| 摘要 |
PURPOSE:To prevent an electrostatic breakdown effectively without enlarging an element area by connecting a protecting transistor having a lower base-collector breakdown voltage to a transistor of protected circuit. CONSTITUTION:There is provided in one substrate a protecting transistor having a base-collector breakdown voltage lower than a base-collector breakdown voltage of a transistor of protected circuit, the collector is connected to an input terminal of the protected circuit, the emitter is connected to a reference level terminal and further the base is connected to the reference level terminal through a resistance means. To arrange such, a p-type base region 12 is formed in an n-type layer grown on an n<+>-type collector buried region 18, an n<+>-type emitter region 14 is formed therein and furthr an n<+>-type region 15 to drop the base-collector breakdown voltage is provided in the region 12 to a protecting transistor, which will be connected to the protected circuit. |
