Patent ID: 7292016

Claim:
A DC-DC converter control circuit for selectively carrying out a boosting operation and a deboosting operation in accordance with a value of a power supply voltage supplied to the DC-DC converter control circuit, the DC-DC converter control circuit comprising: an error amplifier that compares an output voltage with a reference voltage; a triangular wave oscillator that outputs a triangular pulse; an activation oscillator that outputs an activation pulse; a deboosting signal output circuit that generates a first switching signal in accordance with the triangular pulse and an output of the error amplifier, and that outputs the first switching signal when the power supply voltage is higher than a first voltage; a boosting signal output circuit that generates a second switching signal in accordance with the triangular pulse and the output of the error amplifier, and that outputs the second switching signal when the power supply voltage is less than the first voltage or outputs the activation pulse after the power supply voltage is supplied to the DC-DC converter control circuit; and a power supply voltage detecting circuit that detects the power supply voltage and prevents the boosting signal output circuit from outputting the activation pulse after the power supply voltage is supplied to the DC-DC converter control circuit and the power supply voltage is higher than the first voltage.