DELAY LOCKED LOOP CIRCUIT AND DELAY LOCKING METHOD

摘要

A delay locked loop circuit includes a phase detecting unit for detecting a phase difference between a reference clock signal and a feedback clock signal, and for producing a phase difference detection signal, a code generating unit for producing a digital code signal according to the phase difference detection signal, a control current generating unit for generating a control current using the digital code signal, and a current controlled delay line for producing the feedback clock signal by delaying the reference clock signal by a delay time varied by the control current.