Patent ID: 7501806

Claim:
A DC-to-DC converter control circuit comprising: an arithmetic circuit for outputting an add-up signal generated by adding an output voltage signal obtained according to an output voltage of a DC-to-DC converter, and an AC current signal obtained according to an AC current component of a coil current; a comparator for comparing the add-up signal with a reference signal; and a reference signal circuit for retaining a DC current component of a coil current signal as an another reference signal, on the basis of a detection signal obtained by adding the coil current signal according to the coil current containing the DC and AC current components to the output voltage signal, wherein the arithmetic circuit comprises an inverting amplifier for inverting a signal variation component of the output voltage signal, at the another reference signal, and adding the same to the output voltage signal, and an adder for adding the detection signal to an output signal from the inverting amplifier, and wherein switching control is executed according to a result of comparison by the comparator.