Keithley 2651A Reference Manual page 206

Model 2651A High Power System SourceMeter® Instrument Reference Manual
The following figure shows a current sweep on a resistive load of 200 Ω. For this example, the
System SourceMeter instrument is programmed to sweep current to 100 mA, limit voltage (6 V) and
limit power (500 mW). When sweeping, the actual source output will vary according to the
programmed source value until the voltage limit is reached. As the figure shows, the output will
source the programmed value until placed in voltage compliance at the 6 V limit. The sweep will then
continue (programmed I-source values will increase along the green sweep points line), but the output
will remain at the same value as when the instrument went into voltage compliance. This continues
until the programmed source value sweeps to a high enough level that the power limit line is reached
(500 mW). At this point, the voltage and the current will start to decrease, lowering the current and
voltage values along the DUT load line. When the last point is swept (100 mA), the actual output
would be 25 mA (at 5 V).
V-source operating boundaries
Model 2651A V-source operating boundaries
The following figure shows the operating boundaries for the V-source. Only the first quadrant of
operation is shown; operation in the other three quadrants is similar.
2651A-901-01 Rev. A / March 2011
Figure 73: Model 2651A I-source load considerations while sweeping I
Programmed I-source sweep operation in voltage and power compliance
10 V
V-meter
5 V
(V )
M
Programmed I-source
Voltage
compliance
limit line
Power
compliance
X
limit line
Sweep
points line
50 mA 100 mA
(I )
S
Section 4: Theory of operation
4-9