how to calculate switch size in chopper OTA op-amp

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emilian6

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I have OTA op-amps in delta sigma modulator. Now I'd like to add chopper to op-amps. How can I calculate the size of the chopper switches. They are in the straight chain of the op-amps and I think they shouldn't change the settling time. So, may I take minimum sized switches?
 

To have low residual offset after chopping, it would be prefarable to have smallest size switches
 

im not sure it will be of goodness when use chopper ota in sigmadelta design, in addition to the size, but also the chopping tone will effect the snr,
 

The value of the switchs should be designed for the required SNR of the system that you using. Also the resistance of the switches should allow correct settling with the clock phases that you use.

Bastos
 

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