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Feb 27th, 2020, 10:44pm
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pnoise/jitter and pnoise/time average discrepancy with Cadence Spectre (Read 61 times)
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pnoise/jitter and pnoise/time average discrepancy with Cadence Spectre
Feb 13th, 2020, 10:39am
Hi everyone,
I try to get the jitter from a clock generator, but I also need the phase noise curve for other reasons:
- When I simulate my circuit with the pnoise/jitter method, I get a RMS Jitter in a given bandwidth of 594.386fs (Jee>RMS).
- And when I simulate with the pnoise/time average method, by calculating my Jitter from the Phase Noise curve, I get 269.2fs.

Assuming that the pnoise>PM>Phase Noise plot is the IEEE definition, say Single-Sideband-to-Carrier Ratio, so-called L(df), "L-script of df",
I compute the RMS jitter as follows in my calculator:
[1 / sqrt(2)*pi*f0] * sqrt{ INTEGRAL[ L(df).df ] }

Of course, here L(df) is converted in linear, L(df)=10^LdBc(df)/10

In your opinion what do I miss??

Thanks a lot in advance for your help!
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English is not my mother tongue, so please excuse my mistakes ^^
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