ESD occurs when a charge is exchanged between two objects of unequal charge or potential. People, with their movement, can cause a build-up of electrons that behave like a capacitor if dielectric isolation is available. For instance, manmade materials, such as the sole of a shoe, achieve dielectric isolation while a person is walking on carpet. Integrated circuit (IC) manufacturers of electrostatic sensitive devices design a level of protection into the IC to increase its robustness. They are typically rated at 1-2 kV contact voltage to protect them against possible board manufacturing incidents. Often the 1~2 kV protection is not enough to protect against the human body model (HBM) which can generate +8 kV transients. Even these on-chip protection circuits can add cost to the design by consuming expensive silicon real estate. The cost effective solution is to provide ESD protection products external to the ICs while near to the interface port.