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Simulators >> Circuit Simulators >> Using transient simulation to predict jitter
https://designers-guide.org/forum/YaBB.pl?num=1312076379

Message started by YCY on Jul 30^th, 2011, 6:39pm

Title: Using transient simulation to predict jitter
Post by YCY on Jul 30^th, 2011, 6:39pm

Hi Frank

I read your post in previous thread
http://www.designers-guide.org/Forum/YaBB.pl?num=1224609785/25#25
You mentioned that jitter could be analyzed using transient noise,
and it has a good matching with that of pnoise.
I don't know how to calculate jitter using transient simulation,
because in the eyeDiagram, Ｉcan only see the peak-to-peak jitter.
I have no idea how to get the rms value.
Could you please provide more information about how to do this?
Thanks a lot.

regards,
YCY

Title: Re: Using transient simulation to predict jitter
Post by sheldon on Aug 1^st, 2011, 4:24am

YCY,

You don't specify what you are looking for, if you are looking
at jitter of a clock signal in Virtuoso, then try using the calculator

rms( period_jitter(Vsig) - avg( period_jitter(Vsig))

Best Regards,

Sheldon

Title: Re: Using transient simulation to predict jitter
Post by YCY on Aug 1^st, 2011, 7:28pm

Hi, Sheldon

Thanks for your reply.

I just wonder how to use transient simulation to find out jitter.
For example, if I connect a chain of inverters and apply a clock signal at input,
then how do I get the edge-to-edge jitter using transient simulation?

Frank mentioned that one can use eyeDiagram function in the calculator to do so,
and I am curious how to do that.

BTW, you said I can use "rms( period_jitter(Vsig) - avg( "period_jitter(Vsig)) in the calculator.
Is period_jitter() a calculator function?
I cannot find that in the calculator in Spectre.
Thanks

regards,
YCY

Title: Re: Using transient simulation to predict jitter
Post by ywguo on Aug 7^th, 2011, 5:21am

Hi YCY,

period_jitter is a function in calculator for VIVA. VIVA is available if you have IC6.x.

However, period_jitter is not present in wavescan.

Yawei

Title: Re: Using transient simulation to predict jitter
Post by YCY on Aug 8^th, 2011, 9:43pm

ywguo wrote on Aug 7^th, 2011, 5:21am:

Hi YCY,

period_jitter is a function in calculator for VIVA. VIVA is available if you have IC6.x.

However, period_jitter is not present in wavescan.

Yawei

Hi, Yawei

Thanks for your response.
No wonder I cannot find it in my calculator (I use IC5141).

Nonetheless, I am still curious about how to get jitter using eyeDiagram().
Does anybody know how to do that?

regards,
YCY