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Simulators >> Circuit Simulators >> pnoise for SC networks with chopper
https://designers-guide.org/forum/YaBB.pl?num=1433226683

Message started by RSA on Jun 1^st, 2015, 11:31pm

Title: pnoise for SC networks with chopper
Post by RSA on Jun 1^st, 2015, 11:31pm

Hi all!

I want to measure the integrated output noise power in a specific frequency range in a Switched Capacitor network; I used pss+timedomain pnoise analysis to get the integrated noise power of the sampled output. Now I want to add a chopper to modulate the flicker noise with the chopping frequency at fs/2 where fs is the rate at which the SC network is varying periodically. Now with this chopping clock added, the network now will be varying at a rate of fs/2 and so time-domain pnoise will give the noise power of output samples, sampled at fs/2 (this is what I am thinking; plz correct me if wrong) whereas the one required is the noise power of samples, sampled at fs. So how do I get the noise power of output samples sampled at fs?

I was thinking of emulating an impulse sampling instead of a square wave sampling and get the continuous time noise PSD from pnoise. But that would require the switch resistance to be very low which inturn would require a very high maxacfrequency for pss.

Is there a better method of obtaining the noise power?

Title: Re: pnoise for SC networks with chopper
Post by davidshw on Jun 2^nd, 2020, 9:35pm

there is a parameter set in pnoise, you can try it.
sampleratio
The ratio between sampled frequency and fund frequency
(sampled frequency/fund frequency).
default value is 1