Abstract: A current detection circuit includes: at least one current detector configured to detect a current flowing through a second switch element of at least one switching output stage configured to connect a first switch element and the second switch element in series; an analog signal generator configured to generate an analog signal corresponding to the current detected by the at least one current detector; a converter configured to receive the analog signal, convert the analog signal to a digital signal corresponding to an integrated value of the analog signal, and output the digital signal; and a corrector configured to correct any one of a drive voltage, an input, and an output of the converter according to an on-DUTY of the second switch element.

Abstract: In a normal state in which a main power supply supplies an input voltage having a first level, a step-down converter is enabled. In this state, the step-down converter steps down the input voltage and supplies a power supply voltage having a second level to a load. In the normal state, a step-up converter is operated in a forward direction. In this state, the step-up converter steps up the power supply voltage so as to charge a backup capacitor using a voltage having a third level. In a power supply disconnection state in which a disconnection of the input voltage occurs, the step-up converter is operated in a reverse direction. In this state, the step-up converter steps down a capacitor voltage across the backup capacitor, and supplies the power supply voltage having the second voltage level to the load.