Synthesizer with lock detector and method of operation thereof

摘要

The present invention provides an apparatus and method for generating a lock detect signal indicative of stability of a frequency of an output signal based upon UP and DN signals received from a phase detector. The apparatus comprises an input that receives the UP and DN signals; a first circuit that combines the received UP and DN signals to obtain a combined signal; a delay stage that operates upon the combined signal to obtain a delayed combined signal; and a second circuit that operates upon the combined signal and the delayed combined signal to obtain the lock detect signal.