DRIVE CIRCUIT

摘要

A drive circuit of a switching circuit comprises a high-side drive circuit (70) for turning of/off a switching element (QH) disposed on the high side of a DC power supply (Vin) by a control signal and a low-side drive circuit (60) disposed on the low side of the DC power supply and adapted for alternately turning on/off a switching element (QL) connected in series to the switching element (QH) and the switching element (QH) by a control signal. A switching element (Qn1), a capacitor (C1), and a switching element (Qn2) are connected in series to both ends of an auxiliary power supply (Vcc1). A switching element (Qp1), a capacitor (C2), and a switching element (Qp2) are connected in series to both ends of the capacitor (C1). A control circuit (10) alternately turns on/off the switching element (Qn1), the switching element (Qn2), the switching element (Qp1), and the switching element (Qp2) and turns on the switching element (Qn1) and the switching element (Qn2) and then the switching element (Qp1) and switching element (Qp2). The capacitor (C2) supplies electric power to the high-side drive circuit.