zoujunjx
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Hello Ken Kundert and other pll specialists, After reading the paper "Predicting the phase noise and jitter of PLL-based frequency synthesizers", I have still many questions, could you give me a hand to resolve my unclear problem. Here I will first list some question about phase noise?
1 About the PSS and Pnoise simulation
I have made PSS and Pnosie simulation on a very common Current-Starved Single-ended VCO. The output frequency of the VCO is dependent on the input control voltage. I made the same simulation on two different input voltages, and finally get the two very different output phase noise spectra.But if i use the differential stage VCO, the two phase noise spectra on the two different input voltage are mostly same, just some small difference at low frequency. Because of the often problems at the convergence, so I just select "accuraty default = liberal" for pss simulation. My question, Is the spectrum actually dependent on the carry frequency in the VCO circuit, or not?
2.About the noise behavioral model of VCO In the paper, flicker_noise function is used to model the noise. (list 4 in the paper ). But wow to verify the behavioral model? Which simulation can be made on this model? PSS and Pnoise or others? How can setup the testbench, because this model is based on phase model, so it maybe have problem on the convergence of simulation.
I will continue my new questions, it is very kind of you to help me better understand your paper. thanks a lot!
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