Esd protection circuit and method with high immunity to hot plug insertion and other transient events

Abstract

Disclosed examples include an ESD protection circuit to protect an IC pad with high immunity against hot-plug surges, switching noise or other transient voltage conditions on the protected pad. The ESD protection circuit includes a clamp transistor and a trigger circuit responsive to rises in the protected pad voltage at or above a first slew rate to turn on the clamp transistor, as well as a second circuit coupled between the control terminal of the clamp transistor and a voltage supply node. The second circuit responds to rises in a voltage of the clamp transistor control terminal at a second, lower slew rate to reduce the voltage of the first control node to at least partially turn the clamp transistor off to reduce leakage current flow through the clamp transistor during transient voltage conditions on the protected pad.