Chip power supply circuit, switching power supply circuit and charger

Abstract

The utility model discloses a chip power supply circuit, a switching power supply circuit and a charger, and the chip power supply circuit comprises an energy storage loop and a voltage stabilizing circuit. The energy storage loop comprises a power supply winding and a first energy storage capacitor; the first end of the power supply winding is grounded, the second end of the power supply winding is connected with the first end of the first energy storage capacitor, the second end of the first energy storage capacitor is connected with the first end of the voltage stabilizing circuit, and the second end of the voltage stabilizing circuit is used for being connected with a PWM chip; the power supply winding is used for being coupled with a primary winding of a transformer and is arranged in the same phase with the primary winding of the transformer; and the energy storage loop is used for charging the first energy storage capacitor by the power supply winding when the primary winding of the transformer is conducted along the first direction. According to the chip power supply circuit, the power supply winding is coupled with the primary winding, loss caused by an overlarge output voltage range can be reduced, and meanwhile the number of turns of the power supply winding is reduced.

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