A damping circuit is described which includes a phase-and-frequency detector, a charge pump, a voltage-current oscillator and a capacitor. The phase-and-frequency detector generates UP and DOWN signals representative of a difference in phase between a pair of digital input signals. The charge pump varies...http://www.google.fr/patents/US5371425?utm_source=gb-gplus-shareBrevet US5371425 - Digital damping method and apparatus for phase-locked loops
Digital damping method and apparatus for phase-locked loops
