| 摘要 |
PURPOSE:To protect an input against an electrostatic breakdown by using a parasitic diode of a transistor for an output circuit used as an input circuit. CONSTITUTION:The source, drain of a Pch transistor 31 of a transistor for an output circuit are fixed to the highest potential instead of the input protective circuit of an input/output cell region, the source, gate of N-ch transistor 32 are fixed to the lowest potential, and a parasitic diode 2 of N-well and drain of the Pch transistor 31 and a P-type substrate and the drain of the Nch transistor 32 formed by connecting the drain of the transistor 31 and the drain of the transistor 32 to the input is used as an input protection. Thus, the input can be protected without installing an input protective circuit in the input/output cell region. |
