Patent ID: 8364993

Claim:
An energy saving circuit for a motherboard, comprising: a switch comprising a control terminal, a first terminal connected to a first voltage pin of a north bridge chip of the motherboard, and a second terminal connected to a second voltage pin of the north bridge chip and a voltage converting circuit; a voltage regulating circuit comprising an input terminal connected to a south bridge chip of the motherboard, and an output terminal connected to the first terminal of the switch and the first voltage pin of the north bridge chip, the voltage regulating circuit converting a first voltage outputted by a first power source and providing the converted voltage to the first voltage pin of the north bridge chip after the voltage regulating circuit receives a first control signal from the south bridge chip; and a logic control circuit comprising an input terminal connected to a super input/output (I/O) chip of the motherboard and an output terminal connected to the control terminal of the switch, wherein the logic control circuit receives a second control signal from the super I/O chip to turn on the switch according to the second control signal, to connect the first voltage pin to the second voltage pin of the north bridge chip via the first and second terminals, the logic control circuit also outputs a third control signal to the voltage regulating circuit to control the voltage regulating circuit to stop providing a voltage to the first voltage pin of the north bridge chip, the voltage converting circuit provides a voltage to the first voltage pin of the north bridge chip via the switch.