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Maxim > Design Support > Technical Documents > Application Notes > 1-Wire® Devices > APP 4491
Maxim > Design Support > Technical Documents > Application Notes > A/D and D/A Conversion/Sampling Circuits > APP 4491
Maxim > Design Support > Technical Documents > Application Notes > Amplifier and Comparator Circuits > APP 4491
Keywords: lightning, integrated circuits, electrical overstress, EOS, electrostatic discharge, ESD, reliability,
spark, triboelectric voltage, short rise time, HBM, human body model, Schottky diodes, Zener diode, transient
suppression, TVS, MOV
APPLICATION NOTE 4491
Damage from a Lightning Bolt or a Spark—It
Depends on How Tall You Are!
By: Bill Laumeister, Strategic Applications Engineer
Sep 12, 2012
Abstract:
Large steel
buildings, automobiles, mountains, even people survive real atmospheric lightning.
Humans can also create their own miniature lightning bolts (sparks) and survive. When those sparks reach an
IC, however, major trouble results. In this tutorial, we will discuss ways to protect printed circuit boards (PCBs)
against ESD destruction. We will show that analog parts with bigger geometries are the best to use to protect
a field-programmable gate array (FPGA) with their small geometries. By taking these measures, the ICs in an
FPGA remain more reliable and deliver consistent quality performance.
A similar version of this article appeared in the July 27, 2012 issue of Power Electronics Technology
magazine.
Introduction
Lightning can be fun and entertaining, or dangerous and destructive. Maybe all these things at once—it just
depends on where you are, what you are doing, and your height. For an IC, lightning is never good.
A few years ago we were in a 10-story, steel-frame hotel building. An afternoon lightning storm approached
across a large open field. Because of the building's steel frame, we felt comfortably safe. Our computers were
not plugged in, so that was no concern. It was a spectacular show for about 10 minutes as the storm passed.
Large steel buildings, automobiles, mountains, even people survive real atmospheric lightning. Humans can
also create their own miniature lightning bolts (sparks) and survive. When those sparks reach an IC, however,
major trouble results. Nanometer-tall transistors need protection to survive even human sparks. In this tutorial,
we will discuss ways to protect printed circuit boards (PCBs) against ESD destruction. We will show that
analog parts with bigger geometries are the best to use to protect a field-programmable gate array (FPGA)
with their small geometries. By taking these measures, the ICs in an FPGA remain more reliable and deliver
consistent quality performance.
A Spark from Two Perspectives
Where do human-generated sparks come from? They are caused by a triboelectric charge. That is a big
word. This happens when two materials come into contact (rubbing helps) and are then separated. Some
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