POWER SUPPLY DEVICE

摘要

The present invention achieves size reduction of an inductor, while reducing radiation noise of an inductor current. A boosting power supply device is provided, for instance, in an ECU mounted in vehicles. The boosting power supply device has a boosting coil, a switching element, and a current control unit 16. In a clamping period when an inductor current flowing in the boosting coil is clamped to a previously set peak setting current, the current control unit 16 controls a switching element 12 to turn on and off using clock signals CK1 at a frequency higher than that of pulse signals SPL, and in the periods other than the clamping period, the current control unit controls the switching element to turn on and off using the pulse signals SPL. In such a manner, the inductor current flowing in the boosting coil is controlled by controlling the switching element to turn on and off.