Digitally controlled phase locked loop system having coarse and fine locking modes

摘要

A phase detector included in a digital television receiver develops first and second phase error signals based on samples of the color reference burst signal taken from one and two horizontal lines respectively. The first phase error signal is used to attain coarse synchronization between a sampling clock signal and the burst signal. The second phase error signal is used to enhance synchronization accuracy after coarse synchronization has been attained.