Patent ID: 7764522

Claim:
A method for controlling a start-up cycle, applied in an integrated circuit of a circuit system of a power supply, and the circuit system setting a normal operating voltage value and obtaining an AC input power, and the input power obtaining a bias voltage power for the normal operation of the integrated circuit, and the integrated circuit setting a start-up voltage value for starting the integrated circuit, a cut-off voltage value for shutting down the integrated circuit, and an idle voltage value, and the start-up cycle of the integrated circuit rising from the idle voltage value to the start-up voltage value through the bias voltage power to start the integrated circuit, or dropping from the start-up voltage value to the cut-off voltage value to shut down the integrated circuit, and the control method comprising the steps of: (A) obtaining an input power average, and determining whether or not the input power average has reached the normal operating voltage value; (B) maintaining the bias voltage power at the idle voltage value, if the input power average has not reached the normal operating voltage value; (C) driving the bias voltage power to raise to the start-up voltage value to start operating the integrated circuit, if the input power average has reached the normal operating voltage value; (D) shutting down the integrated circuit and continuing dropping the bias voltage power to the idle voltage value, and then rising from the idle voltage value to the start-up voltage value, if an overload of the circuit system causes a drop of the bias voltage power from the start-up voltage value to the cut-off voltage value, so as to repeat starting and shutting down the integrated circuit until the overload state is released.