A phase locked loop (PLL) and a method for charging the PLL are disclosed. The charge circuit includes: a threshold judging module, adapted to output a signal to a receiving module, and when the voltage of a filter reaches a preset threshold, output a valid signal to the receiving module; the receiving module, adapted to receive a trigger signal and output a first control signal to a charging module, and when the signal from the threshold judging module is a valid signal, adapted to output a second control signal to the charging module; the charging module, adapted to charge the filter when receiving the first control signal and stop charging the filter when receiving the second control signal. So that a better voltage may be provided to the PLL to shorten the locking time of the PLL.