Patent ID: 8040120

Claim:
A switching DC-DC converter comprising: at least one power switch; a pulse width modulating unit configured to control on/off timing of the power switch; an inductor having one end connected to the power switch; a smoothing unit connected to the other end of the inductor and configured to produce a smoothed DC output voltage; an output voltage detecting unit configured to detect the DC output voltage; an error amplifying unit configured to compare the detected output voltage and a reference voltage and configured to supply an amplified error signal between the detected output voltage and the reference voltage to the pulse width modulating unit; and a single oscillating unit connected to an output of the output voltage detecting unit and an output of the error amplifying unit and operable on a first oscillating mode and a second oscillation mode, wherein the oscillating unit on the first oscillating mode controls a switching frequency of the power switch based on the detected output voltage, and wherein the oscillating unit on the second oscillating mode controls the switching frequency of the power switch based on the amplified error signal.