5: Typical applications  Model 3762 10-Channel High Voltage Multiplexer Card 
 
5-2  3762-900-01 Rev. A / July 2017 
 
Guarded application 
Non-driven guarded measurements are made with the set up shown in the next figure. The jumper is 
installed to provide a guard that completely encloses HI and LO. This guards HI and LO from other 
channels on the card for improved channel isolation. 
Figure 9: Guarded floating measurement 
 
 
Driven guard application 
If multiple sources are switched to a DUT using a driven guard, as shown in the next figure, the guard 
must be switched. The jumper for each channel in use is removed so that the various sources will not 
try to drive the guards. Instrument LO is not switched or is switched by another card in the next two 
figure. 
Figure 10: 3762 Single pole switch with switched guard 
 
 
Note that the previous figure labeled B is the same configuration for connecting one source to 
multiple DUTs. In this case, the jumper is removed to reduce the capacitive loading on the guard. 
LO and GUARD are shorted at both ends of the signal path to allow for the switched guard. LO for the 
sources and the DUT must have an external connection.