Sampling Overview
This gives you a brief overview of sampling. For more details on sampling
techniques, refer to Feeling Comfortable with Digitizing Oscilloscopes
that is supplied with your oscilloscope. You can also get a copy of
HP product note 54720A-1, Bandwidth and Sampling Rate in Digitizing
Oscilloscopes, by contacting you nearest Hewlett-Packard Sales Office or by
calling the Hewlett-Packard Customer Information Center at 1-800-452-4844.
Real-time sampling
In the real-time sampling mode, all of the data is acquired from one time base
sweep. As with any digitizing oscilloscope, the more data that is acquired,
the better the oscilloscope can reproduce the waveform on the display.
Therefore, this sampling mode has a maximum sampling rate of 2-GSa/s on
each plug-in slot. A two-wide plug-in, like the HP 54721A, uses two plug-in
slots for a maximum sampling rate of 4 GSa/s. A four wide plug-in, like the
HP 54722A, uses four plug-in slots for a maximum sampling rate of 8 GSa/s.
Also, this sampling mode is typically used on signals that happen either once
or infrequently. Because you may have only one chance to capture the data,
you will want to use the maximum sampling rate available.
A simple fact of real-time sampling is that the higher the sampling rate
relative to the bandwidth of the signal, the better the oscilloscope can
reconstruct the signal. The oscilloscope can best reproduce signals when the
sample rate is about four times or greater than the highest frequency
components in the signal. That is why the HP 54713A plug-in has a 500-MHz
bandwidth. It uses one slot, and one-fourth of 2 GSa/s is 500 MHz. The
HP 54721A plug-in has a bandwidth of about 1 GHz because it uses two slots,
and one-fourth of 4 GSa/s is 1 GHz.
How the Oscilloscope Works
Sampling Overview
1–11
To Next Page
Loading...
