Noise analysis of sample and hold amplifier

[Chinmaye]

Dear all,
I am trying to simulate .noise in cadence for a flip-around sample and hold circuit. The sampling frequency is 4MHz. I have connected the inputs to common mode. The freq range is from 1 to 2MHz. I see peaking in the noise response at 165KHz. I think I am missing out on something.
Is there anything that I am missing out on?

 

[guntherleet]

Because your circuit is periodic you need to run pss and then pnoise analysis

 

[AMS012]

I agree with guntherleet. You should not do acnoise on a circuit that is not time invariant.

Sample and hold falls into the category of what is called Linear Periodically Time Varying (LPTV) circuits, whose steady state depends on the switching frequency. Go through the literature to get more about it.