Patent ID: 7157888

Claim:
A light loading control circuit for controlling a switching circuit having an input switching unit and an output switching unit, the input switching unit selectively coupling a first terminal of an inductor to an input voltage and a ground potential, the output switching unit selectively coupling a second terminal of the inductor to an output voltage and the ground potential, the light loading control circuit comprising: a phase control unit for operating the switching circuit in a plurality of phase cycles, each of which has: a rising phase for increasing an inductor current flowing through the inductor; a falling phase for decreasing the inductor current; and a maintaining phase for keeping the inductor current approximately constant, and a sleep control unit for operating the switching circuit in a sleep period after the output voltage reaches a predetermined sleep reference voltage, for preventing the first terminal and the second terminal from being respectively coupled to two selected from a group consisting of the input voltage, the output voltage, and the ground potential.