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Measurements >> Phase Noise and Jitter Measurements >> how to get phase noise from clock periods data
https://designers-guide.org/forum/YaBB.pl?num=1218170137

Message started by end_ru on Aug 7^th, 2008, 9:35pm

Title: how to get phase noise from clock periods data
Post by end_ru on Aug 7^th, 2008, 9:35pm

Hi all,

I am new in this area. Suppose that I have a non-ideal clock waveform with non-equal periods, e.g. first cycle period = 1 ns, second cycle period = 1.001 ns, etc:
- How can I get the phase noise using this data?
- Can I just directly apply FFT to it?
- If yes, how to determine the x-axis value if I put it into a plot?

Thanks in advance! =D

Title: Re: how to get phase noise from clock periods data
Post by Miconos on Aug 17^th, 2008, 1:12am

from this kind of data what you can do is claculate Jitter and not phase noise. from the jitter you can clculater intgrated phase noise.

Title: Re: how to get phase noise from clock periods data
Post by trond on Aug 20^th, 2008, 5:48am

Hello

If you have a look at the paper "Predicting the phase noise and jitter of PLL-based frequency synthesizers" which is on this website there in Listing 17 is a wee matlab script that does the trick.

Regards,