PSS Analysis of Frequency Divider

I am doing PSS analysis for phase noise measuremnt of a FRequency Divider.

Input frequency is 2.5 GHz which is given through a 'vpulse' of analogLib. and Output Frequency is supposed to be 125 MHz.

How to set the PSS analysis so to get PSS analysis done for the fundamental frequency of 125 MHz???

Please help ASAP.

Use Shooting-Newton-PSS. Don't use HB-PSS.
Set like followings.

pss pss fund=125M harmsvec=[20] maxacfreq=25G

pnoise (Vout 0) pnoise sweeptype=relative relharmnum=20
+ start=100 stop=100k dec=11 maxsideband=200

pancho_hideboo said:

Use Shooting-Newton-PSS. Don't use HB-PSS.
Set like followings.

pss pss fund=125M harms=0 maxacfreq=25G

pnoise (Vout 0) pnoise sweeptype=relative relharmnum=1
+ start=100 stop=100k dec=11 maxsideband=200

Click to expand...

Thank you for the reply.

I am using Shooting-Newton method.

Please see the attached snapshots of vpulse source and PSS analysis setup. I am confused about what to set against the parameter "Frequency Name for 1/period" in vpulse CDF window.





Please suggest what to set in PSS setup window also.

Before going on frequency divider, do you surely understand Shooting-Newton-PSS for conventional amplifier ?

samiran_dam said:

Please suggest what to set in PSS setup window also.

Click to expand...

If you would like to utilize full power of Cadence Spectre, you have to understand syntax of netlist of Cadence Spectre.

As first step, read results of "spectre -h pss" and "spectre -h pnoise".

Important parameters for your circuits are :

fund=125M harmsvec=[20] maxacfreq=25G for pss statement

sweeptype=relative relharmnum=20 maxsideband=200 for pnoise statement

samiran_dam said:

I am confused about what to set against the parameter "Frequency Name for 1/period" in vpulse CDF window.

Click to expand...

"Frequency Name for 1/period" is not mandatory for PSS.

Disable "Auto Calculate" in PSS Analysis Setup Window.
Then enter 125MHz directly as fundamental frequency.

Even if you set 125MHz as fundamental frequency of PSS, you can never run PSS correctly for frequency divider circuits.

I say my answers repeatedly.
If you would like to utilize full power of Cadence Spectre, you have to understand syntax of netlist of Cadence Spectre.

As first step, read results of "spectre -h pss" and "spectre -h pnoise".

Important parameters for your circuits are :

fund=125M harmsvec=[20] maxacfreq=25G for pss statement

sweeptype=relative relharmnum=20 maxsideband=200 for pnoise statement