Patent ID: 7949886

Claim:
A power supply system for a motherboard, comprising: a power circuit configured for providing power for a south bridge of the motherboard, an input terminal of the power circuit is connected to a power supply, and an output terminal of the power circuit is connected to a reset pin of the south bridge; and a controller comprising first and second transistors, a first terminal of the first transistor is configured for receiving a control signal from the south bridge, a second terminal of the first transistor is connected to a first terminal of the second transistor, a second terminal of the second transistor is connected to the reset pin of the south bridge, each of the first and second transistors has a third terminal grounded; when the motherboard is functioning normally, the control signal is at a first logic level, the second terminal of the second transistor is at a high voltage level; when clearing complementary metal oxide semiconductor (CMOS) information in the south bridge, the control signal is at a second logic level, the second terminal of the second transistor and the reset pin of the south bridge are at a low voltage level, to clear the CMOS information.