Andrew Beckett
Senior Fellow
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Life, don't talk to me about Life...
Posts: 1742
Bracknell, UK
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No, this will not give you any kind of jitter information.
If you're looking at the pss-td results, then this will only be a single period of the fundamental frequency. If you're looking at the pss-tran (or whatever it is called), then this is just the initial transient used for partial settling before the shooting interval starts. In either case, these do not include any noise sources.
In pnoise, the noise sources are added as small signal noise sources around each of the devices in the circuit. It will then compute the transfer functions of these to the output (including any noise folding effects) giving you the total noise at the output of the circuit in a desired band. You can also strobe the noise using tdnoise.
All of this is discussed in Ken's paper on jitter and phase noise in the Analysis section (see links at the top of the site's web page). Also, there is a "jitter" mode for pnoise now (introduced in IC5141) which allows you to measure jitter more conveniently/directly for both driven and autonomous circuits.
Spectre does now have a transient noise analysis (as from MMSIM60 onwards), but in general you would usually be better off using pnoise/tdnoise if you can (it would normally be quicker and more accurate). There have been discussions to this effect in this forum before, if my memory serves me correctly. Transient noise analyses are best for looking in a qualitative way where noise results in some large signal effect, particularly in non-periodic circuits (or at least circuits where the period is not constant).
Regards,
Andrew.
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