| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a MOSFET comprising an input buffer circuit is broken when the signal of an external supply voltage higher than an internal supply voltage is inputted to an input circuit which receives an input signal varying between an external supply voltage higher than an internal supply voltage and a ground voltage, and which supplies an output signal varying between an internal supply voltage and a ground voltage. SOLUTION: The input buffer circuit has a protective diode between an input signal node and a ground power supply. It connects a gate electrode for an n-channel MOSFET and a p-channel MOSFET to an input signal node, and its output node is a drain electrode for the n-channel MOSFET and the p-channel MOSFET. The thickness of a gate oxide film of the n-channel MOSFET is made thicker than that of a MOSFET comprising an internal circuit. The p-channel MOSFET is of a high pressure-proof structure. COPYRIGHT: (C)2005,JPO&NCIPI
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