Electrifying startup circuit and electrifying startup method thereof

The invention relates to an electrifying startup circuit and an electrifying startup method thereof. The electrifying startup circuit simultaneously realizes an electrifying time-delay control function and a current limiting protection function by using a multiplexing pin of a chip in which a power switching tube and a control circuit are integrated and using an external RC time-delay circuit, so the electrifying startup circuit starts to work after a certain time delay. A control chip is provided with at least three pins such as the multiplexing pin, an input pin and an output pin, wherein the multiplexing pin is connected with the RC time-delay circuit; the input pin is connected with an input voltage source; the output of the output pin is used for supplying power to lower level connected equipment; a first reference voltage source is arranged in the control chip; the output pin outputs a voltage signal; and the delay time is determined by first capacitance and a first reference voltage. As the electrifying time-delay control and the output current limiting protection share the same multiplexing pin of the integrated control chip, the number of pins of the chip is reduced, and the volume of the chip is reduced; and an output voltage of the electrifying startup circuit is slowly risen according to a certain rising slope, so that damage to subsequent circuits or influence on normal work of the subsequent circuits due to the overshoot of the output voltage in the electrifying process is avoided.