LM2771 www.ti.com SNVS435A–MARCH2006–REVISEDMAY2013 LM2771 Low-Ripple 250mA Switched Capacitor Step-Down DC/DC Converter CheckforSamples:LM2771 FEATURES DESCRIPTION 1 • Low-NoiseFixedFrequencyOperation The LM2771 is a switched capacitor step-down 2 regulator that produces a 1.5V output without the use • 1.5VOutputVoltage of an inductor. It is capable of supplying loads up to • Li-Ion(3.6V)to1.5Vwith81%Efficiency 250mA. The LM2771 operates with an input voltage • 1.7%OutputVoltageAccuracy from 2.7V to 5.5V, and requires only 3 low-cost ceramiccapacitors. • VeryLowOutputRipple:8mV@250mA • OutputCurrentsupto250mA The LM2771 uses a regulated 0.5x charge pump to give power conversion efficiencies nearly twice as • 2.7Vto5.5VInputRange high as an LDO. Pre-regulated 1.1MHz fixed- • ShutdownDisconnectsLoadfromVIN frequency switching results in very low ripple and • 1.1MHzSwitchingFrequency noise on both the input and the output. When output currents are low (<30mA typ.), the part automatically • NoInductors…SmallSolutionSize switches to a low-ripple PFM regulation mode to • CurrentLimitandThermalProtection maintain high efficiency over the entire load range. At • WSON-10Package(3mm×3mm× 0.8mm) input voltages below 3.5V (Typ), the charge pump goes into pass mode, with efficiencies similar to an APPLICATIONS LDO. • DSP,Memory,andMicroprocessorPower Supplies • MobilePhonesandPagers • PortableElectronicDevices Typical Application Circuit VOUT: 1.5V VIN = 3.0V to 5.5V IOUT up to 250 mA VIN VOUT CIN COUT 1 PF LM2771 4.7PF GND C1+ Cfly EN 1 PF C1- Capacitors: 1 PF - TDK C1005X5R1A105K 4.7 PF - TDK C1608X5R0J475K or equivalent Figure1. Figure2.LM2771Efficiencyvs. Low-DropoutLinearRegulator(LDO)Efficiency 1 Pleasebeawarethatanimportantnoticeconcerningavailability,standardwarranty,anduseincriticalapplicationsof TexasInstrumentssemiconductorproductsanddisclaimerstheretoappearsattheendofthisdatasheet. Alltrademarksarethepropertyoftheirrespectiveowners. 2 PRODUCTIONDATAinformationiscurrentasofpublicationdate. Copyright©2006–2013,TexasInstrumentsIncorporated Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarilyincludetestingofallparameters.

LM2771 SNVS435A–MARCH2006–REVISEDMAY2013 www.ti.com Connection Diagram Figure3. 10-PinNon-PullbackLeadlessFramePackage(WSON-10) PackageNumberDSC0010A VIN 1 10 EN EN 10 1 VIN GND 2 9 GND GND 9 2 GND VOUT 3 8 NC NC 8 3 VOUT NC 4 7 C1+ C1+ 7 4 NC NC 5 6 C1- C1- 6 5 NC Die-Attach Die-Attach Pad: GND Pad: GND Top View Bottom View PinDescriptions Pin# Name Description 1 V InputVoltage:RecommendedV operatingrange3.0Vto5.5V. IN IN 2 GND Ground 3 V OutputVoltage OUT 4 NC NoConnect 5 NC NoConnect 6 C1- FlyingCapacitor1:NegativeTerminal 7 C1+ FlyingCapacitor1:PositiveTerminal 8 NC NoConnect 9 GND Ground 10 EN EnablePinLogicInput.ApplyingalogicHIGHvoltagesignalenablesthepart.AlogicLOW voltagesignalplacesthethedeviceinshutdown. Thesedeviceshavelimitedbuilt-inESDprotection.Theleadsshouldbeshortedtogetherorthedeviceplacedinconductivefoam duringstorageorhandlingtopreventelectrostaticdamagetotheMOSgates. Absolute Maximum Ratings(1)(2)(3) V PinVoltage -0.3Vto6.0V IN ENPinVoltage -0.3Vto(V +0.3V)w/6.0Vmax IN ContinuousPowerDissipation(4) InternallyLimited JunctionTemperature(T ) 150ºC J-MAX StorageTemperatureRange -65ºCto+150ºC MaximumLeadTemperature(5) 265ºC HumanBodyModel 2.0kV ESDRating(6) MachineModel 200V (1) AbsoluteMaximumRatingsindicatelimitsbeyondwhichdamagetothecomponentmayoccur.OperatingRatingsareconditionsunder whichoperationofthedeviceisspecified.OperatingRatingsdonotimplyensuredperformancelimits.Forspecifiedperformancelimits andassociatedtestconditions,seetheElectricalCharacteristicstables. (2) IfMilitary/Aerospacespecifieddevicesarerequired,pleasecontacttheTexasInstrumentsSalesOffice/Distributorsforavailabilityand specifications. (3) AllvoltagesarewithrespecttothepotentialattheGNDpins. (4) Internalthermalshutdowncircuitryprotectsthedevicefrompermanentdamage.ThermalshutdownengagesatT=150ºC(typ.)and J disengagesatT=140ºC(typ.). J (5) Fordetailedinformationonsolderingrequirementsandrecommendations,pleaserefertoTexasInstruments'ApplicationNote1187 (LiteratureNumberSNOA401):LeadlessLeadframePackage(LLP). (6) TheHumanbodymodelisa100pFcapacitordischargedthrougha1.5kΩresistorintoeachpin.Themachinemodelisa200pF capacitordischargeddirectlyintoeachpin.MIL-STD-8833015.7 2 SubmitDocumentationFeedback Copyright©2006–2013,TexasInstrumentsIncorporated ProductFolderLinks:LM2771

LM2771 www.ti.com SNVS435A–MARCH2006–REVISEDMAY2013 Operating Ratings(1)(2) InputVoltageRange 2.7Vto5.5V RecommendedLoadCurrentRange 0mAto250mA JunctionTemperature(T)Range -30°Cto+110°C J AmbientTemperature(T )Range(3) -30°Cto+85°C A (1) AbsoluteMaximumRatingsindicatelimitsbeyondwhichdamagetothecomponentmayoccur.OperatingRatingsareconditionsunder whichoperationofthedeviceisspecified.OperatingRatingsdonotimplyensuredperformancelimits.Forspecifiedperformancelimits andassociatedtestconditions,seetheElectricalCharacteristicstables. (2) AllvoltagesarewithrespecttothepotentialattheGNDpins. (3) Maximumambienttemperature(T )isdependentonthemaximumoperatingjunctiontemperature(T =110ºC),the A-MAX J-MAX-OP maximumpowerdissipationofthedeviceintheapplication(P ),andthejunction-toambientthermalresistanceofthepart/package D-MAX intheapplication(θ ),asgivenbythefollowingequation:T =T –(θ ×P ). JA A-MAX J-MAX-OP JA D-MAX Thermal Properties Junction-to-AmbientThermalResistance(θ ),WSON-10Package(1) 55°C/W JA (1) Junction-to-ambientthermalresistanceishighlyapplicationandboard-layoutdependent.Inapplicationswherehighmaximumpower dissipationexists,specialcaremustbepaidtothermaldissipationissues. Electrical Characteristics(1)(2) LimitsinstandardtypefaceareforT =25ºC.Limitsinboldfacetypeapplyoverthefulloperatingjunctiontemperaturerange J (-30°C≤T ≤+110°C).Unlessotherwisenoted,specificationsapplytotheLM2771TypicalApplicationCircuit(pg.1)with: J V =3.6V;V(EN)=1.8V,C =C =1.0µF,C =4.7µF.(3) IN IN 1 OUT Symbol Parameter Condition Min Typ Max Units 3.0V≤V ≤5.5V 1.455 1.545 IN 1.5 0mA≤I ≤200mA (−3%) (+3%) OUT 3.0V≤V ≤5.5V 1.475 1.525 V 1.5VOutputVoltageRegulation IN 1.5 V OUT I =150mA (−1.7%) (+1.7%) OUT 3.0V<V ≤5.5V, 1.445 1.545 IN 1.5 0mA≤I ≤250mA (−3.7%) (+3%) OUT V =1.5V V /I OutputLoadRegulation OUT 0.17 mV/mA OUT OUT 0mA≤I ≤250mA OUT V /V OutputLineRegulation 0.1 %/V OUT IN E PowerEfficiency I =200mA 81 % OUT I QuiescentSupplyCurrent I =0mA(4) 45 50 µA Q OUT V FixedFrequencyOutputRipple 40mA≤I ≤250mA 8 mV R OUT V PFM–ModeOutputRipple I <40mA 12 mV R–PFM OUT I ShutdownCurrent V(EN)=0V 0.1 0.5 µA SD F SwitchingFrequency 3.2V≤V ≤5.5V 0.80 1.1 1.40 MHz SW IN R Open–LoopOutputResistance I =200mA(5) 1.0 Ω OL OUT V =5.5V ICL OutputCurrentLimit 0VIN≤V ≤0.2V(6) 500 mA OUT t Turn-onTime 150 µs ON V Logic-lowInputVoltage 3.0V≤V ≤5.5V 0 0.5 V IL IN V Logic-highInputVoltage 3.0V≤V ≤5.5V 0.95 V V IH IN IN I Logic-highInputCurrent V(EN)=1.8V(7) 5 µA IH I Logic-lowInputCurrent LogicInput=0V 0.1 µA IL (1) AllvoltagesarewithrespecttothepotentialattheGNDpins. (2) MinandMaxlimitsarespecifiedbydesign,test,orstatisticalanalysis.Typicalnumbersarenotensured,butdorepresentthemost likelynorm. (3) C ,C ,C :Low-ESRSurface-MountCeramicCapacitors(MLCCs)usedinsettingelectricalcharacteristics. IN OUT 1 (4) V issetto1.6Vduringthistest. OUT (5) Openloopoutputresistancecanbeusedtopredictoutputvoltagewhen,underlowV andhighI conditions,V fallsoutof IN OUT OUT regulation.V =V /2−(R ×I ) OUT IN OL OUT (6) Maximuminputcurrentisequaltohalfthemaximumoutputcurrentforbuck-modeswitchedcapacitorconverters. (7) Thereisa350kΩpull-downresistorconnectedinternallybetweentheENpinandGND. Copyright©2006–2013,TexasInstrumentsIncorporated SubmitDocumentationFeedback 3 ProductFolderLinks:LM2771

LM2771 SNVS435A–MARCH2006–REVISEDMAY2013 www.ti.com Block Diagram LM2771 VIN 1.3M C1+ SWITCH GAIN SWITCH ARRAY 700k CONTROL CONTROL 1 GND 1R.2e5f.V G = 1 , , 2 , C1- PFM Current VOUT Control Sense 1.1 MHz OSC. EN Enable/ EN Shutdown Control Soft-Start 0.8V Ramp Ref. 4 SubmitDocumentationFeedback Copyright©2006–2013,TexasInstrumentsIncorporated ProductFolderLinks:LM2771

LM2771 www.ti.com SNVS435A–MARCH2006–REVISEDMAY2013 Typical Performance Characteristics Unlessotherwisespecified:V =3.6V,C =C =1.0µF,C =4.7µF,T =25ºC.Capacitorsarelow-ESRmulti-layer IN IN 1 OUT A ceramiccapacitors(MLCC's). OutputVoltage OutputVoltage vs. vs. InputVoltage OutputCurrent Efficiency Efficiency vs. vs. InputVoltage OutputCurrent InputVoltageRipple,Load=6Ω(250mA) OutputVoltageRipple,Load=6Ω(250mA) CH1:V ,C =1µF;Scale:50mV/Div,ACCoupled CH2:V ,C =4.7µF;Scale:20mV/Div,ACCoupled IN IN OUT OUT CH2:V ,C =10µF;Scale:50mV/Div,ACCoupled Timescale:200ns/Div IN IN Timescale:200ns/Div Copyright©2006–2013,TexasInstrumentsIncorporated SubmitDocumentationFeedback 5 ProductFolderLinks:LM2771

LM2771 SNVS435A–MARCH2006–REVISEDMAY2013 www.ti.com Typical Performance Characteristics (continued) Unlessotherwisespecified:V =3.6V,C =C =1.0µF,C =4.7µF,T =25ºC.Capacitorsarelow-ESRmulti-layer IN IN 1 OUT A ceramiccapacitors(MLCC's). LoadStep,15mAto200mA LoadStep,200mAto15mA CH2:V ;Scale:20mV/Div,ACCoupled CH2:V ;Scale:20mV/Div,ACCoupled OUT OUT CH4:I ;Scale:200mA/Div CH4:I ;Scale:200mA/Div OUT OUT Timescale:20µs/Div Timescale:10µs/Div OscillatorFrequency vs. LineStep,3.6Vto4.5VwithLoad=7.5Ω(200mA) InputVoltage CH1:V ;Scale:1V/Div,ACCoupled IN CH2:V ;Scale:20mV/Div,ACCoupled OUT Timescale:40µs/Div StartupandShutdownBehavior,Load=6Ω(250mA) CH1:V ;Scale:2V/Div,DCCoupled EN CH2:V ;Scale:500mV/Div,DCCoupled OUT Timescale:100µs/Div 6 SubmitDocumentationFeedback Copyright©2006–2013,TexasInstrumentsIncorporated ProductFolderLinks:LM2771

LM2771 www.ti.com SNVS435A–MARCH2006–REVISEDMAY2013 OPERATION DESCRIPTION OVERVIEW TheLM2771isaswitchedcapacitorconverterthatproducesaregulated,lowvoltageoutput.Thecoreofthepart is a highly efficient charge pump that utilizes fixed frequency pre-regulation and Pulse Frequency Modulation to minimize ripple and power losses over wide input voltage and output current ranges. A description of the principal operational characteristics of the LM2771 is detailed in the CIRCUIT DESCRIPTION, and EFFICIENCY PERFORMANCEsections.ThesesectionsrefertodetailsintheBlockDiagram. CIRCUIT DESCRIPTION The core of the LM2771 is a two-phase charge pump controlled by an internally generated non-overlapping clock. The charge pump operates by using an external flying capacitor, C1, to transfer charge from the input to the output. At input voltages below 3.5V (typ.) the LM2771 operates in a "pass mode", with the input current being equal to the load current. At input voltages above 3.5V (typ.) the part utilizes a gain of ½, resulting in an inputcurrentequaltohalftheloadcurrent. The two phases of the switched capacitor switching cycle will be referred to as the "charge phase" and the "discharge phase". During the charge phase, the flying capacitor is charged by the input supply. After half of the switching cycle [ t = 1/(2×F ) ], the LM2771 switches to the discharge phase. In this configuration, the charge SW thatwasstoredontheflyingcapacitorinthechargephaseistransferredtotheoutput. The LM2771 uses fixed frequency pre-regulation to regulate the output voltage to 1.5V during moderate to high load currents. The input and output connections of the flying capacitor is made with internal MOS switches. Pre- regulation limits the gate drive of the MOS switch connected between the voltage input and the flying capacitor. Controlling the on resistance of this switch limits the amount of charge transferred into and out of the flying capacitorduringthechargeanddischargephases,andinturnhelpstokeeptheoutputrippleverylow. When output currents are low (<30mA typ.), the LM2771 automatically switches to a low-ripple Pulse Frequency Modulation (PFM) form of regulation. In PFM mode, the flying capacitor stays in the discharge phase until the outputvoltagedropsbelowapredeterminedtrippoint.Whenthisoccurs,theflyingcapacitorswitchesbacktothe charge phase. After being charged, the flying capacitor repeats the process of staying in the discharge phase andswitchingtothechargephasewhennecessary. EFFICIENCY PERFORMANCE Charge-pump efficiency is derived in the following two ideal equations (supply current and other losses are neglectedforsimplicity): I =G×I E=(V ×I )÷(V ×I )=V ÷(G×V ) (1) IN OUT OUT OUT IN IN OUT IN In the equations, G represents the charge pump gain. Efficiency is at its highest as G×V approaches V . IN OUT Refer to the efficiency graph in the Typical Performance Characteristics section for detailed efficiency data. The transition between Pass mode and the gain of ½ is clearly distinguished by the sharp discontinuity in the efficiencycurve. SHUTDOWN The LM2771 is in shutdown mode when the voltage on the enable pin (EN) is logic-low. In shutdown, the LM2771 draws virtually no supply current. When in shutdown, the output of the LM2771 is completely disconnectedfromtheinput.Theinternalfeedbackresistorswillpulltheoutputvoltagedownto0V. SOFT-START The LM2771 employs soft start circuitry to prevent excessive input inrush currents during startup. At startup, the output voltage gradually rises from 0V to the nominal output voltage. This occurs in 150µs (typ.). Soft-start is engaged when the part is enabled, including situations where voltage is established simultaneously on the V IN andENpins. Copyright©2006–2013,TexasInstrumentsIncorporated SubmitDocumentationFeedback 7 ProductFolderLinks:LM2771

LM2771 SNVS435A–MARCH2006–REVISEDMAY2013 www.ti.com THERMAL SHUTDOWN Protection from damage related to overheating is achieved with a thermal shutdown feature. When the junction temperature rises to 150ºC (typ.), the part switches into shutdown mode. The LM2771 disengages thermal shutdown when the junction temperature of the part is reduced to 140ºC (typ.). Due to the high efficiency of the LM2771, thermal shutdown and/or thermal cycling should not be encountered when the part is operated within specified input voltage, output current, and ambient temperature operating ratings. If thermal cycling is seen under these conditions, the most likely cause is an inadequate PCB layout that does not allow heat to be sufficientlydissipatedoutoftheWSONpackage. CURRENT LIMIT PROTECTION The LM2771 charge pump contains current limit protection circuitry that protects the device during V fault OUT conditionswhereexcessivecurrentisdrawn.Outputcurrentislimitedto500mA(typ). Application Information RECOMMENDEDCAPACITORTYPES The LM2771 requires 3 external capacitors for proper operation. Surface-mount multi-layer ceramic capacitors are recommended. These capacitors are small, inexpensive and have very low equivalent series resistance (ESR, ≤ 15mΩ typ.). Tantalum capacitors, OS-CON capacitors, and aluminum electrolytic capacitors generally arenotrecommendedforusewiththeLM2771duetotheirhighESR,ascomparedtoceramiccapacitors. For most applications, ceramic capacitors with an X7R or X5R temperature characteristic are preferred for use withtheLM2771.Thesecapacitorshavetightcapacitancetolerance(asgoodas±10%)andholdtheirvalueover temperature(X7R:±15%over-55ºCto125ºC;X5R:±15%over-55ºCto85ºC). Capacitors with a Y5V or Z5U temperature characteristic are generally not recommended for use with the LM2771. These types of capacitors typically have wide capacitance tolerance (+80%, -20%) and vary significantly over temperature (Y5V: +22%, -82% over -30ºC to +85ºC range; Z5U: +22%, -56% over +10ºC to +85ºC range). Under some conditions, a 1µF-rated Y5V or Z5U capacitor could have a capacitance as low as 0.1µF. Such detrimental deviation is likely to cause Y5V and Z5U capacitors to fail to meet the minimum capacitancerequirementsoftheLM2771. Net capacitance of a ceramic capacitor decreases with increased DC bias. This degradation can result in lower capacitance than expected on the input and/or output, resulting in higher ripple voltages and currents. Using capacitors at DC bias voltages significantly below the capacitor voltage rating will usually minimize DC bias effects.ConsultcapacitormanufacturersforinformationoncapacitorDCbiascharacteristics. Capacitance characteristics can vary quite dramatically with different application conditions, capacitor types, and capacitor manufacturers. It is strongly recommended that the LM2771 circuit be thoroughly evaluated early in the design-in process with the mass-production capacitors of choice. This will help ensure that any such variability in capacitancedoesnotnegativelyimpactcircuitperformance. Thetablebelowlistssomeleadingceramiccapacitormanufacturers. Manufacturer ContactInformation AVX www.avx.com Murata www.murata.com Taiyo-Yuden www.t-yuden.com TDK www.component.tdk.com Vishay-Vitramon www.vishay.com 8 SubmitDocumentationFeedback Copyright©2006–2013,TexasInstrumentsIncorporated ProductFolderLinks:LM2771

LM2771 www.ti.com SNVS435A–MARCH2006–REVISEDMAY2013 OUTPUTCAPACITORANDOUTPUTVOLTAGERIPPLE The output capacitor in the LM2771 circuit (C ) directly impacts the magnitude of output voltage ripple. Other OUT prominent factors also affecting output voltage ripple include input voltage, output current and flying capacitance. Due to the complexity of the regulation topology, providing equations or models to approximate the magnitude of the ripple can not be easily accomplished. But one important generalization can be made: increasing (decreasing)theoutputcapacitancewillresultinaproportionaldecrease(increase)inoutputvoltageripple. In typical high-current applications, a 4.7µF low-ESR ceramic output capacitor is recommended. Different output capacitance values can be used to reduce ripple, shrink the solution size, and/or cut the cost of the solution. But changing the output capacitor may also require changing the flying capacitor and/or input capacitor to maintain good overall circuit performance. Performance of the LM2771 with different capacitor setups in discussed in the sectionRECOMMENDEDCAPACITORCONFIGURATIONS. HighESRintheoutputcapacitorincreasesoutputvoltageripple.Ifaceramiccapacitorisusedattheoutput,this is usually not a concern because the ESR of a ceramic capacitor is typically very low and has only a minimal impact on ripple magnitudes. If a different capacitor type with higher ESR is used (tantalum, for example), the ESR could result in high ripple. To eliminate this effect, the net output ESR can be significantly reduced by placing a low-ESR ceramic capacitor in parallel with the primary output capacitor. The low ESR of the ceramic capacitor will be in parallel with the higher ESR, resulting in a low net ESR based on the principles of parallel resistancereduction. INPUTCAPACITORANDINPUTVOLTAGERIPPLE The input capacitor (C ) is a reservoir of charge that aids a quick transfer of charge from the supply to the flying IN capacitor during the charge phase of operation. The input capacitor helps to keep the input voltage from drooping at the start of the charge phase when the flying capacitor is connected to the input. It also filters noise ontheinputpin,keepingthisnoiseoutofsensitiveinternalanalogcircuitrythatisbiasedofftheinputline. Much like the relationship between the output capacitance and output voltage ripple, input capacitance has a dominantandfirst-ordereffectoninputripplemagnitude.Increasing(decreasing)theinputcapacitancewillresult in a proportional decrease (increase) in input voltage ripple. Input voltage, output current, and flying capacitance alsowillaffectinputripplelevelstosomedegree. In typical high-current applications, a 1µF low-ESR ceramic capacitor is recommended on the input. Different input capacitance values can be used to reduce ripple, shrink the solution size, and/or cut the cost of the solution. But changing the input capacitor may also require changing the flying capacitor and/or output capacitor to maintain good overall circuit performance. Performance of the LM2771 with different capacitor setups is discussedbelowinRECOMMENDEDCAPACITORCONFIGURATIONS. FLYINGCAPACITOR The flying capacitor (C ) transfers charge from the input to the output. Flying capacitance can impact both output 1 current capability and ripple magnitudes. If flying capacitance is too small, the LM2771 may not be able to regulate the output voltage when load currents are high. On the other hand, if the flying capacitance is too large, the flying capacitor might overwhelm the input and output capacitors, resulting in increased input and output ripple. Polarized capacitors (tantalum, aluminum electrolytic, etc.) must not be used for the flying capacitor, as they couldbecomereverse-biasedduringLM2771operation. RECOMMENDEDCAPACITORCONFIGURATIONS The data in Table 1can be used to assist in the selection of a capacitor configuration that best balances solution sizeandcostwiththeelectricalrequirementsoftheapplication. As previously discussed, input and output ripple voltages will vary with output current and input voltage. The numbers provided show expected ripple voltage when V = 3.6V and load currents are between 10mA and IN 200mA. The table offers first look at approximate ripple levels and provides a comparison for the different capacitorconfigurationspresented,butisnotintendedtoensureperformance. Copyright©2006–2013,TexasInstrumentsIncorporated SubmitDocumentationFeedback 9 ProductFolderLinks:LM2771

LM2771 SNVS435A–MARCH2006–REVISEDMAY2013 www.ti.com Table1.LM2771PerformancewithDifferentCapacitorConfigurations (1) CAPACITOR TYPICAL TYPICAL CONFIGURATION INPUT OUTPUT (V =3.6V) RIPPLE RIPPLE IN C =1µF, IN C =4.7µF, 45mV 8mV OUT C =1µF 1 C =1µF, IN C =2.2µF, 94mV 19mV OUT C =1µF 1 C =0.47µF, IN C =4.7µF, 105mV 11mV OUT C =1µF 1 C =0.47µF, IN C =3.3µF, 102mV 16mV OUT C =1µF 1 C =0.47µF, IN C =3.3µF, 120mV 15mV OUT C =0.33µF 1 (1) RefertothetextintheRecommendedCapacitorConfigurationssectionfordetailedinformationonthedatainthistable LayoutGuidelines Proper board layout will help to ensure optimal performance of the LM2771 circuit. The following guidelines are recommended: • PlacecapacitorsasclosetotheLM2771aspossible,andpreferablyonthesamesideoftheboardastheIC. • Use short, wide traces to connect the external capacitors to the LM2771 to minimize trace resistance and inductance. • Use a low resistance connection between ground and the GND pin of the LM2771. Using wide traces and/or multipleviastoconnectGNDtoagroundplaneontheboardismostadvantageous. 10 SubmitDocumentationFeedback Copyright©2006–2013,TexasInstrumentsIncorporated ProductFolderLinks:LM2771

LM2771 www.ti.com SNVS435A–MARCH2006–REVISEDMAY2013 REVISION HISTORY ChangesfromOriginal(May2013)toRevisionA Page • ChangedlayoutofNationalDataSheettoTIformat.......................................................................................................... 10 Copyright©2006–2013,TexasInstrumentsIncorporated SubmitDocumentationFeedback 11 ProductFolderLinks:LM2771

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) LM2771SD/NOPB ACTIVE WSON DSC 10 1000 Green (RoHS SN Level-1-260C-UNLIM -30 to 110 L2771 & no Sb/Br) (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) 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 1

PACKAGE MATERIALS INFORMATION www.ti.com 24-Aug-2017 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) LM2771SD/NOPB WSON DSC 10 1000 178.0 12.4 3.3 3.3 1.0 8.0 12.0 Q1 PackMaterials-Page1

PACKAGE MATERIALS INFORMATION www.ti.com 24-Aug-2017 *Alldimensionsarenominal Device PackageType PackageDrawing Pins SPQ Length(mm) Width(mm) Height(mm) LM2771SD/NOPB WSON DSC 10 1000 210.0 185.0 35.0 PackMaterials-Page2

MECHANICAL DATA DSC0010A SDA10A (Rev A) www.ti.com

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