Fast-locking phase-locked loop, frequency divider, and communication device

Abstract

The present disclosure provides a phase-locked loop, a frequency divider and a communication device that enable fast locking. The phase-locked loop comprises a phase frequency detector, a charge pump, a loop filter, a voltage-controlled oscillator, a fast-locking control unit and a frequency divider, wherein the frequency divider comprises a plurality of cascaded frequency division units and a reset/set control circuit, the reset/set control circuit being configured to receive the reset signal outputted by the fast-locking control unit, and in response to transition of the reset signal from a low level to the high level, change a state code combination composed of respective state codes of the cascaded frequency division units from the first state to the second state, to cause transition of a feedback signal outputted by the frequency divider from the low level to the high level. With the frequency divider and phase-locked loop, fast locking can be achieved.