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Simulators >> RF Simulators >> SpectreRF Settings for Figures in sc-filters.pdf
https://designers-guide.org/forum/YaBB.pl?num=1153345041

Message started by dwingram on Jul 19^th, 2006, 2:37pm

Title: SpectreRF Settings for Figures in sc-filters.pdf
Post by dwingram on Jul 19^th, 2006, 2:37pm

I am trying to reproduce some of the figures found in the document, sc-netlists.pdf. Specifically the ones on pp. 14-15, figures 6-8. I have run through the simulations and it is clear that the setup for each simulation doesn't directly correspond to these figures. Even though I can come close, it would be very convenient to be able to reproduce them identically, within reason.

Regards,
dwingram

Title: Re: SpectreRF Settings for Figures in sc-filters.p
Post by Ken Kundert on Jul 20^th, 2006, 9:37am

Have you tried downloading the netlists?

-Ken

Title: Re: SpectreRF Settings for Figures in sc-filters.p
Post by dwingram on Jul 20^th, 2006, 9:53am

Thanks for the reply.

I have downloaded the netlists and have run the simulations many times. The results I have obtained do not appear to directly map to the figures to which I referred in the document. I am confident that it is simply a misunderstanding on my part.

For example, Figure 8 illustrates the transfer functions from the input, for sidebands up to +/- 25, to the output at baseband. The graph shows transfer functions out to ~10MHz, but in the pss analysis statement, maxacfreq=6MHz. It is not clear to me how the pxf analysis can evaluate sidebands beyond maxacfreq.

Title: Re: SpectreRF Settings for Figures in sc-filters.p
Post by dwingram on Jul 20^th, 2006, 11:46am

Ken,

I believe my problem with this analysis is that I have been simulation using the switched capacitor filter netlist and not the track and hold netlist. Thanks for replying earlier.

Regards,
dwingram

Title: Re: SpectreRF Settings for Figures in sc-filters.p
Post by dwingram on Jul 20^th, 2006, 2:27pm

Now that I have the right circuit running, I can reproduce Figures 6 and 7 from the document, but my attempt at Figure 8 is not quite what you display in the document.

I am running the tah.ckt netlist using spectre version 6.1.0.151.

Thanks,
dwingram

Title: Re: SpectreRF Settings for Figures in sc-filters.p
Post by Ken Kundert on Jul 28^th, 2006, 4:53pm

There was an error in the paper. To get the results shown in Fig 8, the PXF analysis must use the node 'sout' rather than the node 'out'. I have updated the paper and the netlists.

-Ken

Title: Re: SpectreRF Settings for Figures in sc-filters.p
Post by dwingram on Jul 31^st, 2006, 9:13am

Ken,

Thanks again for the assistance, I have confirmed the simulation results match Figure 8.

dwingram