| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit comprising an electrostatic discharge protection circuit, capable of effectively preventing an internal-circuit breakdown caused by an electrostatic surge. SOLUTION: The electrostatic discharge protection circuit 3 connected between a pad 1 for external connection and a circuit 2 to be protected is inserted between the pad 1 and a grounding cable, comprises a first NMOS transistor QN1 and a second NMOS transistor QN2 mutually connected in series, and comprises a first gate electric potential control circuit 4 and a second gate electric potential control circuit 5. The circuit 4 is connected to the gate of the first NMOS transistor, has a capacitive element C with the potential of the gate being set to the same potential as that of power line at the normal operation, and is substantially the ground level at the occurrence of the electrostatic surge. The circuit 5 is connected to the second NMOS transistor, with the potential of the gate set to the ground level at normal operation. COPYRIGHT: (C)2007,JPO&INPIT
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