US Patent 7505238 ESD configuration for low parasitic capacitance I/O

An I/O ESD protection configuration of an integrated circuit that includes an ESD protection circuit connected between an I/O pad and an internal circuit at a first node and to an inductor at a second node. The inductor is connected between the second node and an external power supply. The external power supply provides a high reverse bias voltage across a diode of the ESD protection circuit. An ESD clamp is connected between the second node and a ground. An ESD discharge current is shunted through the ESD protection circuit and through the ESD clamp during a positive I/O ESD event. The inductor can be chosen to tune out a parasitic capacitance of the ESD clamp. The inductor can also block high frequency signals between the I/O pad and the external power supply, thereby minimizing the parasitic capacitance of the diode of the ESD protection circuit at high frequency.