EDNE April 2012 - (Page 22)

PROtEct POE systEms fRom LIghtnIng suRges And otheR eLectRIcAL hAzARds The increased use of Poe broadens The range of locaTions in which you can use eTherneT—from indoors To camPus layouTs or firsT- and lasT-mile TelePhony aPPlicaTions. These uses increase exPosure To lighTning-induced surges, esd, and accidenTal Power faulTs. ProPer design ProTecTs Poe equiPmenT from These hazards. imagE: JamEs ThEw/shUTTERsTOCK P PhilliP haVens and chad maraK • liTTelfuse inc OE (power over Ethernet) has been rapidly gaining popularity because it eliminates the requirements for separate power supplies and power cables for connected equipment and for locating equipment near an ac outlet. Recent increases have occurred in the amount of power that POE PSE (power-supply equipment) can deliver—from 15.4W for POE to 30W for POE+. These increases have in turn increased the number of potential applications. Ethernet now delivers sufficient power for VOIP telephony, to power extended-range wireless-access points, and to operate surveillance cameras, for which it can also power pan and tilt functions. www.edn-europe.com 22 EDN EUROPE | APRIL 2012 http://www.edn-europe.com

Table of Contents for the Digital Edition of EDNE April 2012

Cover
Contents
International Rectifier
Contents
RS Components
Masthead
Comment
International Rectifier
Pulse
Analog Devices
FTDI
Digikey
Mouser
Baker's best
Digikey
Test & Measurement
Agilent Technologies
Digikey
Protect POE systems
Hirose
Coilcraft
Mesago
Cover Story
Digikey
Signal Integrity
RS Components insert
Balancing GBWP and quiescent current
Noise wars
Design Idea
Product Roundup
Tales from the cube

EDNE April 2012