EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: Circlotron on March 19, 2018, 04:15:43 am
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Say I look at a very small repetitive waveform with lots of uncorrelated noise. Switch to averaging mode and the noise goes way down and I can make out the signal. If I wind up the Y sensitivity so that the signal is a reasonable size, does this mean that the noise which would now be off the top and bottom of the screen would be overloading the Y amplifier and perhaps affecting the results, or is this taken care of by the averaging?
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Hi Circlotron,
on a DSO the averaging is made in the digital domain and therefore after the ADC. This means that if you saturate the converter and/or the input amplifier you will end with a distorted signal. This is valid only when in real time but on modern DSO you can acquire your signal with an higher Volt/Div setting, Stop the acquisition and then vertically zoom the waveform (in this case the zoom in is performed in the digital domain where usually there is much more headroom).
Best,
0xfede
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I expect that would work, but you would probably not have much vertical resolution. Might be good enough though.
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If this is not enough for your measurement you may also want to add a low pass filter between the DUT and the DSO.
Best,
0xfede