flicker noise simulation in cadence

[naisare]

cadence noise simulation

Hi,

I would like to do the flicker noise(1/f noise) simulation of differential opamp using cadence tool.

Which analysis I should do? Is it noise , pnoise or pss analysis?
How to give the necessary parameters for these analysis? Do anyone have an example schematic for noise simulation?

Thanks

 

[PaloAlto]

noise simulation cadence

You just have to put your opamp in the right DC operating point, (also the common mode) and then do a noise analisis. If your transistor models include the 1/f noise, and they normally do, you would get the right results.

You will see that you have 1/f noise in your models because your noise spectral density plot (noise vs frequency) shows higher noise at low frequencies decreasing with freq(1/f)

 

[naisare]

plot flicker noise cadence

Thanks..
I could get the flicker noise plot with noise analysis.

Now, I used choper stabalization method to remove this flicker noise.
But there is no change in the flicker noise result after the choping also.
I expect the PSD should show the flicker noise shifted to choping frequency.

I expect the problem in the simulation rather than in design, since the design is already proven..

Since the chopping method needs transient simulation, Is it ok if I do only the noise analysis which is purely frequency sweep. or do I need to do PSS simulation also..

thx