ESD clamp with a layout-alterable trigger voltage and a holding voltage above the supply voltage

摘要

An ESD device that includes a gate and an n-drain region isolated from the gate and formed at least partially within an n-well region, which in turn is formed at least partially within a deep n-well region. The doping levels of the n-drain region, the n-well region and the deep n-well region are in a descending order. The ESD device has trigger and holding voltages, above the operation voltage of its protected circuit, which are layout-configurable by altering the distance between the n-drain and a side edge of the n-well region.