Patent ID: 7675757

Claim:
A DC-DC converter, comprising: a first switching element configured to ON/OFF control a current fed from a primary side to a secondary side; a second switching element provided in parallel to the first switching element, configured to be controlled at a substantially same timing as an ON/OFF timing of the first switching element, and being lower in current rating than the first switching element; a resistance having one end and another end, the one end being connected with a node of a primary side of the second switching element, and the other end being connected with the primary side of the first switching element; a third switching element connected between a node of the secondary side of the first switching element and a ground and configured to be capable of being ON/OFF controlled in nearly reverse phase to the ON/OFF timing of the first switching element; and a shutdown timing signal generation circuit configured to generate a signal transferring the first switching element and the second switching element to an off state, based on a voltage developed across the resistance.