TCA4311ADGKR

TCA4311A TI1 | Alldatasheet

Document overview

• Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
• PDF pages: 22

Technical content

www.ti.com SCPS226 –JANUARY 2011 HOTSWAPPABLE2-WIREBUSBUFFERS Check forSamples: TCA4311A 1FEATURES

• OperatingPower-Supply VoltageRange of • ApplicationsIncludeHot Board Insertionand 2.7-Vto5.5-V Bus Extension
• Supports BidirectionalData TransferofI2C • Low ICC Chip Disableof<1 mA Bus Signals • READY Open-Drain Output
• SDA and SCL LinesAre BufferedWhich • Supports Clock Stretching,Arbitration,and IncreasesFanout Synchronization
• 1-V Precharge on AllSDA and SCL Lines • Powered-OffHigh-Impedance I2C Pins PreventsCorruptionDuring LiveBoard • Open-Drain I2C PinsInsertionand Removal From Backplane • Latch-Up Performance Exceeds 100 mA Per• SDA and SCL InputLinesAre IsolatedFrom JESD 78,Class IIOutputs • ESD ProtectionExceeds JESD 22• Accommodates Standard Mode and FastMode – 8000-V Human-Body Model (A114-A)I2C Devices – 200-V Machine Model (A115-A)• Improved Noise Immunity – 1000-V Charged-DeviceModel (C101) D OR DGK PACKAGES (TOP VIEW) DESCRIPTION/ORDERING INFORMATION The TCA4311A isa hotswappable I2C bus bufferthatsupportsI/Ocardinsertionintoa livebackplanewithout corruptionofthedataand clockbusses.Controlcircuitrypreventsthebackplanefrom beingconnectedtothe carduntila stopcommand or bus idleoccurson thebackplanewithoutbus contentionon thecard.When the connectionismade, thisdeviceprovidesbidirectionalbuffering,keepingthebackplaneand cardcapacitances isolated.Duringinsertion,the SDA and SCL linesare prechargedto 1 V to minimizethe currentrequiredto chargetheparasiticcapacitanceofthechip. When theI2C bus isidle,theTCA4311A can be putintoshutdown mode by settingtheEN pinlow.When EN is high,the TCA4311A resumes normal operation.Italso includesan open drainREADY outputpin,which indicatesthatthe backplaneand card sidesare connectedtogether.When READY ishigh,the SDAIN and SCLIN areconnectedtoSDAOUT and SCLOUT. When thetwo sidesaredisconnected,READY islow. Both the backplaneand card may be powered withsupplyvoltagesrangingfrom 2.7 V to 5.5 V, withno restrictionson whichsupplyvoltageishigher. The TCA4311A has standardopen-drainI/Os.The sizeof the pullupresistorsto the I/Osdepends on the system,buteach sideofthisbuffermust have a pullupresistor.The deviceisdesignedtowork withStandard Mode and FastMode I2C devicesinadditiontoSMBus devices.StandardMode I2C devicesonlyspecify3 mA in a genericI2C system where StandardMode devicesand multiplemastersarepossible.Under certainconditions, highterminationcurrentscan be used. Pleasebe aware thatan importantnoticeconcerningavailability,standardwarranty,and use incriticalapplicationsofTexas Instrumentssemiconductorproductsand disclaimerstheretoappearsattheend ofthisdatasheet. PRODUCTION DATA informationiscurrentas ofpublicationdate. Copyright© 2011,Texas InstrumentsIncorporatedProductsconform to specificationsper the terms of the Texas Instrumentsstandardwarranty.Productionprocessingdoes not necessarilyincludetestingofallparameters.

SCPS226 –JANUARY 2011 www.ti.com Table1. ORDERING INFORMATION TA PACKAGE (1)(2) ORDERABLE PART NUMBER TOP-SIDE MARKING Tube TCA4311AD PREVIEW SOIC – D –40°C to85°C Tape and reel TCA4311ADR PREVIEW MSOP – DGK Tape and reel TCA4311ADGKR 6KS (1) Package drawings,thermaldata,and symbolizationareavailableatwww.ti.com/packaging. (2) Forthemost currentpackage and orderinginformation,see thePackage OptionAddendum attheend ofthisdocument,orsee theTI websiteatwww.ti.com. TERMINAL FUNCTIONS SOIC (D)OR MSOP (DGK) PACKAGE DESCRIPTION PIN NUMBER NAME Active-highchipenablepin.IfEN islow,theTCA4311A isina lowcurrent(<1 mA) mode. Italso disablestherise-timeaccelerators,disablesthebus prechargecircuitry,drivesREADY low,isolates1 EN SDAIN fromSDAOUT and isolatesSCLIN fromSCLOUT. EN shouldbe high(atVCC )fornormal operation.ConnectEN toVCC ifthisfeatureisnotbeingused. 2 SCLOUT Serialclockoutput.ConnectthispintotheSCL bus on thecard. 3 SCLIN Serialclockinput.ConnectthispintotheSCL bus on thebackplane.

4 GND Supplyground

Connectionflag/rise-timeacceleratorcontrol.READY islowwhen eitherEN isloworthestart-up 5 READY sequence describedintheoperationsectionhas notbeen completed.READY goes highwhen EN is highand start-upiscomplete.Connecta 10-kΩ resistorfromthispintoVCC toprovidethepullup. 6 SDAIN Serialdatainput.ConnectthispintotheSDA bus on thebackplane. 7 SDAOUT Serialdataoutput.ConnectthispintotheSDA bus on thecard. Supplypower.Main inputpower supplyfrombackplane.Thisisthesupplyvoltageforthedeviceson 8 VCC thebackplaneI2C busses.ConnectpullupresistorsfromSDAIN and SCLIN (andalsofromSDAOUT and SCLOUT) tothispin.Placea bypasscapacitorofatleast0.01mF closetothispinforbestresults.

2 SubmitDocumentationFeedback Copyright© 2011,Texas InstrumentsIncorporated

ProductFolderLink(s):TCA4311A

100□k RCH1 100□k RCH3 0.5□pF READY UVLO 3SCLIN CONNECT Stop□Bit□and□Bus□Idle GND CONNECT 20□pF RD S QB 0.5□µA 0.55□V / 0.45□V CC CC V – 1□VCC 2□mA 95 µs Delay , Rising Only Backplane-To-Card Connection CONNECTCONNECT

2 SCLOUT

7 SDAOUT

8 VCC

1□V Precharge 100□k RCH2 100□k RCH4 2□mA 2□mA Slew□Rate Detector CONNECT ENABLE 2-Wire□Bus□Buffer□and□Hot□Swap□Controller 2□mA Slew□Rate Dectector Backplane-To-Card Connection Slew□Rate Dectector Slew□Rate Dectector ENABLE TCA4311A www.ti.com SCPS226 –JANUARY 2011 BLOCK DIAGRAM Copyright© 2011,Texas InstrumentsIncorporated SubmitDocumentationFeedback 3 ProductFolderLink(s):TCA4311A

SCPS226 –JANUARY 2011 www.ti.com ABSOLUTE MAXIMUM RATINGS (1) overoperatingfree-airtemperaturerange(unlessotherwisenoted) MIN MAX UNIT VCC Supplyvoltagerange –0.5 7 V VI/O I2C bus voltagerange(2) SDAIN, SCLIN, SDAOUT, SCLOUT –0.3 7 V VI Inputvoltagerange(2) EN –0.3 7 V IIK Inputclamp current VI< 0 –50 mA IOK Outputclamp current VO < 0 –50 mA IO Continuousoutputcurrent ±50 mA ICC ContinuouscurrentthroughVCC orGND ±100 mA D package 97 qJA Package thermalimpedance(3) °C/W DGK package 172 Tstg Storagetemperaturerange –65 150 °C (1) Stressesbeyond thoselistedunder"absolutemaximum ratings"may cause permanentdamage tothedevice.These arestressratings only,and functionaloperationofthedeviceattheseorany otherconditionsbeyond thoseindicatedunder"recommended operating conditions"isnotimplied.Exposuretoabsolute-maximum-ratedconditionsforextendedperiodsmay affectdevicereliability. (2) The inputnegative-voltageand outputvoltageratingsmay be exceeded iftheinputand outputcurrentratingsareobserved. (3) The package thermalimpedance iscalculatedinaccordancewithJESD 51-7. RECOMMENDED OPERATING CONDITIONS MIN MAX UNIT VCC Supplyvoltage 2.7 5.5 V SDA and SCL inputs 0.7× VCC 5.5 VIH High-levelinputvoltage V EN input 2 5.5 SDA and SCL inputs –0.5 0.3× VCC VIL Low-levelinputvoltage V EN input –0.5 0.8 VCC = 3 V 3 IOL Low-leveloutputcurrent mA VCC = 4.5V 3 TA Operatingfree-airtemperature –40 85 °C

4 SubmitDocumentationFeedback Copyright© 2011,Texas InstrumentsIncorporated

ProductFolderLink(s):TCA4311A

www.ti.com SCPS226 –JANUARY 2011

ELECTRICAL CHARACTERISTICS

overoperatingfree-airtemperaturerange(unlessotherwisenoted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT Power Supply VCC Positivesupplyvoltage 2.7 5.5 V ICC Supplycurrent VCC = 5.5V,VSDAIN = VSCLIN = 0 V 5.1 7 mA SupplycurrentinshutdownISD VEN = 0 V 0.1 mAmode Start-UpCircuitry VPRE Prechargevoltage SDA, SCL floating 0.8 1 1.2 V tIDLE Bus idletime 50 95 150 ms VEN EN thresholdvoltage 0.5× VCC 0.9× VCC V VDIS Disablethresholdvoltage EN Pin 0.1× VCC 0.5× VCC V IEN EN inputcurrent EN from0 V toVCC ±0.1 ±1 mA tEN Enabletime 95 ms Disabletime(EN totDIS 30 nsREADY) SDAIN toREADY delaytSTOP 1.2 msafterSTOP SCLOUT/SDAOUT totREADY 0.8 msREADY READY OFF stateleakageIOFF ±0.1 mAcurrent VOL READY outputlowvoltage IPULLUP = 3 mA 0.4 V Rise-TimeAccelerators Transientboostedpull-upIPULLUPAC Positivetransitionon SDA, SCL, VCC = 2.7V, 1 2 mAcurrent Input-OutputConnection VOS Input-outputoffsetvoltage 10 kΩ toVCC on SDA, SCL, VCC = 3.3V,(1) 0 100 175 mV C IN Digitalinputcapacitance 10 pF Outputlowvoltage,input=VOL SDA, SCL pins,ISINK = 3 mA, 0 0.4 V0 V II Inputleakagecurrent SDA, SCL pins= VCC = 5.5V ±5 mA (1) The connectioncircuitryalwaysregulatesitsoutputtoa highervoltagethanitsinput.The magnitudeofthisoffsetvoltageas a function ofthepullupresistorand VCC voltageisshown intheTypicalPerformanceCharacteristicssection. Copyright© 2011,Texas InstrumentsIncorporated SubmitDocumentationFeedback 5 ProductFolderLink(s):TCA4311A

SCPS226 –JANUARY 2011 www.ti.com OPERATION Start-Up When theTCA4311A firstreceivespower on itsVCC pin,eitherduringpower-uporduringliveinsertion,itstarts inan undervoltagelockout(UVLO) state,ignoringany activityon theSDA and SCL pinsuntilVCC risesabove 2.5V. Duringthistime,the1 V prechargecircuitryisalsoactiveand forces1 V through100-kΩ nominalresistorstothe SDA and SCL pins.Because theI/Ocardisbeingpluggedintoa livebackplane,thevoltageon thebackplane SDA and SCL busses may be anywhere between 0 V and VCC . Prechargingthe SCL and SDA pinsto 1 V minimizesthe worst-casevoltagedifferentialthese pins willsee at the moment of connection,therefore minimizingtheamount ofdisturbancecaused by theI/Ocard. Once the TCA4311A comes out of UVLO, itassumes thatSDAIN and SCLIN have been insertedintoa live system and thatSDAOUT and SCLOUT arebeingpowered up atthesame timeas itself.Therefore,itlooksfor eithera stopbitor bus idleconditionon the backplanesideto indicatethe completionof a data transaction. When eitherone occurs,thepartalsoverifiesthatboththeSDAOUT and SCLOUT voltagesarehigh.When all oftheseconditionsaremet,theinput-to-outputconnectioncircuitryisactivated,joiningtheSDA and SCL busses on theI/Ocardwiththoseon thebackplane,and therisetimeacceleratorsareenabled. Connection Circuitry Once theconnectioncircuitryisactivated,thefunctionalityoftheSDAIN and SDAOUT pinsisidentical.A low forcedon eitherpinat any timeresultsinboth pinvoltagesbeinglow.For properoperation,logiclow input voltagesshouldbe no higherthan0.4V withrespecttotheground pinvoltageoftheTCA4311A. SDAIN and SDAOUT entera logichighstateonlywhen alldeviceson bothSDAIN and SDAOUT releasehigh.The same is trueforSCLIN and SCLOUT. This importantfeatureensures thatclockstretching,clocksynchronization, arbitrationand theacknowledgeprotocolalwayswork,regardlessofhow thedevicesinthesystem are tiedto theTCA4311A. Anotherkey featureoftheconnectioncircuitryisthatitprovidesbidirectionalbuffering,keepingthebackplane and cardcapacitancesisolated.Because ofthisisolation,thewaveforms on thebackplanebusses lookslightly differentthanthecorrespondingcardbus waveforms,as describedhere. InputtoOutput OffsetVoltage When a logiclow voltage,VLOW1 , is drivenon any of the TCA4311A's data or clockpins,the TCA4311A regulatesthevoltageon theothersideofthechip(callitVLOW2 ) toa slightlyhighervoltage,as directedby the followingequation: VLOW2 = VLOW1 + 75 mV + (VCC /R)× 100 where R isthebus pullupresistanceinohms (Ω).For example,ifa deviceisforcingSDAOUT to10 mV where VCC = 3.3V and thepullupresistorR on SDAIN is10 kΩ,thenthevoltageon SDAIN = 10 + 75 + (3.3/10000)× 100 = 118 mV. See theTypicalPerformanceCharacteristicssectionforcurvesshowing theoffsetvoltageas a functionofVCC and R. PropagationDelays Duringa risingedge,therise-timeon each sideisdeterminedby thecombined pullupcurrentoftheTCA4311A boostcurrentand thebus resistorand theequivalentcapacitanceon theline.Ifthepullupcurrentsarethesame, a differenceinrise-timeoccurswhich isdirectlyproportionaltothedifferenceincapacitancebetween thetwo sides.ThiseffectisdisplayedinFigure1 forVCC = 3.3V and a 10-kΩ pullupresistoron each side(50pF on one sideand 150 pF on theother).Sincetheoutputsidehas lesscapacitancethantheinput,itrisesfasterand the effectivetPLH isnegative. There isa finitepropagationdelay,tPHL ,throughtheconnectioncircuitryforfallingwaveforms.Figure2 shows thefallingedge waveforms forthesame VCC ,pullupresistorsand equivalentcapacitanceconditionsas used in Figure1.An externalNMOS devicepullsdown thevoltageon thesidewith150 pF capacitance;theTCA4311A pullsdown thevoltageon theoppositeside,witha delayof55 ns.Thisdelayisalwayspositiveand isa function of supplyvoltage,temperatureand the pullupresistorsand equivalentbus capacitanceson both sidesof the bus.The TypicalPerformanceCharacteristicssectionshows tPHL as a functionoftemperatureand voltagefor

6 SubmitDocumentationFeedback Copyright© 2011,Texas InstrumentsIncorporated

ProductFolderLink(s):TCA4311A

52.0 52.025 0.0 1.0 2.5 –0.5 0.5 1.5 3.0 2.0 3.5 52.075 52.1 52.125 t (s) (V) 52.15 52.175 VXSDAIN Delay: 72.258 VXSDAOUT 54.0 54.2 0.0 1.0 2.5 –0.5 0.5 1.5 3.0 2.0 3.5 54.4 54.6 54.8 t (s) (V) VXSDAOUT VXSDAIN TCA4311A www.ti.com SCPS226 –JANUARY 2011 10-kΩ pullupresistorsand 100 pF equivalentcapacitanceon bothsidesofthepart.By comparisonwithFigure2, theVCC = 3.3V curveshows thatincreasingthecapacitancefrom50 pF to100 pF resultsina tPHL increasefrom 55 ns to75 ns.Largeroutputcapacitancestranslatetolongerdelays(up to150 ns).Users must quantifythe differenceinpropagationtimesfora risingedge versusa fallingedge intheirsystemsand adjustsetupand hold timesaccordingly. Figure1.Input-OutputConnection tPLH Figure2.Input-OutputConnection tPHL Rise-TimeAccelerators Once connectionhas been established,rise-timeacceleratorcircuitson allfourSDA and SCL pinsareactivated. These allowtheusertochoose weaker DC pullupcurrentson thebus,reducingpower consumptionwhilestill meetingsystem rise-timerequirements.Duringpositivebus transitions,theTCA4311A switchesin2 mA (typical) ofcurrenttoquicklyslewtheSDA and SCL linesonce theirDC voltagesexceed 0.6V. Usinga generalruleof 20 pF ofcapacitanceforeverydeviceon thebus (10 pF forthedeviceand 10 pF forinterconnect),choose a pullupcurrentso thatthebus willriseon itsown ata rateofatleast1.25V/ms toguaranteeactivationofthe accelerators. For example,assume an SMBus system withVCC = 3 V, a 10-kΩ pullupresistorand equivalentbus capacitance of200 pF.The rise-timeofan SMBus system iscalculatedfrom(VIL(MAX) – 0.15V) to(VIH(MIN)+ 0.15V),or0.65 V to2.25V. Ittakesan RC circuit0.92timeconstantstotraversethisvoltagefora 3 V supply;inthiscase,0.92 × (10 kΩ × 200 pF) = 1.84 ms.Thus, the system exceeds the maximum allowedrise-timeof 1 ms by 84%. However,usingtherise-timeaccelerators,whichareactivatedata DC thresholdofbelow 0.65V, theworst-case rise-timeis:(2.25V – 0.65V) × 200 pF/1mA = 320 ns,whichmeets the1 ms rise-timerequirement. READY DigitalOutput Thispinprovidesa digitalflagwhich islow when eitherEN islow or thestart-upsequence describedearlierin thissectionhas notbeen completed.READY goes highwhen EN ishighand start-upiscomplete.The pinis drivenby an open drainpull-downcapableofsinking3 mA whileholding0.4V on thepin.Connect a resistorof 10 kΩ toVCC toprovidethepullup. EN Low CurrentDisable Groundingthe EN pindisconnectsthe backplanesidefrom the card side,disablesthe rise-timeaccelerators, drivesREADY low,disablesthebus prechargecircuitryand putsthepartina near-zerocurrentstate.When the pinvoltageisdrivenalltheway toVCC ,thepartwaitsfordatatransactionson boththebackplaneand cardsides tobe complete(asdescribedintheStart-Upsection)beforereconnectingthetwo sides. Copyright© 2011,Texas InstrumentsIncorporated SubmitDocumentationFeedback 7 ProductFolderLink(s):TCA4311A

SCPS226 –JANUARY 2011 www.ti.com ResistorPull-UpValue Selection The system pullupresistorsmust be strongenough toprovidea positiveslewrateof1.25V/ms on theSDA and SCL pins,inordertoactivatetheboostpullupcurrentsduringrisingedges.Choose maximum resistorvalueR usingtheformula: R ≤ (VCC(MIN) – 0.6)(800,000)/C where R isthepullupresistorvalueinohms, VCC(MIN) istheminimum VCC voltageand C istheequivalentbus capacitanceinpicofarads(pF). Inaddition,regardlessofthebus capacitance,alwayschoose R ≤ 16 kΩ forVCC = 5.5V maximum, R ≤ 24 kΩ forVCC = 3.6 V maximum. The start-upcircuitryrequireslogichigh voltageson SDAOUT and SCLOUT to connectthebackplanetothecard,and thesepullupvaluesareneeded toovercome theprechargevoltage. Systems With DisparateSupply Voltages Inlarge2-wiresystems,theVCC voltagesseen by devicesatvariouspointsinthesystem can differby a few hundred millivoltsor more. This situationiswellmodeled by a seriesresistorin the VCC line,as shown in Figure15.ForproperoperationoftheTCA4311A, make surethatVCC(BUS) ≥ VCC(TCA4311A) – 0.5V.

8 SubmitDocumentationFeedback Copyright© 2011,Texas InstrumentsIncorporated

ProductFolderLink(s):TCA4311A

–50 –25 0 25 50 Temperature (°C) I (mA)PULLUPAC 75 100 2.7 V2.5 V 3 V 5 V 100 –40 25 85 T emperature, T (°C)A tPHL 2.7 V 3.3 V 5.5 V 52.0 52.025 0.0 1.0 2.5 –0.5 0.5 1.5 3.0 2.0 3.5 52.075 52.1 52.125 t (s) (V) 52.15 52.175 VXSDAIN Delay: 72.258 VXSDAOUT 54.0 54.2 0.0 1.0 2.5 –0.5 0.5 1.5 3.0 2.0 3.5 54.4 54.6 54.8 t (s) (V) VXSDAOUT VXSDAIN TCA4311A www.ti.com SCPS226 –JANUARY 2011 TYPICAL PERFORMANCE CHARACTERISTICS Figure3.Input/OutputtPLH vs Temperature Figure4.IPULLUPAC vs Temperature Figure5. Figure6. Copyright© 2011,Texas InstrumentsIncorporated SubmitDocumentationFeedback 9 ProductFolderLink(s):TCA4311A

10,000 20,000 30,000 Voffset33V Voffset5V 40,000 TCA4311A SCPS226 –JANUARY 2011 www.ti.com TYPICAL PERFORMANCE CHARACTERISTICS (continued) Figure7.

10 SubmitDocumentationFeedback Copyright© 2011,Texas InstrumentsIncorporated

ProductFolderLink(s):TCA4311A

D.U.T. VCC VCC VI VO RT R 10 k L Ω C 100 pF L SDAn/SCLn ENABLE READ Y ten tdistidle(READ Y) SCLIN SCLOUT SDAOUT SDAIN ENABLE READ Y ten tstp(READ Y) TCA4311A www.ti.com SCPS226 –JANUARY 2011 PARAMETER MEASUREMENT INFORMATION R L = Load resistor C L = Load capacitanceincludesjigand probecapacitance R T = Terminationresistanceshouldbe equaltotheoutputimpedance Z0 ofthepulsegenerators. Figure8. TestCircuitryforSwitchingTimes Figure9. Timing forten,tidle(READY),and tdis Figure10. tstp(READY) That Can Occur Afterten Copyright© 2011,Texas InstrumentsIncorporated SubmitDocumentationFeedback 11 ProductFolderLink(s):TCA4311A

SCLOUT , SDAOUT SCLIN, SDAIN ENABLE READ Y tstp(READ Y) tidle(READ Y) ten TCA4311A SCPS226 –JANUARY 2011 www.ti.com PARAMETER MEASUREMENT INFORMATION (continued) Figure11. tstp(READY) That Can Occur Afterten and tidle(READY)

12 SubmitDocumentationFeedback Copyright© 2011,Texas InstrumentsIncorporated

ProductFolderLink(s):TCA4311A

Staggered□Connector R13 10□k R12 10□k R14 10□k I/O□Peripheral□Card□NEN SDAIN SCLIN TCA4311 V CC GND CARDN_SCL CARDN_SDASDAOUT SCLOUT READY EN SDAIN SCLIN V CC GND SDAOUT SCLOUT READY EN Card Enable/Disable SDAIN SCLIN V CC GND SDAOUT SCLOUT READY 10□k 10□k R10 10□k I/O□Peripheral□Card□2 TCA4311 CARD2_SCL CARD2_SDA 10□k 10□k 10□k I/O□Peripheral□Card□1 TCA4311 CARD_SCL CARD_SDA 10□k V CC 10□k Backplane Backplane Connector SDA BD_SEL SCL C1R3 10□k 10□k R11 10□k 0.01□µF 0.01□µF Power□Supply Hot□Swap Power□Supply Hot□Swap Card Enable/Disable Card Enable/Disable Staggered□Connector Staggered□Connector Power□Supply Hot□Swap 0.01□µF TCA4311A www.ti.com SCPS226 –JANUARY 2011

APPLICATION INFORMATION

LiveInsertionand CapacitanceBufferingApplication Figure12 throughFigure13 illustratetheusage oftheTCA4311A inapplicationsthattakeadvantageofbothits hot swap controllingand capacitancebufferingfeatures.In allof theseapplications,note thatifthe I/Ocards were pluggeddirectlyintothebackplane,allofthebackplaneand cardcapacitanceswould add directlytogether, making rise-and fall-timerequirementsdifficultto meet. Placinga TCA4311A on the edge of each card, however,isolatesthe card capacitancefrom the backplane.For a givenI/O card,the TCA4311A drivesthe capacitanceof everythingon the card and the backplanemust driveonlythe capacitanceof the TCA4311A, whichislessthan10 pF. Figure12 shows theTCA4311A ina CompactPCI™ configuration.Connect VCC and EN totheoutputofone of theCompactPCI power supplyHot Swap circuits.Use a pullupresistortoEN fora cardsideenable/disable. VCC is monitoredby a filteredUVLO circuit.With the VCC voltagepowering up afterallotherpins have establishedconnection,the UVLO circuitensuresthatthe backplaneand card data and clockbusses are not connecteduntilthetransientsassociatedwithliveinsertionhave settled.Owing totheirsmallcapacitance,the SDAIN and SCLIN pinscause minimaldisturbanceon thebackplanebusses when theymake contactwiththe connector. Figure12. InsertingMultipleI/OCards intoa LiveBackplane Using theTCA4311A ina CompactPCI System Copyright© 2011,Texas InstrumentsIncorporated SubmitDocumentationFeedback 13 ProductFolderLink(s):TCA4311A

100□k EN SDAIN SCLIN V GND CC SDAOUT SCLOUT READY EN SDAIN SCLIN V GND CC SDAOUT SCLOUT READY 10□k 10□k R10 10□k I/O□Peripheral□Card□2 TCA4311 CARD2_SCL CARD2_SDA 10□k 10□k I/O□Periperal□Card□1 TCA4311 C2□0.1 Fµ 100□kC4□0.1 Fµ CARD_SCL CARD_SDA 10□k VCC 10□k Backplane Backplane Connector SDA SCL 0.01 Fµ 0.01 Fµ 10k TCA4311A SCPS226 –JANUARY 2011 www.ti.com Figure13 shows theTCA4311A ina PCI application,where allofthepinshave thesame length.Inthiscase, connectan RC seriescircuiton theI/Ocardbetween VCC and EN. An RC productof10 ms providesa filterto preventtheTCA4311A frombecoming activateduntilthetransientsassociatedwithliveinsertionhave settled. Figure13. InsertingMultipleI/OCards intoa LiveBackplane Using theTCA4311A ina PCI System Repeater/BusExtenderApplication Users who wishtoconnecttwo 2-wiresystemsseparatedby a distancecan do so by connectingtwo TCA4311A back-to-back,as shown in Figure14. The I2C specificationallowsfor400 pF maximum bus capacitance, severelylimitingthelengthofthebus.The SMBus specificationplacesno restrictionon bus capacitance,butthe limitedimpedances of devicesconnected to the bus requiresystems to remain smallifrise-and fall-time specificationsare to be met. The strongpullupand pulldownimpedances of the TCA4311A are capableof meetingrise-and fall-timespecificationsforone nanofaradofcapacitance,thusallowingmuch more interconnect distance.Inthissituation,thedifferentialgroundvoltagebetween thetwo systemsmay limitthealloweddistance, because a validlogiclow voltagewithrespecttotheground atone end ofthesystem may violatetheallowed VOL specificationwithrespecttothegroundattheotherend.Inaddition,theconnectioncircuitryoffsetvoltages oftheback-to-backTCA4311A add together,directlycontributingtothesame problem.

14 SubmitDocumentationFeedback Copyright© 2011,Texas InstrumentsIncorporated

ProductFolderLink(s):TCA4311A

10□k 5.1□k 10□k 5.1□k V CC =□5□V 10□k 10□k 10□k 2-Wire□System□1 EN SDAIN SCLIN TCA4311 GND V CC 0.01 Fµ SDAOUT SCLOUT READY SCL1 To□Other System□1 Devices SDA1 0.01 Fµ 10□k 2-Wire□System□2 TCA431 1 EN SDAIN SCLIN SDAOUT SCLOUT READY Long Distance Bus VCC SCL1 SDA1 To□Other System□2 Devices GND VCC 10□k V CC (BUS) 10□k R DROP VCC (TCA4311) SDA SCL 10□k 10□k 10□k SDAIN EN SCLIN TCA4311 VCC GND SCL2 SDA2SDAOUT SCLOUT READY 0.01 Fµ 10□k V CC 3.3□V 10□k EN SCLIN SCLOUT SDAIN SDAOUT 1 5 6 7 3 2 GND TCA431 1 READY 0.01 Fµ 10□k 10□k Input – Output Connection t PLH 52.0 52.025 0.0 1.0 2.5 –0.5 0.5 1.5 3.0 2.0 3.5 52.075 52.1 52.125 t (s) (V) 52.15 52.175 VXSDAIN Delay: 72.258 VXSDAOUT t (s) 0.0 1.0 2.5 –0.5 0.5 1.5 3.0 2.0 3.5 (V) VXSDAOUT VXSDAIN TCA4311A www.ti.com SCPS226 –JANUARY 2011 Figure14. Repeater/BusExtenderApplication Figure15.System With DisparateVCC Voltages Copyright© 2011,Texas InstrumentsIncorporated SubmitDocumentationFeedback 15 ProductFolderLink(s):TCA4311A

www.ti.com 6-Jan-2012 Addendum-Page 1 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Qty Eco Plan (2) Lead/ Ball Finish MSL Peak Temp (3) Samples (Requires Login) TCA4311AD PREVIEW SOIC D 8 50 TBD Call TI Call TI TCA4311ADGKR ACTIVE MSOP DGK 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TCA4311ADR ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.

*All dimensions are nominal Device Package Type Package Drawing Pins SPQ Reel Diameter (mm) Reel Width W1 (mm) (mm) (mm) (mm) (mm) W (mm) Pin1 Quadrant PACKAGE MATERIALS INFORMATION www.ti.com 1-Mar-2012 Pack Materials-Page 1

*All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) TCA4311ADGKR MSOP DGK 8 2500 358.0 335.0 35.0 TCA4311ADR SOIC D 8 2500 346.0 346.0 29.0 PACKAGE MATERIALS INFORMATION www.ti.com 1-Mar-2012 Pack Materials-Page 2

Texas InstrumentsIncorporatedand itssubsidiaries(TI)reservetherighttomake corrections,modifications,enhancements,improvements, and otherchanges toitsproductsand servicesatany timeand todiscontinueany productorservicewithoutnotice.Customersshould obtainthelatestrelevantinformationbeforeplacingordersand shouldverifythatsuch informationiscurrentand complete.Allproductsare soldsubjecttoTI’s termsand conditionsofsalesuppliedatthetimeoforderacknowledgment. TIwarrantsperformanceofitshardwareproductstothespecificationsapplicableatthetimeofsaleinaccordancewithTI’s standard warranty.Testingand otherqualitycontroltechniquesareused totheextentTIdeems necessarytosupportthiswarranty.Exceptwhere mandated by governmentrequirements,testingofallparametersofeach productisnotnecessarilyperformed. TIassumes no liabilityforapplicationsassistanceorcustomerproductdesign.Customersareresponsiblefortheirproductsand applicationsusingTIcomponents.To minimizetherisksassociatedwithcustomerproductsand applications,customersshouldprovide adequatedesignand operatingsafeguards. TIdoes notwarrantorrepresentthatany license,eitherexpressorimplied,isgrantedunderany TIpatentright,copyright,mask work right, orotherTIintellectualpropertyrightrelatingtoany combination,machine,orprocessinwhichTIproductsorservicesareused.Information publishedby TIregardingthird-partyproductsorservicesdoes notconstitutea licensefromTItouse such productsorservicesora warrantyorendorsementthereof.Use ofsuch informationmay requirea licensefroma thirdpartyunderthepatentsorotherintellectual propertyofthethirdparty,ora licensefromTIunderthepatentsorotherintellectualpropertyofTI. ReproductionofTIinformationinTIdatabooks ordatasheetsispermissibleonlyifreproductioniswithoutalterationand isaccompanied by allassociatedwarranties,conditions,limitations,and notices.Reproductionofthisinformationwithalterationisan unfairand deceptive businesspractice.TIisnotresponsibleorliableforsuch altereddocumentation.Informationofthirdpartiesmay be subjecttoadditional restrictions. ResaleofTIproductsorserviceswithstatementsdifferentfromorbeyond theparametersstatedby TIforthatproductorservicevoidsall expressand any impliedwarrantiesfortheassociatedTIproductorserviceand isan unfairand deceptivebusinesspractice.TIisnot responsibleorliableforany such statements. TIproductsarenotauthorizedforuse insafety-criticalapplications(suchas lifesupport)where a failureoftheTIproductwouldreasonably be expectedtocause severepersonalinjuryordeath,unlessofficersofthepartieshave executedan agreementspecificallygoverning such use.Buyersrepresentthattheyhave allnecessaryexpertiseinthesafetyand regulatoryramificationsoftheirapplications,and acknowledgeand agreethattheyaresolelyresponsibleforalllegal,regulatoryand safety-relatedrequirementsconcerningtheirproducts and any use ofTIproductsinsuch safety-criticalapplications,notwithstandingany applications-relatedinformationorsupportthatmay be providedby TI.Further,Buyersmust fullyindemnifyTIand itsrepresentativesagainstany damages arisingoutoftheuse ofTIproductsin such safety-criticalapplications. TIproductsareneitherdesignednorintendedforuse inmilitary/aerospaceapplicationsorenvironmentsunlesstheTIproductsare specificallydesignatedby TIas military-gradeor"enhanced plastic." Onlyproductsdesignatedby TIas military-grademeet military specifications.Buyersacknowledgeand agreethatany such use ofTIproductswhichTIhas notdesignatedas military-gradeissolelyat theBuyer's risk,and thattheyaresolelyresponsibleforcompliancewithalllegaland regulatoryrequirementsinconnectionwithsuch use. TIproductsareneitherdesignednorintendedforuse inautomotiveapplicationsorenvironmentsunlessthespecificTIproductsare designatedby TIas compliantwithISO/TS 16949 requirements.Buyersacknowledgeand agreethat,iftheyuse any non-designated productsinautomotiveapplications,TIwillnotbe responsibleforany failuretomeet such requirements. FollowingareURLs where you can obtaininformationon otherTexas Instrumentsproductsand applicationsolutions: Products Applications Audio www.ti.com/audio Automotiveand Transportationwww.ti.com/automotive Amplifiers amplifier.ti.com Communicationsand Telecom www.ti.com/communications Data Converters dataconverter.ti.com Computers and Peripherals www.ti.com/computers DLP ® Products www.dlp.com Consumer Electronics www.ti.com/consumer-apps DSP dsp.ti.com Energyand Lighting www.ti.com/energy Clocksand Timers www.ti.com/clocks Industrial www.ti.com/industrial Interface interface.ti.com Medical www.ti.com/medical Logic logic.ti.com Security www.ti.com/security Power Mgmt power.ti.com Space,Avionicsand Defense www.ti.com/space-avionics-defense Microcontrollers microcontroller.ti.com Videoand Imaging www.ti.com/video RFID www.ti-rfid.com OMAP MobileProcessors www.ti.com/omap WirelessConnectivity www.ti.com/wirelessconnectivity TIE2E Community Home Page e2e.ti.com MailingAddress:Texas Instruments,PostOfficeBox 655303,Dallas,Texas 75265 Copyright© 2012,Texas InstrumentsIncorporated