When faced with excessive conducted emissions from switching power supplies, one of the first things to investigate and to determine the adequacy of is the power line filter. Line-powered switching supplies generally have both common mode and differential mode sections of the filter as shown in the generalized schematic in Figure 1. When using a line impedance … [Read more...]
EMC LIVE 2017! The Time is Now – FREE Registration is Open!
Join the fastest growing online EMC event of the year. EMC Live teaches the latest in practical solutions to electromagnetic interference (EMI) challenges - all for FREE, and all LIVE. Learn directly from industry professionals during 3 days of technical webinar presentations, product demonstrations, and an abundance of resources from whitepapers to application … [Read more...]
ESD Effects of Digital ICs
One issue I see fairly often with unshielded consumer or commercial products is CPU resets during periods of immunity testing, such as during electrostatic discharge (ESD) testing. Untreated, this can lead to field failures and associated customer satisfaction issues. The remedy is usually quite simple and IC manufacturers even mention the solution, but it’s usually buried … [Read more...]
Energy Harvesting is Not Fiction Anymore
“About what we did dream today, are the ideas from tomorrow. The tomorrow ideas are the products from the days after tomorrow.” Our environment is changing and everything is becoming “electronified”. Our glasses, our hand gloves, shirts, shoes etc., can be connected already today with our smartphones and can send commands to the machinery surrounding us. We want this comfort, … [Read more...]
Narrowband Versus Broadband Harmonic Signals
Radiated and conducted emissions measurements are often comprised of both narrowband and broadband sources. So what differentiates “narrowband” and “broadband” signals? Narrowband Versus Broadband Signals The definition of whether a signal is narrowband or broadband as measured using a spectrum analyzer, depends entirely on the receiver bandwidth (resolution bandwidth, or … [Read more...]
Review of IEC 60601-1-2: 2014 (4th Edition)
Introduction IEC 60601-1-2:2014 Edition 4 was published February 2014 and replaces IEC 60601-1-2 Edition 3 published on 2007. It pertains to EMC for medical electrical equipment and medical electrical systems. The European version (EN60601-1-2:2015) is identical to its IEC counterpart with exception of references to the EN versions of the 61000-4-x series and the addition of … [Read more...]
Troubleshooting EFT
EFT Phenomenon Recently I tested a medical device for EFT susceptibility. The requirement is that the medical device must be immune to EFT bursts generated per IEC 61000-4-4. Per this standard EFT bursts are applied in four steps. For level 4, steps 1 and 2 are +/-2kV at 5kHz, and steps 3 and 4 are +/-2kV at 100kHz. For each step, these bursts are applied at 300ms interval for … [Read more...]
Assembling A Low Cost EMI Troubleshooting Kit – Part 2 (Immunity)
This article concludes the two-part series, Assembling Your Own EMI Troubleshooting Kit – Part 1, which included a listing of the major components of a complete EMI trouble shooting kit that can be easily transported where needed. Most of the probes and tools listed in Part 1 were useful for troubleshooting radiated emissions. In Part 2, we’ll discuss several other useful … [Read more...]
Radio Equipment Directive, 2014/53/EU
Editor’s Note: The Radio Equipment Directive (RED), 2014/53/EU, must be used for new products manufactured after June 13, 2016 and becomes mandatory for all products June 13, 2017. Abstract This article provides an update on changes occurring as a result of the new Radio Equipment Directive (RED) 2014/53/EU which can be used from June of 2016. It looks at the changes in … [Read more...]
Gaps In Return Planes – Bad News for EMI
Currently, there is an ongoing discussion among SI and EMC engineers on the fine points of PC board design for best signal integrity and EMI performance. Among the topics it seems designing in gaps or slits in ground return planes always comes up. Gaps can also occur mistakenly due to the addition of some connectors or other object that creates gaps in the copper. In fact, … [Read more...]
