Patent ID: 6246738
Filing Date: 2001-06-12
Classification: H03D,H03L,H04J,H04L

Abstract:
A phase detector for use in a phase locked loop having a voltage controlled oscillator, said phase detector comprising:(a) a counter clocked by a clock signal produced by said voltage controlled oscillator;(b) a latch coupled to said counter and clocked by a modulated clock signal to latch values output by said counter;(c) a phase modulator for modulating a synchronization clock reference signal to produce said modulated clock signal; and,(d) an accumulator coupled to said latch and clocked by said modulated clock signal to receive and average said latch values and to produce a phase error signal representative of phase difference between said voltage controlled oscillator clock signal and said synchronization clock reference signal, said phase error signal coupled to said voltage controlled oscillator to reduce said phase difference.