problems about simulate flicker noise of chopper amplifier with PSS & PNOISE

[webbubm]

hi all~
From papers I read about chopper stabilization, the flicker noise in the PSD of chopper amplifier should be modulated to odd harmonics of chopping frequency.
And I use a simple fully differential op-amp to simulate this function with PSS & PNOISE. The beat frequency is 10kHz.
From the simulation below , the flicker noise is modulated to the chopping frequency(10kHz) and it's odd harmonics. But there two things that I confused.
there is a peak from the plot at about 100kHz. If I change the chopping frequency to 1kHz ,the peak is moved to 10kHz about ten times of chopping frequency. second, the flicker noise is also at low frequency after chopping.
Is there something wrong ? please help me~

---------- Post added at 05:27 ---------- Previous post was at 05:26 ----------

 

[Mary_D]

Hello ,

I am doing my thesis project and it involves a chopper amplifier, I would like to see how the chopper is shifting the amp noise to the clock frequency, would you please give me some instruction on how to use PSS and PNOISE analysis since we do not have any sort of tutorial in our university..and I really dont know what to do..how did you arrive to your plot please?

Thank you very much!

Regards