LMD18400 TI1

Document overview

  • Manufacturer or author: Provided By www.digicamel.com(FREE DATASHEET DOWNLOAD SITE)
  • PDF pages: 26

Technical content

www.ti.com SNVS094C –JUNE 1996–REVISED APRIL 2013 LMD18400QuadHighSideDriver Check forSamples: LMD18400 1FEATURES APPLICATIONS 2• Four IndependentOutputs with>3A Peak,1A • Relay and SolenoidDrivers Continuous CurrentCapability • High Impedance Automotive FuelInjector

  • 1.3Ω Maximum ON ResistanceOver Drivers Temperature • Lamp Drivers
  • True InstantaneousPower LimitforEach • Power Supply Switching Switch • Motor Drivers
  • High SurvivalVoltage(60VDC ,80V Transient)
  • Shorted Load (toGround and Supply) DESCRIPTION Protection The LMD18400 isa fullyprotectedquad high side driver.It containsfour common-drain DMOS N-• OvervoltageShutdown atVCC > 35V channelpower switches,each capableofswitchinga• LS TTL/CMOS Compatible Logic Inputsand continuous1 Amp load (>3 Amps transient)to aOutputs common positivepower supply.The switchesarefully
  • <10 µA Supply Currentin“Sleep” Mode protected from excessive voltage,current and temperature.An instantaneouspower sensingcircuit• −5V Output Clamp forDischargingInductive calculatesthe productof the voltageacrossand theLoads currentthrougheach DMOS switchand limitsthe• SerialData Interfacefor11 DiagnosticChecks: power toa safelevel.The devicecan be disabledto – Switch ON/OFF Status produce a “sleep” conditionreducing the supply currenttolessthan10 µA. SeparateON/OFF control– Open or Shorted Load of each switch is provided through standard– OperatingTemperature LSTLL/CMOS logiccompatibleinputs. – ExcessiveSupply Voltage A MICROWIRE compatibleserialdata interfaceis• Two Direct-outputErrorFlags builtin to provideextensivediagnosticinformation. This informationincludesswitch statusreadback, output load fault conditionsand thermal and overvoltageshutdown status.There are also two direct-outputerrorflagsto providean immediate indicationofa generalsystem faultand an indication ofexcessiveoperatingtemperature. The LMD18400 is packaged in a specialpower dissipatingleadframethatreduces the junctionto case thermalresistancetoapproximately20°C/W. Pleasebe aware thatan importantnoticeconcerningavailability,standardwarranty,and use incriticalapplicationsof Texas Instrumentssemiconductorproductsand disclaimerstheretoappearsattheend ofthisdatasheet. 2Alltrademarksarethepropertyoftheirrespectiveowners. PRODUCTION DATA informationiscurrentas ofpublicationdate. Copyright© 1996–2013,Texas InstrumentsIncorporatedProductsconform to specificationsper the terms of the Texas Instrumentsstandardwarranty.Productionprocessingdoes not necessarilyincludetestingofallparameters.

SNVS094C –JUNE 1996–REVISED APRIL 2013 www.ti.com TypicalApplication Connection Diagram Figure1. See Package Number NFH0020A

2 SubmitDocumentationFeedback Copyright© 1996–2013,Texas InstrumentsIncorporated

ProductFolderLinks:LMD18400

www.ti.com SNVS094C –JUNE 1996–REVISED APRIL 2013 These deviceshave limitedbuilt-inESD protection.The leadsshouldbe shortedtogetherorthedeviceplacedinconductivefoam duringstorageorhandlingtopreventelectrostaticdamage totheMOS gates. ABSOLUTE MAXIMUM RATINGS (1)(2) SupplySurvivalVoltage(Pin20) Transient(t= 10 ms) 80V Continuous −0.5Vto+60V OutputTransientCurrent(EachSwitch) 3.75A OutputTransientCurrent (Total,AllSwitches) 6A OutputSteadyStateCurrent (EachSwitch) 1A LogicInputVoltage (Pins3,9,10,11,12) −0.3Vto+16V LogicInputVoltage(Pins4,7) −0.3Vto+6V ErrorFlagVoltage 16V ESD Susceptibility(3) 2000V Power Dissipation(4) 5W InternallyLimited JunctionTemperature(TJMAX 150°C) 150°C StorageTemperatureRange −65°C to+150°C Lead Temperature(Soldering,10 sec.) +260°C (1) AbsoluteMaximum Ratingsindicatelimitsbeyond whichdamage tothedevicemay occur.OperatingRatingsindicateconditionsfor whichthedeviceisintendedtobe functional,butdo notensurespecificperformancelimits.Forensuredspecificationsand test conditions,see theElectricalCharacteristics. (2) IfMilitary/Aerospacespecifieddevicesarerequired,pleasecontacttheTexas InstrumentsSalesOffice/Distributorsforavailabilityand specifications. (3) Human body model;100 pF dischargethrougha 1.5kΩ resistor.Allpinsexceptpins8 and 13 whichareprotectedto1000V and pins1, 2,18 and 19 whichareprotectedto500V. (4) The maximum power dissipationisa functionofTJMAX ,θJA,and TA and islimitedby thermalshutdown.The maximum allowablepower dissipationatany ambienttemperatureisPD = (TJMAX –TA)/θJA.Ifthisdissipationisexceeded,thedietemperaturewillriseabove 150°C and thedevicewilleventuallygo intothermalshutdown.FortheLMD18400 thejunction-to-ambientthermalresistance,θJA,is60°C/W. Withsufficientheatsinkingthemaximum continuouspower dissipationforthepackage willbe,IDC MAX 2 × R ON (MAX) × 4 switches1A2 × 1.3Ω × 4 = 5.2W). OPERATING RATINGS (1) AmbientTemperatureRange (TA) −25°C to+85°C SupplyVoltageRange 7V to28V (1) AbsoluteMaximum Ratingsindicatelimitsbeyond whichdamage tothedevicemay occur.OperatingRatingsindicateconditionsfor whichthedeviceisintendedtobe functional,butdo notensurespecificperformancelimits.Forensuredspecificationsand test conditions,see theElectricalCharacteristics.

ELECTRICAL CHARACTERISTICS

VCC = 12V,C CP = 0.01µFd,unlessotherwiseindicated.Boldfacelimitsapplyovertheentireoperatingtemperaturerange, −25°C ≤ TA ≤ +85°C, allotherlimitsareforTA = TJ = +25°C. Typical Limit UnitsParameter Conditions (1) (2) (Limit) DC CHARACTERISTICS SupplyCurrent EnableInput= 0V 0.04 10 µA (Max) EnableInput= 5V,Inputs= 0V 7.5 15 mA (Max) EnableInput= 5V,Inputs= 5V Open Loads 7.5 15 mA (Max) (1) TypicalvaluesareatTJ = +25°C and representthemost likelyparametricnorm. (2) Alllimitsare100% productiontestedat+25°C. Limitsattemperatureextremesarespecifiedthroughcorrelationand acceptedStatistical QualityControl(SQC) methods. Copyright© 1996–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 3 ProductFolderLinks:LMD18400

SNVS094C –JUNE 1996–REVISED APRIL 2013 www.ti.com ELECTRICAL CHARACTERISTICS (continued) VCC = 12V,C CP = 0.01µFd,unlessotherwiseindicated.Boldfacelimitsapplyovertheentireoperatingtemperaturerange, −25°C ≤ TA ≤ +85°C, allotherlimitsareforTA = TJ = +25°C. Typical Limit UnitsParameter Conditions (1) (2) (Limit) OutputLeakage EnableInput= 0V,Inputs= 0V 0.01 300 µA (Max)(Pins1,2,18,19) Rds ON IOUT = 1A, (3) 0.8 1.3 Ω (Max) ShortCircuitCurrent VCC = 12V, (3) 1.2 0.6 A (Min) VCC = 7V, (3) 2.4 A VCC = 28V, (3) 0.6 A Maximum OutputCurrent VCC −VO = 4V, (3) 3.75 A Lead ErrorThresholdVoltage Pins1,2,18,19 4.1 V Open Load DetectionCurrent Pins1,2,18,19 150 µA NegativeClamp OutputVoltage IO = 1A, (3) −5 V OvervoltageShutdown Threshold 31 40 V (Max) OvervoltageShutdown Hysteresis 0.75 V ErrorOutputLeakage Current VPIN 13 = 12V 0.001 10 µA (Max) ThermalWarningTemperature VPIN 13 < 0.8V 145 °C ThermalShutdown Temperature VPIN 17 < 0.8V 170 °C ThermalWarningTemperature VPIN 13 < 0.8V 145 °C AC CHARACTERISTICS SwitchTurn-OnDelay(td(ON)) Enable(Pin3)= 5V,IOUT = 1A 5 10 µs (Max) SwitchTurn-OnRiseTime (tON ) IOUT = 1A 7 15 µs (Max) SwitchTurn-OffDelay(td(OFF)) Enable(Pin3)= 5V,IOUT = 1A 0.5 2 µs (Max) SwitchTurn-OffFallTime (tOFF ) IOUT = 1A 0.15 1 µs (Max) EnableTime (tEN ) Measured withSwitch1,Pin9 = 5V 30 50 µs (Max) ErrorReportingDelay(tError) Enable(Pin3)= 5V,Switch1 Load Opened 75 150 µs (Max) Data SetupTime (tDS ) C L = 30 pF 200 500 ns (Min) TRI-STATE Control(t1H ,tOH ) Pin8,Hi-ZEnableTime 2 µs Data ClockFrequency 3 1 MHz (Max) DIGITAL CHARACTERISTICS Logic“1”InputVoltage Pins3,4,7,9,10,11,12 2.0 V (Min) Logic“0”InputVoltage Pins3,4,7,9,10,11,12 0.8 V (Max) Logic“1”InputCurrent Pins4,7 0.001 1 µA (Max) Logic“0”InputCurrent Pins4,7 −0.001 −1 µA (Max) TRI-STATE OutputCurrent Pin8,Pin4 = 5V 0.05 10 µA (Max) Pin8 = 0V −0.05 −10 µA (Max) EnableInputCurrent Pin3 = 2.4V 12 25 µA (Max) ChannelInputResistance Pins9,10,11,12 75 15 kΩ (Min) ErrorOutputSinkCurrent Pin13 = 0.8V 4 1.6 mA (Min) Logic“1”OutputVoltage Pin8 IOUT = −360 µA 4.4 2.4 V (Min) IOUT = −10 µA 5.1 4.5 V (Min) IOUT = −10 µA 5.5 V (Min) Logic“0”OutputVoltage Pin8 0.4 V (Max)IOUT = 100 µA ThermalShutdown OutputSourceCurrent Pin17 = 2.4V 5 3 µA (Min) ThermalShutdown OutputSinkCurrent Pin17 = 0.8V 360 250 µA (Min) (3) PulseTestingtechniquesused.Pulsewidthis< 5 ms witha dutycycle< 1%.

4 SubmitDocumentationFeedback Copyright© 1996–2013,Texas InstrumentsIncorporated

ProductFolderLinks:LMD18400

www.ti.com SNVS094C –JUNE 1996–REVISED APRIL 2013 TIMING SPECIFICATION DEFINITIONS Figure2. SwitchingTurn ON/OFF Figure3. Enable Turn-On Figure4. ErrorReportingDelay Figure5. Data Setup Time Copyright© 1996–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 5 ProductFolderLinks:LMD18400

SNVS094C –JUNE 1996–REVISED APRIL 2013 www.ti.com TYPICAL PERFORMANCE CHARACTERISTICS Forallcurves,VCC = 12V,Temperatureisthejunctiontemperatureunlessotherwisenoted. Switch ON Resistance “Sleep Mode ” Supply Current vs Temperature vs Temperature Figure6. Figure7. Maximum Power Dissipation ShortCircuitCurrent vs Ambient Temperature vs Temperature Figure8. Figure9. ErrorSense Threshold Voltage Clamp Characteristics vs vs Temperature Temperature Figure10. Figure11.

6 SubmitDocumentationFeedback Copyright© 1996–2013,Texas InstrumentsIncorporated

ProductFolderLinks:LMD18400

www.ti.com SNVS094C –JUNE 1996–REVISED APRIL 2013 TYPICAL PERFORMANCE CHARACTERISTICS (continued) Forallcurves,VCC = 12V,Temperatureisthejunctiontemperatureunlessotherwisenoted. Turn ON Rise Time Turn ON Delay Time vs Temperature vs Temperature Figure12. Figure13. Switch SelectLogic Input Resistance Turn OFF Time vs vs Temperature Temperature Figure14. Figure15. Enable ThresholdVoltage ErrorOutput Voltage vs Temperature vs Sink Current Figure16. Figure17. Copyright© 1996–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 7 ProductFolderLinks:LMD18400

SNVS094C –JUNE 1996–REVISED APRIL 2013 www.ti.com FUNCTIONAL BLOCK DIAGRAM TRUTH TABLE Enable Chip Select Switch Control Error Thermal SD Input Input Input Output Output Conditions (Pin3) (Pin4) (Pins9,10,11,12) (Pin13) (Pin17)

0 X X 1 0 “Sleep”Mode, ISUPPLY < 10 µA

1 X 0 1 1 SelectedSwitchisOFF

1 X 1 1 1 SelectedSwitchisON, Normal Operation

1 X 0 0 1 SwitchisOFF but:

a.Load isOpen Circuited,or b.Load isShortedtoVCC ,or c.TJ > +145°C, or d.VCC > +35V

1 X 1 0 1 SwitchisON, but:

a.Load isShortedtoGround,or b.SwitchisinPower Limit,or c.TJ > +145°C, or d.VCC > +35V and SwitchisActuallyOFF

1 X 1 0 0 TJ > +170°C, AllSwitchesareOFF

1 1 X X X Data OutputPinisTRI-STATE 1 0 X X X Data OutputPinisEnabledand Ready toOutput DiagnosticInformation

8 SubmitDocumentationFeedback Copyright© 1996–2013,Texas InstrumentsIncorporated

ProductFolderLinks:LMD18400

www.ti.com SNVS094C –JUNE 1996–REVISED APRIL 2013 APPLICATIONS INFORMATION BASIC OPERATION High-sidedriversare used extensivelyin automotiveand industrialapplicationsto switchpower to ground referredloads.The majoradvantageofusinghigh-sidedrive,as opposed tolow-sidedrive,istoprotecttheload from being energizedin the event thatthe load drivewireis inadvertentlyshortedto ground as shown in Figure18.A high-sidedrivercan sense a shortedconditionand open thepower switchtodisabletheloadand eliminatethe excessivecurrentdrainon the power supply.The LMD18400 can controland protectup to four separategroundreferencedloads. Figure18. High-Sidevs Low-Side Drive The LMD18400 combines low voltageCMOS logiccontrolcircuitrywitha highvoltageDMOS process.Each DMOS power switchhas an individualON/OFF controlinput.When commanded ON, theoutputoftheswitchwill connectthe loadto the VCC supplythrougha maximum resistanceof 1.3Ω (theON resistanceof the DMOS switch).The voltageappliedtotheloadwilldepend upon theloadcurrentand thedesignedcurrentcapabilityof theLMD18400. When a switchiscommanded OFF, theloadwillbe disconnectedfrom thesupplyexceptfora smallleakagecurrentoftypicallylessthan0.01µA. The LMD18400 can be continuallyconnectedtoa livepower source,a carbatteryforexample,whiledrawing lessthan10 µA fromthepower sourcewhen putintoa “sleep”condition.This“sleep”mode isenactedby taking theEnableInput(pin3)low.Duringthismode thesupplycurrentforthedeviceistypicallyonly0.04µA. Special low currentconsumptionstandbycircuitryisused toholdtheDMOS switchesOFF toeliminatethepossibilityof supplyvoltagetransientsfromturningon any oftheloads(acommon problemwithMOS power devices).When inthe“sleep”mode, alldiagnosticand logiccircuitryisinactive.When theEnableInputistakentoa logic1,the switchesbecome “armed”and readytorespondtotheircontrolinputaftera short,30 µs,enabledelaytime.This delayintervalpreventstheswitchesfromtransientturn-on.Figure19 shows theswitchcontrollogic. Copyright© 1996–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 9 ProductFolderLinks:LMD18400

SNVS094C –JUNE 1996–REVISED APRIL 2013 www.ti.com Figure19. ControlLogic forEach Power Switch Each DMOS switchisturnedON when itsgate isdrivenapproximately3.5V more positivethan itssource voltage.Because thesourceoftheswitchistheoutputterminaltotheloaditcan be takentoa voltageverynear the VCC supplypotential.To ensure thatthereissufficientvoltageavailableto drivethe gatesof the DMOS devicea chargepump circuitisbuiltin.Thiscircuitiscontrolledby an internal300 kHz oscillatorand usingan external10 nF capacitorconnectedfrompin14 togroundgeneratesa voltagethatisapproximately20V greater thantheVCC supplyvoltage.Thisprovidessufficientgatevoltagedriveforeach oftheswitcheswhichisapplied undercommand ofstandard5V logicinputlevels. The turn-ontimeforeach switchisapproximately12 µs when drivinga 1A loadcurrent.Thisrelativelyslow switchingtime is beneficialin minimizingelectromagneticinterference(EMI) relatedproblems createdfrom switchinghighcurrentlevels. PROTECTION CIRCUITRY The LMD18400 has extensiveprotectioncircuitrybuiltin.With any power device,protectionagainstexcessive voltage,currentand temperatureconditionsisessential.To achievea “fail-safe” system implementation,the loads are deactivatedautomaticallyby the LMD18400 in the event of any detectedovervoltageor over- temperaturefaultconditions. VoltageProtection The VCC supplycan range from −0.5V to +60 VDC withoutany damage to the LMD18400. The CMOS logic circuitryisbiasedfrom an internal5.1V regulatorwhich protectstheselowervoltagetransistorsfrom thehigher VCC potentials.Inordertoprotecttheloadsconnectedtotheswitchoutputshowever,an overvoltageshutdown circuitis employed. Should the VCC potentialexceed 35V allof the switchesare turned OFF thereby disconnectingtheloads.This35V thresholdhas 750 mV ofhysteresistopreventpotentialoscillations. Additionally,thereis an undervoltagelockoutfeaturebuiltin.With VCC lessthan 5V itbecomes uncertain whetherthelogiccircuitrycan holdtheswitchesintheircommanded state.To avoidthisuncertainty,allofthe switchesareturnedOFF when VCC dropsbelow approximately5V. Figure20 illustratestheshutoffofan output duringa 0V to80V VCC supplytransient.

10 SubmitDocumentationFeedback Copyright© 1996–2013,Texas InstrumentsIncorporated

ProductFolderLinks:LMD18400

www.ti.com SNVS094C –JUNE 1996–REVISED APRIL 2013 Figure20. Overvoltage/UndervoltageShutdown The LMD18400 has been designedtodrivealltypesofloads.When drivinga groundreferencedinductiveload such as a relayor solenoid,the voltageacrossthe load willreversein polarityas the fieldin the inductor collapseswhen thepower switchisturnedOFF. ThiswillpulltheoutputpinoftheLMD18400 belowground.This negativetransientvoltageisclamped atapproximately−5V toprotecttheIC.Thisclampingactionisnotdone withdiodesbutratherthepower DMOS switchturningback on momentarilytoconducttheinductorcurrentas it de-energizesas shown inFigure21. Figure21. Turn-OFF Conditionswithan InductiveLoad When theoutputinductanceproducesa negativevoltage,thegateoftheDMOS transistorisclamped at0V. At −3.5V,thesourceofthepower deviceislessthanthegateby enough tocause theswitchtoturnON again. Duringthisnegativetransientconditionthe power limitingcircuitryto protectthe switchisdisableddue to the gatebeingheldat0V. The maximum currentduringthisclampinginterval,whichisequaltothesteadystateON currentthroughtheinductor,shouldbe keptlessthan1A. Anotherconcernduringthisintervalhas todo withthe sizeof an inductiveloadand the amount of timerequiredto de-energizeit.With largerinductorsitmay be possiblefortheadditionalpower dissipationtocause thedietemperaturetoexceed thethermalshutdownlimit.If thisoccursalloftheotherswitcheswillturnOFF momentarily(seesectionon THERMAL MANAGEMENT ). Power Limiting The LMD18400 utilizesa trueinstantaneouspower limitcircuitratherthansimplecurrentlimitingtoprotecteach switch.Thisprovidesa highertransientcurrentcapabilitywhilestillmaintaininga safepower dissipationlevel. The power dissipationineach switch(theproductoftheDrain-to-Sourcevoltageand theoutputcurrent,Vds × IOUT )iscontinuallymonitoredand limitedto15W by varyingthegatevoltageand thereforetheON resistanceof the switch.Basicallythe ON resistancewillbe as low as possibleuntil15W isbeingdissipated.To maintain 15W, theON resistanceincreasestoreducetheloadcurrent.Thisresultsina decreaseoftheoutputvoltage. Forresistiveloads,theoutputvoltagewhen inpower limitwillbe: (1) Copyright© 1996–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 11 ProductFolderLinks:LMD18400

SNVS094C –JUNE 1996–REVISED APRIL 2013 www.ti.com Thisprovidesa maximum transientcurrent,and drain-to-sourcevoltagecharacteristicas shown inFigure22. Figure22. Maximum Output CurrentwithInstantaneousPower Limiting Figure23. Drivinga Lamp /SoftTurn-On ofa Lamp Load The steadystatecurrenttotheloadislimitedby thepackage power dissipation,ambienttemperatureand the ON resistanceoftheswitchwhich has a positivetemperaturecoefficientas shown intheTypicalPerformance Characteristics. Thisdynamic currentlimitingoftheswitchesisbeneficialwhen drivinglamp and largecapacitiveloads.Lamps requirea largeinrushcurrent,on theorderof10 timesthenormaloperatingcurrent,when firstswitchedon with a coldfilament.The LMD18400 willlimitthisinitialcurrenttothelevelwhere 15W isdissipatedintheswitch.As thefilamentwarms up thevoltageacrossthelamp increasestherebydecreasingthevoltageacrosstheswitch which permitsmore currentto fullylightthe lamp. With limitedinrushcurrentthe lifetimeof a lamp load is increasedsignificantly.Figure23 illustratesthesoftturn-onofa lamp load. The same principleofincreasingoutputcurrentas thevoltageacrosstheloadincreasesallowslargecapacitive loadstobe chargedmore quicklyby an LMD18400 driverthanas opposed toa driverwitha fixed1A current limitprotectionscheme. Figure24 shows theoutputresponsewhiledrivinga largecapacitiveload.

12 SubmitDocumentationFeedback Copyright© 1996–2013,Texas InstrumentsIncorporated

ProductFolderLinks:LMD18400

www.ti.com SNVS094C –JUNE 1996–REVISED APRIL 2013 Thermal Protection The dietemperatureoftheLMD18400 iscontinuallymonitored.Shouldany conditionscause thedietemperature toriseto+170°C, allofthepower switchesare turnedOFF automaticallytoreducethepower dissipation.Itis importanttorealizethatthethermalshutdown affectsallfouroftheswitchestogether.Thatis,ifjustone switch loadisenough toheatthedietothethermalshutdown threshold,alloftheotherswitches,regardlessoftheir power dissipationconditions,willbe switchedOFF. Allof the switcheswillbe re-enabledwhen the die temperaturehas cooled to approximately+160°C. Untilthe high temperatureforcingconditionshave been removed the switcheswillcycleON and OFF thus maintainingan average die temperatureof +165°C. The LMD18400 willsignalthat excessivetemperaturesexistthrough severaldiagnosticoutput signals(see DIAGNOSTICS ). Figure24. Drivinga Large CapacitiveLoad DIAGNOSTICS The LMD18400 has extensivecircuitdiagnosticinformationreportingcapability.Use of thisinformationcan produce systems withintelligentfeedbackof switchstatusas wellas loadfaultconditionsfortroubleshooting purposes.Allofthediagnosticinformationiscontainedinan 11-bitword.Thisdatacan be clockedoutofthe LMD18400 ina serialfashionas shown inFigure25.The shiftregisterisparallelloadedwiththediagnosticdata whenever theChip Selectinputisata Logic1 and changes totheserialshiftmode when Chip Selectistakento a Logic0.The Data Outputline(pin8) isbiasedinternallyfrom a 5.1V regulatorwhich setstheLogic1 output voltage.Thispinhas low currentsourcingcapabilityso any loadon thispinwillreducetheLogic1 outputlevel whichisspecifiedtobe atleast2.4Vwitha 360 µA load. The datainterfaceisMICROWIRE compatibleinthatdataisclockedoutoftheLMD18400 on thefallingedge of theclock,tobe clockedintothecontrollingmicroprocessoron therisingedge.Any number ofdevicescan share a common dataoutputlinebecause thedataoutputpinisheldina highimpedance (TRI-STATE)conditionuntil thedeviceisselectedby takingitsChip SelectInputlow.FollowingChip Selectgoinglow thereisa shortdata setup time interval(500 ns Min) required.This isnecessaryto allowthe firstdata bitof informationto be establishedon the data outputlinepriorto the firstrisingclockedge which willinputthe data bitintothe controller.When all11 bitsofdiagnosticdatahave been shiftedoutthedataoutputgoes toa Logic1 leveluntil theChipSelectlineisreturnedhigh. Figure25 alsoindicatesthesignificanceofthediagnosticdatabits.The first4 bitsindicatean outputloaderror condition,one foreach channelinsuccession(seeLOAD ERROR DETECTION ). Bits5 through8 providea readbackofthecommanded ON/OFF statusofeach switch. A unique featureof the LMD18400 isthatitprovidesan earlywarningof excessiveoperatingtemperature. Shouldthedietemperatureexceed +145°C, bit9 willbe settoa Logic0.Actingon thisinformationa system can be programmed to take correctiveaction,shuttingOFF specificloadsperhaps,whilethe LMD18400 isstill operatingnormally(notyetinthermalshutdown).Ifthisearlywarningisignoredand thedevicecontinuestorise intemperature,thethermalshutdown circuitrywillcome intoactionata dietemperatureof+170°C. Shouldthis occurbit10 ofthediagnosticdatastreamwillbe settoa Logic0 indicatingthatthedeviceisinthermalshutdown and alloftheoutputshave been shutOFF. The finaldata bit,bit11, indicatesan overvoltageconditionon the VCC supply(VCC isgreaterthan 35V) and againindicatesthatallofthedriversareOFF. Copyright© 1996–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 13 ProductFolderLinks:LMD18400

SNVS094C –JUNE 1996–REVISED APRIL 2013 www.ti.com The diagnosticdata can be read periodicallyby a controlleror onlyin the event of a generalsystem error indicationto determinethe cause of any system problem.Thisgeneralindicationof a faultisprovidedby an ErrorFlagoutput(pin13).Thispingoes low whenever any typeoferrorisdetected.There isa built-indelayof approximately75 µs from the timean errorisdetecteduntilpin13 istakenlow.Thisisto helpmask short durationerrorconditionssuch as may be caused by drivinghighlycapacitiveloads(>2 µF).A lamp loadmay generatea shortedloaderrorforseveralhundredmillisecondsas itturnson whichshouldbe ignored. Figure25. SerialDiagnosticData Assignments The ErrorFlagoutputpinisan open draintransistorwhichrequiresa pull-upresistortoa positivevoltageofup to16V. Typicallythispull-upistothesame 5V supplywhichisbiasingtheEnableinputand any otherexternal logiccircuitry.The ErrorFlagpinsofseveralLMD18400 packages can be connectedtogetherwithjustone pull- up resistorto providean all-encompassinggeneralsystem errorindication.Upon detectionof an error,each devicecouldthenbe polledfordiagnosticinformationtodeterminethesourceofthefaultcondition. A second directoutputerrorflagisforan indicationofThermalShutdown (pin17).Thisactivelow flagprovides an immediateindicationthatthedietemperaturehas reached+170°C and thatthedrivetoallfourswitcheshas been removed.Thisoutputispulledup totheinternal5.1V logicregulatorthrougha small(5µA) currentsource so use ofa bufferon thispinisrecommended. Figure26. Thermal Shutdown Flagand Shutdown Input

14 SubmitDocumentationFeedback Copyright© 1996–2013,Texas InstrumentsIncorporated

ProductFolderLinks:LMD18400

www.ti.com SNVS094C –JUNE 1996–REVISED APRIL 2013 A usefulfeatureof pin17 isthatitcan alsobe used as a shutdown input.Drivingthispinlow immediately switchesallofthedriversOFF, justthesame as ifthermalshutdown temperatureshas been reached,yetallof thecontrollogicand diagnosticcircuitsremainactive.Thisisusefulindesigning“fail-safe” systems where the loadscan be disabledunderany sortofexternallydetectedsystem faultcondition.The diagnosticlogichowever does not distinguishbetween normal thermalshutdown or the factthatpin17 has been drivenlow.As such, variousswitcherrorsand an over-temperatureindicationwillbe reportedinthediagnosticdatastream. Figure26 illustratestheuse ofpin17 as bothan outputthermalshutdown flagand as an inputtoshutdown only theswitches.Directlytyingpin17 to+5V willpreventtheinternalthermalshutdown circuitryfrom disablingthe switches.For reliabilitypurposeshowever thisisnotrecommended as therewillthenbe no limittothemaximum dietemperature. RefertotheTRUTH TABLE fora summary oftheactionofthesedirect-outputerrorflags. LOAD ERROR DETECTION An importantfeatureof the LMD18400 isthe abilityto detectopen or shortedload connections.Figure27 illustratesthedetectioncircuitused witheach ofthedrivers. Figure27. DetectionCircuitryforOpen/Shorted Loads A voltagecomparatormonitorsthevoltagetotheloadand compares ittoa fixed4.1V referencelevel.When a switchisOFF, thegroundreferencedloadshouldhave no voltageacrossit.Under thiscondition,an internal50 kΩ resistorconnectedtoVCC willprovidea smallamount ofcurrenttotheload.Iftheloadresistanceislarge enough tocreatea voltagegreaterthan4.1V an Open Load Errorwillbe indicatedforthatswitch.The maximum loadresistancethatwillnotgeneratean Open Load Errorwhen a switchisOFF can be foundby: (2) To make thisOpen Load Errorthresholdmore sensible,an externalpull-upresistorcan be added from the outputtotheVCC supply. Alsowhen a switchiscommanded OFF, shouldtheloadbe shortedtotheVCC supply,thissame circuitrywill againindicatean error. When a switchiscommanded ON, the loadisexpectedto have a voltageacrossitthatapproachesthe VCC potential.Iftheoutputvoltageislessthanthe4.1V thresholdan errorwillagainbe reported,indicatingthatthe loadiseithershortedtoground or thatthedriverisinpower limitand notabletopulltheoutputvoltageany closertoVCC .The minimum loadresistancethatwillnotgeneratea ShortedLoad Errorwhen a switchisON can be foundby: (3) Figure28 indicatestherangeofloadresistancefornormaloperation,open load,and shortedloadorpower limit indication. Copyright© 1996–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 15 ProductFolderLinks:LMD18400

SNVS094C –JUNE 1996–REVISED APRIL 2013 www.ti.com Figure28. Load ResistanceDetectedas Errors THERMAL MANAGEMENT Itisparticularlyimportantto considerthe totalamount of power beingdissipatedby allfourswitchesinthe LMD18400 at alltimes.Any combinationof the switchesdrivingloads willcause an increasein the die temperature.Shouldthedietemperaturereachthethermalshutdownthresholdof+170°C, alloftheswitcheswill be disabled. Carefulcalculationoftheworstcase totalpower dissipationrequiredatany pointintime,togetherwithproviding sufficientheatsinkingwillpreventthisfromoccurring. The LMD18400 ispackaged witha specialleadframethathelpsdissipateheatthroughthetwo ground pinson each sideofthepackage.The thermalresistancefrom junction-to-case(θJC) forthispackage isapproximately 20°C/W. The thermalresistancefrom junction-to-ambient(θJA), withoutany heatsinking,is approximately 60°C/W. Figure29 illustrateshow the copper foilof a printedcircuitboard can be designed to provide heatsinkingand reducetheoveralljunction-to-ambientthermalresistance. The power dissipationineach switchisequalto: where

  • R ON istheON resistanceoftheswitch(1.3Ω maximum) (4) These equationsholdtrueuntilthepower dissipationreachesthemaximum limitof15W. With resistiveloads, the15W power limitthresholdwillbe reachedwhen: (5) Inductiveloads willcreateadditionalpower dissipationwhen switchedOFF. Figure30 shows the idealized voltageand currentwaveformsforan inductiveload.

16 SubmitDocumentationFeedback Copyright© 1996–2013,Texas InstrumentsIncorporated

ProductFolderLinks:LMD18400

www.ti.com SNVS094C –JUNE 1996–REVISED APRIL 2013 Maximum Power Dissipatedand JunctiontoAmbient Thermal Resistancevs Size Figure29. Recommended PC Board Layout toReduce theThermal Resistancefrom Junction-to-Ambient Figure30. Switchingan InductiveLoad When switchedON, theworstcase power dissipationis: (6) The steady-stateON currentoftheinductorshouldbe keptlessthan1A perpower switch. The additionalpower dissipationduringturn-off,as the inductorisde-energizedand the voltageacrossthe inductorisclamped to−5V,can be foundby: (7) forthetimeinterval,tCLAMP .whichisthetimerequiredfortheinductorcurrenttofalltozero: (8) The sizeoftheinductorwilldeterminethetimedurationforthisadditionalpower dissipationinterval.Even though thepeak currentiskeptlessthan1A, theswitchduringthisintervalwillsee a voltageacrossitofVCC + 5V with no power limitprotection.Ifthe inductoristoo large,the time intervalmay be long enough to heat the die temperatureto+170°C therebyshuttingOFF allotherloadson thepackage. Copyright© 1996–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 17 ProductFolderLinks:LMD18400

SNVS094C –JUNE 1996–REVISED APRIL 2013 www.ti.com The totalaveragepower dissipationduringa fullON/OFF switchingcycleofan inductiveloadwillbe: (9) Due tothecommon cut-offofallloadsforcedby thermalshutdown,thethermaltimeconstantsofthepackage become a concern.Figure31 providesan indicationofthetimeittakestoheatthedietothermalshutdown with a step increasein package power dissipationfrom an initialjunctiontemperatureof +25°C. This data was measured usinga PC board layoutprovidinga thermalresistancefrom junctionto ambientof approximately 35°C/W. Less heatsinkingwill,ofcourse,resultinfasterthermalshutdownofthepower switches. Figure31. Approximate timerequiredforthedietoreach the170°C thermalshutdown pointfrom 25°C fordifferenttotalpackage power dissipationlevels. Figure32. ON/OFF SwitchingofMultipleVoltageRegulatedCircuitLoads

18 SubmitDocumentationFeedback Copyright© 1996–2013,Texas InstrumentsIncorporated

ProductFolderLinks:LMD18400

www.ti.com SNVS094C –JUNE 1996–REVISED APRIL 2013 Figure33. UnipolarDrivefora 4-Phase StepperMotor Figure34. Recommended Connection IfNo DiagnosticsareRequired Copyright© 1996–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 19 ProductFolderLinks:LMD18400

SNVS094C –JUNE 1996–REVISED APRIL 2013 www.ti.com Loads willbe energizedthroughtheintrinsicdiodesinparallelwiththepower switches.The Schottkydiodewilladd approximately0.2Vtothelogicinputswitchingthresholdsand thelogicoutputlowlevels. Figure35. Simple protectionoftheLMD18400 againstsupply voltagereversal Figure36. Simple Light“Chaser”

20 SubmitDocumentationFeedback Copyright© 1996–2013,Texas InstrumentsIncorporated

ProductFolderLinks:LMD18400

www.ti.com SNVS094C –JUNE 1996–REVISED APRIL 2013 PositivetemperaturecoefficientoftheswitchON resistanceprovidesballastingtoevenlysharetheloadcurrent between theswitches.Any combinationofswitchescan be paralleled.Requiredpeak loadcurrentwilldepend upon themotorload.Motorspeed controlcan be providedby a PWM signalofup to20 kHz appliedtothemotordriveinput lines. Figure37. Parallelingswitchesforhighercurrentcapability Copyright© 1996–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 21 ProductFolderLinks:LMD18400

SNVS094C –JUNE 1996–REVISED APRIL 2013 www.ti.com

REVISION HISTORY

Changes from RevisionB (April2013)toRevisionC Page

22 SubmitDocumentationFeedback Copyright© 1996–2013,Texas InstrumentsIncorporated

ProductFolderLinks:LMD18400

www.ti.com 12-Jul-2014 Addendum-Page 1 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Qty Eco Plan (2) Lead/Ball Finish (6) MSL Peak Temp (3) Op Temp (°C) Device Marking (4/5) Samples LMD18400N NRND PDIP NFH 20 18 TBD Call TI Call TI -25 to 85 LMD18400N LMD18400N/NOPB ACTIVE PDIP NFH 20 18 Pb-Free (RoHS) CU SN Level-1-NA-UNLIM -25 to 85 LMD18400N (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. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width. 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.

www.ti.com 12-Jul-2014 Addendum-Page 2 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.

www.ti.com N20A (Rev G)

Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All semiconductor products (also referred to herein as “components”) are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its components to the specifications applicable at the time of sale, in accordance with the warranty in TI’s terms and conditions of sale of semiconductor products. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by applicable law, testing of all parameters of each component is not necessarily performed. TI assumes no liability for applications assistance or the design of Buyers’products. Buyers are responsible for their products and applications using TI components. To minimize the risks associated with Buyers’products and applications, Buyers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right relating to any combination, machine, or process in which TI components or services are used. Information published by TI regarding third-party products or services does not constitute a license to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of significant portions of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional restrictions. Resale of TI components or services with statements different from or beyond the parameters stated by TI for that component or service voids all express and any implied warranties for the associated TI component or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. Buyer acknowledges and agrees that it is solely responsible for compliance with all legal, regulatory and safety-related requirements concerning its products, and any use of TI components in its applications, notwithstanding any applications-related information or support that may be provided by TI. Buyer represents and agrees that it has all the necessary expertise to create and implement safeguards which anticipate dangerous consequences of failures, monitor failures and their consequences, lessen the likelihood of failures that might cause harm and take appropriate remedial actions. Buyer will fully indemnify TI and its representatives against any damages arising out of the use of any TI components in safety-critical applications. In some cases, TI components may be promoted specifically to facilitate safety-related applications. With such components, TI’s goal is to help enable customers to design and create their own end-product solutions that meet applicable functional safety standards and requirements. Nonetheless, such components are subject to these terms. No TI components are authorized for use in FDA Class III (or similar life-critical medical equipment) unless authorized officers of the parties have executed a special agreement specifically governing such use. Only those TI components which TI has specifically designated as military grade or “enhanced plastic”are designed and intended for use in military/aerospace applications or environments. Buyer acknowledges and agrees that any military or aerospace use of TI components which have not been so designated is solely at the Buyer's risk, and that Buyer is solely responsible for compliance with all legal and regulatory requirements in connection with such use. TI has specifically designated certain components as meeting ISO/TS16949 requirements, mainly for automotive use. In any case of use of non-designated products, TI will not be responsible for any failure to meet ISO/TS16949. Products Applications Audio www.ti.com/audio Automotive and Transportation www.ti.com/automotive Amplifiers amplifier.ti.com Communications and 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 Energy and Lighting www.ti.com/energy Clocks and 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, Avionics and Defense www.ti.com/space-avionics-defense Microcontrollers microcontroller.ti.com Video and Imaging www.ti.com/video RFID www.ti-rfid.com OMAP Applications Processors www.ti.com/omap TI E2E Community e2e.ti.com Wireless Connectivity www.ti.com/wirelessconnectivity Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2014, Texas Instruments Incorporated