help:how to simulate CMRR and PSRR in Spectra

[jacklee]

hello guys......
i'm designning a opa in a BGR,how do i simulate CMRR and PSRR in spectra?
thank u!

 

[Robert Qi]

Add a ac signal on the power supply , and do ac analysis, then u can get the PSRR.

 

[princerock]

Hello,

I think you should do the xf analysis. And when ploting your result, choose your diffirential input signal at first and the common mode input signal as second. Then you can use calculator to minus the above two curves (in dB). In this way you got the CMRR.

For PSRR, just replace the common mode source by the supply source. Do the same thing as said above.

Hope this can helps.

princerock

 

[jacklee]

Robort,princerock,thank you!