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Design >> RF Design >> Noise Figure in switched cap, with Pnoise
https://designers-guide.org/forum/YaBB.pl?num=1628850506

Message started by sparky on Aug 13^th, 2021, 3:28am

Title: Noise Figure in switched cap, with Pnoise
Post by sparky on Aug 13^th, 2021, 3:28am

Hi, I am trying to get Noise Figure in track and hold circuit with RC>>Ts/2 as shown in added image.

NF= 10logF, where F is Noise Factor
and F = (Ni+Nsys)/Ni.

In my circuit Nsys =0 (Sys include only switch and cap, there is no res(noise generator)). so, F should be =1, so the Noise figure should be = 0.
But, cadence giving me F = 1.96 and NF = 2.92.

Please help, what I am doing wrong. I have added image of schematic and setiing of PSS and Pnoise

Title: Re: Noise Figure in switched cap, with Pnoise
Post by sparky on Aug 13^th, 2021, 3:30am

pss analysis setting

Title: Re: Noise Figure in switched cap, with Pnoise
Post by sparky on Aug 13^th, 2021, 3:32am

Pnoise

Title: Re: Noise Figure in switched cap, with Pnoise
Post by sparky on Aug 13^th, 2021, 3:33am

pnoise2

Title: Re: Noise Figure in switched cap, with Pnoise
Post by Frank Wiedmann on Aug 16^th, 2021, 4:12am

This question has been answered by Andrew Beckett at https://community.cadence.com/cadence_technology_forums/f/custom-ic-design/48795/noise-figure-of-track-and-hold-circuit