Section 4: Source-measure considerations
Model 2461 Interactive SourceMeter® Instrument Reference Manual
4-14
2461-901-01 A/November 2015
The connections for the floating configuration are shown below. To float the SMU, FORCE and
SENSE LO must be isolated from chassis ground. To do this, do not connect FORCE and SENSE LO
to chassis ground.
Figure 154: Connections for floating the Model 2461
The external voltage source can be a source-measure unit (SMU) of a second Model 2461 instrument
or other instrument. Keep in mind that if the combined outputs of the sources exceed ±42 V, a safety
shield is required for the device under test (DUT). Refer to the following warnings.
The maximum floating (common mode) voltage for a source-measure unit (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; refer to
Safety shield
(on page 4-11).