Patent ID: 7888977

Claim:
An electronic device for delivering direct current (DC) power, comprising: a load; a power end, for receiving a power of high voltage level; an upper gate switch, comprising a first end coupled to the power end, a second end, and a third end, for conducting connection between the first end and the third end according to the signal level of the second end; a lower gate switch, comprising a first end coupled to the third end of the upper gate switch, a second end, and a third end coupled to a ground, for conducting connection between the first end and the third end according to the signal level of the second end; an inductor, comprising an end coupled to the third end of the upper gate switch and the first end of the lower gate switch, and another end coupled to the load; and a switch control unit, coupled to the second end of the upper gate switch and the second end of the lower gate switch, for switching the upper gate switch between an ON state and an OFF state, and switching the lower gate switch between an ON state and a semi-ON state, comprising: a receiving end, for receiving a first control signal, a second control signal and a third control signal; an inverter, for controlling the conduction of the upper gate switch according to the first control signal; a normal state control unit, for controlling the lower gate switch according to the second control signal and the third control signal; and a sub-threshold control unit, for controlling the lower gate switch according to the third control signal.