Patent ID: 6636079
Filing Date: 2003-10-21
Classification: H03D,H03L,H04N

Abstract:
A phase comparing circuit, comprising:a phase comparator configured to detect phase difference between first and second input signals; a charge pump circuit configured to output a signal in accordance with said detected phase difference; and a feed forward circuit connected between said phase comparator and a first signal transmission path in said charge pump circuit, said feed forward circuit being configured to provide the signal in accordance with said phase difference to said charge pump circuit; wherein said phase comparator includes: a second signal transmission path which outputs a signal in sync with said first input signal; and a third signal transmission path which outputs a signal in sync with said second input signal, wherein said feed forward circuit includes: a first capacitor having a first end connected to said second signal transmission path, and a second end connected to said first signal transmission path; and a second capacitor having a first end connected to said third signal transmission path, and a second end connected to said first signal transmission path.