Frank_Heart
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Posts: 29
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Hi, All,
If we have a 1st Order RC filter, we know the total thermal noise at output is KT/C, spreading from 0 to inf.
While for a uniform quantifier with LSB= VLSB, we will say the total quantification noise is VLSB*VLSB/12, spreading from -0.5*FS to 0.5*FS.
Then how to understand this negative frequency from 0.5*Fs to 0?
Is it because quantification noise is not a "physical" noise, which is from mathematics definition? Only sampling system will 'create' negative half on the spectrum?
Sometimes it is really annoying, as in some simulator, the plotted FFT will only show the positive part, and with the number doubled (I think spectre is in this way?). While in some simulator, they didn't.
Any thoughts on this?
Thanks Frank
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