Control circuit of DC-DC converter applying offset to coil current, DC-DC converter applying offset to coil current and control method of DC-DC converter

摘要

A DC-DC converter or the like capable of generating a stable output voltage is provided. A control circuit 11 of a current mode step-down DC-DC converter 1 includes a slope compensation circuit SC and an offset circuit IF1. The slope compensation circuit SC adds an increase gradient m2 due to slope compensation to an increase gradient of a coil current waveform Vsense in a range wherein an ON period Ton of a switch SW1 exceeds ½ of an operating cycle T. An offset circuit IF1 applies an offset voltage Voffset which becomes smaller depending on the ON period Ton in excess of ½ of an operating cycle T, to a coil current waveform Vsense.