How to simulate switch capacitor circuit in ADS

[iexplorer]

I wonder how to simulate switch capacitor circuit such as SC filter 's frequency response in ADS , in cadence I can use PSS and PXF , but how can I do it in ADS?Does anyone know it ? Thanks very much!

 

[khouly]

i think u don't have other option rather than the transient smulation.

u can't use the HB engine in ADS

Khouly

 

[iexplorer]

But how can I get the frequency response in tran? Could u please explain that in details, thanks

 

[LvW]

I wonder how to simulate switch capacitor circuit such as SC filter 's frequency response in ADS , in cadence I can use PSS and PXF , but how can I do it in ADS?Does anyone know it ? Thanks very much!

I don´t know ADS. However, you can do an exact ac analysis (frequency response) with the help of each general purpose simulation program if you replace each s/c unit with a time continuous equivalent (consisting of a positive or negative resistance and a delay unit). If you are interested I can give you some more information and references.

 

[iexplorer]

Thanks,LvW
use CT subsitute is a good idea, but unfortunately, we can not get some second order effect such as charge inject or parasite in our simulation , it's not very convenient for performance improve,isn't it?

 

[LvW]

Yes, I agree with that. Substitution of s/c elements by continuous time units can be recommended when you are interested in the principle and ideal frequency response
(e.g. for tutorial purposes). Parasitic effects are hard to cover.

 

[khouly]

for switched capacitor circuit use the transent analysis , then FFT to get the frequency response of the circuit

khouly

 

[iexplorer]

Thanks khouly
I have tried this before,but still have some problem , when you do FFT with trans sim, you get the output spectrum with center freq and harmonics, so you can only get voltage or power of one point frequency , I wonder if there is some way to get the steady state and do AC sim ?

 

[khouly]

in ADS i don't think AC simulation can handle this. if u are interested in the steady state , u need to run the transient for long time.

another way. u can use the HB with large order about 9 to 13 ,
i didn't try it before. but u need to ask agilent guys

khouly