US Patent 7202707 High frequency binary phase detector

A phase detector includes a first flip flop having a data input coupled to a first clock signal at a first frequency and a clock input coupled to a second clock signal at a second frequency. The frequency of the first clock signal is a multiple of the frequency of the second clock signal. The phase detector also includes a second flip flop having a data input coupled to an output of the first flip flop and a clock input coupled to the second clock signal.