Keithley SourceMeter 2600 Series Reference Manual page 134

3-18 DUT Test Connections
Output-off states
When an SMU is turned off, it may not be completely isolated from the external
circuit that it is connected to. There are three output-off states for a Series 2600
SMU: Normal, High Impedance or Zero. For the Models 2602 and 2612, each
SMU channel can have its own unique output-off state.
Normal output-off state
For the normal output-off state (which is the default setting), the SMU will source
0V. When running firmware version earlier than 1.2.0, current compliance will set
to 10% full scale of the present current range, or 100µA (whichever is smaller).
When running firmware version 1.2.0 or later, current compliance determined by
the smuX.source.offlimiti command (default 1mA) will be used. Therefore,
the SMU may source or sink a very small amount of power. In most cases, this
source or sink power level is not significant.
High-impedance output-off state
For the high-impedance output-off state, the output relay opens when the output
is turned off. This disconnects external circuitry from the input/output of the SMU.
To prevent excessive wear on the output relay, do not use this output off state for
tests that turn the output off and on frequently.
Zero output-off state
When in this output-off state, the SourceMeter is configured as follows:
When the V-Source is the selected source:
•
•
•
•
When the I-Source is the selected source:
•
•
•
•
While in the zero output-off state, the SourceMeter can be used as an I-Meter
since it will output 0V, but measure current.
2600S-901-01 Rev. A / May 2006
Series 2600 System SourceMeters Reference Manual
The programmed V-Source value remains on the display.
Internally, the V-Source is set to 0V.
The current compliance setting remains the same as the output-on value.
Real compliance detection remains active.
Measurements are performed and displayed.
The programmed I-Source value remains on the display.
Internally, the V-Source is selected and set to 0V.
Current compliance is set to the programmed Source I value or to 10% full
scale of the present current range, whichever is greater.
Measurements are performed and displayed.
Return to Section 3 topics