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Design >> RF Design >> Sampled noise simulation in sc gain stage
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Message started by reactgary on Jul 10^th, 2006, 11:23pm

Title: Sampled noise simulation in sc gain stage
Post by reactgary on Jul 10^th, 2006, 11:23pm

Hi all,

I am currently having simulation on a SC gain stage. After reading some posts here, and the paper of Ken. I tried to setup a spectrerf simulation.
However, I got some trouble in parameter setup. Basically, the problems come from a SC cmfb.

The clock freq of the gain stage is 1kHz and I have set the SC cmfb to 0.5kHz
When I start a spectreRF simulation, the fundmental freq would be 0.5kHz

I tried to have a sampled noise from 0-0.5kHz, max sideband = 100, ref sideband = 0 and maxac freq to be 100*0.5 = 50kHz
Although I finish the simulation successfully, but I dun know if this parameter is correct. Moreover, I do not have method to verify my result.

Would anyone give me some comment on my setting (sampled noise freq, ref sideband, and max freq).

Thanks

Gary

Title: Re: Sampled noise simulation in sc gain stage
Post by Mighty Mouse on Jul 13^th, 2006, 7:07am

Are you trying to characterize the noise of the SC gain stage, or just the common-mode feedback?

maxsideband looks reasonable.
refsideband is right because it indicates that the input and output are at the same frequency.
maxacfreq looks good. In addition Spectre will tell you if it is too small.

- MM -