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Simulators >> Circuit Simulators >> Using monte carlo and histogram for offset in spectre
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Message started by skiIC on May 3^rd, 2012, 4:04pm

Title: Using monte carlo and histogram for offset in spectre
Post by skiIC on May 3^rd, 2012, 4:04pm

I am using cadence spectre 6.1.4 and wanting to do a histogram plot after running Monte Carlo. The input is a diff pair part of a sense amp. When I run a transient then to get my baseline number that I think is the offset. i then step it up by 1mV to run with MC. for 100 sample and set my sigma to 3 does this create enough sample for the histogram distribution or do I need more? Then for the histogram what do I use for parameters to show a correct plot?

Title: Re: Using monte carlo and histogram for offset in spectre
Post by sheldon on May 5^th, 2012, 9:41am

Ski,

Are you referring to Virtuoso IC614? Spectre is a simulator. The
basic recommendation would be to up version to the most recent
IC615 ISR release. There have been a significant enhancements
in to statistical analysis tools, in particular, support for confidence
intervals and Monte Carlo auto-stop are new for IC615. I think that
the issue of the appropriate number of samples to select is complex
question, which is why using some of the new tools, such as, Monte
Carlo auto-stop, might be useful. Another option is to use one of
the alternative sampling methods, for example, orthogonal sampling.
Using orthogonal sampling should give better estimates with fewer
points. Also since you are simulating a sense amp, you might want
to consider using High Sigma Yield estimation since you probably
are looking for more than 3 sigma yield.

Best Regards,

Sheldon