Problem in PSS Convergence

[nishanthpv]

I designed one 4th order switched capacitor biquad filter in UMC 180 nm technology using cadence software (version 5.10.41).This circuit is operating on a two phase non overlapping clock generator (i/p frequency = 1 kHz). To simulate this circuit I used, PSS and PAC analyses in Spectre RF tool(Analog Design Environment). For single ended topology it is converging. But for double ended, simulation is not converging. But working of the filter ensured by doing transient analysis( It passes in band signals and it attenuates out of band signals ). Here I am adding screen shots of simulation windows. I request somebody to point me out the mistakes.
Thanks in advance,
Nishanth
https://obrazki.elektroda.pl/9375240200_1350640031.jpg

 

[superleaf]

You can see this material:Simulating Switched-Capacitor Filters with SpectreRF~

I designed one 4th order switched capacitor biquad filter in UMC 180 nm technology using cadence software (version 5.10.41).This circuit is operating on a two phase non overlapping clock generator (i/p frequency = 1 kHz). To simulate this circuit I used, PSS and PAC analyses in Spectre RF tool(Analog Design Environment). For single ended topology it is converging. But for double ended, simulation is not converging. But working of the filter ensured by doing transient analysis( It passes in band signals and it attenuates out of band signals ). Here I am adding screen shots of simulation windows. I request somebody to point me out the mistakes.
Thanks in advance,
Nishanth
https://obrazki.elektroda.pl/9375240200_1350640031.jpg