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aaron_do

Senior Fellow

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Posts: 1398

PSS + sampled PAC
Dec 04^th, 2013, 10:56pm

Hi all,

I am trying to run PSS + sampled PAC on a sample and hold, and I have noticed two problems.

1) I used the "sampled PAC" analysis directly in spectreRF, and it allows me to plot the PAC waveforms for specific time instances. However, when I try to do a parametric sweep of a DC bias (for example), I can no longer plot the waveform at a specific time instance, and the waveform is always averaged over time. How can I get around this?

2) One solution I tried for the above was to use normal (not sampled) PAC analysis, and then add an ideal sample and hold at those nodes I want to analyze (sah_ideal from analogLib). However, when I do this, the PAC node voltage is attenuated by about 80 dB. Does anybody know the reason for this?

thanks,
Aaron

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Frank Wiedmann

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Posts: 678
Munich, Germany

Re: PSS + sampled PAC
Reply #1 - Dec 5^th, 2013, 6:41am

I have never tried this combination. This may well be a bug. By looking at the analysis statements in the netlist, you might be able to find out if the bug is likely to be in ADE or in SpectreRF. I suggest that you present your problem at http://www.cadence.com/community/forums/33.aspx and if that does not help, contact Cadence Support.

I am not sure if the sah_ideal from ahdlLib works properly in pac analysis. It has a hidden state (see http://www.designers-guide.org/Analysis/hidden-state.pdf) that is not flagged as an error because the module is marked as an (* instrument_module *).

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aaron_do Senior Fellow Offline Posts: 1398	Re: PSS + sampled PAC Reply #2 - Dec 5^th, 2013, 4:41pm Thanks for the help. Aaron
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