Keithley 2601B Reference Manual page 236

Section 4: Theory of operation Series 2600B System SourceMeter® Instrument Reference Manual
The following figure shows a voltage sweep on a resistive load of 800 Ω. For this example, the
System SourceMeter instrument is programmed to sweep voltage to 10 V, limit current (6 mA) and
limit power (50 mW). When sweeping, the actual source output will vary according to the programmed
source value until the current limit is reached. As the figure shows, the output will source the
programmed value until placed in current compliance at the 6 mA 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 (50
mW). At this point, the current and voltage will start to decrease, lowering the current and voltage
values along the DUT load line. When the last point is swept (10 V), the actual output would be 4 V
(at 5 mA).
Figure 95: Programmed V-source sweep operation in current and power compliance
V-source sink operating boundaries
The quadrant within which the Series 2600B operates depends on the device-under-test (DUT)
connected to the Series 2600B output. The following example illustrates this operation by using the
Series 2600B configured as a voltage source to discharge a 12 V power source (a battery).
Figure 96: Sourcing voltage while sinking current
4-10 2600BS-901-01 Rev. B / May 2013