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Modeling >> Behavioral Models >> PLL noise modeling
https://designers-guide.org/forum/YaBB.pl?num=1238170332

Message started by tea on Mar 27^th, 2009, 9:12am

Title: PLL noise modeling
Post by tea on Mar 27^th, 2009, 9:12am

Good morning Ken and all

I am reading two of your articles: "Predicting the Phase Noise of PLL-Based Frequency Synthesizers" and " Modeling PLLs with Jitter". It is very inspiring!!
Sorry i am kind of new to this and new to SpectreRF as well. I have a few silly questions if you don't mind. Thank you in advance!

in both of your articles, you mentioned to characterize the noise, we need to run PSS/PNoise. Then use the result in the model. You described the modeling methodology on PLL jitter modeling in "Modeling PLLs with Jitter" and you described phase noise modeling in the other article i mentioned. I am trying to implement this in my models. so here are my silly questions, i just want to make sure i am doing it right

1) for jitter, you mean, run PSS, then run PNoise, set the noise source to Jitter, then plot the noise vs. output frequency. and based on the PLL output clock frequency, find out the jitter amont from the plot. put it in the model, right? of couse, add a dist_normal to randomize it as well

2)for phase noise, you mean, run PSS, set the noise type to sources, plot out the phase noise vs output frequency, based on the output frequency of the PLL, find out the corresponding phase noise value, use flicker_noise to add it to the output. for white noise, should i just set the source to timedomain and get the plot? add it to the output as well?

3)so, i assume i can put both jitter and phase noise in one model as well? will it be more accurate?

sorry for so many questions

thanks very much

jasmine