Power supply device

Abstract

A power supply device includes an output semiconductor element and a clamp circuit. The output semiconductor element is provided between a power supply line and an output terminal. The output semiconductor element is driven and switched so as to supply electric power to an inductive load connected to the output terminal. The clamp circuit clamps a voltage applied between the power supply line and the output terminal due to a counter electromotive force generated in the inductive load when the output semiconductor element turns OFF, with reference to an operation reference voltage of the output semiconductor element. Thus, it is possible to provide a power supply device including a clamp circuit which can effectively clamp a negative voltage surge derived from a counter electromotive force generated in an inductive load, at a low clamp voltage.

Dependencies are inferred from the claim text.