Patent ID: 6765772
Filing Date: 2004-07-20
Classification: H01L

Abstract:
An electrostatic discharge protection device located between a pad and an internal circuit, and coupled between a first power wire and a second power wire, comprising:a switching circuit for outputting an enable signal when receiving a detecting result signal; a voltage detecting device comprising at least one serial diode connected between the first power wire and the switching circuit, and outputting the detecting result signal when a voltage level of the first power wire reaches a first predetermined voltage level; a first switch coupled to a connection point between the pad and the internal circuit, wherein the first switch includes a first controlling gate connected to the second power wire and is turned on when a voltage level of the pad reaches a second predetermined voltage level; a second switch coupled to the connection point between the pad and the internal circuit, wherein the second switch includes a second controlling gate connected to the first power wire and is turned on when the voltage level of the pad reaches a third predetermined voltage level lower than the second predetermined voltage level; a third switch coupled to the connection point between the pad and the internal circuit, wherein the third switch includes a third controlling gate; and a driving circuit coupled to the switching circuit for outputting a ground level signal to the third controlling gate and causing the third switch to electrically break down concurrent with the first switch when the driving circuit receives the enable signal and the voltage level of the pad reaches the second predetermined voltage level.