3762 10-Channel High Voltage Multiplexer Card User's Manual Section 5:
3762-900-01 Rev. A / July 2017 5-3
Four-wire application
Connecting multiple DUTs to one instrument using either a Kelvin technique or external sense as with
a Source Measure Unit (SMU), requires two cards operating in four-pole mode. This is shown in the
next figure.
The Guard and Shield are connected to the card end only and not to the device under test. Also, on
the source-measure instrument, the Guard connection is not always made. It may not be required at
high current levels, such as when circuit leakage is lower than high current accuracy requirements.
Figure 11: 3762 Source with external sense or Kelvin Measurement
HI and Sense HI (S+) are switched through one card. The jumper is installed to provide a guard all
the way to the DUT. Since this is a driven guard, it is connected only to the guard of the instrument
and not terminated at the DUT.
LO and Sense LO (S-) are switched through the second card. The jumper is installed to provide
shielding for these lines. The shield on the cabling is installed to provide shielding for these lines. The
shield on the cabling should cover as much of the signal lines as possible, and should be terminated
only at the instrument. Shields are typically at circuit low or earth ground.
This configuration combines sense and Kelvin configurations so that guard on the card is driven for
the High leads and provides a shield for the Low leads.