Patent ID: 7016450

Claim:
A clock recovery circuit for generating an output signal that is synchronized with an input signal; the clock recovery circuit comprising: a charge pump for generating a charging current according to a phase difference between the input signal and the output signal; a first filter electrically connected to the charge pump for generating an output voltage corresponding to the charging current; a second filter for adjusting the output voltage of the first filter; a switch circuit electrically connected in series between the first filter and the second filter for controlling the electrical connection between the first filter and the second filter; and an oscillator for adjusting a phase or frequency of the output signal according to a voltage; wherein when the charge pump is operating, the switch circuit disconnects the first filter from the oscillator, and when the charge pump stops operating, the switch circuit connects the first filter and the oscillator such that the oscillator adjusts the frequency or phase of the output signal according to the output voltage of the first filter.