The Designer's Guide Community
Forum
Welcome, Guest. Please Login or Register. Please follow the Forum guidelines.
Mar 28th, 2024, 11:51pm
Pages: 1
Send Topic Print
a question about pss+pnoise simulation in a chopper-aplifier (Read 2148 times)
ehsan_nazarzadeh
New Member
*
Offline



Posts: 1

a question about pss+pnoise simulation in a chopper-aplifier
Jul 20th, 2016, 11:51pm
 
I try to simulate a chopper instrumentation amplifier. Chopping frequency is 5 KHz and cut-off frequency is 700 Hz. I use pss+pnoise analysis to see the noise spectrum and measure the integrated noise, but it seem to be wrong. Is it necessary to put an ideal “Sample-and-Hold” circuit in chopper-amplifier structure and then run pss+pnoise analysis? If “YES”, then which sampling frequency should I choose? If “NO”, then what are the correct settings of pss+pnoise analysis?
Back to top
 

Capture_007.JPG
View Profile   IP Logged
Ken Kundert
Global Moderator
*****
Offline



Posts: 2384
Silicon Valley
Re: a question about pss+pnoise simulation in a chopper-aplifier
Reply #1 - Jul 24th, 2016, 12:59am
 
Seems to be wrong? That is rather vague. Perhaps you could elaborate?

My experience with these types of simulationsis that you need to be careful that the interpolation of the flicker noise by the waveform tool does not corrupt the result. Make sure you have several analysis points below the flicker noise corner frequency.

To know whether you need to sample the output of your circuit, you need to think about the circuit that follows the chopper. If is a sampling circuit, then you should sample.

You do not need to build a sample and hold. The simulator can sample the result for you, though the interface is rather awkward.

-Ken
Back to top
 
 
View Profile WWW   IP Logged
Pages: 1
Send Topic Print
Copyright 2002-2024 Designer’s Guide Consulting, Inc. Designer’s Guide® is a registered trademark of Designer’s Guide Consulting, Inc. All rights reserved. Send comments or questions to editor@designers-guide.org. Consider submitting a paper or model.