Keithley 2657A, Reference Manual, Page: 75 / 805

Model 2657A High Power System SourceMeter® Instrument Reference Manual Section 2: General operation
2657A-901-01 Rev. B/December 2012 2-51
Item Description Qty Notes
(1) Protective earth (safety ground) for Model
2657A 1 Keithley Instruments Model CA-568-120 is a protective
earth (safety ground) cable assembly supplied with the
instrument.
(2) Interlock connection for Model 2657A 1 Pin 24 (INT) and Pin 22 (5 VDC) connected to test
fixture lid switch. Keithley Instruments Model 7709-308
is a 25-pin interlock male connector and can be used for
custom connections.
(3) Interlocked metal safety enclosure 1 Select a safety enclosure with an interlock that has a
normally-open (NO) switch.
(4) Protective earth (safety ground) for test
fixture 1 Redundant grounds may be required for specific test
setups (for example, setups that clamp LO).
(5) Panel mount SHV connector 4 Must be acquired by customer.
(6) Model SHV-CA-553 SHV to high-voltage
triaxial cable assembly (male to male) 4
(7) Model 2657A High Power System
SourceMeter
®
instrument
1
Contact check connections
The contact check function prevents measurement errors due to excessive resistance in the source
or sense leads. See
Contact check measurements (on page 2-37) for operation.
Contact check requires both source and sense connections. Refer to 4-wire remote sensing
connections (on page 2-47) for connection scheme.
Multiple SMU connections
The Model 2657A High Power System SourceMeter instrument and its associated cabling are
designed to be safe when operated correctly in a 3000 V system. They are only warranted to the
maximum voltage and current ratings of the instrument. Connecting two Model 2657A instruments
in parallel or in series may result in voltages or power levels that exceed the safety mechanisms.
This increases the risk of instrument damage and the possibility of personal injury or death due to
electric shock. The user assumes all of the associated risks of combining the outputs of two or more
Model 2657A instruments.
Connections to LO on the Model 2657A are not necessarily at 0 V. Hazardous voltages could exist
between LO and chassis ground. Make sure that high-voltage precautions are taken throughout the
test system. Alternatively, limit hazardous levels by adding external protection to limit the voltage
between LO and chassis. Failure to make sure high-voltage precautions are used throughout the test
system or a failure to limit hazardous levels could result in severe personal injury or death from
electric shock.
WARNING
WARNING