Patent ID: 9141575
Filing Date: 2015-09-22
Classification: G06F,Y02D

Abstract:
1. A power supply circuit, comprising: a first electronic switch mounted near a front universal serial bus (USB) interface on a motherboard, wherein a control terminal of the first electronic switch is connected to a USB controller on the motherboard for receiving a first control signal, a first terminal of the first electronic switch is connected to the front USB interface, a second terminal of the first electronic switch is connected to a system power supply on the motherboard; a second electronic switch mounted near a rear USB interface on the motherboard, wherein a control terminal of the second electronic switch is connected to the control terminal of the first electronic switch, a first terminal of the second electronic switch is connected to the rear USB interface, a second terminal of the second electronic switch is connected to the second terminal of the first electronic switch; and a third electronic switch, wherein a control terminal of the third electronic switch is connected to the USB controller to receive a second control signal, a first terminal of the third electronic switch is connected to the front USB interface and the rear USB interface, a second terminal of the third electronic switch is connected to a standby power supply; wherein when the motherboard is in a work mode, the first control signal is at high level and the second control signal is at low level, the first terminal of the first electronic switch is connected to the second terminal of the first electronic switch, the first terminal of the second electronic switch is connected to the second terminal of the second electronic switch, the first terminal of the third electronic switch is disconnected from the second terminal of the third electronic switch, the system power supply supplies system power to the front USB interface and the rear USB interface through the first and second electronic switches respectively; and wherein when the motherboard is in a sleep mode or when the motherboard is powered off, the first control signal is at a low level, and the second control signal is at a high level, the first terminal of the first electronic switch is disconnected from the second terminal of the first electronic switch, the first terminal of the second electronic switch is disconnected from the second terminal of the second electronic switch, the first terminal of the third electronic switch is connected to the second terminal of the third electronic switch, the standby power supply supplies standby power to the front USB interface and the rear USB interface through the third electronic switch.