The validity of the entire ESD test hinges on the accurate generation and delivery of a specific current waveform to the device under test. An out-of-specification waveform will lead to erroneous classifications, either overstating or understating a device’s true ESD robustness. This section defines the precise parameters and acceptable limits for the MM current waveforms at key voltage levels.

Table 1: Waveform Specification

The test system must produce current waveforms that comply with the parameters outlined in the table below.

The two primary waveforms used to qualify the test system are:

• Shorting Wire Waveform: This is a damped sinusoidal pulse generated by discharging the simulator through the 18 AWG shorting wire. The critical parameter for this waveform is Ipsi, defined as the peak current of the first oscillation of the sinusoid. This waveform is used for routine verification.
• 500 Ohm Resistor Waveform: Generated by discharging through the 500 ohm precision resistor, this waveform is used during initial equipment qualification and periodic recalibration. It is characterized by a sharp initial peak (Ipr) followed by an exponential-like decay. The current value at 100 nanoseconds (I100) serves as a key checkpoint on this decay curve to ensure proper system impedance.

The following section outlines the procedures required to confirm that the test equipment consistently meets these critical waveform specifications.