5.1.2 ESD Protection

Static charge is an unbalanced electrical charge at rest, typically created by the physical contact of different materials. One surface gains electrons, whereas the other surface loses electrons. This results in an unbalanced electrical condition known as a static charge. When a static charge moves from one surface to another, it is referred to as an electrostatic discharge (ESD). It can occur only when the voltage differential between the two surfaces is sufficiently high to break down the dielectric strength of the medium separating the two surfaces.

ESD can occur in any one of four ways: a charged body can touch an integrated circuit (IC), a charged IC can touch a grounded surface, a charged machine can touch an IC, or an electrostatic field can induce a voltage across a dielectric sufficient to break it down.

The main threat of ESD damage occurs during the assembly and manufacturing of circuits. After assembly and installation, the main protection required for the bus pins is surge protection.