A simple solution for low-driving-current output buffer failed at the low voltage ESD zapping event

With the channel current, the driver acts as the trigger device for I/O during ESD zapping event. The driver location in I/O transistor plays a key role in I/O ESD protection. The I/O will fail at low-voltage ESD zapping event if its driver is located at transistor edge, while it can pass the high-voltage ESD zapping if its driver is located at transistor center.