Modeling and Reliability Considerations of Over-Driving Active ESD Protection Clamp

Boosted RC Rail Clamp ESD Protection enables over-driving the bigFET clamp by dynamic increase of Vgs, during the ESD event, saving a significant area required for high rating ESD protection. This paper describes the efforts to design an I/O library for 1.8V only process, tolerant to input over-voltage of up to 4V. Boosted RC Rail Clamp was adequate and predictable solution that also enabled high ESD rating. The challenging measurements and modeling of nominal transistors for gate voltages above Vdd, are described, as well as reliability considerations.