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PLL reference model for PSS+PNOISE

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I am looking for a simple PLL reference model or design with mostly ideal components and adjustable parameters such as Kvco, Kpfd, LFP and reference/VCO phase-noise -  which can be used in PSS+PNOISE simulations.

Background is that I developed and simulated a real PLL in Cadence with transient and PSS+PNOISE. The transient behaviour (lock-time, step-response, loop-bandwidth, phase-margin) etc. is matching the theoretical simulations I have done with both ADIsimPLL and a custom Matlab-tool.

But the PLL phase-noise result of the PSS+PNOISE is about 6dB lower than the theoretically expected phase-noise.This of course calls for a factor of 20*log(2) - but it is not - I have checked that already.

In addition the phase-noise of the CP+PFD seems to be the dominant factor for low offsets in the ADIsimPLL/Matlab simulations, but in the PSS simulations it seems that this noise is very low, or not enabled at all.

I was fiddling a lot to find the reason for the discrepancy, but did not yet suceed.

Therefore I am searching for a more or less ideal and simple PLL reference model for PSS in which I can set the key-parameters for the blocks and do the simulation.

Does someone have such a model at hand and can share it ?


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