a switching power supply device has lower correction circuit losses , and enables adjustments without affecting overcurrent limiting or other characteristics . an integrated circuit ic for power supply control generates a switching signal based on a feedback signal from a feedback circuit and a voltage signal from a current detection input terminal , and outputs the switching signal from an output terminal to a switching element . a voltage controlled oscillator is provided which , when the load is judged to be light based on the magnitude of the feedback signal , lowers the switching frequency . the correction circuit is connected between the output terminal of the integrated circuit and the signal input terminal for current detection , acts only when the switching element is on , and has the function of further lowering the switching frequency set in the integrated circuit .