Apple Inc.
High Speed ESD Protection Circuit

Abstract:

An ESD protection circuit is disclosed. The ESD protection circuit is coupled between a first node and a second node that is coupled to an input of a functional circuit. A first protection circuit is coupled to the first node. The circuit further includes a first path and a second path. The first path includes a second protection circuit that is coupled to the second node, and is AC coupled to the first node. A second circuit path includes a third protection circuit, a resistor coupled between the third protection circuit and the first node, and a switch having a first terminal coupled to the resistor and the third protection circuit. A shunt circuit includes a transistor having a gate terminal coupled to the second terminal of the switch. The transistor, when activated, shunts current from the second node to ground.