Apparatus and method to reduce jitter in a phase locked loop

摘要

A circuit and method to reduce jitter and/or noise in a phase-locked loop (PLL). A voltage-controlled oscillator (VCO) control signal is tapped and filtered to create a low-noise, filtered VCO control signal. The filtered and unfiltered control signals are individually weighted and then combined to create a modified VCO control signal which reduces the jitter and/or the noise by reducing an effect of VCO gain on the jitter and/or the noise.