| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-efficiency step-down chopper circuit that allows preventing malfunction of a switching element.SOLUTION: In a step-down chopper circuit, an N channel MOS transistor 2, a rectifier diode 10, and a reactor 5 are connected in series between an input terminal T1 and an output terminal T3, an anode of a reflux diode 4 is connected to an input terminal T2 and an output terminal T4, and a cathode of the reflux diode 4 is connected to a source of the transistor 2. A resonance voltage VL occurring in the reactor 5 is divided by a parallel connection body of a parasitic capacitor 10c of the rectifier diode 10, a parasitic capacitor 4c of the reflux diode 4, and a parasitic capacitor 2c of the transistor 2, and the divided voltage is applied to the transistor 2. Accordingly, the resonance voltage applied to the transistor 2 can be reduced. |
