A management circuit for a power supply is provided. The power supply includes a power factor correction circuit and a power conversion circuit. An output of the power factor correction circuit is coupled to an input of the power conversion circuit. The management circuit includes a power factor correction controller, a pulse width modulation controller and a control circuit. The power factor correction controller controls power factor correction of the power factor correction circuit. The pulse width modulation controller controls power conversion of the power conversion circuit. The control circuit selectively activates the pulse width modulation controller according to a first activated signal generated by an input power of the power supply. After the pulse width modulation controller is activated, the control circuit generates a second activated signal based on the first activated signal. The control circuit activates the power factor conversion controller according to the second activated signal.
