| 摘要 |
PURPOSE:To improve the withstand voltage for an external surge voltage by connecting part of the control electrode of an output transistor with the prescribed potential for setting the transistor in the portion in nonconductive state. CONSTITUTION:When a surge voltage which exceeds the withstand voltage of an output transistor Q1 is applied externally if output transistors Q1, Q2 are in nonconductive state, the surge voltage is applied from metal wirings 14 connected with an output terminal 21 to transistors Q1, Q3 is flowed through the channel of the gate electrode 12 for driving the transistor Q1 to its source, but also flowed simultaneously to the channel of the gate electrode 13 of the protecting transistor Q3 fixed to the ground potential. Accordingly, as a result, a current amount per unit channel area is reduced, and the terminal 21 is endured for a larger surge voltage. Thus, the current amount flowed per unit area of the output transistor reduces to improve the protecting function of the output terminal. |
