| 摘要 |
PROBLEM TO BE SOLVED: To stably and effectively protect a signal output circuit with an ESD(electrostatic discharge) protection function from ESD destruction. SOLUTION: Buffer circuits Q11, Q13 output signals in a semiconductor integrated circuit including a 1st transistor Q11 of which the source and drain are connected to a 1st power supply VSS and an output terminal OUT, respectively, and the gate is connected to an input terminal IN for an internal signal of a semiconductor to the outside of the semiconductor integrated circuit through the output terminal OUT. Drain and source of a 2nd transistor Q12 are connected to the output terminal OUT and the gate of the 1st transistor Q11, respectively. A voltage detection circuit 14 detects the voltage of the output terminal OUT, and under a previously set condition corresponding to the voltage of a 2nd power supply VDD, supplies a signal for turning on the 2nd transistor Q12 to the gate of the 2nd transistor Q12. COPYRIGHT: (C)2005,JPO&NCIPI
|
