APPARATUS AND METHODS FOR CONTROLLING DELAY USING A DELAY UNIT AND A PHASE LOCKED LOOP

摘要

An apparatus for controlling a delay includes a phase locked loop and a delay unit. The phase locked loop generates an oscillation signal having a frequency substantially identical to that of a reference signal. The delay unit includes a delay cell block that outputs delayed signals by delaying the reference signal sequentially by a uniform delay interval. The delay unit controls the delay interval based on a frequency/phase difference between a first input signal and a second input signal of the phase locked loop, and outputs one of the delayed signals as a delayed reference signal. Related methods are also described.