| 摘要 |
PURPOSE:To prevent an auxiliary GTO from being damaged by accurate and frequent ON-OFF control of main and auxiliary GTO by a method wherein a switching control element is laid between a gate of main GTO and a cathode of auxiliary GTO to connect a control terminal of the element to the gate of auxiliary GTO in common. CONSTITUTION:An auxiliary GTO 24 is formed of P1, N1, P2 and N3 layers while a gate electrode 3 of auxiliary GTO is provided on the central surface of P2 layer. A cathode electrode 32 of auxiliary GTO is provided on the surface of N3 layer on the concentric circle with gate electrode 31. On the other hand, a main GTO 21 is formed of P1, N1, P2 and N2 layers provided on the same wafer as that of auxiliary GTO 24. Gate electrodes 33a, 33b of main GTO are provided on the surface of P2 layer on the concentric circle with the gate electrode 31 of auxiliary GTO 24. Next a cathode electrode 34 of main GTO is provided on the surface of N2 layer on the concentric circle with the gate electrode 31 of auxiliary GTO 24. Besides, a gate control power supply circuit 12 is connected between a gate terminal G and an auxiliary gate terminal Gk. Through these procedures, the main and auxiliary GTOs may be ON-OFF controlled without fail. |
