Electrostatic discharge input protection for reducing input resistance

摘要

An ESD protection structure for protecting an internal circuit comprising a primary protection device, a secondary protection device, and a substrate pickup is presented. The primary protection device and secondary protection device share a common source, and this common source implementation lowers the trigger voltage of the primary protection device to be about the same as the trigger voltage of the secondary protection device, thereby eliminating the need to use an isolation resistor between the primary and secondary protection devices.