rnd_chmfr_ECNFINAL

ENGINEERINGCHANGENOTICETitle:RoundedChamferAppliesto:USB2.0SpecificationSummaryofECNThisECNdefinesaroundedchamferdesignoptionforthemini-Bplug,whichisrecommendedforallnewandexistingdesigns.Thepreviousflatchamferdesignisallowed,butnotrecommended.ReasonsforECNConsumersbenefitfromthisECNbecauseroundedchamfermini-Bplugsresultinlongerlastingmini-Breceptacles.Manufacturersalsobenefit.Connectorswithroundedchamferplugscanachievemorematingcyclesthanconnectorswithflatchamferplugs.Thisallowstheroundedchamferconnectorstobeusedinapplicationsthatmayrequiremoredurabilitythantheflatchamferplugscanachieve.AssessmentofImpactonCurrentSpecificationandCurrentUSBProductsThisECNmodifiestheMini-BConnectorECNtotheUSB2.0SpecificationbyreplacingFigure6-15withthetwoattachedfigures.Figure1belowshowsboththeroundedchamferandflatchamferplugoptions.Theroundedchamferoptionincludesanoterecommendingitfornewandexistingdesigns.Theflatchamferoptionincludesanoteindicatingthatitisallowed,butnotrecommendedfornewandexistingdesigns.UsersofcurrentUSBproductsarenotaffectedbythechangefromflatchamfertoroundedchamfermini-Bplugs.Bothtypesofplugsmatethesamewithmini-Breceptacles.Theonlydifferenceistheincreasedlifeofthereceptaclewhenusingtheroundedchamferplugs.HardwareImplicationsTherearenoissues.Receptaclelifeisincreasedwiththeuseofroundedchamferplugs.SoftwareImplicationsNoneComplianceTestingImplicationsTherearenocompliancetestingissues.Devicemfrsarestillallowedtouseflatchamferplugsiftheysodesire.TheOTGchecklistdoesincludeaquestionthatasksdevicemfrsiftheplughasaflatchamferoraroundchamfer.SpecificationChangesThisECNmodifiestheMini-BConnectorECNoftheUSB2.0SpecificationbyreplacingFigure6-15withthetwoattachedfigures.FIGURE1FIGURE2