The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Measurements >> Phase Noise and Jitter Measurements >> pss/pnoise vs transient
https://designers-guide.org/forum/YaBB.pl?num=1380047988

Message started by Frank99 on Sep 24^th, 2013, 11:39am

Title: pss/pnoise vs transient
Post by Frank99 on Sep 24^th, 2013, 11:39am

hi,

I am running simulations on a crystal oscaillator to verify the period jitter using a few different approach.

A. running pss and pnoise td gives Jc[1k] rms=50fs, peak2peak_BER=10e-3]=300fs
B. running long transient simulation and using the built-in period_jitter function gives 300fs
C. using the same transient data and plot eye diagram. use crosshair to measure the width of the rising(or falling) edge gives 30fs.

i initially thought result from A and B and C should all agree but now i have doubt.

question
1. result A and B matched, but I was told pss/pnoise uses device noise
where as transient (default) does not have device noise in the model.
is this true? if so how do i get the device noise into a transient simulation?

2. B and C uses the same data, and i expected the result to match. Any idea as to why?

3. is there any other way to verify the period jitter again pss/pnoise other then transient

4. (unrelated) in the noise summary, the strobe noise sim provides noise at a particular threshold.
however in the noise summary from a pnoise type=source, it only provide a single number. user guide says this noise summary is an average noise over the cycle. any idea on what the formula is?

thank you very much for your help.

Frank

Title: Re: pss/pnoise vs transient
Post by specialest on Dec 1^st, 2014, 5:23pm

have the same question here. I simulate crystal oscillator and squaring buffer together. Lots of questions in different simulation approaches.