SEMICONDUCTOR INPUT PROTECTIVE DEVICE

摘要

PURPOSE:To provide input protection without the change of input characteristics caused by an input protector by a method wherein a negative potential or a potential higher than a VSS potential is applied to the gate electrode of a protective transistor. CONSTITUTION:The output of an oscillation circuit 1 is connected to the input terminal of a charge pump capacitor 2 through an amplifier 9. The output terminal 3 of the capacitor 2 is connected to two terminals of a 1st transistor 4 and one terminal of a 2nd transistor 5. The other one terminal of the transistor 4 is connected to a reference potential 6 and the other two terminals of the transistor 5 are connected to the output terminal 7 of a substrate bias generating circuit. When the potential of the output terminal 3 becomes higher than the reference potential 6, the transistor 4 is turned ON and a current is applied to the reference potential 6 to make the potential of the output terminal 3 a reference potential.