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Simulators >> Circuit Simulators >> ring oscillator
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Message started by youchen on Oct 13^th, 2008, 3:34pm

Title: ring oscillator
Post by youchen on Oct 13^th, 2008, 3:34pm

Can anyone help me with this? Thanks.

1. is 'pnoise' the proper analysis to calculate period jitter of a ring oscillator? The manual says that the analysis 'pss' is run ahead of 'pnoise', so I also have difficulty understanding what the periodic steady state within each cycle is for a ring oscillator (the settled high/low state or the threshold crossing state)?

2. If I am interested in the timing delay variations of digital logic circuits (for example a NAND gate) resulting from device noise, like thermal, shot and flicker noise, is 'pnoise' the appropriate analysis?

Title: Re: ring oscillator
Post by Ken Kundert on Oct 13^th, 2008, 9:37pm

Yes, you would use pnoise to compute either the phase noise or jitter of a ring oscillator. The periodic steady state is not "within" the cycle, it is the whole cycle.

Pnoise is also used for jitter simulations of logic circuits.

As an introduction, you might want to take a look at "Noise in mixers, oscillators, samplers, and logic: an introduction to cyclostationary noise" on the Theory page of this site.

-Ken

Title: Re: ring oscillator
Post by youchen on Oct 14^th, 2008, 9:52am

Thanks, Ken.