Introduction to EMC Design For Compliance

Welcome

• We want to use electromagnetic energy

for our own purposes

• We don’t want unintended emissions –

either radiated or conducted

• Our circuits inherently generate

electromagnetic fields

• Our task is to design products that meet

radiated and conducted emission limits

• Also our job to make sure that our products

don’t interfere with themselves

What is EMC?

Circuit Board Examples

Probably going to fail EMCProbably going to pass EMC

• 50% first time failure rate on average

• Some labs report >90% failure rate

• Less money on development costs

• Less money on testing costs

• Faster time to market

• Produce more products per year

• Cleaner power supplies

• Better signal integrity

• Better immunity performance

Why Bother With EMC?

Benefits for Engineers

• EMC knowledge is in demand

• Improve your employability

• Demand for EMC is increasing

- Clock rates rising

- EMC testing expanding

• Higher salary/ hourly rate

EMC consultants regularly charge >$150/h!

Branches of EMC Knowledge

Test & Measurement

Signal IntegrityS/N Ratio

Noise MarginOvershoot

RingingEye Diagrams

CrosstalkJitter

Design for Compliance

Emissions Immunity

IC, PCB, System

Troubleshooting

Internal External

RadiatedConducted

FlickerHarmonicsMag. Field

ESDRadiated

EFTSurge

ConductedMag. FieldDips, dropsRingwave

Full/Pre-Compliance

Real Issues

Interference

Susceptibility

Regulatory

Power Integrity

Coupling

Simulation

Emissions

Immunity

1. Clearly define the problem for all of their engineers

2. Engineers are trained in design for compliance

3. Have a robust process for reviewing and checking their design

4. Investment in pre-compliance test equipment

5. Ongoing training for new and experienced engineers

6. EMC considered early in the design cycle

7. Learn from their mistakes

8. View EMC as a predicable and solvable problem

9. Management see value in investing in solutions

Processes and Mindsets of Companies Who Pass

1. The problem is not well defined

2. Very few companies have a robust EMC pre-scan/review procedure

3. EMC design knowledge is not efficiently taught to new engineers

4. EMC considered late in design cycle

5. No feedback loop from EMC labs to industry

6. Belief that EMC is a ‘black art’

7. Belief that failures are random. Can’t predict everything

8. Lack of visibility of the issue from management

... And the Companies Who Normally Fail

Introduction to topics covered:• EMC design rules

• Foundation concepts

• PCB stackups and PDN impedance

• Coupling mechanisms

• Return paths

• System and board level grounding

• Decoupling capacitor selection, placement

and routing

• Filtering

Introduction to this Course

• Shielding

• Signal integrity

• SMPS design

• EMI cost reduction

• Isolated power supplies

• Tools & resources

1. Electromagentic Compatibility Engineer, H. Ott

2. EMC Design Techniques, K. Armstrong

3. EMC for PCBs, K. Armstrong

4. EMC for Product Designers, T. Williams

Recommended Books

Meet the Instructors

Andy Eadie – The test + measurement + hardware guy

Dr. Moises Ferber – The theoretical + SMPS guy

Antonio Aquino – The signal/power integrity + simulation guy

• Use forums to ask questions

• Mark each module as complete once finished

• Access Design Review Pro tool

How to Navigate the Website

Let’s get started!

End of Introduction