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Design >> Analog Design >> Simulating switched-capacitor filter in spectreRF.
https://designers-guide.org/forum/YaBB.pl?num=1142834688

Message started by raul on Mar 19^th, 2006, 10:04pm

Title: Simulating switched-capacitor filter in spectreRF.
Post by raul on Mar 19^th, 2006, 10:04pm

I have read and run the netlists included on the article posted in this website; "Simulating switched-capacitor filters with SpectreRF". But I really want to use the schematic editor instead of running the netlist in the command line. I've found one problem though; the vsource component doesn't allow me to define two frequencies in the symbol from the analogLib. This corresponds to the line in the netlist that implements the input source "Vin" on the first netlist tah.ckt. Can anyone help me figure out what's wrong?

Title: Re: Simulating switched-capacitor filter in spectr
Post by Andrew Beckett on Mar 22^nd, 2006, 10:56pm

Really? Are you using the analogLib/vsource/symbol component? If so, then set "Source Type" to "sine", and then uncheck the checkbox labelled "Display second sinusoid" and fill in the parameters for it there.

I was wondering if you were perhaps using the older "vsin" component, but even that has parameters for the second frequency (called Amplitude 2, Frequency 2, for example). This still is netlisted as a spectre vsource component - it's kept for compatibility reasons - I'd use vsource these days though, as it's a more direct interface to the underlying spectre source.

Regards,

Andrew.

Title: Re: Simulating switched-capacitor filter in spectr
Post by raul on Mar 22^nd, 2006, 11:13pm

i had not seen the box to select the second sinusoid. thanks a lot.

Title: Re: Simulating switched-capacitor filter in spectr
Post by xwcwc1234 on Apr 18^th, 2006, 12:33am

I need to simulating noise performance of a chopping amplifier . Anyone know how to simulate it using SpectreRF ?

Title: Re: Simulating switched-capacitor filter in spectr
Post by Ken Kundert on Apr 23^rd, 2006, 9:29am

Choppers are very much like switched-cap filters, so you can use the same paper as a reference (http://www.designers-guide.org/Analysis/sc-filters.pdf).

-Ken