USB TYPE-C INTERFACE CIRCUIT AND CHARGING METHOD THEREOF, USB DEVICE

A interface circuit includes: a power supply circuit, configured to output a DC voltage; a voltage conversion circuit, configured to convert the DC voltage to a target voltage, wherein the voltage conversion circuit is a step-down conversion circuit; a first Type-C port and a second Type-C port, configured to be connected to the respective loads; a switch circuit, connected to the power supply circuit, the voltage conversion circuit, the first Type-C port and the second Type-C port respectively; and a USB controller, configured to communicate with the first Type-C port and the second Type-C port respectively, and regulate the DC voltage and the target voltage according to supply voltages of the loads connected to the first Type-C port and the second Type-C port, and control the switch circuit to apply the DC voltage or the target voltage to a Type-C port connected to a corresponding load.