文档介绍：ESD Protection Design Seminar Jim Sutherland Senior Applications Engineer
Outline
What is ESD?
What damage can it cause?
Why is the problem growing?
What are the issues for the designer?
How can we measure it?
How can we protect equipment from ESD?
What Is ESD?
ESD = Electro Static Discharge
Generation
Triboelectric (friction causes accumulation of charge)
Induction (field induces charge)
Discharge
Dielectric (air) breakdown
Electric field increases when charged bodies approach each other
Current flow into circuitry
ESD Damage of ICs
Permanent
Oxide breakdown, shorts, opens, latch-up
Temporary
Latch-up, ground bounce
Latent
Degradation from an ESD event
ESD problem is growing
Circuits/Systems
Old - Robust ICs & Low speed signals
New - Sensitive ICs & High speed signals
Environment
Old - Manufacturing / Corporate
New - Home / Outdoors / Person
ESD Issues for the Designer
Must meet ESD specifications
Select ESD ponents
Minimize signal degradation (from R,L & C)
Board space / weight / proper ponent cost
Assembly cost
Lifetime cost (stability)
Test the system
International ESD Standards
Human Body Model (HBM) - for devices
EIA/JESD22-A114-A
ANSI/EOS/ESD--1993
MIL-STD-883 (method 3015)
IEC 1000-4-2:1995 - for systems
Machine Model (MM) - mon
EIA/JESD22-A115-A
ANSI/EOS/ESD--1993
Charge Device Model (CDM) - mon
JESD22-c101
Human Body Model (HBM)
Discharge from 100pF capacitor through kOhm resistor
6 ESD pulses
3 positive, 3 negative
> 1 sec separation
Pin-to-pin testing
N(N-1)/binations
Used ponent characterization
Widely used
HBM Current Waveform
Rise Time: 2 nS < Tr <10 nS
IEC 1000-4-2:1995 Standard
Discharge from 150 pF capacitor through 330 ohm resistor
6 ESD pulses
3 positive, 3 negative
Used for system characterization
“Contact” v. “Air” discharge
Different levels
Different applications