PROTECTION CIRCUIT AND SEMICONDUCTOR INTEGRATED CIRCUIT

摘要

PROBLEM TO BE SOLVED: To reduce manufacturing costs of a semiconductor integrated circuit on which a protection circuit is mounted.SOLUTION: A protection circuit has: first and second transistors serially connected between a power source terminal and a signal terminal; a first resistance element connecting a gate back gate of the first transistor to the power source terminal; a second resistance element connecting a gate back gate of the second transistor to the signal terminal; a partial pressure circuit including third to sixth resistance elements serially connected between the power source terminal and the signal terminal, and generating an intermediate voltage of the power source voltage and a voltage of the signal terminal to a second node connecting fourth and fifth resistance elements to each other, in which the second node is connected to the first node; a first diode connecting the gate back gate of the first transistor to a third node connecting the fifth and sixth resistance elements to each other; and a second diode connecting the gate back gate of the second transistor to a fourth node connecting the third and fourth resistance elements to each other.