Patent ID: 6977488

Claim:
A DC—DC converter, comprising: an inductive element with one terminal connected to a voltage input terminal via a first switching element and connected to a reference potential via a second switching element and with the other terminal connected to a voltage output terminal via a third switching element and connected to the reference potential via a fourth switching element, a feedforward control circuit, which outputs a first control signal used for turning on and off the first and second switching elements periodically corresponding to the input voltage applied to the voltage input terminal and outputs the first control signal that keeps the first switching element in the on state and the second switching element in the off state when the input voltage drops below a prescribed reference value, and a feedback control circuit, which outputs a second control signal used for turning on and off the third and fourth switching elements periodically corresponding to the voltage output from the voltage output terminal and outputs the second control signal that controls the ratio of the on time of the third switching element so that the output voltage is kept at a prescribed voltage level.