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.