Section 2: Connections and configuration
Model 4200A-SCS Parameter Analyzer Reference Manual
2-8
4200A-901-01 Rev. C / February 2017
Figure 12: Basic preamplifier local sense connections
Using the ground unit
The ground unit (GNDU) provides convenient access to circuit COMMON through the GNDU FORCE
terminal or the GNDU COMMON binding post terminal. The GNDU also has a SENSE terminal. The
SENSE LO signal of each instrument installed in the 4200A-SCS is connected to the GNDU SENSE
terminal. As a result, all SMU measurements are made relative to GNDU SENSE, which by default is
connected to COMMON.
Although the ground unit is intended for circuit COMMON connections when using multiple SMUs, it
can also be used for circuit COMMON connections when using only one SMU.
Ground unit and SMU local sense connections
The next figure shows a typical local sense connection scheme using two SMUs, two DUTs, and the
ground unit. Make connections as follows:
•
Connect the two SMU FORCE terminals to the two DUT HI terminals.
•
Connect both DUT LO terminals together, and connect GNDU FORCE to the common DUT LO
connection point.
Figure 13: Ground unit and SMU local sense connections schematic
