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Simulators >> RF Simulators >> Multi-frequency Switched Capacitor Circuit with SpectreRF
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Message started by Bradford Hunter on Oct 14^th, 2013, 10:19am

Title: Multi-frequency Switched Capacitor Circuit with SpectreRF
Post by Bradford Hunter on Oct 14^th, 2013, 10:19am

I have a switched capacitor integrator that I am trying to perform noise analysis on using SpectreRF pss and pnoise. The integrator switches at a fundamental frequency and the integrator amplifier is chopped at a much lower frequency (say 1000 times lower). The amplifier chopping cancels out the contribution of flicker noise. Is there an efficient way to run a pss analysis with two vastly different switching frequency time scales? The memory usage for the pss analysis exceeds 100 GB of swap space before I finally stop the simulation prematurely. qpss analysis doesn't seem appropriate because it requires one source to be sinusoidal. Both of the integrator switching sources are square by design. At the moment I am running the amplifier chopping at 2 times the frequency of the integrator clocking, but the input referred noise shape from pnoise is not entirely accurate. In practice, the flicker noise will be moved to a much lower frequency due to the lower chopping rate.

Title: Re: Multi-frequency Switched Capacitor Circuit with SpectreRF
Post by RFICDUDE on Oct 20^th, 2013, 6:12pm

You could also use transient noise analysis. It may take a long time to simulate if you are trying to resolve the flicker noise contribution. But it won't take so much memory to run.