Patent ID: 8243404

Claim:
An ESD protection circuit with a merged triggering mechanism, comprising: a ESD detection circuit, coupled to a first conductive line receiving a first voltage level and a second conductive line receiving a second voltage level, for detecting an ESD voltage from the first conductive line or the second conductive line to generate a control signal, wherein the first voltage level is higher than the second voltage level; a first type ESD protection device, for outputting a first trigger current; a second type ESD protection device, for receiving a second trigger current; and a trigger circuit coupled between the first voltage level and the second voltage level, for constituting a conductive path according to the control signal, such that the trigger circuit receives the first trigger current from the first type ESD protection device and output the second trigger current to the second type ESD protection device; an input/output pad; wherein the ESD detection circuit is not directly connected to the input/output pad, and the trigger circuit comprises a first switch and a second switch, wherein the first switch is controlled by the control signal to conduct the first type ESD protection device and the second type ESD protection device, wherein the second switch is controlled by the control signal to control a conductive path formed by the first voltage level, the second voltage level and the ESD detection circuit.