Soft start circuit, switching power supply, chip and electronic device

Abstract

The application relates to the technical field of circuits, and discloses a soft-starting circuit, which comprises a first capacitor, a second capacitor, a first comparison circuit, a second comparison circuit and a charge-discharge circuit. The first comparison circuit is used for comparing the voltage value of the second capacitor with a preset reference voltage, and a first signal is output according to a first comparison result. The second comparison circuit is used for comparing the voltage value of the first capacitor with the preset reference voltage, and a second signal is output according to a second comparison result. The charge-discharge circuit charges and discharges the first capacitor and the second capacitor according to the first signal and the second signal until the voltage of the second capacitor rises to a set voltage. In this way, the first capacitor and the second capacitor are repeatedly charged and discharged according to the first signal and the second signal, so that the voltage of the second capacitor can slowly reach a specified voltage value, thereby reducing the inrush current. The application further discloses a switching power supply, a chip and an electronic device.

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