Delay-locked loop with dynamically biased charge pump

摘要

A delay-locked loop, including a phase detector configured to receive two signals, one of the signals being delayed relative to the other of the signals, the phase detector having an UP output and a DOWN output. The delay-locked loop also includes a charge pump system operatively coupled with the phase detector, the charge pump system including (1) a charge pump configured to be responsive to assertion of actuating signals from the UP output and the DOWN output so as to control pumping of charge from the charge pump system, such pumped charge being usable to control a delay line carrying one of the two signals, so as to control relative delay occurring between the two signals; and (2) a feedback control loop configured to dynamically adjust at least one bias signal at the charge pump so as to minimize net charge pumped from the charge pump system during simultaneous assertion of actuating signals from the UP output and the DOWN output.

主权项

1. A delay-locked loop, comprising:
a first delay line; a second delay line; a first phase detector coupled to outputs of the first and second delay lines, the first phase detector including an UP output and a DOWN output; a second phase detector coupled to inverted outputs of the first and second delay lines, the second phase detector including an UP output and a DOWN output; a first charge pump coupled to the first phase detector so that the UP output of the first phase detector is coupled to a first charge pump input of the first charge pump and so that the DOWN output of the first phase detector is coupled to a second charge pump input of the first charge pump, where the first charge pump is configured to pump charge via a charge pump output of the first charge pump based on a bias condition and on levels at the first charge pump input of the first charge pump and the second charge pump input of the first charge pump; and a second charge pump coupled to the second phase detector so that the UP output of the second phase detector is coupled to a first charge pump input of the second charge pump and so that the DOWN output of the second phase detector is coupled to a second charge pump input of the second charge pump, where the second charge pump is configured to pump charge via a charge pump output of the second charge pump based on a bias condition and on levels at the first charge pump input of the second charge pump and the second charge pump input of the second charge pump.