摘要 |
Aspects of the invention include a switching power supply device that includes a zero current detecting circuit that detects zero current of electric current flowing through the inductor to turn ON the switching element, an ON width generating circuit that determines the ON width of the switching element to turn OFF the switching element, and an OFF width detecting circuit that detects the OFF width of the switching element based on the output of the ON width generating circuit and the output of the zero current detecting circuit, and holds the OFF width until the next operating cycle. Aspects of the invention also include an ON width adjusting circuit that is included in the ON width generating circuit and adjusts the ON width of the switching element in the next operation cycle according to the width detected by the OFF width detecting circuit. |