2600AS-901-01 Rev. B / September 2008
Return to
4-13
Series 2600A System SourceMeter® Instruments Reference Manual
Section 4: Source-Measure Concepts
Load considerations
The boundaries the SourceMeter instrument operates in depends on the load (DUT) that is
connected to the output.
shows operation examples for resistive loads that are 2k
Ω
and
800
Ω
, respectively. For these examples, the SourceMeter instrument is programmed to source
10V and limit 10mA.
, the SourceMeter instrument is sourcing 10V to the 2k
Ω
load and subsequently
measures 5mA. As shown, the load line for 2k
Ω
intersects the 10V voltage source line at 5mA.
shows what happens if the resistance of the load is decreased to 800
Ω
. The DUT load
line for 800
Ω
intersects the current compliance limit line placing the SourceMeter instrument in
compliance. In compliance, the SourceMeter instrument will not be able to source its programmed
voltage (10V). For the 800
Ω
DUT, the SourceMeter instrument will only output 8V (at the 10mA
limit).
Notice that as resistance decreases, the slope of the DUT load line increases. As resistance
approaches infinity (open output), the SourceMeter instrument will source virtually 10V at 0mA.
Conversely, as resistance increases, the slope of the DUT load line decreases. At zero resistance
(shorted output), the SourceMeter instrument will source virtually 0V at 10mA.
Regardless of the load, current will never exceed the programmed compliance of 10mA.
