Digital phase lock clock generator without local oscillator

摘要

A digital phase lock loop that does not depend on a voltage controlled oscillator (VCO) for phase locking. A phase detector (PD), terminated with a latch, controls an up/down counter that programs an increase/decrease of delay on the delay line. The tapped output of the delay line goes through a two phase generator which in turn feeds back to the PD for comparison with the reference clock. This process is repeated until phase locking is obtained.