| 摘要 |
PURPOSE:To spare increase in area for a PNPN switching element, by forming an anode region of a breakdown preventive diode identically with a resistor semiconductor region between a gate and cathode. CONSTITUTION:A semiconductor switching circuit is constituted by PNPN switch Q1, Q2 formed equivalently by PNP transistor TRQ1 and NPN TRQ2 and TRQ3 for gate turn-off. In this circuit a diode D1 prevents breakdown caused by reverse voltage. The resistor R1, R2 in this circuit are formed in a P type diffusion layer formed on a N type Si substrate 30. The diode D1 forms an anode region in a layer 31 and a cathode region in the substrate 30. Because the connection of the diode D1 to the inbetween part of the gate/cathode of TRQ1, Q2 means connection of the N type diffusion layer 32 for ohmic contact to a terminal G by means of a metallic wiring layer 34. This practically means no increase in the required area. |
