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Design >> Analog Design >> Noise simulation in SAR ADCs
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Message started by RobG on Feb 9^th, 2015, 2:20pm

Title: Noise simulation in SAR ADCs
Post by RobG on Feb 9^th, 2015, 2:20pm

I designing a 12 bit SAR adc and I'm wondering if there are any clever ways of simulating noise. I can evaluate the parts individually with small signal noise analysis and they seem fine, but I lose performance when I do a transient noise analysis.

I am suspicious of the transient noise simulation for some reasons worth a thread of its own... Is there a way I can analyze this with pnoise, etc? I have a lot of redundancy so it is only the last few comparisons that determine the error.

Title: Re: Noise simulation in SAR ADCs
Post by sheldon on Feb 9^th, 2015, 3:25pm

RobG,

If you are a Cadence user and can access the support site,
there is a video and Rapid Adoption Kit, that discusses simulation
of SARADC designs. The problem is that there are many sources
of error and you need to be able to not only simulate the noise
but know which noise source is limiting performance. Transient
noise does not directly provide that information.

Sheldon

Title: Re: Noise simulation in SAR ADCs
Post by RobG on Feb 9^th, 2015, 4:15pm

Thanks - I wouldn't have known about that. Yes it is cadence.

I put a question on the cadence site about multithreading not threading if you know the answer to that... http://community.cadence.com/cadence_technology_forums/f/38/t/31549

Title: Re: Noise simulation in SAR ADCs
Post by Ken Kundert on Feb 11^th, 2015, 1:34pm

You should be able to use a pnoise analysis. You just need to make the circuit periodic. I would thing applying a DC input and simulating a single conversion should do it. You might want to spend a little time thinking about your circuit and making sure all the noise sources would be exercised in such a test.

-Ken