EMI-EMC for Beginners

8/19/2019 EMI-EMC for Beginners

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Analog Devices Confidential Information—not for external distribution

ESD, EFT, Surge and EMC

Beginners GuidePart-1

► Anoop K

► [email protected]

►[email protected]

mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]


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Analog Devices Confidential Information

Agenda

►EMC and key terms

►ESD,EFT and Surge

►EMC-4 compliant RS485 Network for different cost/performance critera


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Electromagnetic Compatibility

►EMC (electromagnetic compatibility)

►EMI (electromagnetic interference)

►Emission Issues

►Susceptibility/Immunity Issues

………EMC is the contr ol of EMI so that unwanted effects are prev


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Overview of EMC test standards…

►Immunity & Susceptibility Testing

Scope EN Standard IEC Standards

Burst/Electrical Fast Transient EN 61000-4-4 IEC 801-4;

IEC 61000-4-4

Conducted Continuous Disturbances from DC to 150 kHz EN 61000-4-16 IEC 61000-4-16

Conducted Disturbances Induced by RF Fields EN 61000-4-6 IEC 61000-4-6

Electrostatic Discharge EN 61000-4-2 IEC 61000-4-2

Generic Immunity - Industrial Environment EN 61000-6-2 IEC 61000-6-2

Generic Immunity - Residential, Commercial & Light Industry EN 61000-6-1 IEC 61000-6-1

Magnetic Field, Damped Oscillatory EN 61000-4-10 IEC 61000-4-10

Magnetic Field, Oscillatory EN 61000-4-12 IEC 61000-4-12

Magnetic Field, Power Frequency EN 61000-4-8 IEC 61000-4-8

Magnetic Field, Pulse EN 61000-4-9 IEC 61000-4-9

Radiated RF Electromagnetic Field EN 61000-4-3 IEC 61000-4-3

Surge EN 61000-4-5 EN 61000-4-5

Voltage Dips, Short Interruptions and Voltage Variations EN 61000-4-11 IEC 61000-4-11


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EMC Characterization Continued…

►Electromagnetic Emission TestingScope Country

Radio Frequency Devices US FCC Pa

Industrial, Scientific, and Medical Equipment US FCC Pa

Food and Drug Administration Reviewer Guideance for Pre-market Notification Submissions US FDA

Industrial, Scientific and Medical (ISM) Radio Frequency Equipment EU EN 550

Broadcast Receivers and Associated Equipment

Generic Emissions - Residential, Commercial, Light Industrial Int'l/EU IEC 610

Generic Emissions - Industrial Int'l/EU IEC 610

Electrical Motor-Operated and Thermal Appliances for Household and Similar Purposes, Electric

Tools and Similar Electric Apparatus

EU EN 550

Information Technology Equipment EU EN 550

Harmonic Current Emissions (usually done with Voltage Fluctuations, EN 61000-3-3) EU EN 610

Information Technology Equipment Australia, New Zealand AS/NZS

Information Technology Equipment Japan VCCI

BSMI Taiwan CNS 13


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Benefits of Good EMC design …

►

Safety

►Reduction in expense

►Increased reliability

►Legality


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Electrostatic Discharge (ESD)…

►Caused by Static Electric Charge

Electrostatic Induction

Triboelectric charging

►Effects

Harmful effects in industries Eg:Oil/Gas etc..

Reliability issue, Life time issues, performance issues etc..


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ESD Continued…

►Damage Prevention in Electronics

Implementation of Electrostatic Discharge Prevented Area (EPA)

ESD protection during transit

Integration of ESD protection to the device (system/part)


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ESD Continued…

ESD Association Handbook• Human Body Model(HBM)

• Charged Device Model (CDM)

IEC 61000-4-2

• International ESD immunity Test Standard

Note: ESD compliance is done both system level and device level.


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IEC 61000-4-2 International Standard:

Contact Discharge

• Direct Contact Transfer Between Two Objects at Differen

Air Discharge

•

A High Electrostatic Field between Two Objects when TheClose Proximity


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Table: Overv iew of Threat Levels

LevelTest Voltage (ContactDischarge)

Test Voltage (Air Discharge)

12kV 2kV

24kV 4kV

36kV 8kV

48kV 15kV

Note: The test set up does con sider the relat ive humidi ty as wel l as the

mater ials used whi le cond uct ing the test


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►Discharge (ESD) Current Waveform

Severit y Levels and Test Volt ages


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►EUT Test Setup

Typic al ESD Test Setup

Test Results

• Normal operation with

specification

• Temporary degradation orwhich is recovered byself-r

• Temporary degradation oror function, which is recintervention or systemreset

• Damage of the systemunrecoverable degradatiofunctionor data


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Electrical Fast Transient (EFT)

►Generated as result of gaseous discharge

►EFT is applicable to both power and data lines

► IEC 61000-4-4 International EFT Immunity Test


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IEC 61000-4-4 International Standard

EFT Test Waveform

IEC 61000-4-4 Test Lev el

Test


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Surge

►Overvoltage from switching / lightning transients

Power System Switching Transients

Lightning Transients

►

IEC 61000-4-5/EN61000-4-5


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IEC 61000-4-4 International Standard

IEC 61000-4-5 Voltage Imp ul se

IEC 61000-4-5 Curren t Impu lse Test Setup


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Theory of Protection

►Suppress the transient at source

►Make the coupling path inefficient

►Make the device less susceptible to the transient


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Typical Protection Scheme

Types:

►Over current protec

►Over voltage prote

Characteristics:

►Primary

► Secondary


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ESD,EFT and Surge Protection Devices

►Mapping of the Dynamic behavior with target device

TVS

Types:

►Unidirectional

►Bidirectional

Characteristics:

►Clamping

►Low dynamic resis


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TSPD

Types:

►Unidirectional

►Bidirectional

Characteristics:

►Crowbar device


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GDT

Types:

►Unidirectional

►Bidirectional

Characteristics:

►Crowbar


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EMC Compliant RS485 Communication Port


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Protection Scheme-1

Protection Level

Bidirectional TVS array CDS


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Protection Scheme-2

Bidirectional TVS array C

TBU-CA065-200-WH

TISP4240M3BJR-S


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Protection Scheme-3

Bidirectional TVS array CD

TBU-CA065-200-WH

TISP4240M3BJR-S

2038-15-SM-RPLF


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Layout & Placement

►Locate the protectio

the bus connector

► Avoid stubs connec

Certified EMC Compliance for RS-485


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Certified EMC Compliance for RS 485

Three Protection Circuits at Different Cost Points

R

D

B

A

RxD

TxD

GND

VCC

B

A

ESD

IEC61000-4-2

EFT

IEC61000-4-4

Su

IEC61

8kV Contact15kV Air

2kV >

8kV Contact15kV Air 2kV > 4

8kV Contact15kV Air

2kV > 6

* Surge rating depends on location of equipment,

Exterior, higher level application specification

R

D

B

A

RxD

TxD

GND

VCC

B

A

R

D

B

A

RxD

TxD

GND

VCC

B

A

► EVAL-CN0313-SDPZ Contains ADI RS-485 Transceivers

Bourns Exte rnal Protection Compo

A l D i d EMC


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Analog Devices and EMC..

►Components with integrated

ESD Protection Overvoltage Protection

EMI Filters

►Reference Designs Complying to EMC Standards

ADA4177-x – ADA4077 with ±32V OVP and EMI


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Input OVP

Input

Voltage

(±42V)

OutputVoltage

(±15V)

PowerSupplies

(±15V)

32V > Power

Supply

32V < Power

Supply

Key Features and Benefits

Input OVP and EMI Filters

Protects the inputs from damage

Easier to pass EMI susceptibility testing Improves Time-to-Market

Improves system precision (to 50X)

Simplifies system design

Reduces BOM costs and PCB footprint

Rail-to-Rail Output improves dynamic range by 7%

Applications

Front end amplifier for standardized sensor input in Process

Control Instrumentation front ends

Motor control current sense

VOS Offset Drift Ib Noise Isy Max Bandwidth Op. Vo

60 µV Max 1 µV/C Max 1 nA Max 8 nV/√Hz 620 µA 3.5 MHz ±2.5 V –

Integrated Input OVP and EMI filters

No Phase Reversal,

Oscillation, or Damage

R

Vout

EMI Filtered

Op Amp

¬Vos

¬V

¬V¬Vos

GND®

GND®

Vout

UnfilteredOp Amp

Input

20dB Lower EMI

O V lt P t ti Di t I t t d


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Over-Voltage Protection – Discrete versus Integrated

D1/D2 ROVP

Reference: Analog Dialogue Volume 46, February 2012, “Robust Amplifiers Provide Integrated Overvoltage Protection”

http://www.analog.com/library/analogdialogue/archives/46-02/ovp.html

VCC

VEE

VIN

ESD

OVP

ESD (HBM) >4kV

JFET

>2kV

40VBreakdown

CurrentLimiting FET

External Solution Integrated Solution

Typical Op

Amp

ADA4177-2

5k

BAS70-4-V

5k

ADA4096-x – 36V OPX96 Performance

http://www.analog.com/library/analogdialogue/archives/46-02/ovp.htmlhttp://www.analog.com/library/analogdialogue/archives/46-02/ovp.html


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36V, RRIO, Precision, µPower, RRIO Op Amp with OVP

Key Features

Internal Input Over Voltage Protection (OVP)

Up to ±32V beyond the Rails

Characterized OVP Parametric Impact

(compared to external OVP solutions)Low Power: 60 µA typical

Unity GBW: 800 kHz at Vsy = ±15V typical550 kHz at Vsy = ±5V typical475 kHz at Vsy = ±1.5V typical

Low Offset Voltage: 35 µV typical

Applications

Process Control (PLC/DSC)

Battery Monitoring and Current Shunt Sensing

Sensor Conditioning

Portable Instrumentation

Wireless Base Stations

Isy GBW Vos Vos Drift Noise IB Vo

75 A max 800 kHz typ 300 V max 1 V/°C typ 27 nV/Hz typ 10 nA max 3 V

PLC Evaluation Board with EMC


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Thank You

EMI-EMC for Beginners

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