摘要 |
A clock signal phase comparator includes a first delay unit for delaying a clock signal for a predetermined time, a first phase detector for comparing an output signal of the first delay unit and a reference clock signal and outputting a first high or low level output signal, a second delay unit for delaying for a predetermined time and outputting the reference clock signal, and a second phase detector for comparing an output signal of the second delay unit and the clock signal and outputting a second high or low level output signal. The phase comparator separately displays the phase comparison results in grades of fast, slow and locking, and when a locked phase is detected, the phase control system is partially or entirely disabled, for thereby reducing current consumption of the system.
|