Comments on “folding of phase noise spectra in charge-pump phase-locked loops induced by frequency division”

摘要

Spectrum folding of the voltage-controlled oscillator's phase noise in a charge-pump phase-locked loop (CP-PLL) has been shown by Levantino et al. to impose a lower bound for the in-band noise floor. This manuscript adds two further contributions to their work: (i) it corrects an approximation error in their original manuscript and (ii) it highlights the additional elevated mid- and high-frequency noise contributions in the wideband case.