Abstract: Determining the location of an ESD event is achieved through the use of an envelope detector or absolute value comparator which identifies the arrival of an electromagnetic waveform generated by an ESD event at each of a plurality of antennas. Arrival times are compared to determine the location of the ESD event. A plurality of N antennas are employed, and each antenna is coupled to a corresponding envelope detector, threshold discriminator, switch, and register. The output of a clock is coupled to the switches, and a microprocessor is coupled to the registers. When an antenna receives a waveform corresponding to ESD, the envelope detector extracts an envelope signal related to the envelope of the waveform and couples the envelope signal to the threshold discriminator. When the envelope signal has a value above a specified threshold, the threshold discriminator sends a signal to latch the current count of the clock into the corresponding register.