Proc. of Int. Conf. on Advances in Power Electronics and Instrumentation Engineering, PEIE
Effect of Electrostatic Discharge on Analog Circuits Rajashree Narendra1, M.L. Sudheer2 and D.C.Pande3 1
BNM Institute of Technology, Bangalore, India E-mail:rajashree.narendra@gmail.com 2 UVCE, Bangalore, India E-mail::mlsudheer@gmail.com 3 EMI/EMC Group, LRDE, Bangalore, India E-mail::pandedc@gmail.com
Abstract— A study of the effects of ESD on analog circuit is carried out. The analog circuit is a RC phase shift oscillator followed by a zero crossing detector (ZCD). The analog circuit is subjected to indirect discharge on horizontal coupling plane and direct air discharge and the effects of ESD on oscillator and ZCD circuit are analyzed. The analog circuit is also modeled using five-spice to check if it is possible to simulate ESD events and predict its behavior. The simulation and experimental results show similar results though not identical in all the cases. Simulation becomes useful in predictions of the effect of ESD at various points in the analog circuit and this helps us in locating weak points of the circuit where extra protection may be needed. Index Terms— Electrostatic discharge, Analog circuits, phase shift oscillator, susceptibility, spice simulation, electromagnetic compatibility, zero crossing detector, direct ESD, Indirect ESD and Five spice.
I. INTRODUCTION Susceptibility tests are performed on a device to determine whether the device is susceptible to RF signals levels having specified amplitude over a specified frequency range. If the device operates acceptably as the signal is applied and swept over the specified frequency range the device is considered to have passed. If not, it has failed. In many cases a device that is adversely affected by the applied signal will return to normal operation when the signal is removed. If the device under investigation is found to be susceptible to the applied signal, the amplitude at which the device exhibits susceptible behavior is called the susceptibility threshold. Thus, for injected signal levels below the susceptibility threshold the device operates acceptably, and at levels above the susceptibility threshold the device does not operate acceptably. The criteria for establishing what constitutes ‘operating acceptably’ are a function of the device and its intended use [1]. In addition to identifying a sensitive component or circuit, susceptibility testing must be able to quantify susceptibility levels and ideally correlate these results with the system level test results. Simply doing a system level test on a device is useless unless susceptibility levels of that device or circuit can be determined and quantified. Most of the electronic components that are considered fairly rugged can be damaged by ESD. Bipolar transistors, the earliest of the solid state devices, are not immune, though less susceptible compared to field effect transistors. There are components that might not be considered at risk, such as resistors and capacitors but they are also affected by ESD. Amplifiers, oscillators are used in applications where they are often DOI: 02.PEIE.2014.5.8 © Association of Computer Electronics and Electrical Engineers, 2014