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2600AS-901-01 Rev. B / September 2008
Return to
4-15
Series 2600A System SourceMeter® Instruments Reference Manual
Section 4: Source-Measure Concepts
Source I measure I, source V measure V
The SourceMeter instrument can measure the function it is sourcing. When sourcing a voltage,
you can measure voltage. Conversely, if you are sourcing current, you can measure the output
current. For these measure source operations, the measure range is the same as the source
range.
This feature is valuable when operating with the source in compliance. When in compliance, the
programmed source value is not reached. Thus, measuring the source lets you measure the
actual output voltage.
Basic circuit configurations
Source I
When configured to source current (I-Source) as shown in
, the SourceMeter instrument
functions as a high-impedance current source with voltage limit capability and can measure
current (I-Meter) or voltage (V-Meter).
For 2-wire local sensing, voltage is measured at the Input/Output terminals of the SourceMeter
instrument. For 4-wire remote sensing, voltage is measured directly at the DUT using the sense
terminals. This eliminates any voltage drops that may be in the test leads or connections between
the SourceMeter instrument and the DUT.
The current source does not require or use the sense leads to enhance current source accuracy.
With 4-wire remote sensing selected, the sense leads must be connected or incorrect operation
will result.
Figure 4-9
Source I configuration
Remote
SENSE HI
IN/OUT HI
Remote
IN/OUT LO
I-Source
x1
V-Meter
SENSE LO
Local
Local
GUARD
+
I-Meter
NOTES: 1. This represents a protection circuit that is very
high impedance until the voltage across it exceeds
approximately 3V. Above 3V, the protection turns
on and allows current to flow through it.
2. Approximately 13k
W
.
1
2
2
1
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