SI3217 设计文档

Rev.0.57/10Copyright©2010bySiliconLaboratoriesAN340SiliconLaboratoriesConfidential.Informationcontainedhereiniscoveredundernon-disclosureagreement(NDA).AN340Si3217XPROSLIC®DESIGNER'SGUIDE1.IntroductionTheSi3217xisafamilyofpin-compatiblesingle-channelProSLICproductsthatimplementacompleteforeignexchangestation(FXS)telephonyinterfacesolutioninonepackageinaccordancewithallrelevantLSSGR,ITUandETSIspecifications.SelectpartsintheproductfamilyalsoimplementSiliconLaboratories’patentedcapacitiveisolationtechnologytoenableseamlessconnectiontoanSi3291xline-sideintegratedcircuittoformacompleteforeignexchangeoffice(FXO)solution.ThetermsFXSandFXOareusedthroughoutthisdocument.Theterm“FXS”referstotheSLIC(SubscriberLineInterfaceCircuit)functionalityoftheSi3217x,whiletheterm“FXO”referstothedataaccessarrangementDAAfunctionalityoftheSi32178andSi3291x.TheFXSchannelfeaturesanintegrateddc-dccontrollerthatsupportstrackingbatterygenerationupto136V.AVDCinputtypicallyintherangeof+7VDCto+20VDCisrequiredforthedc-dcconverter.Otherinputvoltagerangesforthedc-dcconverterarepossiblebyselectingtheappropriateconverterBOMcomponents.TheSi3217xProSLICintegratedcircuitsoperatefroma+3.3VdigitalsupplyandinterfacetostandardSPI/PCMorGCIdigitalinterfaces.TheSi3217xproductfamilyisavailableina5x7mm42-pinQFNpackage.TheSi32911/19line-sideFXOdevicesareavailablein16-pinSOICpackages.Table1providesasummaryoftheSi3217xproductfamily.TheSi3291xline-sideintegratedcircuits,whicharerequiredtocompleteoneFXOchannel,aresummarizedinTable2.TheSi3217xandSi32911/19productfamilyaredesignedtoeasilyimplementtelephonysystemscomprising1FXS,2FXS,1FXS/1FXO,2FXS/1FXOandotherpossiblecombinationsofFXSandFXOchannels.Table3ProvidesasummaryofthedifferencesbetweentheSi32911andSi32919line-sidedevices.Table1.Si3217xFamilyofDevicesSi3217xPartNumberWidebandModeFXOInterfaceDTMFDetectionPulseMeteringMaxVbatSi32178–110VSi32177–136VSi32176–110VSi32171–110VTable2.Si3291xLine-Side(FXO)DeviceFamilySi3291xPartNumberRegionRingerThresholdsOn-HookSpeedsSi32911FCC/CTR2112Si32919Global33AN3402Rev.0.5FortheFXS,theaudiopathdirectionsaredefinedfromtheperspectiveofatelephonethatisconnectedtotheFXSchannel,sothattheTXpathconveysthesignalsentfromthetelephonetowardsthePCM/GCIbus,andtheRXpathconveystheaudiosignalsentfromthePCM/GCIbustowardsthetelephone.ThePCMbusDTXoutputpinandDRXinputpinsarealsodefinedaccordingtothisFXSconvention.SincetheFXOisconnectedattheCPE(CustomerPremiseEquipment)endofthewireline,itsdefinitionforTXandRXaudiopathsarethesameasforatelephone,withTXbeingthesignalsenttowardstheCO(CentralOffice)andRXbeingthesignalreceivedfromtheCO.ThePCMBusDTX(output)andDRX(input)pinsaresharedbytheFXSandFXO,andtheFXSconventionisusedforthesetwopins.1.1.Si3217xandSi3291xKeyFeaturesThekeyfeaturesoftheSi3217xaresummarizedinthesectionsthatfollow.1.1.1.Si3217xandSi3291xGeneralFeaturesThefollowingfeaturesapplytotheSi3217xand/orSi3291x:PCMandSPIbusdigitalinterfaceswithprogrammableinterruptsSPIdaisy-chainingforupto32channels(5-bitSPIChannelID)GCI/IOM-2modesupportSi3217xdevicesareavailableina42-pinQFNpackageSi3291xdevicesareavailableina16-pinSOICpackage1.1.2.FXSFeatureSummaryTheFXSchannelinallSi3217xdevicesfeaturesanintegrateddc-dcconvertercontrollerthattrackstheactipandringringingwaveformsintheringingstateorthedcvoltagesintheon-hookoroff-hookstatestoprovideoptimalpowerconsumptionandminimizehigh-voltageintegratedcircuit(HVIC)powerdissipation.TheFXSchannelinallSi3217xdevicesprovidestandardvoicebandaudio(200Hzto3.4kHz)with8-bitµ-LaworA-Lawcompandingor16-bitlinearsamplingat8kHz.TheSi32178(wideband)includesFXOsupportandisintendedtobecombinedwiththeSi3291xFXOline-sidedevicetoformacompleteFXOchannelinadditiontotheFXSchannel.TheSi32176/Si32177(FXSonly)andSi32178(FXSandFXO)providesoftware-selectableFXSaudiooperation,featuringawidebandaudiomode(50Hzto7kHz)with16-bitlinearsamplingat16kHzaswellasthestandardvoicebandaudiomode(200Hzto3.4kHz)with8-bitµ-LaworA-Lawcompandingor16-bitlinearsamplingat8kHz.Table3.Si32911andSi32919DifferencesCountryComplianceFXOControlBitsRegister(Decimal)Si32911ValidSettingsSi32919ValidSettingsFeatureACIM[3:0]300000,0010XACImpedancesOHS160XOn-HookSpeedRZ160XRingerImpedanceRT160XRingerThresholdsSQ1,SQ05900XSparkQuenchingNote:‘X’indicatesthatallpossiblesettingsaresupported.TheSi32911hasrestrictedsettingsinREG30,REG16andREG59,asshownabove,andwritingothervaluesthanthoseindicatedhasnoeffect.IftheACIM[3:0]fieldinREG30iswrittenwithvaluesotherthan0or2whileusingtheSi32911line-sidedevice,theFXOignoresthesettinganddefaultstothe600actermination.RefertotheFXOregisterdefinitionsforREG30,REG16andREG59forfurtherdetails.See4.8.FXOControlRegistersonpage366.AN340Rev.0.53TheSi32171(FXSonly)featurespulsemeteringandDTMFdecoding.TheSi32171istargetedtothewirelesslocalloop(WLL)market,andsupportspulsemeteringfortheWLLpayphoneenvironment.FXSkeyfeatures:PerformsallBORSCHTfunctionsIntegrateddc-dcconverterIdealforshort/mediumloopapplications(VoCable,VoDSL,VoIP,WLL)Narrowband(200Hzto3.4kHz)Codecwith8-bitsamplingat8kHzWideb