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Simulators >> RF Simulators >> noise analysis
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Message started by nobody on Dec 28^th, 2009, 3:01am

Title: noise analysis
Post by nobody on Dec 28^th, 2009, 3:01am

Hello, all

I have a question about how to do the noise simulation of a "flip-around" SHA in the hold phase. To be more precisely, I question the total output noise @ the hold phase because the magnitude of noise is much larger than expected. If I hook up the circuit like Fig.1 called " charge transferred SHA" ,typically gain= cs/cf=2, the magnitude of output noise looks good. Fig.2 shows the way I did the simulation. An ideal cmfb is added and ideal baluns are used to convert differential and common signals.
Thanks a lot.

*** spice deck ***
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Title: Re: noise analysis
Post by Ken Kundert on Dec 28^th, 2009, 8:50am

Look at http://www.designers-guide.org/Analysis/sc-filters.pdf for an explanation of how to perform noise analysis of a sample and hold amplifier (SHA).

-Ken