Measure Current Range (Pmu) - Keithley 4200A-SCS User Manual

Model 4200A-SCS Pulse Card (PGU and PMU) User's Manual

Measure Current Range (PMU)

The measure range determines the full-scale measurement span that is applied to the signal.
Therefore, it affects both the accuracy of the measurements and the maximum signal that can be
measured.
The current measure range affects the time required to obtain settled measurements. Lower current
ranges require additional time to reach a settled signal level. If the pulse timing parameters are too
short for one or more current measure ranges, some ranges will be unavailable.
As shown in the following table, available current measurement ranges for the PMU depend on the
selected voltage source range. The 10 mA measure range for the 10 V source range has better
accuracy than the 10 mA range for the 40 V source range.
Fixed current measurement ranges (PMU only)
10 V range
10 mA
200 mA
−
If you are using an RPM, additional current measurement ranges become available to the PMU. The
following table lists the current measurement ranges for the PMU when using the RPM. The 10 mA
measure range for the 10 V source range has better accuracy than the 10 mA range for the 40 V
source range.
Current measurement ranges for the PMU with RPM
10 V range
100 nA
1 µA
10 µA
100 µA
1 mA
10 mA
200 mA
The current range options are:
•
Auto: The instrument automatically optimizes the measurement range as the test progresses.
This option provides the best resolution when the measurements span several decades. However,
time delays can occur with range changes that can limit the measurement speed.
•
Limited Auto: A compromise between Auto and a fixed range option. It allows you to specify the
minimum range that the PMU uses when it automatically optimizes the current measurements.
This option reduces test time when you do not need maximum resolution at minimum currents.
The available ranges are limited by the chosen pulse timing parameters. For additional
information, see PMU minimum settling times versus current measure range.
•
Specific ranges: You can select a fixed measurement range.
The available ranges are limited by the pulse timing parameters. For additional information, see
minimum settling times versus current measure range
4200A-PMU-900-01 Rev. A December 2020
40 V range
100 µA
10 mA
800 mA
40 V range
100 µA
10 mA
800 mA
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Section 3: Setting up PMUs and PGUs in Clarius
(on page 3-34).
PMU
3-9