Model 4200A-SCS Source-Measure Unit (SMU) User's Manual
Section 5: Source-measure concepts
4200A-SMU-900-01 Rev. A December 2020
5-17
Notice that as resistance increases, the slope of the DUT load line increases. As resistance
approaches infinity (open output), the SMU sources virtually 0 mA at 40 V. However, as resistance
decreases, the slope of the DUT load line decreases. At zero resistance (shorted output), the SMU
sources 10 mA at virtually 0 V.
Regardless of the load, voltage will never exceed the programmed compliance of 40 V.
V-Source operating boundaries
The following figures show the operating boundaries for the voltage source. Only the first quadrant of
operation is covered; operation in the other three quadrants is similar.
As shown in the following figure, the 4200-SMU or 4201-SMU can output up to 21 V at 105 mA, or
210 V at 10.5 mA. The 4210-SMU or 4211-SMU can output up to 21 V at 1.05 mA, or 210 V at
1.5 mA.
Figure 89: V-Source operating boundaries
The following figure shows the limit lines for the voltage source. The voltage source limit line
represents the maximum source value possible for the selected voltage source range. For example,
the voltage source limit line is at 21 V for the 20 V source range. The current compliance limit line
represents the actual compliance in effect. These limit lines are boundaries that represent the
operating limits of the SMU for this quadrant of operation. The operating point can be anywhere
inside (or on) these limit lines. The limit line boundaries for the other quadrants are similar.
