Hi all,

I am relatively new to this field and have a few questions that is troubling me. Can anyone answer these questions?

What is the difference between source phase noise function vs the time domain sphi(f) calculation in Section 6 of Ken's "Predicting the phase noise and jitter of PLL-based frequency synthesizers" in Spectre? I am trying to characterize the phase noise of a divider and have found the phase noise function to give a lower noise curve than using the strobed noise analysis. Can anyone shed some light on what does the source phase noise function in Spectre calculating? Spectre reports phase noise in dBc/Hz, for a divider, is the carrier the divider's output frequency? The phase noise PSD in (35) of Section 6 seems to be rad2/Hz, how do we get to dBc/Hz?

If I am characterizing a PFD without the CP, then should I be using a time domain strobed analysis? Is the general rule to use the source phase noise function for continous time signals and the time domain strobed analysis for discrete time signals?

I appreciate any help with these questions.

Thanks,
ams_design