Model 4200A-SCS Parameter Analyzer Reference Manual
Section 5: Pulse measure and pulse generator units
4200A-901-01 Rev. C / February 2017
5-49
Step 2. Verify the pulse shape
To check that the pulse shape provides a flat, settled portion near the end of the pulse top:
1. Configure the test for Waveform Capture.
2. Ensure that voltage, current, and time waveforms are measured. See
(on page 6-75).
3. Enable the status for each PMU channel in the test. See
4. Select a voltage level for each channel that puts the device into the area of the curve that is
questionable. If the a large portion of the pulse I-V curve is under question, viewing the waveform
shape at two or three different voltage levels may be necessary.
5. Configure the ranges to match the pulse I-V test.
6. Configure the connection and load-line effect compensation (LLEC). To match the pulse I-V test
conditions, enabling LLEC allows the PMU to compensate for lower voltage levels at the test
device when current is flowing. See
7. Configure the graph with the time value on the x-axis, all voltage measurements on Y1, and
current measurements on Y2. On the graph, click
Graph Settings
and select
Define Graph
to
open the Graph Definition dialog box. By default, the voltage waveforms are blue and use the left
(Y1) axis; the current waveforms are red and use the right (Y2) axis.
8. Save the project.
9. Run the test and view the waveform on the graph. While viewing the graph, check that the
voltage has a fairly flat top, without significant ringing or oscillations.
There may be current peaks during the pulse transitions. The peaks during the transitions are
expected; see
PMU capacitive charging/discharging effects
(on page 5-42). The current waveform
may show settling, but should not have significant ringing. An example of a good waveform shape is
shown in
PMU and RPM measure ranges are not source ranges
(on page 5-44).
Due to interconnect and DUT settling time requirements, low current measurements
(< ~10 mA) may require a wider pulse than the recommended minimum timing values. This is
especially important for <1 mA level current measurements using the 4225-RPM. See
settling times versus current measure range
(on page 5-41)
A waveform graph may show a Measurement Overflow condition.
This overflow during the pulse transitions does not affect the spot mean measurements, because the
spot mean is taken during the settled portion of the pulse top. Note that this error would not occur
during pulse I-V, because the spot mean measurement window does not include the rising or falling
edges of the pulse. Refer to
(on page 6-97),
PMU and RPM measure ranges are
(on page 6-99) for more information.
