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Design >> RF Design >> �Simulating Switched Capacitor Filters with Spectr
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Message started by briand on Aug 9^th, 2007, 5:54pm

Title: �Simulating Switched Capacitor Filters with Spectr
Post by briand on Aug 9^th, 2007, 5:54pm

I have a question about the �Simulating Switched Capacitor Filters with SpectreRF� paper.

For the simple track and hold, Sc(f) is listed as eq 16. �Next eq 17 which is the total noise is calculated by integrating eq 16 from 0 in infinity. �The result of eq 17 is kt/C.

In the results section eq 19 evaluates eq 16 at DC. �My simulation matches up for this.

Next I try to get the total noise by integrating over the output from unsmpledNoise^2 with Cadence�s AWD. �I�ve attached this waveform. �The result is 284p.

If I calculate kt/C I get: (13.81e-24)*300/10p=414.3p.

I would expect these numbers to be very close. �Is this a numerical problem or am I making a mistake? �I know I�m not going to infinity but I�m expecting the spectrum to be so flat that it doesn�t matter.

Thanks,
Brian