Mitigating the effects of ESD using ESD capacitor and TVS diode

Abstract

Electrostatic discharge (ESD) can extremely damage and affect the operation of the electronic devices which is mainly due to the discharge of static electricity through the human or an object contact to the electronic devices. Though ESD protection has been made in many ICs internally, it can only sustain a certain level of voltage surge. To withstand high voltage surge mainly above 4kV, external ESD protection devices such as ESD capacitor and TVS (Transient Voltage Suppressor) are used for signal integrity considerations. For automotive application using 12V battery, a circuit model which has the capability to explain the behaviour of the ESD protection device for 8kV is proposed. Comparison between simulation by LTspiceXVII and calculated results are shown and also presents the pros and cons of two different approaches. When comparing ESD capacitor to TVS diode, the result shows 32.8 percentage reduce in voltage, 1 percentage increase in current and 1.43 percentage reduce in power dissipation. In addition to the theoretically calculated capacitor value, other capacitors are used and its results were presented.