FREQUENCY SYNTHESIS METHOD OF FAST LOCKING BASED ON PHASE-LOCKED LOOP FREQUENCY AND CIRCUIT THEREOF

摘要

A frequency synthesis method of fast locking based on phase-locked loop frequency and a circuit thereof, the method comprising the steps of: configuring data for a phase-locked loop unit when a locking timeslot starts; charging a loop filter; the phase-locked loop unit outputs a locking instruction when the output frequency of a voltage controlled oscillator is within the range of the configuration data of the phase-locked loop unit; disconnecting the power source according to the locking instruction. The present invention charges the loop filter before the locking timeslot starts, and disconnects the power source according to a locking instruction signal, thus shortening the locking time of the phase-locked loop.