STEP-UP/DOWN DC-DC CONVERTER AND SWITCHING CONTROL CIRCUIT

摘要

In order to prevent the needless flow of current in a step-up/down DC-DC converter, a switching control circuit is provided with: an error amplification circuit (21) which outputs a voltage according to the output voltage of a DC-DC converter; an inverting amplifier circuit that inverts the output of the error amplification circuit on the basis of a predetermined voltage; a waveform generation circuit (25) that generates a triangular waveform; a first voltage comparison circuit (22) into which the output of the error amplification circuit and the waveform generation circuit are inputted; a second voltage comparison circuit (24) into which the output of the inverting amplifier circuit and the output of the waveform generating circuit are inputted; and a peak value detection circuit (26) which detects the peak value of the triangular wave generated by the waveform generation circuit and supplies a voltage corresponding to said peak value to the inverting amplifier circuit.