Patent ID: 8410767

Claim:
A control circuit of a DC-DC converter comprising: a differential amplifier configured to output a differential output in accordance with an output voltage to be outputted through a coil and a reference voltage; a first control circuit configured to compare the differential output with a coil current flowing to the coil and to determine an ON period in an operating cycle of a main switching element which is included in a current path of the coil current; a slope compensation circuit configured to add an increase gradient due to slope compensation to an increase gradient of the coil current in a range wherein the ON period exceeds a certain period of time; and an offset circuit configured to apply an offset to the coil current, the offset becoming smaller depending on the ON period in excess of the certain period of time, wherein the DC-DC converter is a step-down DC-DC converter; and the offset circuit decreases the offset by a first increase gradient at which the increase gradient due to slope compensation is equal to an absolute value, in a range wherein the ON period exceeds a certain period of time.