noise question

[jim]

Is there a simple explanation for how to use noise figure? For
example, if a component advertises 3nV/ sq rt Hz, do I just plug in
the bandwidth I'm running it at ,take the sq rt and multiply it by the
nV for my noise density? What would I see on my scope? I 've got
several electronics books but none seem to explain how to use these
figures to predict what noise level I will see,at least not in any
easy to understand way. Any help? Thanks ahead. jm

 

[Kevin Aylward]

jim wrote:

Is there a simple explanation for how to use noise figure? For
example, if a component advertises 3nV/ sq rt Hz, do I just plug in
the bandwidth I'm running it at ,take the sq rt and multiply it by the
nV for my noise density?

Yes.

What would I see on my scope?

A lot of gibberish. You need a spectrum analyser ti see how the noise
actually varies with frequency. The scope only give you a rough idea of
the average and peak values of the noise.


Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
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