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Development in our fast-paced world is difficult
enough without having to stare down EMI demons.
Exorcise those demons before they get into your
design! Prudent printed circuit board layout pays
dividends as good layout, proper component selection
and good planning will reduce surprises at
test-time. EMC design is more critical than ever as
designs must comply with domestic and international
standards. FCC, CISPR, IEC, CE Marking, CCC all
require conformance to EMC specifications. In the
world of global competitiveness, missing the mark
may mean missing the market. Find out how to do more
from the experts at Wurth Electronics and Washington
Labs. Join us for this informative and interactive
design session, followed by laboratory
demonstrations.
Engineers involved in product development, EMC and
compliance will enjoy this seminar where they’ll
learn techniques to reduce trace radiation,
crosstalk, power supply emissions, proper decoupling
and filtering. Test and compliance requirements for
international markets will also be discussed. You’ll
learn:
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Techniques to reduce trace radiation, crosstalk,
power supply emissions
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Proper decoupling and filtering
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Test and compliance requirements for international
markets
Join our instructors, Oliver Opitz from Wurth
Electronics and Steve Koster from Washington Labs,
for this one day FREE seminar with lab
demonstrations. Lunch included! To register, Click
HERE .
For more information contact us at 301/216-1500.
Tech tips:
Rule #1: Control frequency, control EMI. Terminations: Transmission line terminations can take several forms—source output buffering, load termination, for example—and can utilize either resistive or capacitive elements or a combination of the two. The end objective is to match the source, T-Line and load impedances to minimize reflection, overshoot and ringing. The added benefit of good termination is to reduce the net spectral energy in digital sources. This lessens the burden on shielding and filtering. The concept is based on the management of the spectral “richness” of a periodic signal. For a perfect square wave, the rise time is zero. This creates a rich spectrum of frequency components that stretch to infinity. There is a “breakpoint” at a frequency of f=1/T (the fundamental frequency). Beyond that, the harmonics decrease monotonically at intervals of n/T, theoretically stretching to infinity.
Real signals have finite risetimes and can be approximated by trapezoidal waves with a risetime of τr. Note in the figure the upper corner frequency is directly proportional to the risetime. For increasingly faster risetimes, the spectrum is stretched. By controlling the risetimes of the signal, a designer limits the “upper corner” frequency of the spectrum, thus reducing the energy that may otherwise cause problems via crosstalk and trace radiation. Proper termination of digital signals can reduce the spectral richness (not to mention provide an overall improvement of signal fidelity and quality).
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