SLIP-DETECTING PHASE DETECTOR AND METHOD FOR IMPROVING PHASE-LOCK LOOP LOCK TIME

摘要

An improved digital phase detector is provided for detecting and compensating for a cycle slip between a reference signal and a frequency source signal, the reference and frequency source signals each comprising pulses, each pulse defined by a leading edge and a trailing edge. The digital phase detector includes a detector circuit for detecting a cycle slip where two successive leading edges of one of the reference and frequency source signals are received before a leading edge of the other signal is received. An output circuit is operatively coupled to the detector circuit for developing a correction signal responsive to said detecting.