Patent ID: 7440247
Filing Date: 2008-10-21
Classification: H01L

Abstract:
1. A gate coupling electrostatic discharge protection circuit with redundant structure, comprising: a first cascade structure, having: a first metal-oxide-semiconductor, having a first source, a first drain electrically coupled with a circuit to be protected from electrostatic discharge such that the electrostatic discharge is drained from the circuit through the first drain, and a first gate electrically coupled with a power source; and a second metal-oxide-semiconductor, having a second source electrically coupled with a ground of said circuit, a second drain electrically coupled with said first source and a second gate electrically coupled with a first level circuit which has at least one metal-oxide-semiconductor; and at least a second cascade structure, having: a third metal-oxide-semiconductor, comprising a third source, a third drain electrically coupled with said circuit to be protected from electrostatic discharge such that the electrostatic discharge is drained from the circuit through the third drain, and a third gate electrically coupled with said power source; a fourth metal-oxide-semiconductor, having a fourth source electrically coupled with said ground of said circuit, a fourth drain electrically coupled with said third source and a fourth gate electrically coupled with a redundant circuit derived from said first level circuit, wherein the resistance of said redundant circuit and said first level circuit matches when said electrostatic discharge is drained to said ground via said first cascade structure and said second cascade structure simultaneously.