SYSTEM AND METHOD FOR CALIBRATING OUTPUT FREQUENCY IN PHASE LOCKED LOOP

摘要

A Digital Calibration System for a Phase Locked Loop includes a Tuning Voltage Controller configured to set the tuning voltage to a value; a Phase Difference Quantizer configured to output a phase difference after comparing a phase of the reference signal with a phase of the feedback signal; a Digital Controller configured to receive the phase difference of the PDQ and control a coarse tuning signal such that an average phase difference of the PDQ is 0; and a Frequency Calibration Logic configured to calibrate the feedback signal in response to the output of the DC.