Agilent Technologies B1500A Training Manual page 55

Module 5
Basic Measurement
Guard Connection for Kelvin connection
Simplified Diagram
Buffer
x1
Guard
Sense
Rs
10K
Force
DUT
SMU
V
With the Kelvin connection, sensing is done at the DUT, eliminating the fraction of an ohm of cable
resistance. The internal sensing resistor Rs is the only feedback path without the Kelvin connection.
Note that the B1500A operates just fine without the sense cable. This is important to know because
in general you do not need the sensing Kelvin connection. Most MOS measurements are high
impedance and the residual cable loss is insignificant.
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