Hi all,

I was trying to simulate an SC lowpass filter using spectre and I found that the output is very small, almost zero...So i guess i didn't give the correct input signal...
The input i used was a dc voltage source with dc level 1V and a PAC of 1V...Can anyone tell me whether this input is correctly set? If not, how should I set it?

Thanks~~

shyboy

Hi, Andrew,

Thanks for your reply...I am new to cadence, so i may be asking silly questions...Is it true that, to simulate an SC filter using Spectre, I need to run a PSS analysis followed by a PAC analysis? Can I simply use just an AC analysis?

shyboy

yes, i did read that paper, but i don't quite understand it...Could you kindly clarify some of my doubts?

1. Vin: if i set the type to dc, how can i specify the frequncy, amplitude, etc.? And where can i find the "alter" statement?

2. pss analysis: What are fundamental tones and beat frequency and what is the correct manner to specify them? And where can i specify the maxacfreq? Also what are the parameters in Options that are normally specified during SC filter simulation?

3. pac analysis: what effect does maxsideband have on the sim result? The paper mainly talked about the effect of maxsideband in the noise analysis, i think...

Sorry for so many questions...BTW, i am a student struggling with a design project, and i don't have much background on this project...So any help from you guys will be appreciated...