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Message started by atharapi on Mar 19th, 2004, 7:39pm

Title: CP/PFD Analysis
Post by atharapi on 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 !

Title: Re: CP/PFD Analysis
Post by Jitter Man on 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.

[glb]Jitter Man[/glb]

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