2 A CURRENT-CELL ..................................................... 6-9
6.5.6 COMPLIANCE VOLTAGE MEASUREMENT AND DISPLAY .................. 6-10
6.6 20 A CURRENT-CELL ARRAY ................................................................................................... 6-10
6.6.1 POSITIVE CURRENT-CELL..................................................................................... 6-10
6.6.2 NEGATIVE CURRENT-CELL ................................................................................. 6-10
6.7 SOFTWARE ....................................................................................................................................... 6-11
TROUBLESHOOTING AND MAINTENANCE....................................................................................................... 7-1
7.1 TROUBLESHOOTING.................................................................................................................... 7-1
7.2 PREVENTATIVE MAINTENANCE........................................................................................... 7-2
PARTS LISTS........................................................................................................................................................................... 8-1
DRAWINGS............................................................................................................................................................................. 9-1

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LIST OF FIGURES
Figure 1.1 Model 7620 Block Diagram ............................................................................................................. 1-2
Figure 1.2 Multiple Cell Approach..................................................................................................................... 1-3
Figure 1.3 Differential Driver.............................................................................................................................. 1-4
Figure 1.4 Positive Output Current-Mirror Cell.............................................................................................. 1-5
Figure 2.1 General Outline .................................................................................................................................. 2-2
Figure 3.1 Front Panel Controls ......................................................................................................................... 3-3
Figure 3.2 Rear Panel ............................................................................................................................................ 3-8
Figure 3.3 GPIB Address Switch...................................................................................................................... 3-10
Figure 3.4 Typical Input Terminal Connections ........................................................................................... 3-10
Figure 4.1 Event Status Bit Operation ............................................................................................................ 4-10
Figure 5.1 A/C Calibration Test Set-up……………………………………………………..……..5-1
Figure 5.2 A/C Calibration Test Set-up............................................................................................................ 5-5

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LIST OF TABLES
Table 2.1 Basic Instrument Specifications....................................................................................................... 2-1
Table 3.1 Recommended Fuses......................................................................................................................... 3-9
Table 3.2 Line Cord Wiring................................................................................................................................ 3-9
Table 4.1 IEEE-488.1 Pin Designations ......................................................................................................... 4-4
Table 4.2 GPIB Device Capabilities................................................................................................................. 4-5
Table 4.3 Remote/Local State Transitions ..................................................................................................... 4-9
Table 4.4 Event Status Register....................................................................................................................... 4-13
Table 4.5 Status Byte Register.......................................................................................................................... 4-14
Table 4.6 Device Error Register...................................................................................................................... 4-17
Table 4.7 Device Frequency Register............................................................................................................. 4-18
Table 4.8 Front Panel Switch Character Designations ............................................................................... 4-19
Table 6.1 Switches and Status Bits.................................................................................................................... 6-6
Table 6.2 Control Bits.......................................................................................................................................... 6-7