Digital phase lock loop system

Abstract From the Canadian patent

A macro phase detector responds to large phase deviation between a locally generated signal and a reference signal for actuating a successive frequency approximation register to effect major count alteration in a counter for controlling a digital-toanalog converter and, in turn, a voltage controlled oscillator. Small phase error is detected by a phase detector averaged, and, employed to alter the count in the counter for introducing sensitive frequency adjustment. A second counter is clocked by the phase detector at one half the rate of the first counter and is used to update the first counter each time the phase difference reverses polarity. Loss of reference signal activates a detector …