Section 5: Source-measure concepts
Model 4200A-SCS Source-Measure Unit (SMU) User's Manual
5-18
4200A-SMU-900-01 Rev. A December 2020
Figure 90: SMU voltage source limit lines
V-Source operation examples
The following figures show operation examples for resistive loads that are 20 kΩ and 8 kΩ,
respectively. For these examples, the SMU is programmed to source 50 V and limit 5 mA. The SMU
is sourcing 50 V to the 20
kΩ load and subsequently measures 2.5 mA, which is within the 5 mA
programmed current limit.
As shown in the following figure, the load line for 20
kΩ intersects the 50 V voltage source line at
2.5 mA.
Figure 91: Normal voltage source operation
The following figure shows what happens if the resistance of the load is decreased to 8 kΩ. The DUT
load line for 8 kΩ intersects the current compliance limit line, which places the SMU in compliance. In
compliance,
the SMU cannot source its programmed voltage (50 V). For the 8 kΩ DUT, the SMU will
only output 40 V (at the 5 mA limit).
