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https://designers-guide.org/forum/YaBB.pl Measurements >> Phase Noise and Jitter Measurements >> How to get PFD/CP jitter ? https://designers-guide.org/forum/YaBB.pl?num=1266817388 Message started by Chris Yang on Feb 21st, 2010, 9:43pm |
Title: How to get PFD/CP jitter ? Post by Chris Yang on Feb 21st, 2010, 9:43pm Dear All, I am trying to follow Ken's article "Predicting the Phase Noise and Jitter of PLL-Based Frequency Synthesizers" and to build a PLL (Integer-N) behavior model to get the pll phase noise performance. When extracting the jitter of PFD/CP, I got 656ns. Is it reasonable? After running Pnoise simulation for PFD/CP, I got -96.1dBc/Hz @ 10Hz -106.6 100 -116.8 1K -126.2 10K -132.9 100K -134.8 1M -135.3 10M I got var(n) which is 6.6e-7 by formula (57) in the article. The current of CP is 25uA and the frequency of PFD is 35MHz. According to formula (58), I got 656ns. I think it is really a large number. Is there any problem in my calculation? Please help me~~ Thanks, Chris |
Title: Re: How to get PFD/CP jitter ? Post by pancho_hideboo on Feb 22nd, 2010, 12:24am Don't do multiple post of same contents. This post is completely same as following. http://www.designers-guide.org/Forum/YaBB.pl?num=1266810763/0#0 |
Title: Re: How to get PFD/CP jitter ? Post by Chris Yang on Feb 24th, 2010, 7:35pm sorry for reposting. I just thought the content is more proper for this category. BTW, does anyone do well on PFD/CP jitter extraction? I still can not get a good result. |
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