
Model 2651A High Power System SourceMeter® Instrument Reference Manual
Section 7: Command reference
2651A-901-01 Rev. A / March 2011
7-331
Usage
SweepVLogMeasureI(
smu, startv, stopv, stime, points
)
smu
System SourceMeter
®
instrument channel (set to
smua
)
startv
Sweep start voltage in volts
stopv
Sweep stop voltage in volts
stime
Settling time in seconds; occurs after stepping the source and before performing a
measurement
points
Number of sweep points (must be
≥
2)
Details
Data for current measurements, voltage source values, and timestamps are stored in
smuX.nvbuffer1.
If all parameters are omitted when this function is called, this function is executed with the parameters set to the
default values.
Performs a logarithmic voltage sweep with current measured at every step (point):
1. Sets
the
smu
to output
startv
amperes, allows the source to settle for
stime
seconds, and then
performs a current measurement.
2. Sets
the
smu
to output the next volts step, allows the source to settle for
stime
seconds, and
then performs a current measurement.
3. Repeats the above sequence until the voltage is measured on the
stopv
volts step.
The source level at each step (
SourceStepLevel
) is automatically calculated as follows:
MeasurePoint = The step point number for a measurement
For example, for a five-point sweep (
points
= 5), a measurement is performed at
MeasurePoint
1, 2, 3, 4,
and 5.
LogStepSize = (log10(stopi) – log10(starti)) / (points – 1)
LogStep = (MeasurePoint – 1) * (LogStepSize)
SourceStepLevel = antilog(LogStep) * startv
Figure 109: SweepVLogMeasureI()
startv
= Current measurement
stopv
stime
stime
stime