Patent ID: 7827432

Claim:
A phase frequency detector comprising: a first edge detector for detecting first-type edges of a first signal to generate a first detection signal; a second edge detector for detecting the first-type edges of a second signal to generate a second detection signal; and a pulse reshaping controller for receiving the first detection signal and the second detection signal, the pulse reshaping controller generating a first control signal to the first edge detector and generating a second control signal to the second edge detector, the pulse reshaping controller generating a first output signal and a second output signal; wherein a pulse width of the first output signal is limited by the pulse reshaping controller, where the pulse reshaping controller comprises: a first latch unit coupled to the first edge detector for latching the first detection signal to generate the first output signal; a first delay unit for delaying the first output signal to generate a first delayed signal; a second latch unit coupled to the second edge detector for latching the second detection signal to generate the second output signal; and a second delay unit for delaying the second output signal to generate a second delay signal; wherein the first delay signal is converted into the first control signal and the second delay signal is converted into the second control signal.