A simple and effective ESD protection structure for high-voltage-tolerant I/O pad

A simple and effective ESD protection structure is proposed for the high-voltage-tolerant I/O pad. It can tolerate a voltage higher than the power supply voltage without the leakage current caused by PMOS in original GGNMOS/GDPMOS protection structure. And it can provide a direct current path under PD/ND mode ESD stress, which is missing in general ESD design for the high-voltage-tolerant I/O pad. It can sustain 2.7A TLP stress according to our simulation result. This protection structure can also be used for high voltage and high power open drain driver and the negative-voltage-tolerant I/O pad.