Patent ID: 7098639

Claim:
A method for controlling a DC-DC converter, wherein the DC-DC converter includes a first capacitor, a second capacitor, a diode connected in series with the first capacitor, and a main switching transistor having a source, a gate, and a drain, the method comprising: connecting the diode and the first capacitor that are connected in series with each other between the source and the drain of the main switching transistor; activating and inactivating the main switching transistor; generating gate voltage to drive the main switching transistor by connecting the second capacitor in parallel to the first capacitor or by disconnecting the second capacitor from the first capacitor in synchronism with the activation and inactivation of the main switching transistor; switching the main switching transistor with the gate voltage; monitoring the voltage of the second capacitor; and controlling the connection and disconnection of the first capacitor and the second capacitor in accordance with the monitored voltage of the second capacitor.