| 摘要 |
PROBLEM TO BE SOLVED: To provide an input and output circuit which can perform a tolerant function at the time of power-off. SOLUTION: 1st, 2nd pull-up transistors between a power source and a pad and 1st, 2nd pull-down transistors between the pad and an earth, a pre-driver which turns off the 1st, the 2nd pull-up transistors and the 1st, the 2nd pull-down transistors if an output enable signal is disabled, an output buffer equipped with 1st circuit which makes small a gate/source voltage of the 1st, the 2nd pull-up transistors and the 1st, the 2nd pull-down transistors when a high voltage is supplied to the pad, 3rd - 5th pull-up transistors which a gate transmitting a input signal of the pad to a 1st node is connected between a power source and 2nd node and is connected with 3rd node, the pad and the 1st node, 3rd pull-down transistors which a gate connected between the 2nd node and the earth is connected to the 1st node. and 2nd circuit which makes small a gate/source voltage of 3rd - 5th pull-up transistors and 3rd pull-down transistor when a high voltage is provided to the pad are provided. COPYRIGHT: (C)2004,JPO
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