Keithley 7076 User manual

Model 7076 General Purpose Matrix Card
Dual 4 x 12
Instruction Manual
Contains Operating and Servicing Information
Publication Date: April 1991
Document Number: 7076-901-01 Rev. B

WARRANTY
Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for aperiod of 1year 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 prows to be defective
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 origi-
nal warranty period, or at least 90 days.
LIMITATION OF WARRANTY
This warranty does not apply to defects resulting from product modification without Keithley’s express written consent, or misuse of
any product ot’ 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, INDI-
RECT, 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 TO ANY PERSON, OR DAMAGE TO PROPERTY.
Keithley Instruments, Inc. * 28775 Aurora Road* Cleveland, OH 44139 - 216-248-0400 -Fax: [phone] - http://www.keithley.com

General Purpose Matrix Card Dual 4 x 12
Model 7076
Instruction Manual
01990, Keithley Instruments, Inc.
All rights reserved.
Cleveland, Ohio, U. S. A.
Document Number: 7076-901-01

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

SAFETY PRECAUTIONS
The following safety precautions should be observed before using the Model 7076 and the associated instruments.
This matrix card is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety
precautions required to avoid possible injury. Read over this manual carefully before using the matrix card.
ALWAYS remove power from the entire system (Model 707, test instruments, DUT, etc.) and discharge any capacitors
before doing any of the following:
1. Installing or removing the matrix card from the mainframe.
2. Connecting or disconnecting cables from the matrix card. The pins of cable connectors are easily accessible making
them extremely hazardous to handle while power is applied.
3. Making internal changes to the card (such as removing or installing jumpers).
Exercise extreme caution when a shock hazard is present at the test f?xture. User-supplied lethal voltages may be present
on the tlxture or the connector jacks. The American National Standards Institute (ANSI) states that ashock hazard exists
when voltage levels greater than 30V RMS or42.4V peak are present. A good safety practice is to expect that hazardous
voltage is present in any unknown circuit before measuring.
Do not connect the card or any other instrumentation to humans.
Inspect the connecting cables and test leads for possible wear, cracks, or breaks before each use.
For maximum safety, do not touch the test fixture, test cables or any instruments while power is applied to the circuit
under test.
Do not touch any object which could provide a current path to the common side of the circuit under test or power line
(earth) ground.
Do not exceed the maximum signal levels of the test fixture, asdefined in the specifications and operation section of this
manual.
Do not connect the matrix card directly to unlimited power circuits. This product is intended to be used with impedance
limited sources. NEVER connect the matrix card directly to ac mains.
When connecting sources, install protective devices to limit fault current and voltage to the card.
The chassis connections must only be used as shield connections for measuring circuits, NOT as safety earth ground
connections.

Model 7076 Dual 4x12 Two-Pole Matrix Card
MATRIXCON”GURATION:Dual4rowsby12columns.Alsocanfigurableas8rowsby
12 mhmns. Jumpers can be removed to isolate any row from the backplane.
CROSSPOINT CONFIGURATION: 2 pole Form A (HI, GUARD).
CONNECTOR TYPE: 25.pin subminiature D connector, two for column connection, one
far row connection.
MAXIMUM SIGNAL LEVEL:
DC Signals: IIOV DC, IA switched, 30VA ksistive load).
AC Signals: 175” AC peak, IA switched, 62SVA (resistive load).
COMMON MODE VOLTAGE: IIOV DC, 175V AC peak pin to pi” or pi” to chassi%
CONTACT LIFE:
Cold Switching: 10s closures.
At M.Mm”rn Signal Level: 105closures.
PATH RESISTANCE (per conductorb <0.5On initial, <1.5R at end of contact life
CONTACTPOTENTIAL: <5pV per crosspaint (HI lo GUARD).
OFFSET CURRENT: <lOOpA.
ISOLATION:
PatlIz >lOw2, <7PF.
Differential: >lOQ l2opF nominal.
Common Mode: >lOQ 2OOpFnominal.
CROSSTALK (IMHr, Mfi 1o;db <-5OdB.
INSERTION LOSS (IMHz, 5On source, 5OR load): 0.05dB typical.
3dB BANDWIDTH (500 load): 15MHz typical.
RELAY DRIVE CURRENT (per crosspoint): 28mA.
RELAY SE’ITLING TIME: <3ms.
ENVIRONMENT:
Operating: 0’ to 5O”C, up to 35°C at 70% R.H.
storage: -250 to WC.
ACCESSORY SUPPLIED: instruction manual, jumpers for 8 x 12 expansion.
5pcifications subject to change without notice.
Column
Jumpers
- (user

Table of Contents
SECTION 1 - General Information
1.1 INTRODUCTION
1.2 FEATURES .
1.3 WARRANTY INFORMATION
1.4 MANUAL ADDENDA
1.5 SAFETY SYMBOLS AND TERMS
1.6 SPECIFICATIONS . .
1.7 UNPACKING AND INSPECTION
1.7.1 Inspection for Damage . . .
1.7.2 Shipping Contents
1.7.3 Instruction Manual
1.8 REPACKING FOR SHIPMENT
1.9 OPTIONAL ACCESSORIES
SECTION 2 - Operation
2.1 INTRODUCTION .......................................
2.2 HANDLING PRECAUTIONS ..............................
2.3 CARD INSTALLATION AND REMOVAL ....................
2.4 BASIC MATRIX CONFIGURATIONS ........................
2.4.1 4x24Matrix .........................................
2.4.2 8xl2Matrix .........................................
2.5 TYPICAL MATRIX SWITCHING SCHEMES ..................
2.5.1 Single-ended Switching. ................................
2.5.2 Differential Switching ..................................
2.5.3 Guarding ...........................................
2.5.4 Sensing .............................................
2.6 CONNECTIONS .......................................
2.6.1 Standard Cable (Model 7075-MTC) ........................
2.6.2 High Isolation Cables (Model 7076-RMTC and Model 707&CMTC)
2.7 MATRIXEXPANSION. ..................................
2.7.1 Backplane Row Jumpers ................................
2.7.2 Narrow Matrix Expansion ...............................
2.7.3 Wide Matrix Expansion .................................
2.7.4 Partial Matrix Implementation ...........................
2.7.5 Mainframe Matrix Expansion ............................
2.8 T(PICAL CONNECTION SCHEMES ........................
2.8.1 Single Card System ....................................
2.8.2 Multiple Card System ..................................
2.8.3 Multiple Mainframe System .............................
2.8.4 Matrix/Multiplexer System ..............................
2.9 BANDWIDTH and CROSSTALK ...........................
1-l
l-1
1-l
1-l
1-l
1-l
1-l
1-l
l-2
l-2
l-2
l-2
2-l
2-l
2-l
2-2
2-6
2-7
2-8
2-8
2-8
2-9
2-9
2-10
2-11
2-13
2-15
2-15
2-17
2-18
2-19
2-19
2-20
2-20
2-21
2-21
2-22
2-25
SECTION 3 - Applications
3.1 INTRODUCTION .............................................................. 3-1
3.2 THICK FILM RESISTOR NETWORK TESTING ....................................... 3-l
3.2.1 Four-terminal Ohms Measurements .............................................. 3-3

3.2.2 VoltageDividerChecks ....................................................
3.3 TRANSISTOR TESTING ....................................................
3.3.1 Current Gain Checks ......................................................
3.3.2 Is and Vm Measurements ..................................................
SECTION 4 - Service Information
4.1
4.2
4.3
4.4
4.4.1
4.4.2
4.4.3
4.4.4
4.4.5
4.4.6
4.4.7
4.4.8
4.5
4.5.1
4.5.2
4.5.3
4.6
4.7
4.7.1
4.7.2
INTRODUCTION ................................
HANDLING AND CLEANING PRECAUTIONS ........
RELAY TEST PROGRAM SET-UP ...................
PERFORMANCE VERIFICATION ...................
Environmental Conditions .......................
Recommended Equipment .......................
Matrix Card Connections ........................
Path Resistance Tests ...........................
Offset Current Tests ............................
Contact Potential Tests ..........................
Path Isolation Tests .............................
Differential and Common Mode Isolation Tests ........
IWNCIPLES OF OPERATION ......................
Card Identification .............................
Switching Circuitry .............................
Power Up Safeguard ............................
SPECIAL HANDLING OF STATIC-SENSITIVE DEVICES
TROUBLESHOOTING ............................
Recommended Equipment .......................
Troubleshooting Procedure .......................
.............
4-l
.............
4-l
.............
4-l
.............
4-2
.............
4-2
............. 4-3
............. 4-3
.............
4-3
............. 4-4
............. 4-6
............. 4-7
............. 4-9
.............
4-12
.............
. 4-12
.............
4-12
.............
4-12
.............
4-13
.............
4-13
............. . 4-13
.............
4-13
SECTION 5 - Replaceable Parts
5.1 INTRODUCTION ..........................................................
5.2 PARTSLIST ..............................................................
5.3 ORDERING INFORMATION .................................................
5.4 FACTORYSERVICE ........................................................
5.5 COMPONENT LAYOUT AND SCHEMATIC DIAGRAM ............................
3-4
. 3-6
3-6
3-8
5-l
5-l
5-l
5-l
5-l

List of Illustrations
SECTION 2 - Operation
Figure 2-l
Figure 2-2
Figure 2-3
Figure 24
Figure 2-5
Figure 2-6
Figure 2-7
Figure 2-8
Figure 2-9
Figure 2-10
Figure 2-11
Figure 2-12
Figure 2-13
Figure 2-14
Figure 2-15
Figure 2-16
Figure 2-17
Figure 2-18
Figure 2-19
Figure 2-20
Figure 2-21
Figure 2-22
Figure 2-23
Figure 2-24
Figure 2-25
Figure 2-26
Matrix Card Installation ..........................................
Model7076 ....................................................
Simplified Component Layout .....................................
Model 7076 Configured as4 x 24 Matrix ..............................
Model7076Configuredas8x12Matrix ..............................
Column Jumper Installation .......................................
Single-ended Switching Example (Using 7075-MTC Cable) ................
Differential Switching Example (Using High Isolation Cables) ..............
Driven Guard Example (Using High Isolation Cables) ....................
Sensing Example (Using High Isolation Cables) .........................
D-sub Receptacle Contact Assignments ...............................
Model 7075-MTC Standard Cable ...................................
D-sub Plug Pin Assignments for High Isolation Cables ...................
Schematic Drawing of Backplane Jumper Configuration (Factory Default) .....
Narrow Matrix Example (4 x 72) ....................................
Dual4x72Matrices ............................ .................
WideMatrixExample(8x36) ........................... . ..........
Partial Matrix Expansion (8 x 36) ....................................
Single Card System Example .......................................
Multiple Card System Example .....................................
Multiple Mainframe Example ......................................
Matrix/Multiplexer System .......................................
-3dB Bandwidth (Crosspoint Al closed, Rs = RL = 5OQ) ...................
-3db Bandwidth (Crosspoint HI2 closed, RS= RRL= 500) .................
Crosstalk (Crosspoints Gl and H2 closed, 5OQ source on ROW G, 500 load on
COLUMN l’, Measurements at ROW H) ..............................
Crosstalk (Cross
COLUMN 11, Mp oints All and 812 closed, 5On source on ROW A, 5OQ load on
easurements at ROW B) ..............................
SECTION 3 - Applications
Figure 3-l
Figure 3-2
Figure 3-3
Figure 34
Figure 35
Figure 3-6
Figure 3-7
Figure 3-8
Thick Film Resistor Network Testing
4-Terminal Ohms Measurements
Voltage Divider Checks . .
Transistor Testing . . .
Transistor Current Gain Checks .
Common Emitter Characteristics of an NPN Silicon Transistor
Transistor IE Measurements .
Transistor VsEMeasurements
.
2-26
......... 3-2
......... 3-3
......... 3-5
......... 3-6
......... 3-7
......... 3-8
......... 3-9
......... 3-10
2-3
24
2-5
2-6
2-7
2-8
2-8
2-8
2-9
2-9
2-10
2-12
2-14
2-16
2-17
2-18
2-18
2-20
2-21
2-22
2-23
2-24
2-25
2-25
2-26

SECTION 4 - Service Information
Figure 4-l
Figure 4-2
Figure 4-3
Figure 4-4
Figure 4-5
Figure 4-6
Figure 4-7
Figure 4-8
Figure 4-9
Figure 4-10
Relay Test Setup . . . . . . . . . ................. 4-2
Path Resistance Testing . . . . . . . . . ................. 44
Common Mode Offset Current Testing ................. 4-5
Differential Mode Offset Current Testing ................. 4-6
Contact Potential Testing . ................. 4-7
Path Isolation Testing (Guarded) ................. 4-8
Differential Isolation Testing . . . ................. 4-11
Common Mode Isolation Testing . ................. 4-11
ID Data Timing Diagram . . ................. 4-12
D-sub Receptacle Contact Assignments . ................. 4-14