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CP/PFD Analysis (Read 2395 times)
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CP/PFD Analysis
Mar 19th, 2004, 7:39pm
Hello All,

I am attempting to do a PSS/PNOISE Analysis of a PFD, Charge Pump and Loop Filter Combination to gain the phase noise of them.

I am using actual transistor and not behavioral components so I am attempting to modify the oscillator phase noise analysis to check the phase noise of this combination.

Any tips or advice ?  I ran a simulation and got convergence failures.

Thank you !
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Jitter Man
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Am I? Or am I so
sane that u just
blew your mind?

Posts: 50

Re: CP/PFD Analysis
Reply #1 - Mar 19th, 2004, 9:59pm
First make sure that your circuit produces a periodic response. If not, you need to change something, because SpectreRF will never converge on a circuit that does not produce a periodic response in steady state. Then set tstab sufficiently large. It may need to be as much as the settling time of the filter. Finally, if you tighten the tolerances, consider loosening them back to the default values.

Jitter Man
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