Section 2: General operation
Model 2657A High Power System SourceMeter® Instrument Reference Manual
2-64
2657A-901-01 Rev. B/December 2012
The Model 2657A connections for the floating configuration are shown below.
Figure 22: Floating the Model 2657A SMU connections
The maximum floating (common mode) voltage for a SMU is 250 V. Exceeding this level may cause
damage to the instrument and create a shock hazard.
Using an external source to float a SMU could create a shock hazard in the test circuit. A shock
hazard exists whenever >42 V peak is present in the test circuit. Appropriately rated cables or
insulators must be provided for all connections to prevent access to live parts.
When >42 V is present, the test circuit must be insulated for the voltage used or surrounded by a
metal safety shield that is connected to a known protective earth (safety ground) and chassis ground
(see
Safety shield
(on page 2-55)).
DUT connection settings
Make sure to properly configure the Model 2657A sense mode for the specific DUT test connection
scheme. Use care to configure both the output-off state and overvoltage protection settings to
supplement safe operation of your test setup.
Sense mode selection
The sense mode can be set to use
2-wire local sensing connections
(on page 2-45) or
The default sense setting is 2-wire local.
DUT
LO
LO
HI
10 V
External Source
HI
Model 2657A LO not
connected to chassis
ground (floating)
Model 2657A
!
SENSE
LO
HI
LO
GUARD
SENSE
HI
LO
3030 VDC
MAX.
250 V
MAX.
Safety shield
Connected to
protective earth
(safety ground)
+ –
WARNING
NOTE
Summary of Contents for 2657A
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