Designer’s Guide Community

‹ Previous topic | Next topic ›

Pages: 1

Questions about Switched capacitor circuits simulation with PSS+PNOIS (Read 2549 times)

lunren

Community Member

Offline

Posts: 82
Asia

Questions about Switched capacitor circuits simulation with PSS+PNOIS
Aug 05^th, 2009, 2:46pm

Hi,

Today I simulated my swiched capacitor circuit (sample and hold) with pss+pnoise. In the simulation, the switched capacitor common mode feedback circuit was replaced by a ideal one. I am wondering how to use the real swiched capacitor CMFB in my simulation?

Why I was confused by this? Because SC-CMFB will take some time to settle down. I am not sure if I use the real SC-CMFB, the simulation results is culculated at correct DC operating point or not. Hope someone can give me some hints about this.

Thanks,

Lunren

Best Regards,

Lunren

IP Logged

HdrChopper Community Fellow Offline Posts: 493	Re: Questions about Switched capacitor circuits simulation with PSS+PNOIS Reply #1 - Aug 5^th, 2009, 5:50pm Hi, You SHOULD use the real CMFB circuit. PSS takes care of looking for the steady state value, meaning that it will iterate as much as it needs until it finds a stable periodic operating point. Only after finding such point it will start pnoise analysis. Hope this helps Tosei
Back to top	Keep it simple IP Logged

lunren Community Member Offline Posts: 82 Asia	Re: Questions about Switched capacitor circuits simulation with PSS+PNOIS Reply #2 - Aug 5^th, 2009, 6:15pm So that means I do not need to set tstart=50u, for example (assuming cmfb settles down after 50us)?
Back to top	Best Regards, Lunren IP Logged

Pages: 1

‹ Previous topic | Next topic ›