270 6000 Series Oscilloscope User’s Guide
6 Displaying Data
•The oscilloscope produces the waveform display from
samples collected from multiple acquisitions. In this case, the
reconstruction filter is not used.
Realtime Sampling and Oscilloscope Bandwidth
To accurately reproduce a sampled waveform, the sample rate
should be at least four times the highest frequency component
of the waveform. If not, it is possible for the reconstructed
waveform to be distort ed or aliased. Aliasi ng is most commonly
seen as jitter on fast edges.
The maximum sample rate for 100 MHz and 300 MHz bandwidth
oscilloscopes is 2 GSa/s.
The maximum sample rate for 1 GHz and 500 MHz bandwidth
oscilloscopes is 4 GSa/s for a single channel in a channel pair.
Channels 1 and 2 constitute a channel pair, and channels 3 and
4 constitute another channel pair. For example, the sample rate
of a 4-channel oscilloscope is 4 GSa/s when channels 1 and 3, 1
and 4, 2 and 3, or 2 and 4 are on.
Whenever both channels in a channel pair are on, the sample
rate for all channels is halved. For example, when channels 1, 2,
and 3 are on, the sample rate for all channels is 2 GSa/s.
When Realtime sampling is on, the bandwidth of the
oscilloscope is limited because the bandwidth of the
reconstruction filter is set to fs/4. For example, a 610x
oscilloscope with channels 1 and 2 on has a bandwidth of
500 MHz when Realtime sampling on and 1GHz when Realtime
sampling is off.
To see the sample rate, press the Menu/Zoom key on the front
panel. The sample rate is displayed in the line just above the
softkeys.
Sample
rate