Electrostatic Discharge: Understand, Simulate And Fix ESD Problems

Electrostatic Discharge: Understand, Simulate and Fix ESD Problems

The basics of electrostatic charge and discharge and the major influencing parameters are presented for humans, furniture and other objects. Statistics of voltages and currents, and the resulting ESD waveforms are given for different environments. Radiated and conductive couplings of ESD into PC boards and cables are explained and calculated. Field amplitude and spectrum versus distance and wave impedance are given. ESD Specifications of MIL-STD-883, -1541, -1686 and IEC 801.2, including recent updates, are reviewed. Both diagnostics and compliance testing are discussed along with test setups and test procedures. Emphasis is on design for ESD immunity at the component, PCB, box packaging and system level. Immunity offered by software and noise inhibiting features are presented. The roles of shielding and aperture-leakage reduction are reviewed and calculated through several examples. Since many ESD problems occur at cable entries, ESD hardening of cables & connectors is covered in depth. To help in troubleshooting, a number of ESD case histories are given including re-radiating ground wires, printer carriages, data terminals with floating trays, microprocessor latch-up and others.