| 摘要 |
PURPOSE:To make a surge input escape to a semiconductor substrate or a well region, by a method wherein, when the surge is inputted, it is received by the drain regions of output transistors and transistors for electrostatic breakdown protection, which are turned into the ON state. CONSTITUTION:When surge is inputted from an output pad 12, it is received not only by the drain regions of output transistors P1, N1 in an output buffer circuit 11, but also by transistors electrostatic breakdown protection. As a result, the transistors P2, N2 are turned on to lead the surge input to a semiconductor substrate or a well region. Thereby deterioration of electrostatic breakdown strength of the output transistors P1, N1 can be prevented, when elements are miniaturized, and the drain areas of the output transistors P1, N1 are reduced. |
