Patent ID: 7355487
Filing Date: 2008-04-08
Classification: H03L

Abstract:
1. A phase lock loop, comprising: a phase frequency detector, receiving a frequency-dividing signal and an input reference signal, and outputting a phase difference signal after comparing the frequency-dividing signal and the input reference signal; a discriminator, receiving the phase difference signal, determining a phase difference between the frequency-dividing signal and the input reference signal, and outputting a discrimination signal when the phase difference is greater than a predetermined value; a charge pump, receiving the phase difference signal and the discrimination signal, and outputting a voltage signal according to the phase difference signal and the discrimination signal; a voltage controlled oscillator, receiving the voltage signal, and outputting an oscillation signal according to the voltage signal; and a frequency divider, used for frequency-dividing the oscillation signal and outputting the result as the frequency-dividing signal input of the phase frequency detector.