The Designer's Guide Community
Forum
Welcome, Guest. Please Login or Register. Please follow the Forum guidelines. Oct 23rd, 2017, 3:44pm
  HomeHelpSearchLoginRegisterPM to admin  
 
Pages: 1
Send Topic Print
Phase noise simulation using a verilog A model (Read 320 times)
iVenky
Community Member
***
Offline



Posts: 55

Phase noise simulation using a verilog A model
Jun 17th, 2017, 5:51pm
 
Hi,

I have an ideal current source for the VCO. The thermal noise of the current source was modeled in a verilog A model using the white_noise() function. When I run pss/pnoise, I observe that phase noise of the VCO is not considering the effect of noise due to this verilogA model. Any suggestions?

I tried verifying the white_noise() verilog A model separately by running a transient noise simulation and it works.

Back to top
 
 

The road to wisdom is through hardwork, determination and sacrifice
View Profile   IP Logged
subtr
Community Member
***
Offline

Analog Enthusiast

Posts: 48
USA
Re: Phase noise simulation using a verilog A model
Reply #1 - Jun 17th, 2017, 9:42pm
 
I expect that your noise is a transient parameter which the simulator even does not recognize as noise. The PSS basically wants to find periodic steady state which might even be hindered by the noise added. I don't think PSS runs a transient noise analysis. I believe PSS gives the sensitivity function which the pnoise can use to find the spectrum. Your noise is in time domain. pnoise is an AC analysis which might not even see your verilogA being there. Probably this is the reason why you see only device noise and not the model noise.
The solution is to do a tran noise analysis and take FFT of the crossing points to get the phase noise spectrum through matlab. This will take the effect of your verilogA into consideration because measurement is done on the transient data.
Back to top
 
 

Regards
Subtr
View Profile   IP Logged
Ken Kundert
Global Moderator
*****
Offline

The Spectre

Posts: 2077
Silicon Valley
Re: Phase noise simulation using a verilog A model
Reply #2 - Jun 17th, 2017, 10:09pm
 
My suggestion is, if you want help, you should give the model. We cannot help you if you give us no information.

-Ken
Back to top
 
 
View Profile WWW   IP Logged
Pages: 1
Send Topic Print
Trouble viewing this site? Copyright © 2002-2014 Designer's Guide Consulting. 'Designer's Guide' is a registered trademark of Designer's Guide LLC. All rights reserved.

Our colleges are not as safe as they seem. Sexual assault is pervasive and the treatment of the victim by the adminstration is often as damaging as the assault: Campus Survivors, Campus Survivors Forum.

Some of our other sites that you might find useful: QuantiPhy.