| 摘要 |
PURPOSE:To enhance the stopping voltage by employing thyristors in which part of a middle layer connected with a gate is reduced in thickness, thereby increasing du/dt withstand value and di/dt withstand value. CONSTITUTION:Thyristors S1, S2 are connected in anti-parallel between main terminals T1 and T2, and resistanrs R1, R2 are connected between the gates and the cathodes of the thyristors S1, S2. A resistor R3 is connected between the gates of the thyristors S1, S2. The thyristors S1, S2 have 4 semiconductor layers 1 of different conductive types at adjacent layers, and one middle layer connected with the gate is reduced partly in thickness. When the resistance value of the resistor R3 is reduced, the thyristors S1, S2 are initially conducted at one middle layer reduced in thickness in response to the polarity of the voltage applied between the anodes and the cathodes. |
