Patent ID: 7532695

Claim:
A clock signal extraction device for extracting an extracted clock signal out of a periodic data signal, comprising: a first clock generator circuit configured to generate a rising edge clock signal, the first clock generator circuit having a first output; a first phase detector configured to detect a first phase difference between a rising edge of the periodic data signal and a rising edge of the rising edge clock signal, the first phase detector having a first input connected to the first output to form a first loop, and wherein the first clock generator circuit and the first phase detector cooperate to reduce the detected first phase difference, a second clock generator circuit configured to generate a falling edge clock signal, the second clock generator circuit having a second output; a second phase detector configured to detect a second phase difference between a falling edge of the periodic data signal and a falling edge of the falling edge clock signal, the second phase generator having a second input connected to the second output to form a second loop, and wherein the second clock generator circuit and the second phase detector cooperate to reduce the detected second phase difference; a third clock generator circuit configured to generate the extracted clock signal and; a controller comprising a phase pump and a loop filter configured to control the third clock generator circuit based on an average of the first phase difference and the second phase difference.