SWITCHING CIRCUIT AND POWER SUPPLY CIRCUIT PROVIDED THEREWITH

摘要

A high-voltage normally-on transistor (T1) and a low-voltage normally-off transistor (T2) are connected in series, and diodes (D1, D2) are provided in inverse parallel with the transistor (T2). A gate terminal of the transistor (T1) is connected to a source terminal of the transistor (T2), and a gate drive circuit (11) that outputs a control signal to a gate terminal of the transistor (T2) is provided. The forward voltage of the diode (D2) is made lower than the forward voltage of the diode (D1), and an inductance component of a path that connects nodes (N2, N3) via the diode (D2) is made larger than an inductance component of a path that connects the nodes (N2, N3) via the diode (D1). Consequently, a switching circuit that includes the transistors connected in series, and achieves a reduction in transient current while turned off is provided.