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ask forPnoise setting enviroment(spectre rf) . (Read 2353 times)

ipmsn5

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Posts: 5
China

ask forPnoise setting enviroment(spectre rf) .
Dec 08^th, 2006, 5:35am

Dear all:

I still do a pnoise simulation for the full pll: PFD+CP+LPF+VCO+feedback divider>
but the convergence problem confused me all the time,I also ask for the cadence CE help,but no good news.
Now I ask for Your help,who can setting the cadence pss&pnoise enviroment and put it on the website.
thanks Huh

share the experiments.thanks

Note: I set the tstab=20us. and the control voltage is stable at 15us.

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Ken Kundert

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Silicon Valley

Re: ask forPnoise setting enviroment(spectre rf) .
Reply #1 - Dec 9^th, 2006, 1:28pm

There is no magic set of settings. If there were, they'd probably be the default. Perhaps if you told us more about what is going wrong?

One thing you might want to try is to run a long transient and using strobing with the strobe period equal to the PSS period. Then choose the tstab value to be the time where all of the strobed signals become constant valued. If they do not become constant valued, then your circuit does not have a periodic-steady state solution and you cannot use PSS. This might happen if your PFD has a dead zone.

-Ken

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