USB-3-1连接器协会规范

UniversalSerialBus3.1Specification,Revision1.05-45.3ConnectorMatingInterfacesThissectiondefinestheconnectormatinginterfaces,includingtheconnectorinterfacedrawings,pinassignments,anddescriptions.5.3.1USB3.1Standard-AConnector5.3.1.1InterfaceDefinitionFigure5-1andFigure5-2showtheUSB3.1Standard-Areceptacleandrequiredgroundspringmatingareas,respectively.Figure5-4showstheStandard-ApluginterfacedimensionsforUSB3.1.Onlythedimensionsthatgovernthematinginteroperabilityarespecified.AllREFdimensionsareinformative.TheUniversalSerialBusPowerDeliverySpecifiationdefinesthemechanicalandelectricalrequirementsfortheInsertionDetectfeaturetosupportcoldsocketcapability.ItmaybeimplementedinaStandard-AreceptacleoraPDStandard-Areceptacle.Implementationisvendor-specific.TheInsertionDetectfeatureshallbeimplementedforcoldsocketStandard-AapplicationsandisoptionalforallotherStandard-Aimplementations.SeetheUniversalSerialBusPowerDeliverySpecifiationforcompleteInsertionDetectrequirements.ExampleconnectorconfigurationsincludingInsertionDetectfeaturesareshowninFigure5-3.AlthoughtheUSB3.1Standard-AconnectorhasbasicallythesameformfactorastheUSB2.0Standard-Aconnector,ithassignificantdifferencesinside.Belowarethekeyfeaturesanddesignareasthatneedattention:•InadditiontotheVbus,D-,D+,andGNDpinsthatarerequiredforUSB2.0,theUSB3.1Standard-Aconnectorincludesfivemorepins:twodifferentialsignalpairsplusoneground(GND_DRAIN).ThetwoaddeddifferentialsignalpairsareforSuperSpeeddatatransfer,supportingdualsimplexSuperSpeedsignaling.TheaddedGND_DRAINpinisfordrainwireterminationandmanagingEMI,RFI,andsignalintegrity.•ThecontactareasofthefiveSuperSpeedpinsarelocatedtowardsthefrontofthereceptacleasblades,whilethefourUSB2.0pinstowardsthebackofthereceptacleasbeamsorsprings.Accordingly,intheplug,theSuperSpeedcontactsarebeamslocatedbehindtheUSB2.0blades.Inotherwords,theUSB3.1Standard-Aconnectorhasatwo-tiercontactsystem.•Thetiered-contactapproachwithintheStandard-AconnectorformfactorresultsinlesscontactareaascomparedtotheUSB2.0Standard-Aconnector.TheconnectorinterfacedimensionstakeintoconsiderationcontactmatingrequirementsbetweentheUSB3.1Standard-AreceptacleandUSB3.1Standard-Aplug,theUSB3.1Standard-AreceptacleandUSB2.0Standard-Aplugs,andtheUSB2.0Standard-AreceptaclesandUSB3.1Standard-Aplug.•TheconnectorinterfacedefinitionavoidsshortingbetweentheSuperSpeedandUSB2.0pinsduringinsertionwhenpluggingaUSB2.0Standard-AplugintoaUSB3.1Standard-AreceptacleoraUSB3.1Standard-AplugintoaUSB2.0Standard-Areceptacle.•TheremaybesomeincreaseintheUSB3.1Standard-Areceptacleconnectordepth(intoasystemboard)tosupportthetwo-tiered-contactsascomparedtotheUSB2.0Standard-Areceptacle.•DrawingsforstackedUSB3.1Standard-Areceptaclesarenotshowninthisspecification.Theyareallowedaslongastheymeetalltheelectricalandmechanicalrequirementsdefinedinthisspecification.WhendesigningastackedUSB3.1Standard-Areceptacle,effortsneedtobeMechanical5-5madetominimizeimpedancediscontinuityofthetopconnectorinthestackbecauseofitslongelectricalpath.AttentiontothehighspeedelectricaldesignofUSB3.1Standard-Aconnectorsisrequired.Inadditiontominimizingtheconnectorimpedancediscontinuities,crosstalkbetweentheSuperSpeeddifferentialsignalpairsandUSB2.0D+/D-pairshouldalsobeminimized.•Thereceptacleconnectorshouldhaveaback-shieldtoensurethatthereceptacleconnectorisfullyenclosed.TheUSB3.1receptacleshouldalsomakegoodcontacttothePCBgroundbyprovidingsufficientnumberofgroundtabstoensurealowimpedancepathtoPCBground.TheUSB3.1receptacleconnectorshouldhavearobustmatinginterfacetotheshieldoftheUSB3.1plugwhenitisinserted.PreviousversionsofthisspecificationrequiredprovidingagroundingspringtabinthemiddleofthesideclosesttotheUSBSuperSpeedsignalcontactsandgroundingspringsonbothsidesoftheshellforUSB3.0Standard-Areceptacles.NewdesignsshallhavethreegroundingspringtabsonthesideclosesttotheUSBSuperSpeedsignalcontacts,twogroundingspringtabsonthesideoppositetheUSBSuperSpeedsignalcontacts,andagroundingspringonbothsidesoftheshelloftheUSB3.1Standard-Areceptacle.SeeFigure5-2.ContinuedonnextpageUniversalSerialBus3.1Specification,Revision1.05-6ContinuedonnextpageMechanical5-7Figure5-1.USB3.1Standard-AReceptacleInterfaceDimensionsUniversalSerialBus3.1Specification,Revision1.05-8ContinuedonnextpageTOPVIEW(SIDENEARESTSUPERSPEEDCONTACTS)Mechanical5-9Figure5-2.ExampleUSB3.1Standard-AReceptaclewithGroundingSpringsandRequiredcontactzonesontheStandard-APlug.EMIcontactzonesBOTTOMVIEW(SIDEOPPOSITESUPERSPEEDCONTACTS)UniversalSerialBus3.1Specification,Revision1.05-10InsertiondetectpinsDetectcircuitisclosedafteramatingpartisinsertedDetectcircuitSpringfingersonthesideofreceptacleshellareEMIfunctionalFigure5-3.ExampleUSB3.1Standard-AMid-MountReceptacleswithInsertionDetectMechanical5-11ContinuedonnextpageUniversalSerialBus3.1Specification,Revision1.05-12ContinuedonnextpageMechanical5-13Figure5-4.USB3.1Standard-APlugInterfaceDimensions5.3.1.2USB3.1Standard-AReferenceFootprintsThisspecificationdoesnotdefinestandardfootprints.Anyfootprintmaybeusedaslongasallmechanicalandelectricalreq