USB协会标准

USB2.0SpecificationEngineeringChangeNotice(ECN)#1:Mini-BconnectorDate:10/20/2000ReasonforECN:TheUSB2.0specifieddevice-sideconnector–theBconnector–istoolargeforusewithanewgenerationofhandheldandmobiledevices,e.g.,cellphoneswhichwouldbenefitfromconnectivitytothePC.ThisECNincorporatesaspecificationofadevice-sideminiconnector(hereafterreferredtoasamini-Bconnector).Thenewconnectoronlyappliestoupstreamfacingports,i.e.,connectorsondevices.SummaryofECN:ThebulkoftheECNspecifiesthemechanicalrequirementsforthemini-Bplug,receptacleandcableassembly.Italsoidentifiestheusagescopeofthisconnector.ThelastpartoftheECNdescribestheminimumtestcriteriaandperformancerequirementsforthenewconnector.BenefitsofECN:TheECNenablesstandardizationofminiaturedevice-sideUSBconnectorsandconsequenteconomiesofscalesandlowercostforanewandgrowingclassofdeviceswhichwillbenefitfromconnectivitytothePC.ThestandardizationalsoallowsleveragingofthecompliancetestandcertificationmodelwhichisalreadyinplaceforUSBconnectors.AssessmentofImpactonCurrentSpecificationandCurrentUSBProducts:TheconnectorspecifiedintheECNwillnothaveanyimpactonhardwareorsoftwareofexistingUSBproducts.ThecurrentUSBspecalreadyallowsforvendor-specificdevicesideconnectors–suchcableassembliesarecalledcaptiveassemblies.AllthattheECNdoesistoidentifyonesuchconnectorforuseindeviceswhichneedthesmallersizeofconnector.Thereisapotentialforsomeend-userconfusionbecauseoftwostandardcableoptions;butthiscanbemitigatedbyappropriateend-usereducation.StructureofECN:TheECNisintheformofanewChapter6withthemini-Bconnectorrequirementsinsertedintotheappropriatelocations.Thisformatenablesspecificationofthenewconnectorincontext.UniversalSerialBusSpecificationRevision2.085Chapter6MechanicalThischapterprovidesthemechanicalandelectricalspecificationsforthecables,connectors,andcableassembliesusedtointerconnectUSBdevices.Thespecificationincludesthedimensions,materials,electrical,andreliabilityrequirements.ThischapterdocumentsminimumrequirementsfortheexternalUSBinterconnect.Substitutematerialmaybeusedaslongasitmeetstheseminimums.6.1ArchitecturalOverviewTheUSBphysicaltopologyconsistsofconnectingthedownstreamhubporttotheupstreamportofanotherhubortoadevice.TheUSBcanoperateatthreespeeds.High-speed(480Mb/s)andfull-speed(12Mb/s)requiretheuseofashieldedcablewithtwopowerconductorsandtwistedpairsignalconductors.Low-speed(1.5Mb/s)recommends,butdoesnotrequiretheuseofacablewithtwistedpairsignalconductors.Theconnectorsaredesignedtobehotplugged.TheUSBIconontheplugsprovidestactilefeedbackmakingiteasytoobtainproperorientation.6.2KeyedConnectorProtocolTominimizeenduserterminationproblems,USBusesa“keyedconnector”protocol.ThephysicaldifferenceintheSeries“A”and“B”(or“mini-B”)connectorsinsuresproperenduserconnectivity.The“A”connectoristheprinciplemeansofconnectingUSBdevicesdirectlytoahostortothedownstreamportofahub.AllUSBdevicesmusthavethestandardSeries“A”connectorspecifiedinthischapter.The“B”(or“mini-B”)“B”connectorallowsdevicevendorstoprovideastandarddetachablecable.Thisfacilitatesendusercablereplacement.Figure6-1Figure6-1illustratesthekeyedconnectorprotocol.UniversalSerialBusSpecificationRevision2.086Series"A"ConnectorsSeries"B"Connectors♦Series"A"plugsarealwaysorientedupstreamtowardstheHostSystem♦Series"B"plugsarealwaysorienteddownstreamtowardstheUSBDevice"A"Plugs(FromtheUSBDevice)"B"Plugs(FromtheHostSystem)"B"Receptacles(UpstreamInputtotheUSBDeviceorHub)"A"Receptacles(DownstreamOutputfromtheUSBHostorHub)Series"mini-B"Connectors♦Series"mini-B"plugsarealwaysorienteddownstreamtowardstheUSBDevice"mini-B"Plugs(FromtheHostSystem)"mini-B"Receptacles(UpstreamInputtotheUSBDeviceorHub)Figure6-1.KeyedConnectorProtocolUniversalSerialBusSpecificationRevision2.087Thefollowinglistexplainshowtheplugsandreceptaclescanbemated:•Series“A”receptaclemateswithaSeries“A”plug.Electrically,Series“A”receptaclesfunctionasoutputsfromhostsystemsand/orhubs.•Series“A”plugmateswithaSeries“A”receptacle.TheSeries“A”plugalwaysisorientedtowardsthehostsystem.•Series“B”receptaclemateswithaSeries“B”plug(male).Electrically,Series“B”receptaclesfunctionasinputstohubsordevices.•Series“B”plugmateswithaSeries“B”receptacle.TheSeries“B”plugisalwaysorientedtowardstheUSBhubordevice.•Series“mini-B”receptaclemateswithaSeries“mini-B”plug(male).Electrically,Series“mini-B”receptaclesfunctionasinputstohubsordevices.•Series“mini-B”plugmateswithaSeries“mini-B”receptacle.TheSeries“mini-B”plugisalwaysorientedtowardstheUSBhubordevice.6.3CableUSBcableconsistsoffourconductors,twopowerconductors,andtwosignalconductors.High-/full-speedcableconsistsofasignalingtwistedpair,VBUS,GND,andanoverallshield.High-/full-speedcablemustbemarkedtoindicatesuitabilityforUSBusage(seeSection6.6.2).High-/full-speedcablemaybeusedwitheitherlow-speed,full-speed,orhigh-speeddevices.Whenhigh-/full-speedcableisusedwithlow-speeddevices,thecablemustmeetalllow-speedrequirements.Low-speedrecommends,butdoesnotrequiretheuseofacablewithtwistedsignalingconductors.6.4CableAssemblyThisspecificationdescribesthreeUSBcableassemblies:standarddetachablecable,high-/full-speedcaptivecable,andlow-speedcaptivecable.Astandarddetachablecableisahigh-/full-speedcablethatisterminatedononeendwithaSeries“A”plugandterminatedontheoppositeendwithaseries“B”(or“mini-B”)“B”plug.Ahigh-/full-speedcaptivecableisterminatedononeendwithaSeries“A”plugandhasavendor-specificconnectmeans(hardwiredorcustomdetachable)ontheoppositeendforthehigh-/full-speedperipheral.Thelow-speedcaptivecableisterminatedononeendwithaSeries“A”plugandhasavendor-specificconnectmeans(hardwiredorcustomdetachable)ontheoppositeendforthelow-speedperipheral.Anyothercableassembliesareprohibited.Thecolorusedforthecableassemblyisvendorspecific;recommendedcolorsarewhite,grey,orblack.6.4.1StandardDetachableCableAssembliesHigh-speedandfull-speeddevicescanutilizethe“B”(or“mini-B”)“B”connector.ThisallowsthedevicetohaveastandarddetachableUSBcable.Thiseliminatestheneedtobuildthedevicewithahardwiredcableandminimizesenduserproblemsifcablereplacementisnecessary.Devicesutilizingthe“B”(or“mini-B”)“B”connectormustbedesignedtoworkwithworstcasemaximumlengthdetachablecable.Standarddetachablecableassembliesmaybeusedonlyonhigh-speedandfull-speeddevices.Usingahigh-/full-speedstandarddetachablecableonalow-speeddevicemayexceedthemaximumlow-speedcablelength.Figure6-2Figure6-2andFigure6-3illustratesastandarddetachablecableassembliesy.UniversalSerialBusSpecificationRevision2.088CSeries"A"PlugtoSeries"B"PlugUSBStandardDetachableCableAssemblySIZEDRAWINGNUMBERREVAN/ADATE2/98SCALE:N/ASHEET1of1HGFEDCBA87654321HGFEDCBA87654321DetailB-B(Series"B"Plug)DetailA-A(Series"A"Plug)213412.032.09.010.511.5341227.012.09.07.515.7OptionalMoldedStrainReliefAlldimensionsareinmillimeters(mm)unlessotherwisenoted.DimensionsareTYPICALandareforgeneralreferencepurposesonly.AluminumMetallizedPolyesterInnerShieldBlack(Ground)28AWGSTCDrainWire>65%TinnedCopperBraidedShieldPolyvinylChloride(PVC)JacketGreen(D+)White(D-)Red(VBUS)DetailC-C(TypicalUSBShieldedCable)IMPORTANTNOTICE:Allstandarddetachablecableassembliesmustbehigh-/full-speed.CCCCAABBOvermoldedSeries"B"Plug(AlwaysdownstreamtowardstheUSBDevice.)OvermoldedSeries"A"Plug(Alwaysupstreamtowardsthe"host"system.)Figure6-22.USBStandardDetachableCableAssemblyUniversalSerialBusSpecificationRevision2.089Figure6-3.USBStandardMini-connectorDetachableCableAssemblyUniversalSerialBusSpecificationRevision2.090Standarddetachablecableassembliesmustmeetthefollowingelectricalrequirements:•ThecablemustbeterminatedononeendwithanovermoldedSeries“A”plugandtheoppositeendisterminatedwithanovermoldedSeries“B”(or“mini-B”)“B”plug.•Thecablemustberatedforhigh-speedandfull-speed.•Thecableimpedancemustmatchtheimpedanceofthehigh-speedandfull-speeddrivers.Thedriversarecharacterizedtodrivespecificcableimpedance.RefertoSection7.1.1fordetails.•Themaximumallowablecablelengthisdeterminedbysignalpairattenuationandpropagationdelay.RefertoSections7.1.14and7.1.17fordetails.•Differencesinpropagationdelaybetweenthetwosignalconductorsmustbeminimized.RefertoSection7.1.3fordetails.•TheGNDleadprovidesacommongroundreferencebetweentheupstreamanddownstreamports.ThemaximumcablelengthislimitedbythevoltagedropacrosstheGNDlead.RefertoSection7.2.2fordetails.Theminimumacceptablewiregaugeiscalculatedassumingtheattacheddeviceishighpower.•TheVBUSleadprovidespowertotheconnecteddevice.Forstandarddetachablecables,theVBUSrequirementisthesameastheGNDlead.6.4.2High-/full-speedCaptiveCableAssembliesAssembliesareconsideredcaptiveiftheyareprovidedwithavendor-specificconnectmeans(hardwiredorcustomdetachable)totheperipheral.High-/full-speedhardwiredcableassembliesmaybeusedwitheitherhigh-speed,full-speed,orlow-speeddevices.Whenusingahigh-/full-speedhardwiredcableonalow-speeddevice,thecablemustmeetalllow-speedrequirements.Figure6-3Figure6-4illustratesahigh-/full-speedhardwiredcableassembly.UniversalSerialBusSpecificationRevision2.091CSeries"A"PlugtoCutEndUSBHigh-/full-speedHardwiredCableAssemblySIZEDRAWINGNUMBERREVAN/ADATE2/98SCALE:N/ASHEET1of1HGFEDCBA87654321HGFEDCBA87654321CutEnd(AlwaysdownstreamtowardstheUSBDevice.)OvermoldedSeries"A"Plug(Alwaysupstreamtowardsthe"host"system.)Alldimensionsareinmillimeters(mm)unlessotherwisenote.DimensionsareTYPICALandareforgeneralreferencepurposesonly.AABBBluntCutTermination(LengthDimensionPoint)PolyvinylChloride(PVC)JacketBluntCutTerminationPreparedTerminationMetallizedMylarInnerShield>65%TinnedCopperBraidedShieldPolyvinylChloride(PVC)JacketRed(VBUS)Black(Ground)Green(D+)White(D-)28AWGSTCDrainWireUserSpecifiedLengthDimensionPointDetailB-B(TypicalTerminations)DetailA-A(Series"A"Plug)123427.012.09.07.515.7OptionalMoldedStrainReliefFigure6-36-4.USBHigh-/full-speedHardwiredCableAssemblyUniversalSerialBusSpecificationRevision2.092High-/full-speedcaptivecableassembliesmustmeetthefollowingelectricalrequirements:•ThecablemustbeterminatedononeendwithanovermoldedSeries“A”plugandtheoppositeendisvendorspecific.Ifthevendorspecificinterconnectistobehotplugged,itmustmeetthesameperformancerequirementsastheUSB“B”connector.•Thecablemustberatedforhigh-speedandfull-speed.•Thecableimpedancemustmatchtheimpedanceofthehigh-speedandfull-speeddrivers.Thedriversarecharacterizedtodrivespecificcableimpedance.RefertoSection7.1.1fordetails.•Themaximumallowablecablelengthisdeterminedbysignalpairattenuationandpropagationdelay.RefertoSections7.1.14and7.1.17fordetails.•Differencesinpropagationdelaybetweenthetwosignalconductorsmustbeminimized.RefertoSection7.1.3fordetails.•TheGNDleadprovidesacommonreferencebetweentheupstreamanddownstreamports.ThemaximumcablelengthisdeterminedbythevoltagedropacrosstheGNDlead.RefertoSection7.2.2fordetails.Theminimumwiregaugeiscalculatedusingtheworstcasecurrentconsumption.•TheVBUSleadprovidespowertotheconnecteddevice.Theminimumwiregaugeisvendorspecific.6.4.3Low-speedCaptiveCableAssembliesAssembliesareconsideredcaptiveiftheyareprovidedwithavendor-specificconnectmeans(hardwiredorcustomdetachable)totheperipheral.Low-speedcablesmayonlybeusedonlow-speeddevices.Figure6-4Figure6-5illustratesalow-speedhardwiredcableassembly.UniversalSerialBusSpecificationRevision2.093CSeries"A"PlugtoCutEndUSBLow-speedHardwiredCableAssemblySIZEDRAWINGNUMBERREVAN/ADATE2/98SCALE:N/ASHEET1of1HGFEDCBA87654321HGFEDCBA87654321DetailA-A(Series"A"Plug)123427.012.09.07.515.7OptionalMoldedStrainReliefAlldimensionsareinmillimeters(mm)unlessotherwisenoted.DimensionsareTYPICALandareforgeneralreferencepurposesonly.AABBCutEnd(AlwaysdownstreamtowardstheUSBDevice.)OvermoldedSeries"A"Plug(Alwaysupstreamtowardsthe"host"system.)IMPORTANTNOTICE:Foruseinlow-speedapplicationsonly.DetailB-B(TypicalTerminations)BluntCutTermination(LengthDimensionPoint)PolyvinylChloride(PVC)JacketBluntCutTerminationPreparedTerminationBlack(Ground)UserSpecifiedLengthDimensionPointRed(VBUS)White(D-)Green(D+)PolyvinylChloride(PVC)JacketFigure6-46-5.USBLow-speedHardwiredCableAssemblyUniversalSerialBusSpecificationRevision2.0956.5ConnectorMechanicalConfigurationandMaterialRequirementsTheUSBIconisusedtoidentifyUSBplugsandthereceptacles.Figure6-5Figure6-6illustratestheUSBIcon.L0.5LLLL0.33L0.33L0.33LL1.50L1.50L1.67L2.33L3.75L5.00L5.17L6.25L8.00LDia:1.67LLDia:1.33LDia:LDia:LDia:LDia:LDia:1.33LAlldimensionsare±5%Figure6-5Figure6-6.USBIcon6.5.1USBIconLocationTheUSBIconisembossed,inarecessedarea,onthetopsideoftheUSBplug.Thisprovideseasyuserrecognitionandfacilitatesalignmentduringthematingprocess.TheUSBIconandManufacturer’slogoshouldnotprojectbeyondtheovermoldsurface.TheUSBIconisrequired,whiletheManufacturer’slogoisrecommended,forbothSeries“A”and“B”(or“mini-B”)“B”plugassemblies.TheUSBIconisalsolocatedadjacenttoeachreceptacle.ReceptaclesshouldbeorientedtoallowtheIconontheplugtobevisibleduringthematingprocess.Figure6-6Figure6-7andFigure6-8illustratesthetypicalplugorientations.UniversalSerialBusSpecificationRevision2.096Manufacturer’sEngravedLogoAATopViewOptionalTop"LocatorDetail"OptionalTop"LocatorDetail"LocatorHeightApproximately0.6mm(0.024")LocatorWidthApproximately0.5mm(0.020")4321EngravedUSBIconSectionA-A(PlugCross-Section)Overmolding0.6mm(0.024")MaxManufacturer’sLogoEngravingRecess0.6mm(0.024")MaxUSBIconEngravingRecessFigure6-6Figure6-7.TypicalUSBPlugOrientationUniversalSerialBusSpecificationRevision2.097Figure6-8.TypicalUSB“Mini-B”ConnectorPlugOrientationUniversalSerialBusSpecificationRevision2.0986.5.2USBConnectorTerminationDataTable6-1Table6-1providesthestandardizedcontactterminatingassignmentsbynumberandelectricalvalueforSeries“A”andSeries“B”connectors.Table6-1.USBSeries“A”andSeries“B”ConnectorTerminationAssignmentContactNumberSignalNameTypicalWiringAssignment1VBUSRed2D-White3D+Green4GNDBlackShellShieldDrainWireTable6-2providesthestandardizedcontactterminatingassignmentsbynumberandelectricalvalueforSeries“mini-B”connectors.Table6-2.USBSeries“mini-B”ConnectorTerminationAssignmentContactNumberSignalNameTypicalWiringAssignment1VBUSRed2D-White3D+Green4IDnotconnected5GNDBlackShellShieldDrainWire6.5.3Series“A”andSeries“B”(or“Mini-B”)“B”ReceptaclesElectricalandmechanicalinterfaceconfigurationdataforSeries"A"andSeries"B"receptaclesareshowninFigure6-7Figure6-9throughFigure6-12andFigure6-8.Also,refertoFigure6-12Figure6-17throughFigure6-20,Figure6-13,andFigure6-14attheendofthischapterfortypicalPCBreceptaclelayouts.UniversalSerialBusSpecificationRevision2.099OvermoldBoot2.67MINFullyMatedSeries"A"ReceptacleandPlugReceptacleFlange1USBSeries"A"ReceptacleandPlugMatingFeatures1Allowaminimumspacingof2.67mmbetweenthefaceofthereceptacleandtheplugovermoldboot.8.0MAXSCALE:N/AInterfaceandMatingDrawingSeries"A"ReceptacleSIZEDRAWINGNUMBERREVAN/ADATE2/98CSHEET1of1HGFEDCBA87654321HGFEDCBA876543210.38±0.138.38±0.088.88±0.204.98±0.25ContactPoint300±20(2)0.50±0.104.13REFCenterLineof5.12ReceptacleContactPrintedCircuitBoard300±20(2)0.50±0.10(2)BCenterLineC12341.84±0.0512.50±0.1011.10±0.10R0.64±0.13(Typical)0.64±0.13(8)5.12±0.101.00±0.05(4)R0.32±0.13(Typical)BCCenterLine3.50±0.05(2)1.00±0.05(2)AUSBSeries"A"ReceptacleInterfaceAlldimensionsareinmillimeters(mm)unlessotherwisenoted.Figure6-7Figure6-9.USBSeries"A"ReceptacleInterfaceandMatingDrawingUniversalSerialBusSpecificationRevision2.0100SCALE:N/AInterfaceandMatingDrawingUSBSeries"B"ReceptacleSIZEDRAWINGNUMBERREVAN/ADATE2/98CSHEET1of1HGFEDCBA87654321HGFEDCBA87654321CCenterLine300+20(4)8.38+0.080.38+0.13(4)8.45+0.105.60+0.101.00+0.05(4)1.25+0.10(4)1243A8.88+0.203.18+0.05BC7.78+0.10450+0.50(2)R0.38(6)3.67+0.080.80+0.081.63+0.05(2)BCenterLineContactPoint4.98+0.25ReceptacleContactBCenterLine300+20(2)ReceptacleHousing0.50+0.10(2)3.67CenterLineReceptacleShellReceptacleShellFullyMatedPlugandReceptacle2.67MINOvermoldBootOvermoldBootUSBSeries"B"ReceptacleandPlugMatingFeatures10.5MAX11.5MAXUSBSeries"B"ReceptacleInterface11Allowaminimumspacingof2.67mmbetweenthefaceofthereceptacleandtheplugovermoldboot.Alldimensionsareinmillimeters(mm)unlessotherwisenoted.Figure6-8Figure6-10.USBSeries"B"ReceptacleInterfaceandMatingDrawingUniversalSerialBusSpecificationRevision2.0101Figure6-11.USBSeries“Mini-B”ReceptacleInterfaceandMatingDrawingUniversalSerialBusSpecificationRevision2.0102Figure6-12.USBSeries“Mini-B”ReceptacleInterfaceDrawing(Detail)UniversalSerialBusSpecificationRevision2.01036.5.3.1ReceptacleInjectionMoldedThermoplasticInsulatorMaterialMinimumUL94-V0rated,thirtypercent(30%)glass-filledpolybutyleneterephthalate(PBT)orpolyethyleneterephthalate(PET)orbetter.TypicalColors:Black,gray,andnatural.The“mini-B”receptacleinsulatormustbeblackincolor.FlammabilityCharacteristics:UL94-V0rated.FlameRetardantPackagemustmeetorexceedtherequirementsforUL,CSA,VDE,etc.OxygenIndex(LOI):Greaterthan21%.ASTMD2863.6.5.3.2ReceptacleShellMaterials6.5.3.2.1Series“A”andSeries“B”SubstrateMaterial:0.30+0.05mmphosphorbronze,nickelsilver,orothercopperbasedhighstrengthmaterials.Plating:1.Underplate:Optional.Minimum1.00micrometers(40microinches)nickel.Inaddition,manufacturermayuseacopperunderplatebeneaththenickel.2.Outside:Minimum2.5micrometers(100microinches)brighttinorbrighttin-lead.6.5.3.2.2Series“mini-B”SubstrateMaterial:0.3mmminimumphosphorbronze,nickelsilver,orothersuitablematerial.Theplatinginformationbelowdescribesanexampleofacceptable"mini-B"receptacleplating.Plating:1.Underplate:Optional.Minimum1.00micrometers(40microinches)nickel.Inaddition,manufacturermayuseacopperunderplatebeneaththenickel.2.Outside:Minimum2.5micrometers(100microinches)brighttinorbrighttin-lead.6.5.3.3ReceptacleContactMaterials6.5.3.3.1Series“A”andSeries“B”SubstrateMaterial:0.30+0.05mmminimumhalf-hardphosphorbronzeorotherhighstrengthcopperbasedmaterial.Plating:Contactsaretobeselectivelyplated.A.OptionI1.Underplate:Minimum1.25micrometers(50microinches)nickel.Copperoverbasematerialisoptional.2.MatingArea:Minimum0.05micrometers(2microinches)goldoveraminimumof0.70micrometers(28microinches)palladium.3.SolderTails:Minimum3.8micrometers(150microinches)brighttin-leadovertheunderplate.B.OptionII1.Underplate:Minimum1.25micrometers(50microinches)nickel.Copperoverbasematerialisoptional.UniversalSerialBusSpecificationRevision2.01042.MatingArea:Minimum0.05micrometers(2microinches)goldoveraminimumof0.75micrometers(30microinches)palladium-nickel.3.SolderTails:Minimum3.8micrometers(150microinches)brighttin-leadovertheunderplate.C.OptionIII1.Underplate:Minimum1.25micrometers(50microinches)nickel.Copperoverbasematerialisoptional.2.MatingArea:Minimum0.75micrometers(30microinches)gold.3.SolderTails:Minimum3.8micrometers(150microinches)brighttin-leadovertheunderplate.6.5.3.3.2Series“mini-B”SubstrateMaterial:0.2mmminimumhalf-hardphosphorbronzeorotherhighstrengthsu