DC-DC converter circuit, power supply selection circuit, and apparatus

摘要

A DC-DC converter circuit (100) has a plurality of input terminals (IN1, IN2) connected to respective DC power supplies, and an output terminal (OUT). The DC-DC converter circuit comprises a power supply selection section (110) for selecting the lowest-voltage DC power supply among those not less than a predetermined voltage. A step-down type regulator section (10) converts the voltage of the selected DC power supply into a lower predetermined voltage, which is output through said output terminal (OUT).