U1882B Datasheet, PDF (4/11 Pages) Keysight Technologies – Measurement Application for InfiniiVision

04 | Keysight | U1881A and U1882B Measurement Application for InfiniiVision and Infiniium Oscilloscopes - Data Sheet
Auto deskewing and U1880A deskew fixture
A power measurement is simply a point-by-point multiplication of
the voltage and current waveforms measured by the voltage and
current probes. To make accurate power measurement and
calculation, it is extremely important to equalize the time delay
between the voltage and current probes using a procedure
known as deskewing. This step is critically important since a
small offset in the timing of the voltage and current traces can
cause a large error in the instantaneous power reading. To
deskew a pair of probes, drive both voltage and current probes
with the same pulse signal using the U1880A deskew fixture.
With only a single click on the menu, deskewing is automatically
performed and its values are saved in the power measurement
software, so the next time you launch the power measurement
application, you can use the saved deskew values or perform
the deskewing again.
The deskew accuracy is a function of the electrical
characteristics of the voltage and current probes as well as the
risetime of the signal under test. In general, higher bandwidth
probes will allow for better risetime fidelity and better deskew
resolution. Keysight's N2790A to N2793A differential probes
are recommended for most applications.
The U1880A deskew fixture is recommended for use with the
following voltage and current probe combinations given various
test signal risetime characteristics.
Figure 2. Deskew dialog
Figure 3. Deskew fixture