Power Over Ethernet Interoperability Guide

ESD Protection of ICs

Just as a steady excess of voltage or current constitutes overstress, rate of change of stress is also a possible overstress (for example, dV/dt-induced stress). The most common example of this is electrostatic discharge (ESD). ESD can cause many types of failures. For example, it can induce latchup. When we walk over a carpet, we can pick up enough electric charge to kill a semiconductor by actual physical contact (contact discharge) or near-contact (air discharge). Therefore, ESD handling has become a major concern in modern manufacturing and test environments.

All modern ICs are designed with rather complex ESD-protection circuitry built around their pins. The idea is to divert or dissipate electrostatic energy safely. ...