Many integrated circuit manufacturers claim their IC’s have built in ESD protection. More often than not the test method to qualify their devices are measured in accordance with the Human Body Model MIL-STD 883. This model uses a 1500 Ohm resistor to discharge a capacitor and the currents injected into the IC are limited to the values shown. This model was meant to address potential ESD problems in the manufacturing environment only. ESD events seen in the field, or at the user level, are much more damaging as will be seen later in this presentation.