Product Sample & Technical Tools & Support & Folder Buy Documents Software Community LM2671 SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 ® LM2671 SIMPLE SWITCHER Power Converter High Efficiency 500-mA Step-Down Voltage Regulator With Features 1 Features 3 Description • Efficiencyupto96% The LM2671 series of regulators are monolithic 1 integrated circuits built with a LMDMOS process. • Availablein8-PinSOIC,PDIP,andWSON These regulators provide all the active functions for a Packages step-down (buck) switching regulator, capable of • SimpleandEasytoDesignWith driving a 500-mA load current with excellent line and • RequiresOnly5ExternalComponents load regulation. These devices are available in fixed output voltages of 3.3 V, 5 V, 12 V, and an adjustable • UsesReadilyAvailableStandardInductors outputversion. • 3.3-V,5-V,12-V,andAdjustableOutputVersions Requiring a minimum number of external • AdjustableVersionOutputVoltageRange:1.21V components, these regulators are simple to use and to37V include patented internal frequency compensation, • ±1.5%MaximumOutputVoltageToleranceOver fixed frequency oscillator, external shutdown, soft LineandLoadConditions start,andfrequencysynchronization. • Ensured500-mAOutputLoadCurrent The LM2671 series operates at a switching frequency • 0.25-Ω DMOSOutputSwitch of 260 kHz, thus allowing smaller sized filter components than what is required with lower • WideInputVoltageRange:8Vto40V frequency switching regulators. Because of its very • 260-kHzFixedFrequencyInternalOscillator high efficiency (> 90%), the copper traces on the • TTLShutdownCapability,LowPowerStandby printed-circuit board are the only heat sinking Mode required. • Soft-StartandFrequencySynchronization A family of standard inductors for use with the • ThermalShutdownandCurrent-LimitProtection LM2671 are available from several different manufacturers. This feature greatly simplifies the 2 Applications design of switch-mode power supplies using these advanced ICs. Also included in the data sheet are • SimpleHighEfficiency(>90%)Step-Down(Buck) selector guides for diodes and capacitors designed to Regulators workinswitch-modepowersupplies. • EfficientPreregulatorforLinearRegulators DeviceInformation(1) PARTNUMBER PACKAGE BODYSIZE(NOM) SOIC(8) 4.90mm×3.91mm LM2674 PDIP(8) 9.81mm×6.35mm WSON(16) 5.00mm×5.00mm (1) For all available packages, see the orderable addendum at theendofthedatasheet. TypicalApplication Forfixedoutputvoltageversions 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectualpropertymattersandotherimportantdisclaimers.PRODUCTIONDATA.

LM2671 SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 www.ti.com Table of Contents 1 Features.................................................................. 1 8.2 FunctionalBlockDiagram.......................................10 2 Applications........................................................... 1 8.3 FeatureDescription.................................................10 3 Description............................................................. 1 8.4 DeviceFunctionalModes........................................11 4 RevisionHistory..................................................... 2 9 ApplicationandImplementation........................ 13 9.1 ApplicationInformation............................................13 5 Description(continued)......................................... 3 9.2 TypicalApplications................................................14 6 PinConfigurationandFunctions......................... 3 10 PowerSupplyRecommendations..................... 26 7 Specifications......................................................... 4 11 Layout................................................................... 27 7.1 AbsoluteMaximumRatings......................................4 11.1 LayoutGuidelines.................................................27 7.2 ESDRatings..............................................................4 11.2 LayoutExamples...................................................27 7.3 RecommendedOperatingConditions.......................4 12 DeviceandDocumentationSupport................. 28 7.4 ThermalInformation..................................................4 7.5 ElectricalCharacteristics–3.3V..............................5 12.1 DocumentationSupport........................................28 7.6 ElectricalCharacteristics–5V.................................5 12.2 ReceivingNotificationofDocumentationUpdates28 7.7 ElectricalCharacteristics–12V...............................5 12.3 CommunityResources..........................................28 7.8 ElectricalCharacteristics–Adjustable......................6 12.4 Trademarks...........................................................28 7.9 ElectricalCharacteristics–AllOutputVoltage 12.5 ElectrostaticDischargeCaution............................28 Versions.....................................................................6 12.6 Glossary................................................................28 7.10 TypicalCharacteristics............................................7 13 Mechanical,Packaging,andOrderable 8 DetailedDescription............................................ 10 Information........................................................... 28 8.1 Overview.................................................................10 13.1 DAP(WSONPackage).........................................28 4 Revision History NOTE:Pagenumbersforpreviousrevisionsmaydifferfrompagenumbersinthecurrentversion. ChangesfromRevisionK(April2013)toRevisionL Page • AddedESDRatingstable,FeatureDescriptionsection,DeviceFunctionalModes,ApplicationandImplementation section,PowerSupplyRecommendationssection,Layoutsection,DeviceandDocumentationSupportsection,and Mechanical,Packaging,andOrderableInformationsection.................................................................................................. 1 • RemovedallreferencestoComputerDesignSoftwareLM267XMadeSimple(Version6.0).............................................. 1 ChangesfromRevisionJ(April2013)toRevisionK Page • ChangedlayoutofNationalDataSheettoTIformat........................................................................................................... 27 2 SubmitDocumentationFeedback Copyright©1998–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2671

LM2671 www.ti.com SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 5 Description (continued) Other features include a ensured ±1.5% tolerance on output voltage within specified input voltages and output load conditions, and ±10% on the oscillator frequency. External shutdown is included, featuring typically 50-μA standby current. The output switch includes current limiting, as well as thermal shutdown for full protection under faultconditions. 6 Pin Configuration and Functions DorPPackage NHNPackage 8-PinSOICorPDIP 16-PinWSON TopView TopView CB 1 8 VSW CB 1 16 VSW NC 2 15 VSW SS 2 7 VIN NC 3 14 VIN SYNC 3 6 GND SS 4 DAP 13 NC NC 5 12 GND FB 4 5 ON/OFF SYNC 6 11 GND NC 7 10 NC FB 8 9 ON/OFF Not to scale Not to scale ConnectDAPtopin11and12 PinFunctions PIN I/O DESCRIPTION NAME SOIC,PDIP WSON Bootstrapcapacitorconnectionforhigh-sidedriver.Connectahigh-quality, CB 1 1 I 100-nFcapacitorfromCBtoVSWPin. Soft-startPin.ConnectacapacitorfromthispintoGNDtocontroltheoutput SS 2 4 I voltageramp.Ifthefeaturenotdesired,thepincanbeleftfloating. Thisinputallowscontroloftheswitchingclockfrequency.Ifleftopen-circuited SYNC 3 6 I theregulatorisswitchedattheinternaloscillatorfrequency,typically260kHz. Feedbacksenseinputpin.Connecttothemidpointoffeedbackdividertoset FB 4 8 I VOUTforADJversionorconnectthispindirectlytotheoutputcapacitorfora fixedoutputversion. Enableinputtothevoltageregulator.High=ONandlow=OFF.Pullthispin ON/OFF 5 9 I highorfloattoenabletheregulator Sourcepinoftheinternalhigh-sideFET.Thisisaswitchingnode.Attachedthis VSW 8 15,16 O pintoaninductorandthecathodeoftheexternaldiode. Powergroundpins.Connecttosystemground.GroundpinsofC andC . GND 6 11,12 — IN OUT PathtoC mustbeasshortaspossible. IN Supplyinputpintocollectorpinofhigh-sideFET.Connecttopowersupplyand VIN 7 14 I inputbypasscapacitorsC .PathfromVINpintohighfrequencybypassC IN IN andGNDmustbeasshortaspossible. 2,3,5,7, NC — — Noconnectpins 10,13 Copyright©1998–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 3 ProductFolderLinks:LM2671

LM2671 SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 www.ti.com 7 Specifications 7.1 Absolute Maximum Ratings overoperatingfree-airtemperaturerange(unlessotherwisenoted)(1)(2) MIN MAX UNIT Supplyvoltage 45 V ON/OFFpinvoltage,V −0.1 6 V SH Switchvoltagetoground –1 V Boostpinvoltage V +8 V SW Feedbackpinvoltage,V −0.3 14 V FB Powerdissipation InternallyLimited Vaporphase(60s) 215 Dpackage Infrared(15s) 220 Leadtemperature °C Ppackage(soldering,10s) 260 WSONpackage SeeAN-1187 Maximumjunctiontemperature 150 °C Storagetemperature,T −65 150 °C stg (1) StressesbeyondthoselistedunderAbsoluteMaximumRatingsmaycausepermanentdamagetothedevice.Thesearestressratings only,whichdonotimplyfunctionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedunderRecommended OperatingConditions.Exposuretoabsolute-maximum-ratedconditionsforextendedperiodsmayaffectdevicereliability. (2) IfMilitary/Aerospacespecifieddevicesarerequired,pleasecontacttheTexasInstrumentsSalesOffice/Distributorsforavailabilityand specifications. 7.2 ESD Ratings VALUE UNIT V Electrostaticdischarge Human-bodymodel(HBM),perANSI/ESDA/JEDECJS-001(1)(2) ±2000 V (ESD) (1) JEDECdocumentJEP155statesthat500-VHBMallowssafemanufacturingwithastandardESDcontrolprocess. (2) Thehumanbodymodelisa100-pFcapacitordischargedthrougha1.5-kΩresistorintoeachpin. 7.3 Recommended Operating Conditions MIN MAX UNIT Supplyvoltage 6.5 40 V Junctiontemperature,T –40 125 °C J 7.4 Thermal Information LM2674 THERMALMETRIC(1) D(SOIC) P(PDIP) NHN(WSON) UNIT 8PINS 8PINS 16PINS R Junction-to-ambientthermalresistance(2) 105 95 — °C/W θJA (1) Formoreinformationabouttraditionalandnewthermalmetrics,seetheSemiconductorandICPackageThermalMetricsapplication report. (2) Junctiontoambientthermalresistancewithapproximately1squareinchofprinted-circuitboardcoppersurroundingtheleads.Additional copperarealowersthermalresistancefurther.ThevalueR fortheWSON(NHN)packageisspecificallydependentonPCBtrace θJA area,tracematerial,andthenumberoflayersandthermalvias.ForimprovedthermalresistanceandpowerdissipationfortheWSON package,seeAN-1187LeadlessLeadframePackage(LLP). 4 SubmitDocumentationFeedback Copyright©1998–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2671

LM2671 www.ti.com SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 7.5 Electrical Characteristics – 3.3 V SpecificationsareforT =25°C(unlessotherwisenoted). J PARAMETER TESTCONDITIONS MIN(1) TYP(2) MAX(1) UNIT SYSTEMPARAMETERS(3) T =25°C 3.251 3.3 3.35 J V =8Vto40V, ILIONAD=20mAto500mA Overfulloperatingtemperature 3.201 3.399 V range V Outputvoltage OUT T =25°C 3.251 3.3 3.35 J V =6.5Vto40V, ILIONAD=20mAto250mA Overfulloperatingtemperature 3.201 3.399 V range η Efficiency V =12V,I =500mA 86% IN LOAD (1) Allroomtemperaturelimitsare100%productiontested.Alllimitsattemperatureextremesareensuredthroughcorrelationusing standardStatisticalQualityControl(SQC)methods.AlllimitsareusedtocalculateAverageOutgoingQualityLevel(AOQL). (2) Typicalnumbersareat25°Candrepresentthemostlikelynorm. (3) Externalcomponentssuchasthecatchdiode,inductor,inputandoutputcapacitors,andvoltageprogrammingresistorscanaffect switchingregulatorperformance.WhentheLM2671isusedasshowninFigure15andFigure21testcircuits,systemperformanceisas specifiedbythesystemparameterssectionoftheElectricalCharacteristics. 7.6 Electrical Characteristics – 5 V SpecificationsareforT =25°C(unlessotherwisenoted). J PARAMETER TESTCONDITIONS MIN(1) TYP(2) MAX(1) UNIT SYSTEMPARAMETERS(3) T =25°C 4.925 5 5.075 J V =8Vto40V, ILIONAD=20mAto500mA Overfulloperatingtemperature 4.85 5.15 V range V Outputvoltage OUT T =25°C 4.925 5 5.075 J V =6.5Vto40V, ILIONAD=20mAto250mA Overfulloperatingtemperature 4.85 5.15 V range η Efficiency V =12V,I =500mA 90% IN LOAD (1) Allroomtemperaturelimitsare100%productiontested.Alllimitsattemperatureextremesareensuredthroughcorrelationusing standardStatisticalQualityControl(SQC)methods.AlllimitsareusedtocalculateAverageOutgoingQualityLevel(AOQL). (2) Typicalnumbersareat25°Candrepresentthemostlikelynorm. (3) Externalcomponentssuchasthecatchdiode,inductor,inputandoutputcapacitors,andvoltageprogrammingresistorscanaffect switchingregulatorperformance.WhentheLM2671isusedasshowninFigure15andFigure21testcircuits,systemperformanceisas specifiedbythesystemparameterssectionoftheElectricalCharacteristics. 7.7 Electrical Characteristics – 12 V SpecificationsareforT =25°C(unlessotherwisenoted). J PARAMETER TESTCONDITIONS MIN(1) TYP(2) MAX(1) UNIT SYSTEMPARAMETERS(3) T =25°C 11.82 12 12.18 J V =15Vto40V, VOUT Outputvoltage ILIONAD=20mAto500mA Overfulloperating 11.64 12.36 V temperaturerange η Efficiency V =24V,I =500mA 94% IN LOAD (1) Allroomtemperaturelimitsare100%productiontested.Alllimitsattemperatureextremesareensuredthroughcorrelationusing standardStatisticalQualityControl(SQC)methods.AlllimitsareusedtocalculateAverageOutgoingQualityLevel(AOQL). (2) Typicalnumbersareat25°Candrepresentthemostlikelynorm. (3) Externalcomponentssuchasthecatchdiode,inductor,inputandoutputcapacitors,andvoltageprogrammingresistorscanaffect switchingregulatorperformance.WhentheLM2671isusedasshowninFigure15andFigure21testcircuits,systemperformanceisas specifiedbythesystemparameterssectionoftheElectricalCharacteristics. Copyright©1998–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 5 ProductFolderLinks:LM2671

LM2671 SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 www.ti.com 7.8 Electrical Characteristics – Adjustable SpecificationsareforT =25°C(unlessotherwisenoted). J PARAMETER TESTCONDITIONS MIN(1) TYP(2) MAX(1) UNIT SYSTEMPARAMETERS(3) VIN=8Vto40V, TJ=25°C 1.192 1.21 1.228 ILOAD=20mAto500mA Overfulloperating V Feedback VOUTprogrammedfor5V temperaturerange 1.174 1.246 V FB voltage VIN=6.5Vto40V, TJ=25°C 1.192 1.21 1.228 ILOAD=20mAto250mA Overfulloperating V VOUTprogrammedfor5V temperaturerange 1.174 1.246 η Efficiency V =12V,I =500mA 90% IN LOAD (1) Allroomtemperaturelimitsare100%productiontested.Alllimitsattemperatureextremesareensuredthroughcorrelationusing standardStatisticalQualityControl(SQC)methods.AlllimitsareusedtocalculateAverageOutgoingQualityLevel(AOQL). (2) Typicalnumbersareat25°Candrepresentthemostlikelynorm. (3) Externalcomponentssuchasthecatchdiode,inductor,inputandoutputcapacitors,andvoltageprogrammingresistorscanaffect switchingregulatorperformance.WhentheLM2671isusedasshowninFigure15andFigure21testcircuits,systemperformanceisas specifiedbythesystemparameterssectionoftheElectricalCharacteristics. 7.9 Electrical Characteristics – All Output Voltage Versions SpecificationsareforT =25°C,V =12Vforthe3.3-V,5-V,andAdjustableversionsandV =24Vforthe12-Vversion, J IN IN andI =100mA(unlessotherwisenoted). LOAD PARAMETERS TESTCONDITIONS MIN TYP MAX UNIT DEVICEPARAMETERS VFEEDBACK=8V 2.5 3.6 for3.3-V,5-V,andadjustableversions IQ Quiescentcurrent mA VFEEDBACK=15V 2.5 for12-Vversions TJ=25°C 50 100 ISTBY Standbyquiescentcurrent ON/OFFpin=0V Overfulloperatingtemperature μA 150 range TJ=25°C 0.62 0.8 1.2 ICL Currentlimit A Overfulloperatingtemperaturerange 0.575 1.25 VIN=40V,ON/OFFpin=0V 1 25 μA IL Outputleakagecurrent VSWITCH=0V VSWITCH=−1V,ON/OFFpin=0V 6 15 mA TJ=25°C 0.25 0.4 RDS(ON) SwitchON-resistance ISWITCH=500mA Overfulloperatingtemperature Ω 0.6 range TJ=25°C 260 fO Oscillatorfrequency Measuredatswitchpin Overfulloperatingtemperature kHz 225 275 range Maximumdutycycle 95% D Minimumdutycycle 0% IBIAS Feedbackbiascurrent VFEEDBACK=1.3V(adjustableversiononly) 85 nA TJ=25°C 1.4 VS/D ON/OFFpinvoltagethresholds V Overfulloperatingtemperaturerange 0.8 2 TJ=25°C 20 IS/D ON/OFFpincurrent ON/OFFpin=0V Overfulloperatingtemperature μA 7 37 range FSYNC Synchronizationfrequency VSYNC=3.5V,50%dutycycle 400 kHz VSYNC Synchronizationthresholdvoltage 1.4 V TJ=25°C 0.63 VSS Soft-startvoltage V Overfulloperatingtemperaturerange 0.53 0.73 TJ=25°C 4.5 ISS Soft-startcurrent μA Overfulloperatingtemperaturerange 1.5 6.9 6 SubmitDocumentationFeedback Copyright©1998–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2671

LM2671 www.ti.com SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 7.10 Typical Characteristics Figure1.NormalizedOutputVoltage Figure2.LineRegulation Figure3.Efficiency Figure4.Drain-to-SourceResistance Figure5.SwitchCurrentLimit Figure6.OperatingQuiescentCurrent Copyright©1998–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 7 ProductFolderLinks:LM2671

LM2671 SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 www.ti.com Typical Characteristics (continued) Figure7.StandbyQuiescentCurrent Figure8.ON/OFFThresholdVoltage Figure9.ON/OFFPinCurrent(Sourcing) Figure10.SwitchingFrequency Figure11.FeedbackPinBiasCurrent Figure12.PeakSwitchCurrent 8 SubmitDocumentationFeedback Copyright©1998–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2671

LM2671 www.ti.com SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 Typical Characteristics (continued) Figure13.DropoutVoltage–3.3-VOption Figure14.DropoutVoltage–5-VOption Copyright©1998–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 9 ProductFolderLinks:LM2671

LM2671 SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 www.ti.com 8 Detailed Description 8.1 Overview The LM2671 provides all of the active functions required for a step-down (buck) switching regulator. The internal power switch is a DMOS power MOSFET to provide power supply designs with high current capability, up to 0.5A,andhighlyefficientoperation. The LM2671 is part of the SIMPLE SWITCHER® family of power converters. A complete design uses a minimum number of external components, which have been predetermined from a variety of manufacturers. Using either this data sheet or TI's WEBENCH® design tool, a complete switching power supply can be designed quickly. Also, see LM2670 SIMPLE SWITCHER® High Efficiency 3A Step-Down Voltage Regulator with Sync for additionalapplicationsinformation. 8.2 Functional Block Diagram 8.3 Feature Description 8.3.1 SwitchOutput ThisistheoutputofapowerMOSFETswitchconnecteddirectlytotheinputvoltage.Theswitchprovidesenergy to an inductor, an output capacitor and the load circuitry under control of an internal pulse-width-modulator (PWM). The PWM controller is internally clocked by a fixed 260-kHz oscillator. In a standard step-down application the duty cycle (Time ON/Time OFF) of the power switch is proportional to the ratio of the power supplyoutputvoltagetotheinputvoltage.ThevoltageontheV pincyclesbetweenV (switchON)andbelow SW IN groundbythevoltagedropoftheexternalSchottkydiode(switchOFF). 10 SubmitDocumentationFeedback Copyright©1998–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2671

LM2671 www.ti.com SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 Feature Description (continued) 8.3.2 Input The input voltage for the power supply is connected to the V pin. In addition to providing energy to the load the IN input voltage also provides bias for the internal circuitry of the LM2671. For ensured performance the input voltage must be in the range of 6.5 V to 40 V. For best performance of the power supply the V pin must always IN bebypassedwithaninputcapacitorplacedclosetothispinandGND. 8.3.3 CBoost AcapacitormustbeconnectedfromtheC pintotheV pin.Thiscapacitorbooststhegatedrivetotheinternal B SW MOSFET above V to fully turn it ON. This minimizes conduction losses in the power switch to maintain high IN efficiency.TherecommendedvalueforCBoostis0.01 μF. 8.3.4 Ground This is the ground reference connection for all components in the power supply. In fast-switching, high-current applications such as those implemented with the LM2671, TI recommends that a broad ground plane be used to minimizesignalcouplingthroughoutthecircuit. 8.3.5 Sync This input allows control of the switching clock frequency. If left open-circuited the regulator is switched at the internal oscillator frequency, typically 260 kHz. An external clock can be used to force the switching frequency and thereby control the output ripple frequency of the regulator. This capability provides for consistent filtering of theoutputripplefromsystemtosystemaswellasprecisefrequencyspectrumpositioningoftheripplefrequency which is often desired in communications and radio applications. This external frequency must be greater than the LM2671 internal oscillator frequency, which could be as high as 275 kHz, to prevent an erroneous reset of the internal ramp oscillator and PWM control of the power switch. The ramp oscillator is reset on the positive going edge of the sync input signal. TI recommends that the external TTL or CMOS compatible clock (between 0 V and a level greater than 3 V) be ac coupled to the SYNC pin through a 100-pF capacitor and a 1-kΩ resistor toground. When the SYNC function is used, current limit frequency foldback is not active. Therefore, the device may not be fullyprotectedagainstextremeoutputshort-circuitconditions. 8.3.6 Feedback This is the input to a two-stage high gain amplifier, which drives the PWM controller. Connect the FB pin directly to the output for proper regulation. For the fixed output devices (3.3-V, 5-V and 12-V outputs), a direct wire connection to the output is all that is required as internal gain setting resistors are provided inside the LM2671. For the adjustable output version two external resistors are required to set the DC output voltage. For stable operationofthepowersupplyitisimportanttopreventcouplingofanyinductorfluxtothefeedbackinput. 8.3.7 ON/OFF This input provides an electrical ON/OFF control of the power supply. Connecting this pin to ground or to any voltage less than 0.8 V is completely turn OFF the regulator. The current drain from the input supply when OFF is only 50 μA. The ON/OFF input has an internal pullup current source of approximately 20 μA and a protection clamp Zener diode of 7 V to ground. When electrically driving the ON/OFF pin the high voltage level for the ON condition must not exceed the 6 V absolute maximum limit. When ON/OFF control is not required this pin must beleftopen. 8.4 Device Functional Modes 8.4.1 ShutdownMode The ON/OFF pin provides electrical ON and OFF control for the LM2671. When the voltage of this pin is lower than1.4V,thedeviceentersshutdownmode.Thetypicalstandbycurrentinthismodeis50 μA. Copyright©1998–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 11 ProductFolderLinks:LM2671

LM2671 SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 www.ti.com Device Functional Modes (continued) 8.4.2 ActiveMode WhenthevoltageoftheON/OFF pinishigherthan1.4V,thedevicestartsswitchingandtheoutputvoltagerises untilitreachesanormalregulationvoltage. 12 SubmitDocumentationFeedback Copyright©1998–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2671

LM2671 www.ti.com SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 9 Application and Implementation NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validateandtesttheirdesignimplementationtoconfirmsystemfunctionality. 9.1 Application Information The LM2671 is a step-down DC-DC regulator. The device is typically used to convert a higher DC voltage to a lower DC voltage with a maximum output current of 0.5 A. The following design procedure can be used to select components for the LM2671. Alternately, the WEBENCH® software may be used to generate complete designs. When generating a design, the WEBENCH software uses iterative design procedure and accesses comprehensivedatabasesofcomponents.Seeti.comformoredetails. When the output voltage is greater than approximately 6 V, and the duty cycle at minimum input voltage is greater than approximately 50%, the designer must exercise caution in selection of the output filter components. When an application designed to these specific operating conditions is subjected to a current limit fault condition, it may be possible to observe a large hysteresis in the current limit. This can affect the output voltage of the deviceuntiltheloadcurrentisreducedsufficientlytoallowthecurrentlimitprotectioncircuittoresetitself. Undercurrentlimitingconditions,theLM267xisdesignedtorespondinthefollowingmanner: 1. At the moment when the inductor current reaches the current limit threshold, the ON-pulse is immediately terminated.Thishappensforanyapplicationcondition. 2. However, the current limit block is also designed to momentarily reduce the duty cycle to below 50% to avoid subharmonicoscillations,whichcouldcausetheinductortosaturate. 3. Therefore, once the inductor current falls below the current limit threshold, there is a small relaxation time duringwhichthedutycycleprogressivelyrisesbackabove50%tothevaluerequiredtoachieveregulation. If the output capacitance is sufficiently large, it might be possible that as the output tries to recover, the output capacitor charging current is large enough to repeatedly re-trigger the current limit circuit before the output has fully settled. This condition is exacerbated with higher output voltage settings because the energy requirement of the output capacitor varies as the square of the output voltage (½ CV2), thus requiring an increased charging current. A simple test to determine if this condition might exist for a suspect application is to apply a short circuit across the output of the converter, and then remove the shorted output condition. In an application with properly selected external components, the output recovers smoothly. Practical values of external components that have beenexperimentallyfoundtoworkwellunderthesespecificoperatingconditionsareC =47µF,L=22 µH. OUT NOTE Even with these components, for a device’s current limit of ICLIM, the maximum load current under which the possibility of the large current limit hysteresis can be minimized is ICLIM/2. For example, if the input is 24 V and the set output voltage is 18 V, then for a desired maximum current of 1.5 A, thecurrentlimitofthechosenswitchermustbeconfirmedtobeatleast3A.Underextremeovercurrentorshort- circuit conditions, the LM267X employs frequency foldback in addition to the current limit. If the cycle-by-cycle inductor current increases above the current limit threshold (due to short circuit or inductor saturation for example) the switching frequency is automatically reduced to protect the IC. Frequency below 100 kHz is typical foranextremeshort-circuitcondition. Copyright©1998–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 13 ProductFolderLinks:LM2671

LM2671 SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 www.ti.com 9.2 Typical Applications 9.2.1 FixedOutputVoltageVersion C =22-μF,50-VTantalum,Sprague199DSeries IN C =47-μF,25-VTantalum,Sprague595DSeries OUT D1=3.3-A,50-VSchottkyRectifier,IR30WQ05F L1=68-μHSumida#RCR110D-680L C =0.01-μF,50-Vceramic B Figure15. TypicalApplicationforFixedOutputVoltageVersions 9.2.1.1 DesignRequirements Table1liststhedesignparametersforthisexample. Table1.DesignParameters PARAMETER VALUE Regulatedoutputvoltage(3.3V,5V,or12V),V 5V OUT MaximumDCinputvoltage,V (max) 12V IN Maximumloadcurrent,I (max) 500mA LOAD 9.2.1.2 DetailedDesignProcedure 9.2.1.2.1 InductorSelection(L1) 1. Select the correct inductor value selection guide from Figure 17 and Figure 18 or Figure 19 (output voltages of 3.3 V, 5 V, or 12 V respectively). For all other voltages, see the design procedure for the adjustable version.Usetheinductorselectionguideforthe5-VversionshowninFigure18. 2. From the inductor value selection guide, identify the inductance region intersected by the maximum input voltage line and the maximum load current line. Each region is identified by an inductance value and an inductor code (LXX). From the inductor value selection guide shown in Figure 18, the inductance region intersectedbythe12-Vhorizontallineandthe500-mAverticallineis47 μH,andtheinductorcodeisL13. 3. Select an appropriate inductor from the four manufacturer's part numbers listed in Table 2. Each manufacturer makes a different style of inductor to allow flexibility in meeting various design requirements. Seethefollowingforsomeofthedifferentiatingcharacteristicsofeachmanufacturer'sinductors: – Schottky: ferrite EP core inductors; these have very low leakage magnetic fields to reduce electro- magneticinterference(EMI)andarethelowestpowerlossinductors – Renco: ferrite stick core inductors; benefits are typically lowest cost inductors and can withstand E•T and transient peak currents above rated value. Be aware that these inductors have an external magnetic field whichmaygeneratemoreEMIthanothertypesofinductors. – Pulse: powered iron toroid core inductors; these can also be low cost and can withstand larger than normalE•Tandtransientpeakcurrents.ToroidinductorshavelowEMI. – Coilcraft: ferrite drum core inductors; these are the smallest physical size inductors, available only as SMTcomponents.BeawarethattheseinductorsalsogenerateEMI—butlessthanstickinductors. Completespecificationsfortheseinductorsareavailablefromtherespectivemanufacturers. 14 SubmitDocumentationFeedback Copyright©1998–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2671

LM2671 www.ti.com SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 The inductance value required is 47 μH. From the table in Table 2, go to the L13 line and choose an inductor part number from any of the four manufacturers shown. In most instances, both through hole and surface mount inductorsareavailable. Table2.InductorManufacturers' PartNumbers IND. SCHOTTKY RENCO PULSEENGINEERING COILCRAFT INDUCTANCE CURRENT DREESFG.. (μH) (A) THHROOLUEGH SMUROFUANCTE THROUGHHOLE SMUROFUANCTE THHROOLUEGH SMUROFUANCTE SMUROFUANCTE L2 150 0.21 67143920 67144290 RL-5470-4 RL1500-150 PE-53802 PE-53802-S DO1608-154 L3 100 0.26 67143930 67144300 RL-5470-5 RL1500-100 PE-53803 PE-53803-S DO1608-104 L4 68 0.32 67143940 67144310 RL-1284-68-43 RL1500-68 PE-53804 PE-53804-S DO1608-683 L5 47 0.37 67148310 67148420 RL-1284-47-43 RL1500-47 PE-53805 PE-53805-S DO1608-473 L6 33 0.44 67148320 67148430 RL-1284-33-43 RL1500-33 PE-53806 PE-53806-S DO1608-333 L7 22 0.52 67148330 67148440 RL-1284-22-43 RL1500-22 PE-53807 PE-53807-S DO1608-223 L9 220 0.32 67143960 67144330 RL-5470-3 RL1500-220 PE-53809 PE-53809-S DO3308-224 L10 150 0.39 67143970 67144340 RL-5470-4 RL1500-150 PE-53810 PE-53810-S DO3308-154 L11 100 0.48 67143980 67144350 RL-5470-5 RL1500-100 PE-53811 PE-53811-S DO3308-104 L12 68 0.58 67143990 67144360 RL-5470-6 RL1500-68 PE-53812 PE-53812-S DO3308-683 L13 47 0.7 67144000 67144380 RL-5470-7 RL1500-47 PE-53813 PE-53813-S DO3308-473 L14 33 0.83 67148340 67148450 RL-1284-33-43 RL1500-33 PE-53814 PE-53814-S DO3308-333 L15 22 0.99 67148350 67148460 RL-1284-22-43 RL1500-22 PE-53815 PE-53815-S DO3308-223 L18 220 0.55 67144040 67144420 RL-5471-2 RL1500-220 PE-53818 PE-53818-S DO3316-224 L19 150 0.66 67144050 67144430 RL-5471-3 RL1500-150 PE-53819 PE-53819-S DO3316-154 L20 100 0.82 67144060 67144440 RL-5471-4 RL1500-100 PE-53820 PE-53820-S DO3316-104 L21 68 0.99 67144070 67144450 RL-5471-5 RL1500-68 PE-53821 PE-53821-S DO3316-683 9.2.1.2.2 OutputCapacitorSelection(C ) OUT Select an output capacitor from the output capacitor table in Table 9. Using the output voltage and the inductance value found in the inductor selection guide, step 1, locate the appropriate capacitor value and voltage rating. Use the 5-V section in the output capacitor table in Table 9. Choose a capacitor value and voltage rating from the line that contains the inductance value of 47 μH. The capacitance and voltage rating values corresponding to the47-μHinductorare: • Surfacemount: – 68-μF,10-V Sprague594Dseries – 100-μF,10-V AVXTPSseries • Throughhole: – 68-μF,10-V SanyoOS-CONSAseries – 150-μF,35-V SanyoMV-GXseries – 150-μF,35-V NichiconPLseries – 150-μF,35-V PanasonicHFQseries The capacitor list contains through-hole electrolytic capacitors from four different capacitor manufacturers and surface mount tantalum capacitors from two different capacitor manufacturers. TI recommends that both the manufacturersandthemanufacturer'sseriesthatarelistedinthetablebeused. Copyright©1998–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 15 ProductFolderLinks:LM2671

LM2671 SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 www.ti.com Table3.OutputCapacitorTable OUTPUTCAPACITOR OUTPUT SURFACEMOUNT THROUGHHOLE INDUCTANCE VOLTAGE (μH) SPRAGUE AVXTPS NICHICON PANASONIC (V) SANYOOS-CON SANYOMV-GX 594DSERIES SERIES PLSERIES HFQSERIES SASERIES(μF/V) SERIES(μF/V) (μF/V) (μF/V) (μF/V) (μF/V) 22 120/6.3 100/10 100/10 330/35 330/35 330/35 33 120/6.3 100/10 68/10 220/35 220/35 220/35 47 68/10 100/10 68/10 150/35 150/35 150/35 3.3 68 120/6.3 100/10 100/10 120/35 120/35 120/35 100 120/6.3 100/10 100/10 120/35 120/35 120/35 150 120/6.3 100/10 100/10 120/35 120/35 120/35 22 100/16 100/10 100/10 330/35 330/35 330/35 33 68/10 10010 68/10 220/35 220/35 220/35 47 68/10 100/10 68/10 150/35 150/35 150/35 5 68 100/16 100/10 100/10 120/35 120/35 120/35 100 100/16 100/10 100/10 120/35 120/35 120/35 150 100/16 100/10 100/10 120/35 120/35 120/35 22 120/20 (2×)68/20 68/20 330/35 330/35 330/35 33 68/25 68/20 68/20 220/35 220/35 220/35 47 47/20 68/20 47/20 150/35 150/35 150/35 12 68 47/20 68/20 47/20 120/35 120/35 120/35 100 47/20 68/20 47/20 120/35 120/35 120/35 150 47/20 68/20 47/20 120/35 120/35 120/35 220 47/20 68/20 47/20 120/35 120/35 120/35 9.2.1.2.3 CatchDiodeSelection(D1) 1. In normal operation, the average current of the catch diode is the load current times the catch diode duty cycle,1-D(Distheswitchdutycycle,whichisapproximatelytheoutputvoltagedividedbytheinputvoltage). The largest value of the catch diode average current occurs at the maximum load current and maximum input voltage (minimum D). For normal operation, the catch diode current rating must be at least 1.3 times greater than its maximum average current. However, if the power supply design must withstand a continuous output short, the diode must have a current rating equal to the maximum current limit of the LM2671. The most stressful condition for this diode is a shorted output condition (refer to Table 4). In this example, a 1-A, 20-VSchottkydiodeprovidesthebestperformance.Ifthecircuitmustwithstandacontinuousshortedoutput, TIrecommendsahigher-currentSchottkydiode. 2. Thereversevoltageratingofthediodemustbeatleast1.25timesthemaximuminputvoltage. 3. Because of their fast switching speed and low forward voltage drop, Schottky diodes provide the best performance and efficiency. This Schottky diode must be placed close to the LM2671 using short leads and shortprinted-circuittraces. 16 SubmitDocumentationFeedback Copyright©1998–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2671

LM2671 www.ti.com SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 Table4.SchottkyDiodeSelectionTable 1-ADIODES 3-ADIODES V R SURFACEMOUNT THROUGHHOLE SURFACEMOUNT THROUGHHOLE SK12 1N5817 SK32 1N5820 20V B120 SR102 — SR302 SK13 1N5818 SK33 1N5821 30V B130 11DQ03 30WQ03F 31DQ03 MBRS130 SR103 — — SK14 1N5819 SK34 1N5822 B140 11DQ04 30BQ040 MBR340 MBRS140 SR104 30WQ04F 31DQ04 40V 10BQ040 — MBRS340 SR304 10MQ040 — MBRD340 — 15MQ040 — — — SK15 MBR150 SK35 MBR350 50V B150 11DQ05 30WQ05F 31DQ05 10BQ050 SR105 — SR305 9.2.1.2.4 InputCapacitor(C ) IN A low ESR aluminum or tantalum bypass capacitor is required between the input pin and ground to prevent large voltagetransientsfromappearingattheinput.ThiscapacitormustbeplacedclosetotheICusingshortleads.In addition,theRMScurrentratingoftheinputcapacitormustbeselectedtobeatleast ½ theDCloadcurrent.The capacitor manufacturer data sheet must be checked to assure that this current rating is not exceeded. The curves shown in Figure 16 show typical RMS current ratings for several different aluminum electrolytic capacitor values. A parallel connection of two or more capacitors may be required to increase the total minimum RMS currentratingtosuittheapplicationrequirements. For an aluminum electrolytic capacitor, the voltage rating must be at least 1.25 times the maximum input voltage. Caution must be exercised if solid tantalum capacitors are used. The tantalum capacitor voltage rating must be twice the maximum input voltage. Table 5 and Table 6 show the recommended application voltage for AVX TPS and Sprague 594D tantalum capacitors. TI also recommends that they be surge current tested by the manufacturer. The TPS series available from AVX, and the 593D and 594D series from Sprague are all surge current tested. Another approach to minimize the surge current stresses on the input capacitor is to add a small inductorinserieswiththeinputsupplyline. Table5.AVXTPS RECOMMENDED VOLTAGE APPLICATIONVOLTAGE RATING 85°CRATING 3.3 6.3 5 10 10 20 12 25 15 35 Copyright©1998–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 17 ProductFolderLinks:LM2671

LM2671 SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 www.ti.com Table6.Sprague594D RECOMMENDED VOLTAGE APPLICATIONVOLTAGE RATING 85°CRATING 2.5 4 3.3 6.3 5 10 8 16 12 20 18 25 24 35 29 50 Use caution when using ceramic capacitors for input bypassing, because it may cause severe ringing at the V IN pin. The important parameters for the input capacitor are the input voltage rating and the RMS current rating. With a maximum input voltage of 12 V, an aluminum electrolytic capacitor with a voltage rating greater than 15 V (1.25× V )isrequired.Thenexthighercapacitorvoltageratingis16V. IN The RMS current rating requirement for the input capacitor in a buck regulator is approximately ½ the DC load current. In this example, with a 500-mA load, a capacitor with a RMS current rating of at least 250 mA is required. The curves shown in Figure 16 can be used to select an appropriate input capacitor. From the curves, locatethe16-VlineandnotewhichcapacitorvalueshaveRMScurrentratingsgreaterthan250mA. Figure16. RMSCurrentRatingsforLowESRElectrolyticCapacitors(Typical) Forathrough-holedesign,a100-μF,16-Velectrolyticcapacitor(PanasonicHFQseries,NichiconPL,SanyoMV- GX series or equivalent) would be adequate. Other types or other manufacturers' capacitors can be used provided the RMS ripple current ratings are adequate. Additionally, for a complete surface mount design, electrolytic capacitors such as the Sanyo CV-C or CV-BS and the Nichicon WF or UR and the NIC Components NACZseriescouldbeconsidered. For surface mount designs, solid tantalum capacitors can be used, but caution must be exercised with regard to the capacitor surge current rating and voltage rating. In this example, checking the Sprague 594D series datasheet,aSprague594D15-μF,25-Vcapacitorisadequate. 9.2.1.2.5 BoostCapacitor(C ) B This capacitor develops the necessary voltage to turn the switch gate on fully. All applications must use a 0.01-μF,50-Vceramiccapacitor.Forthisapplication,andallapplications,usea0.01-μF,50-Vceramiccapacitor. 18 SubmitDocumentationFeedback Copyright©1998–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2671

LM2671 www.ti.com SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 9.2.1.2.6 Soft-StartCapacitor(C )–Optional SS This capacitor controls the rate at which the device starts up. The formula for the soft-start capacitor C is SS Equation1. where • I =soft-startcurrent(4.5μAtypical) SS • t =soft-starttime(selected) SS • V =soft-startthresholdvoltage(0.63Vtypical) SSTH • V =outputvoltage(selected) OUT • V =schottkydiodevoltagedrop(0.4Vtypical) SCHOTTKY • V =inputvoltage(selected) (1) IN Forthisapplication,selectingastart-uptimeof10msandusingEquation2 forC . SS (2) Ifthisfeatureisnotdesired,leavethispinopen.With certain soft-start capacitor values and operating conditions, the LM2671 can exhibit an overshoot on the output voltage during turnon. Especially when starting up into no load or low load, the soft-start function may not be effective in preventing a larger voltage overshoot on the output. With larger loads or lower input voltages during start-up this effect is minimized. In particular, avoid using soft-startcapacitorsbetween0.033µFand1 µF. 9.2.1.2.7 FrequencySynchronization(optional) The LM2671 (oscillator) can be synchronized to run with an external oscillator, using the sync pin (pin 3). By doing so, the LM2671 can be operated at higher frequencies than the standard frequency of 260 kHz. This allowsforareductioninthesizeoftheinductorandoutputcapacitor. Asshowninthedrawingbelow,asignalappliedtoaRCfilteratthesyncpincausesthedevicetosynchronizeto the frequency of that signal. For a signal with a peak-to-peak amplitude of 3 V or greater, a 1-kΩ resistor and a 100-pFcapacitoraresuitablevalues. Forallapplications,usea1-kΩ resistoranda100-pFcapacitorfortheRCfilter. Copyright©1998–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 19 ProductFolderLinks:LM2671

LM2671 SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 www.ti.com 9.2.1.3 ApplicationCurves forcontinuousmodeoperation Figure17.LM2671-3.3 Figure18.LM2671-5 Figure19.LM2671-12 Figure20.LM2671-ADJ 9.2.2 AdjustableOutputVoltageVersion C =22-μF,50-VTantalum,Sprague199DSeries IN C =47-μF,25-VTantalum,Sprague595DSeries OUT D1=3.3-A,50-VSchottkyRectifier,IR30WQ05F L1=68-μHSumida#RCR110D-680L R1=1.5kΩ,1% C =0.01-μF,50-Vceramic B Figure21. TypicalApplicationforAdjustableOutputVoltageVersions 20 SubmitDocumentationFeedback Copyright©1998–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2671

LM2671 www.ti.com SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 9.2.2.1 DesignRequirements Table7liststhedesignparametersforthisexample. Table7.DesignParameters PARAMETER VALUE Regulatedoutputvoltage,V 20V OUT Maximuminputvoltage,V (max) 28V IN Maximumloadcurrent,I (max) 500mA LOAD Switchingfrequency,F Fixedatanominal260kHz 9.2.2.2 DetailedDesignProcedure 9.2.2.2.1 ProgrammingOutputVoltage SelectR andR ,asshowninFigure21. 1 2 Usethefollowingformulatoselecttheappropriateresistorvalues. where • V =1.21V (3) REF SelectR tobe1kΩ,1%.SolveforR . 1 2 (4) SelectavalueforR between240Ω and1.5kΩ.Thelowerresistorvaluesminimizenoisepickupinthesensitive 1 feedbackpin.Forthelowesttemperaturecoefficientandthebeststabilitywithtime,use1%metalfilmresistors. (5) R =1kΩ(16.53− 1)=15.53kΩ,closest1%valueis15.4kΩ. 2 R =15.4kΩ. 2 9.2.2.2.2 InductorSelection(L1) 1. CalculatetheinductorVolt•microsecondconstantE •T(V •μs)fromEquation6. where • V =internalswitchsaturationvoltage=0.25V SAT • V =diodeforwardvoltagedrop=0.5V (6) D CalculatetheinductorVolt•microsecondconstant(E •T)withEquation7. (7) 2. Use the E • T value from the previous formula and match it with the E • T number on the vertical axis of the inductorvalueselectionguideshowninFigure20. E•T=21.6(V•μs) (8) 3. Onthehorizontalaxis,selectthemaximumloadcurrentinEquation9. I (max)=500mA (9) LOAD 4. Identify the inductance region intersected by the E • T value and the maximum load current value. Each region is identified by an inductance value and an inductor code (LXX). From the inductor value selection guide shown in Figure 20, the inductance region intersected by the 21.6 (V • μs) horizontal line and the 500- mAverticallineis100μH,andtheinductorcodeisL20. 5. Select an appropriate inductor from the four manufacturer's part numbers listed in Table 2. For information Copyright©1998–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 21 ProductFolderLinks:LM2671

LM2671 SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 www.ti.com on the different types of inductors, see the inductor selection in the fixed output voltage design procedure. From the table in Table 2, locate line L20, and select an inductor part number from the list of manufacturers' partnumbers. 9.2.2.2.3 OutputCapacitorSelection(C ) OUT 1. Select an output capacitor from the capacitor code selection guide in Table 8. Using the inductance value found in the inductor selection guide, step 1, locate the appropriate capacitor code corresponding to the desired output voltage. Use the appropriate row of the capacitor code selection guide, in Table 8. For this example,usethe15-Vto20-Vrow.Thecapacitorcodecorrespondingtoaninductanceof100 μHisC20. 2. Select an appropriate capacitor value and voltage rating, using the capacitor code, from the output capacitor selection table in Table 9. There are two solid tantalum (surface mount) capacitor manufacturers and four electrolytic (through hole) capacitor manufacturers to choose from. TI recommends using the manufacturers andthemanufacturer'sseriesthatarelistedinthetable. From the output capacitor selection table in Table 9, choose a capacitor value (and voltage rating) that intersectsthecapacitorcode(s)selectedinsectionA,C20. ThecapacitanceandvoltageratingvaluescorrespondingtothecapacitorcodeC20are: – Surfacemount: – 33-μF,25-V Sprague594Dseries – 33-μF,25-V AVXTPSseries – Throughhole: – 33-μF,25-V SanyoOS-CONSCseries – 120-μF,35-V SanyoMV-GXseries – 120-μF,35-V NichiconPLseries – 120-μF,35-V PanasonicHFQseries Other manufacturers or other types of capacitors may also be used, provided the capacitor specifications (especially the 100-kHz ESR) closely match the characteristics of the capacitors listed in the output capacitor table.Seethecapacitormanufacturers'datasheetforthisinformation. Table8.CapacitorCodeSelectionGuide CASE OUTPUT INDUCTANCE(μH) STYLE (1) VOLTAGE(V) 22 33 47 68 100 150 220 SMandTH 1.21–2.5 — — — — C1 C2 C3 SMandTH 2.5–3.75 — — — C1 C2 C3 C3 SMandTH 3.75–5 — — C4 C5 C6 C6 C6 SMandTH 5–6.25 — C4 C7 C6 C6 C6 C6 SMandTH 6.25–7.5 C8 C4 C7 C6 C6 C6 C6 SMandTH 7.5–10 C9 C10 C11 C12 C13 C13 C13 SMandTH 10–12.5 C14 C11 C12 C12 C13 C13 C13 SMandTH 12.5–15 C15 C16 C17 C17 C17 C17 C17 SMandTH 15–20 C18 C19 C20 C20 C20 C20 C20 SMandTH 20–30 C21 C22 C22 C22 C22 C22 C22 TH 30–37 C23 C24 C24 C25 C25 C25 C25 (1) SM-SurfaceMount,TH-ThroughHole 22 SubmitDocumentationFeedback Copyright©1998–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2671

LM2671 www.ti.com SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 Table9.OutputCapacitorSelectionTable OUTPUTCAPACITOR CAP. SURFACEMOUNT THROUGHHOLE REF. DESG. SPRAGUE594D AVXTPSSERIES SANYOOS-CONSA SANYOMV-GX NICHICONPL PANASONICHFQ # SERIES(μF/V) (μF/V) SERIES(μF/V) SERIES(μF/V) SERIES(μF/V) SERIES(μF/V) C1 120/6.3 100/10 100/10 220/35 220/35 220/35 C2 120/6.3 100/10 100/10 150/35 150/35 150/35 C3 120/6.3 100/10 100/35 120/35 120/35 120/35 C4 68/10 100/10 68/10 220/35 220/35 220/35 C5 100/16 100/10 100/10 150/35 150/35 150/35 C6 100/16 100/10 100/10 120/35 120/35 120/35 C7 68/10 100/10 68/10 150/35 150/35 150/35 C8 100/16 100/10 100/10 330/35 330/35 330/35 C9 100/16 100/16 100/16 330/35 330/35 330/35 C10 100/16 100/16 68/16 220/35 220/35 220/35 C11 100/16 100/16 68/16 150/35 150/35 150/35 C12 100/16 100/16 68/16 120/35 120/35 120/35 C13 100/16 100/16 100/16 120/35 120/35 120/35 C14 100/16 100/16 100/16 220/35 220/35 220/35 C15 47/20 68/20 47/20 220/35 220/35 220/35 C16 47/20 68/20 47/20 150/35 150/35 150/35 C17 47/20 68/20 47/20 120/35 120/35 120/35 C18 68/25 (2×)33/25 47/25 (1) 220/35 220/35 220/35 C19 33/25 33/25 33/25 (1) 150/35 150/35 150/35 C20 33/25 33/25 33/25 (1) 120/35 120/35 120/35 C21 33/35 (2×)22/25 (2) 150/35 150/35 150/35 C22 33/35 22/35 (2) 120/35 120/35 120/35 C23 (2) (2) (2) 220/50 100/50 120/50 C24 (2) (2) (2) 150/50 100/50 120/50 C25 (2) (2) (2) 150/50 82/50 82/50 (1) TheSCseriesofOs-Concapacitors(othersareSAseries) (2) ThevoltageratingsofthesurfacemounttantalumchipandOs-Concapacitorsaretoolowtoworkatthesevoltages. 9.2.2.2.4 CatchDiodeSelection(D1) 1. In normal operation, the average current of the catch diode is the load current times the catch diode duty cycle, 1-D (D is the switch duty cycle, which is approximately V /V ). The largest value of the catch diode OUT IN average current occurs at the maximum input voltage (minimum D). For normal operation, the catch diode current rating must be at least 1.3 times greater than its maximum average current. However, if the power supply design must withstand a continuous output short, the diode must have a current rating greater than the maximum current limit of the LM2671. The most stressful condition for this diode is a shorted output condition. Refer to the table shown in Table 4. Schottky diodes provide the best performance, and in this example a 1- A, 40-V Schottky diode would be a good choice. If the circuit must withstand a continuous shorted output, a highercurrent(atleast1.2A)Schottkydiodeisrecommended. 2. Thereversevoltageratingofthediodemustbeatleast1.25timesthemaximuminputvoltage. 3. Because of their fast switching speed and low forward voltage drop, Schottky diodes provide the best performance and efficiency. The Schottky diode must be placed close to the LM2671 using short leads and shortprinted-circuittraces. Copyright©1998–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 23 ProductFolderLinks:LM2671

LM2671 SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 www.ti.com 9.2.2.2.5 InputCapacitor(C ) IN A low ESR aluminum or tantalum bypass capacitor is required between the input pin and ground to prevent large voltagetransientsfromappearingattheinput.ThiscapacitormustbeplacedclosetotheICusingshortleads.In addition,theRMScurrentratingoftheinputcapacitormustbeselectedtobeatleast ½ theDCloadcurrent.The capacitor manufacturer data sheet must be checked to assure that this current rating is not exceeded. The curves shown in Figure 16 show typical RMS current ratings for several different aluminum electrolytic capacitor values. A parallel connection of two or more capacitors may be required to increase the total minimum RMS currentratingtosuittheapplicationrequirements. For an aluminum electrolytic capacitor, the voltage rating must be at least 1.25 times the maximum input voltage. Caution must be exercised if solid tantalum capacitors are used. The tantalum capacitor voltage rating must be twice the maximum input voltage. The Table 10 and Table 11 show the recommended application voltage for AVX TPS and Sprague 594D tantalum capacitors. TI also recommends that they be surge current tested by the manufacturer. The TPS series available from AVX, and the 593D and 594D series from Sprague are all surge current tested. Another approach to minimize the surge current stresses on the input capacitor is to add a small inductorinserieswiththeinputsupplyline. Table10.AVXTPS RECOMMENDED VOLTAGE APPLICATIONVOLTAGE RATING 85°CRATING 3.3 6.3 5 10 10 20 12 25 15 35 Table11.Sprague594D RECOMMENDED VOLTAGE APPLICATIONVOLTAGE RATING 85°CRATING 2.5 4 3.3 6.3 5 10 8 16 12 20 18 25 24 35 29 50 Use caution when using ceramic capacitors for input bypassing, because it may cause severe ringing at the V IN pin. The important parameters for the input capacitor are the input voltage rating and the RMS current rating. With a maximum input voltage of 28 V, an aluminum electrolytic capacitor with a voltage rating of at least 35V(1.25× V )isrequired. IN The RMS current rating requirement for the input capacitor in a buck regulator is approximately ½ the DC load current. In this example, with a 500-mA load, a capacitor with a RMS current rating of at least 250 mA is required. The curves shown in Figure 22 can be used to select an appropriate input capacitor. From the curves, locatethe35-VlineandnotewhichcapacitorvalueshaveRMScurrentratingsgreaterthan250mA. 24 SubmitDocumentationFeedback Copyright©1998–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2671

LM2671 www.ti.com SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 Figure22. RMSCurrentRatingsforLowESRElectrolyticCapacitors(Typical) For a through-hole design, a 68-μF, 35-V electrolytic capacitor (Panasonic HFQ series, Nichicon PL, Sanyo MV- GX series or equivalent) would be adequate. Other types or other manufacturers' capacitors can be used provided the RMS ripple current ratings are adequate. Additionally, for a complete surface mount design, electrolytic capacitors such as the Sanyo CV-C or CV-BS and the Nichicon WF or UR and the NIC Components NACZseriescouldbeconsidered. For surface mount designs, solid tantalum capacitors can be used, but caution must be exercised with regard to the capacitor surge current rating and voltage rating. In this example, checking the Sprague 594D series data sheet,aSprague594D15-μF,50-Vcapacitorisadequate. 9.2.2.2.6 BoostCapacitor(C ) B This capacitor develops the necessary voltage to turn the switch gate on fully. All applications must use a 0.01-μF,50-Vceramiccapacitor.Forthisapplication,andallapplications,usea0.01-μF,50-Vceramiccapacitor. If the soft-start and frequency synchronization features are desired, look at steps 6 and 7 in Detailed Design Procedure. Copyright©1998–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 25 ProductFolderLinks:LM2671

LM2671 SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 www.ti.com 9.2.2.3 ApplicationCurves ContinuousModeSwitchingWaveforms,VIN=20V,VOUT=5V, DiscontinuousModeSwitchingWaveforms,VIN=20V, ILOAD=500mA,L=100μH,COUT=100μF,COUTESR=0.1Ω VOUT=5V,ILOAD=300mA,L=15μH,COUT=68μF(2×), A:VSWpinvoltage,10V/div. COUTESR=25mΩ B:Inductorcurrent,0.2A/div A:VSWpinvoltage,10V/div. C:Outputripplevoltage,50mV/divac-coupled B:Inductorcurrent,0.5A/div C:Outputripplevoltage,20mV/divac-coupled Figure23.HorizontalTimeBase:1μs/div Figure24.HorizontalTimeBase:1μs/div LoadTransientResponseforContinuousMode,VIN=20V, LoadTransientResponseforDiscontinuousMode,VIN=20V, VOUT=5V,L=100μH,COUT=100μF,COUTESR=0.1Ω VOUT=5V,L=47μH,COUT=68μF,COUTESR=50mΩ A:Outputvoltage,100mV/div,ac-coupled A:Outputvoltage,100mV/div,ac-coupled B:Loadcurrent:100-mAto500-mAloadpulse B:Loadcurrent:100-mAto400-mAloadpulse Figure25.HorizontalTimeBase:50μs/div Figure26.HorizontalTimeBase:200μs/div 10 Power Supply Recommendations The LM2671 is designed to operate from an input voltage supply up to 40 V. This input supply must be well regulatedandabletowithstandmaximuminputcurrentandmaintainastablevoltage. 26 SubmitDocumentationFeedback Copyright©1998–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2671

LM2671 www.ti.com SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 11 Layout 11.1 Layout Guidelines Layout is very important in switching regulator designs. Rapidly switching currents associated with wiring inductance can generate voltage transients which can cause problems. For minimal inductance and ground loops, the wires indicated by heavy lines (in Figure 15 and Figure 21) must be wide printed-circuit traces and mustbekeptasshortaspossible.Forbestresults,externalcomponentsmustbeplacedasclosetotheswitcher ICaspossibleusinggroundplaneconstructionorsinglepointgrounding. If open core inductors are used, take special care as to the location and positioning of this type of inductor. Allowingtheinductorfluxtointersectsensitivefeedback,ICgroundpath,andC wiringcancauseproblems. OUT When using the adjustable version, take special care as to the location of the feedback resistors and the associated wiring. Physically place both resistors near the IC, and route the wiring away from the inductor, especiallyanopencoretypeofinductor. 11.2 Layout Examples C =15-μF,25-VSolidTantalumSprague,594Dseries IN C =68-μF,10-VSolidTantalumSprague,594Dseries OUT D1=1-A,40-VSchottkyRectifier,surfacemount L1=47-μH,L13CoilcraftDO3308 C =0.01-μF,50-Vceramic B Figure27. TypicalSurfaceMountPCBLayout,FixedOutput(4xSize) C =15μF,50VSolidTantalumSprague,594Dseries IN C =33μF,25VSolidTantalumSprague,594Dseries OUT D1=1-A,40-VSchottkyRectifier,surfacemount L1=100-μH,L20CoilcraftDO3316 C =0.01-μF,50-Vceramic B R1=1kΩ,1% R2=UseformulainDetailedDesignProcedure Figure28. TypicalSurfaceMountPCBLayout,AdjustableOutput(4xSize) Copyright©1998–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 27 ProductFolderLinks:LM2671

LM2671 SNVS008L–SEPTEMBER1998–REVISEDJUNE2016 www.ti.com 12 Device and Documentation Support 12.1 Documentation Support 12.1.1 RelatedDocumentation Forrelateddocumentationseethefollowing: • AN-1187LeadlessLeadframPackage(LLP) • LM2670SIMPLESWITCHER®HighEfficiency3AStep-DownVoltageRegulatorwithSync 12.2 Receiving Notification of Documentation Updates To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper right corner, click on Alert me to register and receive a weekly digest of any product information that has changed.Forchangedetails,reviewtherevisionhistoryincludedinanyreviseddocument. 12.3 Community Resources The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. TIE2E™OnlineCommunity TI'sEngineer-to-Engineer(E2E)Community.Createdtofostercollaboration amongengineers.Ate2e.ti.com,youcanaskquestions,shareknowledge,exploreideasandhelp solveproblemswithfellowengineers. DesignSupport TI'sDesignSupport QuicklyfindhelpfulE2Eforumsalongwithdesignsupporttoolsand contactinformationfortechnicalsupport. 12.4 Trademarks E2EisatrademarkofTexasInstruments. SIMPLESWITCHER,WEBENCHareregisteredtrademarksofTexasInstruments. Allothertrademarksarethepropertyoftheirrespectiveowners. 12.5 Electrostatic Discharge Caution Thesedeviceshavelimitedbuilt-inESDprotection.Theleadsshouldbeshortedtogetherorthedeviceplacedinconductivefoam duringstorageorhandlingtopreventelectrostaticdamagetotheMOSgates. 12.6 Glossary SLYZ022—TIGlossary. Thisglossarylistsandexplainsterms,acronyms,anddefinitions. 13 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of thisdocument.Forbrowser-basedversionsofthisdatasheet,refertotheleft-handnavigation. 13.1 DAP (WSON Package) The die attach pad (DAP) can and must be connected to the PCB Ground plane. For CAD and assembly guidelinesrefertoAN-1187LeadlessLeadframPackage(LLP). 28 SubmitDocumentationFeedback Copyright©1998–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2671

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 PACKAGING INFORMATION Orderable Device Status Package Type Package Pins Package Eco Plan Lead/Ball Finish MSL Peak Temp Op Temp (°C) Device Marking Samples (1) Drawing Qty (2) (6) (3) (4/5) LM2671LD-ADJ NRND WSON NHN 16 1000 TBD Call TI Call TI -40 to 125 S0008B LM2671LD-ADJ/NOPB ACTIVE WSON NHN 16 1000 Green (RoHS SN Level-3-260C-168 HR -40 to 125 S0008B & no Sb/Br) LM2671M-12/NOPB ACTIVE SOIC D 8 95 Green (RoHS SN Level-1-260C-UNLIM -40 to 125 2671 & no Sb/Br) M-12 LM2671M-3.3/NOPB ACTIVE SOIC D 8 95 Green (RoHS SN Level-1-260C-UNLIM -40 to 125 2671 & no Sb/Br) M3.3 LM2671M-5.0 NRND SOIC D 8 95 TBD Call TI Call TI -40 to 125 2671 M5.0 LM2671M-5.0/NOPB ACTIVE SOIC D 8 95 Green (RoHS SN Level-1-260C-UNLIM -40 to 125 2671 & no Sb/Br) M5.0 LM2671M-ADJ NRND SOIC D 8 95 TBD Call TI Call TI -40 to 125 2671 MADJ LM2671M-ADJ/NOPB ACTIVE SOIC D 8 95 Green (RoHS SN Level-1-260C-UNLIM -40 to 125 2671 & no Sb/Br) MADJ LM2671MX-12/NOPB ACTIVE SOIC D 8 2500 Green (RoHS SN Level-1-260C-UNLIM -40 to 125 2671 & no Sb/Br) M-12 LM2671MX-3.3/NOPB ACTIVE SOIC D 8 2500 Green (RoHS SN Level-1-260C-UNLIM -40 to 125 2671 & no Sb/Br) M3.3 LM2671MX-5.0/NOPB ACTIVE SOIC D 8 2500 Green (RoHS SN Level-1-260C-UNLIM -40 to 125 2671 & no Sb/Br) M5.0 LM2671MX-ADJ/NOPB ACTIVE SOIC D 8 2500 Green (RoHS SN Level-1-260C-UNLIM -40 to 125 2671 & no Sb/Br) MADJ LM2671N-12/NOPB ACTIVE PDIP P 8 40 Green (RoHS Call TI | SN Level-1-NA-UNLIM -40 to 125 LM2671 & no Sb/Br) N-12 LM2671N-3.3/NOPB ACTIVE PDIP P 8 40 Green (RoHS Call TI | SN Level-1-NA-UNLIM -40 to 125 LM2671 & no Sb/Br) N-3.3 LM2671N-5.0/NOPB ACTIVE PDIP P 8 40 Green (RoHS SN Level-1-NA-UNLIM -40 to 125 LM2671 & no Sb/Br) N-5.0 LM2671N-ADJ/NOPB ACTIVE PDIP P 8 40 Green (RoHS SN Level-1-NA-UNLIM -40 to 125 LM2671 & no Sb/Br) N-ADJ (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. Addendum-Page 1

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 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) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based flame retardants must also meet the <=1000ppm threshold requirement. (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. 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. Addendum-Page 2

PACKAGE MATERIALS INFORMATION www.ti.com 29-Sep-2019 TAPE AND REEL INFORMATION *Alldimensionsarenominal Device Package Package Pins SPQ Reel Reel A0 B0 K0 P1 W Pin1 Type Drawing Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant (mm) W1(mm) LM2671LD-ADJ WSON NHN 16 1000 178.0 12.4 5.3 5.3 1.3 8.0 12.0 Q1 LM2671LD-ADJ/NOPB WSON NHN 16 1000 178.0 12.4 5.3 5.3 1.3 8.0 12.0 Q1 LM2671MX-12/NOPB SOIC D 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1 LM2671MX-3.3/NOPB SOIC D 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1 LM2671MX-5.0/NOPB SOIC D 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1 LM2671MX-ADJ/NOPB SOIC D 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1 PackMaterials-Page1

PACKAGE MATERIALS INFORMATION www.ti.com 29-Sep-2019 *Alldimensionsarenominal Device PackageType PackageDrawing Pins SPQ Length(mm) Width(mm) Height(mm) LM2671LD-ADJ WSON NHN 16 1000 210.0 185.0 35.0 LM2671LD-ADJ/NOPB WSON NHN 16 1000 210.0 185.0 35.0 LM2671MX-12/NOPB SOIC D 8 2500 367.0 367.0 35.0 LM2671MX-3.3/NOPB SOIC D 8 2500 367.0 367.0 35.0 LM2671MX-5.0/NOPB SOIC D 8 2500 367.0 367.0 35.0 LM2671MX-ADJ/NOPB SOIC D 8 2500 367.0 367.0 35.0 PackMaterials-Page2

MECHANICAL DATA NHN0016A LDA16A (REV A) www.ti.com

PACKAGE OUTLINE D0008A SOIC - 1.75 mm max height SCALE 2.800 SMALL OUTLINE INTEGRATED CIRCUIT C SEATING PLANE .228-.244 TYP [5.80-6.19] .004 [0.1] C A PIN 1 ID AREA 6X .050 [1.27] 8 1 2X .189-.197 [4.81-5.00] .150 NOTE 3 [3.81] 4X (0 -15 ) 4 5 8X .012-.020 B .150-.157 [0.31-0.51] .069 MAX [3.81-3.98] .010 [0.25] C A B [1.75] NOTE 4 .005-.010 TYP [0.13-0.25] 4X (0 -15 ) SEE DETAIL A .010 [0.25] .004-.010 0 - 8 [0.11-0.25] .016-.050 [0.41-1.27] DETAIL A (.041) TYPICAL [1.04] 4214825/C 02/2019 NOTES: 1. Linear dimensions are in inches [millimeters]. Dimensions in parenthesis are for reference only. Controlling dimensions are in inches. Dimensioning and tolerancing per ASME Y14.5M. 2. This drawing is subject to change without notice. 3. This dimension does not include mold flash, protrusions, or gate burrs. Mold flash, protrusions, or gate burrs shall not exceed .006 [0.15] per side. 4. This dimension does not include interlead flash. 5. Reference JEDEC registration MS-012, variation AA. www.ti.com

EXAMPLE BOARD LAYOUT D0008A SOIC - 1.75 mm max height SMALL OUTLINE INTEGRATED CIRCUIT 8X (.061 ) [1.55] SYMM SEE DETAILS 1 8 8X (.024) [0.6] SYMM (R.002 ) TYP [0.05] 5 4 6X (.050 ) [1.27] (.213) [5.4] LAND PATTERN EXAMPLE EXPOSED METAL SHOWN SCALE:8X SOLDER MASK SOLDER MASK METAL OPENING OPENING METAL UNDER SOLDER MASK EXPOSED METAL EXPOSED METAL .0028 MAX .0028 MIN [0.07] [0.07] ALL AROUND ALL AROUND NON SOLDER MASK SOLDER MASK DEFINED DEFINED SOLDER MASK DETAILS 4214825/C 02/2019 NOTES: (continued) 6. Publication IPC-7351 may have alternate designs. 7. Solder mask tolerances between and around signal pads can vary based on board fabrication site. www.ti.com

EXAMPLE STENCIL DESIGN D0008A SOIC - 1.75 mm max height SMALL OUTLINE INTEGRATED CIRCUIT 8X (.061 ) [1.55] SYMM 1 8 8X (.024) [0.6] SYMM (R.002 ) TYP [0.05] 5 4 6X (.050 ) [1.27] (.213) [5.4] SOLDER PASTE EXAMPLE BASED ON .005 INCH [0.125 MM] THICK STENCIL SCALE:8X 4214825/C 02/2019 NOTES: (continued) 8. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate design recommendations. 9. Board assembly site may have different recommendations for stencil design. www.ti.com

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IMPORTANTNOTICEANDDISCLAIMER TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS” AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS. These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable standards, and any other safety, security, or other requirements. These resources are subject to change without notice. TI grants you permission to use these resources only for development of an application that uses the TI products described in the resource. Other reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third party intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims, damages, costs, losses, and liabilities arising out of your use of these resources. TI’s products are provided subject to TI’s Terms of Sale (www.ti.com/legal/termsofsale.html) or other applicable terms available either on ti.com or provided in conjunction with such TI products. TI’s provision of these resources does not expand or otherwise alter TI’s applicable warranties or warranty disclaimers for TI products. Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2020, Texas Instruments Incorporated