INNER ELEMENT PROTECTING CIRCUIT OF CMOS INTEGRATED CIRCUIT

摘要

PROBLEM TO BE SOLVED: To protect an inner element against static damages by a method wherein input signal to the inner element is limited in level. SOLUTION: An inner element protecting circuit comprises a first clamp element 32 and a second clamp element 34. The first clamp element 32 is provided adjacent to a second circuit 20 and connected between a first voltage source 35 and a conductor 15 so as to clamp an overshoot signal transmitted to the conductor 15. A second clamp element 34 is provided adjacent to the second circuit 20 and connected between a second voltage source 36 and the conductor 15 so as to clamp an overshoot signal transmitted to the conductor 15. Input signal voltage is limited in amplitude by the clamp elements 32 and 34 comprised in the inner element protecting circuit, whereby inner elements contained in the second circuit 20 are protected against the damage caused by static electricity.