ESD protection for I/O ports

Electrostatic discharge (ESD) can threaten an electronic system when someone replaces a cable or even touches an I/O port. Discharges that accompany these routine events can disable the port by destroying one or more of its interface ICs (see Figure 1). Such failures can also be costly—they raise the cost of warranty repairs while diminishing the product’s perceived quality. These and other factors, coupled with the increasing amount of electrical communication between computers and computerrelated equipment, lend emphasis to the need for engineers to understand ESD.