TIME TO DIGITAL CONVERTER CAPABLE OF DETECTING NOT ONLY A PHASE DIFFERENCE OF INPUTTED TWO SIGNALS BUT ALSO A FREQUENCY DIFFERENCE AND A DIGITAL PHASE LOCKED LOOP

摘要

PURPOSE: A time to digital converter and a digital phase-locked loop are provided to improve a phase-alignment accuracy by detecting not only a phase error but also a frequency error.;CONSTITUTION: A converter(120) receives a first signal and a second signal. The converter gradually delays the second signal using delay elements. The converter outputs the phase error of the second signal about the first signal. A phase frequency detector(110) receives a third signal from one node among the first signal and the node of a plurality of delay elements. The phase-frequency detector outputs a phase difference about the first signal and the third signal. A frequency detector(130) outputs the frequency error of the second signal about the first signal to a digital code using the second signal and the output signal of the phase-frequency detector.;COPYRIGHT KIPO 2010