Section 3: Setting up SMUs in Clarius
Model 4200A-SCS Source-Measure Unit (SMU) User's Manual
3-18
4200A-SMU-900-01 Rev. A December 2020
The lowest allowable compliance is based on the load and the source value. For example, if you are
sourcing 1 V to a 1
kΩ resistor, the lowest allowable current compliance is 1 mA (1 V/1 kΩ = 1 mA).
Setting a compliance lower than 1 mA limits the source.
For another example, assume the following conditions:
•
Current compliance: 10 mA
•
Voltage sourced by the instrument: 10 V
•
DUT resistance: 10 Ω
With a source voltage of 10 V and a DUT resistance of 10 Ω, the current through the DUT should be
10 V / 10
Ω = 1 A. However, because compliance is set to 10 mA, the current cannot exceed 10 mA,
and the voltage across the resistance is limited to 100 mV. In effect, the 10 V voltage source is
transformed into a 10 mA current source.
In steady-state conditions, the set compliance value restricts the instrument output unless there are
fast transient load conditions.
When measurement autorange is disabled, the maximum and minimum compliance values cannot be
set below the minimum value. When autorange is enabled, the programmed compliance value cannot
be set below 10 nA when sourcing voltage, or below 20 mV when sourcing current.
Dual Sweep
When you select Dual Sweep, the instrument sweeps from start to stop, then from stop to start. When
you clear Dual Sweep, the instrument sweeps from start to stop only.
The following figure compares a single sweep to a dual sweep.
Figure 46: Single and dual sweep examples (linear voltage sweep; 0 V to 4 V in 1 V steps)
