Digital phase-locked loop (DPLL), method for controlling jitter in digital phase-locked loop (DPLL), method for optimizing dither in digitally controlled oscillator (DCO), and self-dithering digital Controlled oscillator (DCO) circuit

摘要

A digital phase locked loop (DPLL) and method include an adjustable delay line configured to receive a reference clock as an input and to output a dithered reference clock signal. A phase and frequency detector (PFD) is configured to compare the dithered reference clock signal with a feedback clock signal to determine phase and frequency differences between the dithered reference clock signal and the feedback clock signal. A digitally controlled oscillator (DCO) is configured to receive early or late determinations from the PFD to adjust an output in accordance therewith, wherein the dithered reference clock signal distributes jitter response to enhance overall operation of the DPLL.