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1/f noise vs RMS an peak-peak calculation

Question asked by Elektrolurch on Jan 25, 2014
Latest reply on Feb 3, 2014 by OliverSedlacek

Hello,

 

I am in the subject of measuring mV signals with maximum accuracy.

The formulas for calculating white noise is described in several data sheets.

But for 1/f noise I didn't see such a formula.

What's confusing to me, that at DC you get infinite nV/rtHz noise level.

Doesn't this translate to infinite RMS and peak-peak level?

 

In Opamp data sheet there is a graph - noise in nV/rtHz over frequency.

How can I calculate the rms (and peak-peak) noise if I would brick-wall (low pass) filter the output at 0.1Hz / 1Hz / 10Hz ?

 

How can I compare the "outcome" of zero-drift OPA versa "normal" OPA (noise) for the above sample rate?

 

PS:

A resistor doesn't have 1/f noise? So a 350 Ohm resistor has 2,4nV/rtHz.

This would mean that at DC to 0.1Hz it would have 0,8nV rms?

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