說明綜合合并

TheFutureofAnalogIC

1.2A,24V,Step-DownConverterinaTSOT23-TheMP2359isamonolithicstep-downswitchmodeconverterwithabuilt-inpowerMOSFET.Itachieves1.2Apeakoutputcurrentoverawideinputsupplyrangewithexcellentloadandlineregulation.Currentmodeoperationprovidesfasttransientresponseandeasesloopstabilization.Faultconditionprotectionincludescycle-by-cyclecurrentlimitingandthermalTheMP2359requiresaminimumnumberofreadilyavailablestandardexternalcomponents.TheMP2359isavailableinTSOT23-6andSOT23-6packages.EVALUATIONBOARDBoard2.1”Xx1.9”Yx

1.2APeakOutput0.35?InternalPowerMOSFETStablewithLowESROutputCeramicUpto92%0.1μAShutdownFixed1.4MHzThermalCycle-by-CycleOverCurrentWide4.5Vto24VOperatingInputOutputAdjustablefrom0.81Vto DistributedPowerBatteryPre-RegulatorforLinearWLEDForMPSgreenstatus,pleasevisitMPSwebsiteunderQualityAssurance.MonolithicPowerSystems,Inc.TYPICAL

EfficiencyvsLoadCurrents 5

VVN=VN=VOUT=

SW

EFFICIENCYEFFICIENCYV@ OFF 4

2

0

LOADCURRENTORDERINGPartTopFreeAirTemperature-40Cto+85-40Cto+85*ForTape&Reel,addsuffix–Z(eg.ForRoHScompliantpackaging,addsuffix–LF(eg.**ForTape&Reel,addsuffix–Z(eg.ForRoHScompliantpackaging,addsuffix–LF(eg.PACKAGETOP162534ABSOLUTEMAXIMUMRATINGS ThermalResistance SupplyVoltage VBSVSW+AllOther VtoContinuousPowerDissipation(TA=+25°C) JunctionTemperature150Lead 260StorageTemperature-65Cto+150RecommendedOperatingConditionsSupplyVoltageVIN Vto24VOutputVoltage VtoAmbientTemperature-40Cto+85CMaxinputcurrentintotheEN

110..SOT23-6220110..Exceedingtheseratingsmaydamagethe ThemaximumallowablepowerdissipationisafunctionofthemaximumjunctiontemperatureTJ(MAX),thejunction-to-ambientthermalresistanceθJA,andtheambienttemperatureTA.ThemaximumallowablecontinuouspowerdissipationatanyambienttemperatureiscalculatedbyPD(MAX)=(TJ(MAX)-TA)/θJA.Exceedingthemaximumallowablepowerdissipationwillcauseexcessivedietemperature,andtheregulatorwillgointothermalshutdown.Internalthermalshutdowncircuitryprotectsthedevicefrompermanentdamage. Thedevicefunctionisnotguaranteedoutsideoftherecommendedoperatingconditions.MeasuredonJESD51-7,4-layerVIN=12V,TA=+25C,unlessotherwiseFeedback4.5V￡VIN￡VFeedbackVFB=Switch-OnResistance?SwitchVEN=0V,VSW=CurrentLimitAOscillatorVFB=Fold-backVFB=MaximumDutyVFB=%MinimumOn-TimeUnderVoltageLockoutThresholdVUnderVoltageLockoutThresholdENInputLowVENInputHighVENInputVEN=VEN=SupplyCurrentVEN=SupplyCurrentVEN=2V,VFB=ThermalShutdownGuaranteedbyPINPin1Bootstrap.AcapacitorisconnectedbetweenSWandBSpinstoformafloatingsupplyacrossthepowerswitchdriver.Thiscapacitorisneededtodrivethepowerswitch’sgateabovethesupplyvoltage.2Ground.Thispinisthevoltagereferencefortheregulatedoutputvoltage.Forthisreasoncaremustbetakeninitslayout.ThisnodeshouldbeplacedoutsideoftheD1toC1groundpathtopreventswitchingcurrentspikesfrominducingvoltagenoiseintothepart.3Feedback.AnexternalresistordividerfromtheoutputtoGND,tappedtotheFBpinsetstheoutputvoltage.Topreventcurrentlimitrunawayduringashortcircuitfaultcondition,thefrequencyfoldbackcomparatorlowerstheoscillatorfrequencywhentheFBvoltageisbelow4On/OffControlInput.PullENabove1.2Vtoturnthedeviceon.Forautomaticenable,connecta100k?resistorbetweenthispinandVinpin.5SupplyVoltage.TheMP2359operatesfroma+4.5Vto+24Vunregulatedinput.C1isneededtopreventlargevoltagespikesfromappearingattheinput.6SwitchVIN=12V,VOUT=3.3V,L=4.7μH,C1=10μF,C2=22μF,TA=+25oC,unlessotherwiseEFFICIENCYEFFICIENCY0

EfficiencyvsLoad

EFFICIENCYEFFICIENCY0

EfficiencyvsLoad LOADCURRENT(

LOADCURRENTFEEDBACKFEEDBACKVOLTAGE

FeedbackVoltagevsDieTemperature

SWITCHINGSWITCHINGFREQUENCY

SwitchingFrequencyvsDieTemperature-50-250255075100125 -50-250255075100125DIETEMPERATURE DIETEMPERATUREVIN=12V,VOUT=3.3V,L=4.7μH,C1=10μF,C2=22μF,TA=+25oC,unlessotherwiseCURRENTCURRENTLIMIT0

CurrentLimitvsDutyCycle

SteadyStateIOUT= DUTYCYCLEShortCircuit ShortCircuit

Start-upthroughNo

Start-upthroughIOUT=1AResistive

Shut-downthroughNo

Shut-downthroughIOUT=1AResistive

TheMP2359isacurrentmodebuckregulator.Thatis,theEAoutputvoltageisproportionaltothepeakinductorcurrent.Atthebeginningofacycle,M1isoff.TheEAoutputvoltageishigherthanthecurrentsenseamplifieroutput,andthecurrentcomparator’soutputislow.Therisingedgeofthe1.4MHzCLKsignalsetstheRSFlip-Flop.ItsoutputturnsonM1thusconnectingtheSWpinandinductortotheinputsupply.TheincreasinginductorcurrentissensedandamplifiedbytheCurrentSenseAmplifier.RampcompensationissummedtotheCurrentSenseAmplifieroutputandcomparedtotheErrorAmplifieroutputbythePWMComparator.WhenthesumoftheCurrentSenseAmplifieroutputandtheSlopeCompensationsignalexceedstheEAoutputvoltage,theRSFlip-FlopisresetandM1isturnedoff.TheexternalSchottkyrectifierdiode(D1)conductstheinductorcurrent.

IfthesumoftheCurrentSenseAmplifieroutputandtheSlopeCompensationsignaldoesnotexceedtheEAoutputforawholecycle,thenthefallingedgeoftheCLKresetstheFlip-Flop.TheoutputoftheErrorAmplifierintegratesthevoltagedifferencebetweenthefeedbackandthe0.81Vbandgapreference.ThepolarityissuchthataFBpinvoltagelowerthan0.81VincreasestheEAoutputvoltage.SincetheEAoutputvoltageisproportionaltothepeakinductorcurrent,anincreaseinitsvoltagealsoincreasescurrentdeliveredtotheoutput.R

Figure1—FunctionalBlockSettingOutputTheexternalresistordividerisusedtosettheoutputvoltage(seetheschematiconfrontpage).Table1showsalistofresistorselectionforcommonoutputvoltages.ThefeedbackresistorR1alsosetsthefeedbackloopbandwidthwiththeinternalcompensationcapacitor(seeFigure1).R2canbedeterminedR2 VOUT-Table1—ResistorSelectionforCommonOutputVoltagesVOUTR1R280.664.949.923.749.916.2549.99.53SelectingtheA1μHto10μHinductorwithaDCcurrentratingofatleast25%percenthigherthanthemaximumloadcurrentisrecommendedformostapplications.Forhighestefficiency,theinductor’sDCresistanceshouldbelessthan200m?.RefertoTable2forsuggestedsurfacemountinductors.Formostdesigns,therequiredinductancevaluecanbederivedfromthefollowingequation.L=VOUT·(VIN-VOUT)VIN·DIL·fSWWhereΔIListheinductorrippleChoosetheinductorripplecurrenttobe30%ofthemaximumloadcurrent.Themaximuminductorpeakcurrentiscalculatedfrom: =I

SelectingtheInputTheinputcapacitorreducesthesurgecurrentdrawnfromtheinputsupplyandtheswitchingnoisefromthedevice.Theinputcapacitorimpedanceattheswitchingfrequencyshouldbelessthantheinputsourceimpedancetopreventhighfrequencyswitchingcurrentfrompassingthroughtheinput.CeramiccapacitorswithX5RorX7RdielectricsarehighlyrecommendedbecauseoftheirlowESRandsmalltemperaturecoefficients.Formostapplications,a4.7μFcapacitorissufficient.SelectingtheOutputTheoutputcapacitorkeepstheoutputvoltageripplesmallandensuresfeedbackloopstability.Theoutputcapacitorimpedanceshouldbelowattheswitchingfrequency.CeramiccapacitorswithX5RorX7RdielectricsarerecommendedfortheirlowESRcharacteristics.Formostapplications,a22μFceramiccapacitorwillbePCBLayoutPCBlayoutisveryimportanttoachievestableoperation.PleasefollowtheseguidelinesandtakeFigure2forreferences.KeepthepathofswitchingcurrentshortandminimizetheloopareaformedbyInputcap,high-sideMOSFETandschottkydiode.KeeptheconnectionofschottkydiodebetweenSWpinandinputpowergroundasshortandwideaspossible.Ensureallfeedbackconnectionsareshortanddirect.Placethefeedbackresistorsandcompensationcomponentsasclosetothechipaspossible.RouteSWawayfromsensitiveanalogareassuchasFB.ConnectIN,SW,andespeciallyGNDrespectivelytoalargecopperareatocoolthechiptoimprovethermalperformanceUnderlightloadconditionsbelow100mA,alargerinductanceisrecommendedforimprovedefficiency.SeeTable2forsuggestedinductors.Alsonotethatthemaximumrecommendedloadcurrentis1Aifthedutycycleexceeds35%.

andlong-termreliability.ForsinglelayerPCB,exposedpadshouldnotbesoldered.123Anexternalbootstrapdiodemayenhancetheefficiencyoftheregulator,theapplicableconditionsofexternalBSTdiodeare:123BSTGNDFBVBSTGNDFBDutycycleishigh:D=VOUT654Inthesecases,anexternalBSTdiodeisrecommendedfromtheoutputofthevoltageregulatortoBSTpin,asshowninFig.3654Figure2—PCB

5Vor3Figure3—AddOptionalExternalBootstrapDiodetoEnhanceEfficiencyTherecommendedexternalBSTdiodeisIN4148,andtheBSTcapis0.1~1μF.Table2—SuggestedSurfaceMountPartMaxRating(A)LxWxH6x6.3x5.1x5.1xWurth5.8x5.8xTYPICALAPPLICATION55BS4OFF 6D3canbeinstalledifVIN<D2canbeinstalledifVOUT<NoneedforbothD2and3B230A-13-Figure4—1.4MHz,3.3VOutputat1AStep-Down56OFF432Figure5—WhiteLEDDriverPACKAGE

TSOT23-641.50641.5013APINTOP RECOMMENDEDLAND 1.00SEATING0.95 SEEDETAILFRONT SIDEDETAIL

ALLDIMENSIONSAREINGAUGE0.25 GAUGE0.25 PACKAGEWIDTHDOESNOTINCLUDEINTERLEADFLASHORPROTRUSION. LEADCOPLANARITY(BOTTOMOFLEADSAFTERFORMING)SHALLBE0.10MILLIMETERSMAX.DRAWINGCONFORMSTOJEDECMO-193,VARIATIONDRAWINGISNOTTO PIN1ISLOWERLEFTPINWHENREADINGTOPMARKFROMLEFTTORIGHT,(SEEEXAMPLETOPMARK)64 64 13APINTOP RECOMMENDEDLAND

0.95

1.45SEATING

FRONT SIDEDETAIL

ALLDIMENSIONSAREINGAUGE0.25GAUGE0.25 0o- PACKAGEWIDTHDOESNOTINCLUDEINTERLEADFLASHORPROTRUSION. LEADCOPLANARITY(BOTTOMOFLEADSAFTERFORMING)SHALLBE0.10MILLIMETERSMAX.DRAWINGCONFORMSTOJEDECMO-193,VARIATIONDRAWINGISNOTTO PIN1ISLOWERLEFTPINWHENREADINGTOPMARKFROMLEFTTORIGHT,(SEEEXAMPLETOPMARK)NOTICE:Theinformationinthisdocumentissubjecttochangewithoutnotice.PleasecontactMPSforcurrentspecifications.UsersshouldwarrantandguaranteethatthirdpartyIntellectualPropertyrightsarenotinfringeduponwhenintegratingMPSproductsintoanyapplication.MPSwillnotassumeanylegalresponsibilityforanysaidapplications.采用TSOT23-6封裝的1.2A、24V、1.4MHz模擬IC技術(shù)的未來描述MP2359是一款具有內(nèi)置功率MOSFET的單片降壓開關(guān)模式轉(zhuǎn)換器。它可在寬輸入電源范圍內(nèi)實(shí)現(xiàn)1.2A峰值輸出電流，并具有出色的負(fù)載和線路調(diào)節(jié)能力。電流模式操M(fèi)P2359需要最少數(shù)量的現(xiàn)成標(biāo)準(zhǔn)外部組件。MP2359采用TSOT23-6和SOT23-6封裝。1.2A0.35。內(nèi)部功率MOSFET開關(guān)穩(wěn)定，具有低ESR輸出陶瓷電容器，效率高達(dá)0.1μA關(guān)斷模式固定1.4MHz頻率熱關(guān)斷逐周期過流保護(hù)4.5V至24V寬工作輸入范圍輸出可在0.81V至15V范圍內(nèi)調(diào)節(jié)采用TSOT23-6和SOT23-6封裝應(yīng)用分布式電源系統(tǒng)電池充電器-用于線性穩(wěn)壓器WLED驅(qū)動(dòng)器的穩(wěn)壓器有關(guān)MPS綠色狀態(tài)，請?jiān)L問MPS網(wǎng)站的質(zhì)量保證部分。“MPS”和“模擬IC技術(shù)的未來”是MonolithicPowerSystems,Inc.的注冊商標(biāo)。典型應(yīng)用效率與負(fù)載電流的關(guān)系12VVOUT6050403020100.010.11負(fù)載電流MP2359修訂版1.212011年7月18日MPS2011年MPS。版MP2359–采用TSOT23-6封裝的1.2A、24V、1.4MHz降壓轉(zhuǎn)換器訂購信息部件號封裝頂部標(biāo)記自由空氣溫度(TA)MP2359DJ*TSOT23-6F8-40°C至+85°CMP2359DT**SOT23-6J6-40°C至+85°C式，添加后綴–Z（例如M2359DJ–Z）；對于符合RoHS標(biāo)準(zhǔn)的封裝，請?zhí)砑雍缶Y–LF（例如MP2359DJ–LF–Z）**對于卷帶式封裝，請?zhí)砑雍缶Y–Z（例如M2359DT–Z）；對于符合RoHS標(biāo)準(zhǔn)的包裝，請?zhí)砑雍缶Y–LF（例如MP2359DT–LF–Z）封裝參考頂視圖1.2.3.SWGNDINFBEN電源電壓VIN26V27VVSW+6V-0.3V至+6V連續(xù)功耗(TA=+25°C)(TSOT23-60.568WSOT23-……0.568W結(jié)溫………………150°C引線溫度..260°C存儲溫度-65°C至+150°C建議工作條件(電源電壓VIN4.5V至24V輸出電壓0.81V至15V環(huán)境溫度-40°C至+85°CEN300μA熱阻(4)θJAθJCTSOT23-..220..110..℃/WSOT23-6220110..°C/W最大允許功耗是最大結(jié)溫TJ(MAXθJATA。任何環(huán)境溫度下的最大允許連續(xù)功耗計(jì)算公式為在JESD51-7、4層PCBMP2359修訂版1.21www.MonolithicP2011年7月18日MPS2011年MPS電氣特性VIN=12V，TA=+25°C參數(shù)符號條件最小值典型值最大值單位反饋電壓VFB4.5V≤VIN≤24V0.7900.8100.830V反饋電流IFBVFB=0.8V0.1μA接通電阻(5)RDS(ON)0.35.開關(guān)漏電流VEN=0V，VSW=0V10μA電流限制(5)1.8A振蕩器頻率fSWVFB=0.6V1.41.7MHz折返頻率VFB=0V460kHz最大占空比VFB=0.6V87最短導(dǎo)通時(shí)間(5)tON100ns欠壓鎖定閾值上升2.52.83.1V欠壓鎖定閾值遲滯150mVEN輸入低電壓0.4VEN輸入高電壓1.2VEN輸入電流VEN=2V2.1μAVEN=0V0.1電源電流（關(guān)斷）ISVEN=0V0.11.0μA電源電流（靜態(tài)）IQVEN=2V，VFB=1V1.0mA熱關(guān)斷(5)150°C1BST引導(dǎo)程序。SWBS引腳之間連接有一個(gè)電容器，以在電GND接地。該引腳是穩(wěn)壓輸出電壓的參考電壓。因此，必須注意其布局。該節(jié)點(diǎn)應(yīng)放置在D1至C1接地路徑之外，以防止開關(guān)電流尖峰將電壓噪聲引入器件中。臉書反饋。從輸出到GND的外部電阻分壓器（分接至FB引腳）可設(shè)置輸出電壓。為了防止在短路故障情況下電流限制失控，頻率折返比較器會在FB電壓低于250mV時(shí)降低振蕩器頻率。4EN開/關(guān)控制輸入。將EN拉至1.2V以上以開啟器件。要自動(dòng)啟用，請連接100k。該引腳和Vin引腳之間的電阻。IN電源電壓。MP2359的工作電壓為+4.5V至+24V未穩(wěn)壓輸入。需要C1來防止輸入處出現(xiàn)大SWMP2359修訂版1.212011年7月18日MPS2011年MPS。版典型性能特性VIN=12V，VOUT=3.3V，L=4.7μH，C1=10μF，C2=22μF，TA=+效率與效率與負(fù)載電流的關(guān)系負(fù)載電流VIN=12VVIN=24VVOUT=5V反饋電壓（％）（％）00.010.11100.010.1110負(fù)載電流(A)負(fù)載電流反饋電壓與開關(guān)頻率與芯片溫度的關(guān)系芯片溫度開關(guān)頻率模具溫度(OC)模具溫度MP2359修訂版1.212011年7月18日MPS2011年MPS。版典型性能特性（續(xù)）除非另有說明，VIN=12V，VOUT=3.3V，L=4.7μH，C1=10μF，C2=22μF，TA=+25oC。電流限制與穩(wěn)態(tài)測試占空比IOUT0.5A3.050mV10V/格。1A/格。IL500mA0.5ILOAD1A/格。0占空比短路進(jìn)入短路恢復(fù)通過啟用空載電流限制(A)啟動(dòng)VEN5V/格。VOUT1V/格。VSW10V/格。IL1A/格。500mA通過使能啟動(dòng)通過使能關(guān)閉通過使能關(guān)閉IOUT=1A阻性負(fù)載無負(fù)載IOUT=1A阻性負(fù)載VENVENVEN5V/5V/5V/VOUT2V/格。VOUT1V/格。VSW10V10V1A/1A/MP2359修訂版1.212011年7月18日MPS2011年MPS。版操作MP2359是一款電流模式降壓穩(wěn)壓器。也就是說，EA輸出電壓與峰值電感電流成正比。一個(gè)周期開始時(shí)，M1截止。EA輸出電壓高于電流檢測放大器輸出，電流比較器輸出較低。1.4MHzCLK信號的上升沿設(shè)置RS觸發(fā)器。其輸出開啟M1，從而將SW引腳和電感器連接至輸入PWMEA電壓時(shí)，RS觸發(fā)器復(fù)位且M1關(guān)閉。外部肖特基整流二極管(D1)傳導(dǎo)電感電流。INENFBGND如果電流檢測放大器輸出和斜率補(bǔ)償信號之和在整個(gè)周期內(nèi)不超過EA輸出，則CLK的下降沿將復(fù)位觸發(fā)器。誤差放大器的輸出對反饋和0.81V帶隙基準(zhǔn)之間的電壓差進(jìn)行積分。極性使得FB引腳電壓低于0.81V會增加EA輸出電壓。由于EA輸出電壓與峰值電感電流成正比，因此其電壓的增加也會增BST軟件MP2359修訂版1.212011年7月18日MPS2011年MPS。版應(yīng)用信息設(shè)置輸出電壓外部電阻分壓器用于設(shè)置輸出電壓（參見首頁原理圖）。表1顯示了常見輸出電壓的電阻器選擇列表。反饋電阻器R1還通過內(nèi)部補(bǔ)償電容器設(shè)置反饋環(huán)路帶寬（見圖1）。R2可由下式確定：R1R2=10.81V表1—通用輸出電壓VOUT(V)R1(k.)R2(k549.9(1%)9.53選擇電感器對于大多數(shù)應(yīng)用，建議選擇直流電流額定值至少比最大負(fù)載電流高25%的1μH至10μH電感器。為了獲得最高效率，電感器的直流電阻應(yīng)小于200m。有關(guān)建議的表面貼裝電感器，請參閱表2V×(V.輸出輸入輸出LV×ΔI×fINLSWΔIL選擇電感紋波電流為最大負(fù)載電流的30%。最大電感峰值電流的計(jì)算公式為：