LM2675
SIMPLESWITCHER®PowerConverterHighEfficiency1AStep-DownVoltageRegulator
GeneralDescription
TheLM2675seriesofregulatorsaremonolithicintegratedcircuitsbuiltwithaLMDMOSprocess.Theseregulatorsprovidealltheactivefunctionsforastep-down(buck)switchingregulator,capableofdrivinga1Aloadcurrentwithexcellentlineandloadregulation.Thesedevicesareavail-ableinfixedoutputvoltagesof3.3V,5.0V,12V,andanadjustableoutputversion.
Requiringaminimumnumberofexternalcomponents,theseregulatorsaresimpletouseandincludepatentedinternalfrequencycompensation(PatentNos.5,382,918and5,514,947)andafixedfrequencyoscillator.
TheLM2675seriesoperatesataswitchingfrequencyof260kHz,thusallowingsmallersizedfiltercomponentsthanwhatwouldbeneededwithlowerfrequencyswitchingregu-lators.Becauseofitsveryhighefficiency(>90%),thecop-pertracesontheprintedcircuitboardaretheonlyheatsinkingneeded.
AfamilyofstandardinductorsforusewiththeLM2675areavailablefromseveraldifferentmanufacturers.Thisfeaturegreatlysimplifiesthedesignofswitch-modepowersuppliesusingtheseadvancedICs.Alsoincludedinthedatasheetareselectorguidesfordiodesandcapacitorsdesignedtoworkinswitch-modepowersupplies.
Otherfeaturesincludeaguaranteed±1.5%toleranceonoutputvoltagewithinspecifiedinputvoltagesandoutputloadconditions,and±10%ontheoscillatorfrequency.Ex-ternalshutdownisincluded,featuringtypically50µAstand-bycurrent.Theoutputswitchincludescurrentlimiting,aswellasthermalshutdownforfullprotectionunderfaultconditions.
TosimplifytheLM2675buckregulatordesignprocedure,thereexistscomputerdesignsoftware,LM267XMadeSimpleversion6.0.
Features
nEfficiencyupto96%
nAvailableinSO-8,8-pinDIPandLLPpackagesnComputerDesignSoftwareLM267XMadeSimple(version6.0)
nSimpleandeasytodesignwith
nRequiresonly5externalcomponentsnUsesreadilyavailablestandardinductors
n3.3V,5.0V,12V,andadjustableoutputversions
nAdjustableversionoutputvoltagerange:1.21Vto37Vn±1.5%maxoutputvoltagetoleranceoverlineandloadconditions
nGuaranteed1Aoutputloadcurrentn0.25ΩDMOSOutputSwitch
nWideinputvoltagerange:8Vto40V
n260kHzfixedfrequencyinternaloscillator
nTTLshutdowncapability,lowpowerstandbymodenThermalshutdownandcurrentlimitprotection
TypicalApplications
nSimpleHighEfficiency(>90%)Step-Down(Buck)Regulator
nEfficientPre-RegulatorforLinearRegulatorsnPositive-to-NegativeConverter
TypicalApplication
01280301
SIMPLESWITCHER®isaregisteredtrademarkofNationalSemiconductorCorporation.Windows®isaregisteredtrademarkofMicrosoftCorporation.
©2005NationalSemiconductorCorporationDS012803www.national.com
LM2675ConnectionDiagrams
16-LeadLLPSurfaceMountPackage
TopView
8-LeadPackage
TopView
01280302
SO-8/DIPPackage
SeeNSCPackageDrawingNumberMO8A/N08E
01280338
LLPPackage
SeeNSCPackageDrawingNumberLDA16A
PackageMarkingandOrderingInformation
TABLE1.
OutputVoltage16LeadLLP
12123.33.35.05.0ADJADJ
SO-8
12123.33.35.05.0ADJADJ
DIP
123.35.0ADJ
LM2675N-12LM2675N-3.3LM2675N-5.0LM2675N-ADJ
LM2675N-12LM2675N-3.3LM2675N-5.0LM2675N-ADJ
ShippedinAnti-StaticRailsShippedinAnti-StaticRailsShippedinAnti-StaticRailsShippedinAnti-StaticRails
LM2675M-12LM2675MX-12LM2675M-3.3LM2675MX-3.3LM2675M-5.0LM2675MX-5.0LM2675M-ADJLM2675MX-ADJ
2675M-122675M-122675M-3.32675M-3.32675M-5.02675M-5.02675M-ADJ2675M-ADJ
ShippedinAnti-StaticRails2500UnitsonTapeandReelShippedinAnti-StaticRails2500UnitsonTapeandReelShippedinAnti-StaticRails2500UnitsonTapeandReelShippedinAnti-StaticRails2500UnitsonTapeandReel
LM2675LD-12LM2675LDX-12LM2675LD-3.3LM2675LDX-3.3LM2675LD-5.0LM2675LDX-5.0LM2675LD-ADJLM2675LDX-ADJ
S000DBS000DBS000EBS000EBS000FBS000FBS000GBS000GB
1000UnitsonTapeandReel4500UnitsonTapeandReel1000UnitsonTapeandReel4500UnitsonTapeandReel1000UnitsonTapeandReel4500UnitsonTapeandReel1000UnitsonTapeandReel4500UnitsonTapeandReel
OrderInformation
PackageMarking
Suppliedas:
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LM2675AbsoluteMaximumRatings(Note1)
IfMilitary/Aerospacespecifieddevicesarerequired,pleasecontacttheNationalSemiconductorSalesOffice/Distributorsforavailabilityandspecifications.SupplyVoltageON/OFFPinVoltageSwitchVoltagetoGroundBoostPinVoltageFeedbackPinVoltageESDSusceptibility
HumanBodyModel(Note2)PowerDissipation
2kV
InternallyLimited
45V
−0.1V≤VSH≤6V
−1VVSW+8V
−0.3V≤VFB≤14V
StorageTemperatureRangeLeadTemperatureMPackage
VaporPhase(60s)Infrared(15s)
NPackage(Soldering,10s)LLPPackage(SeeAN-1187)MaximumJunctionTemperature
+150˚C+215˚C+220˚C+260˚C
−65˚Cto+150˚C
OperatingRatings
SupplyVoltage
6.5Vto40V
JunctionTemperatureRange
−40˚C≤TJ≤+125˚C
ElectricalCharacteristics
LM2675-3.3SpecificationswithstandardtypefaceareforTJ=25˚C,andthosewithboldtypefaceapplyoverfull
OperatingTemperatureRange.Symbol
Parameter
Conditions
Typical(Note4)
SYSTEMPARAMETERSTestCircuitFigure2(Note3)VOUTVOUTη
OutputVoltageOutputVoltageEfficiency
VIN=8Vto40V,ILOAD=20mAto1AVIN=6.5Vto40V,ILOAD=20mAto500mAVIN=12V,ILOAD=1A
3.33.386
3.251/3.2013.251/3.201
3.350/3.3993.350/3.399
VV%
Min(Note5)
Max(Note5)
Units
LM2675-5.0
Symbol
Parameter
Conditions
Typical(Note4)
SYSTEMPARAMETERSTestCircuitFigure2(Note3)VOUTVOUTη
OutputVoltageOutputVoltageEfficiency
VIN=8Vto40V,ILOAD=20mAto1AVIN=6.5Vto40V,ILOAD=20mAto500mAVIN=12V,ILOAD=1A
5.05.090
4.925/4.8504.925/4.850
5.075/5.1505.075/5.150
VV%
Min(Note5)
Max(Note5)
Units
LM2675-12
Symbol
Parameter
Conditions
Typical(Note4)
SYSTEMPARAMETERSTestCircuitFigure2(Note3)VOUTη
OutputVoltageEfficiency
VIN=15Vto40V,ILOAD=20mAto1AVIN=24V,ILOAD=1A
1294
11.82/11.64
12.18/12.36
V%
Min(Note5)
Max(Note5)
Units
LM2675-ADJ
Symbol
Parameter
Conditions
Typ(Note4)
SYSTEMPARAMETERSTestCircuitFigure3(Note3)VFBFeedbackVoltageFeedbackVoltage
VIN=8Vto40V,ILOAD=20mAto1AVOUTProgrammedfor5V(seeCircuitofFigure3)
VIN=6.5Vto40V,ILOAD=20mAto500mAVOUTProgrammedfor5V(seeCircuitofFigure3)
1.210
1.192/1.174
1.228/1.246
V
Min(Note5)
Max(Note5)
Units
VFB1.2101.192/1.1741.228/1.246V
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LM2675LM2675-ADJ
Symbolη
ParameterEfficiency
(Continued)
Conditions
VIN=12V,ILOAD=1A
Typ(Note4)90
Min(Note5)
Max(Note5)
%Units
AllOutputVoltageVersions
SpecificationswithstandardtypefaceareforTJ=25˚C,andthosewithboldtypefaceapplyoverfullOperatingTempera-tureRange.Unlessotherwisespecified,VIN=12Vforthe3.3V,5V,andAdjustableversionsandVIN=24Vforthe12Vver-sion,andILOAD=100mA.SymbolIQParameters
QuiescentCurrent
Conditions
VFEEDBACK=8V
For3.3V,5.0V,andADJVersionsVFEEDBACK=15VFor12VVersions
ISTBYICLILStandbyQuiescentCurrentCurrentLimit
OutputLeakageCurrent
VIN=40V,ON/OFFPin=0VVSWITCH=0V
VSWITCH=−1V,ON/OFFPin=0V
RDS(ON)fODIBIASVS/DIS/DθJASwitchOn-ResistanceOscillatorFrequencyMaximumDutyCycleMinimumDutyCycleFeedbackBiasCurrent
ON/OFFPin
VoltageThesholdsON/OFFPinCurrentThermalResistance
ON/OFFPin=0V
NPackage,JunctiontoAmbient(Note6)MPackage,JunctiontoAmbient(Note6)VFEEDBACK=1.3VADJVersionOnlyISWITCH=1A
MeasuredatSwitchPinON/OFFPin=0V
501.55160.25260950851.42095105
0.87
2.037
2251.25/1.2
100/1502.1/2.225150.30/0.50275
µAAµAmAΩkHz%%nAVµA˚C/W
2.5
mA
Typ2.5
Min
Max3.6
UnitsmA
DEVICEPARAMETERS
Note1:AbsoluteMaximumRatingsindicatelimitsbeyondwhichdamagetothedevicemayoccur.OperatingRatingsindicateconditionsforwhichthedeviceisintendedtobefunctional,butdeviceparameterspecificationsmaynotbeguaranteedundertheseconditions.Forguaranteedspecificationsandtestconditions,seetheElectricalCharacteristics.
Note2:Thehumanbodymodelisa100pFcapacitordischargedthrougha1.5kΩresistorintoeachpin.
Note3:Externalcomponentssuchasthecatchdiode,inductor,inputandoutputcapacitors,andvoltageprogrammingresistorscanaffectswitchingregulatorperformance.WhentheLM2675isusedasshowninFigures2,3testcircuits,systemperformancewillbeasspecifiedbythesystemparameterssectionoftheElectricalCharacteristics.
Note4:Typicalnumbersareat25˚Candrepresentthemostlikelynorm.
Note5:Alllimitsguaranteedatroomtemperature(standardtypeface)andattemperatureextremes(boldtypeface).Allroomtemperaturelimitsare100%productiontested.AlllimitsattemperatureextremesareguaranteedviacorrelationusingstandardStatisticalQualityControl(SQC)methods.AlllimitsareusedtocalculateAverageOutgoingQualityLevel(AOQL).
Note6:Junctiontoambientthermalresistancewithapproximately1squareinchofprintedcircuitboardcoppersurroundingtheleads.Additionalcopperareawilllowerthermalresistancefurther.SeeApplicationInformationsectionintheapplicationnoteaccompanyingthisdatasheetandthethermalmodelinLM267XMadeSimplesoftware(version6.0).ThevalueθJ−AfortheLLP(LD)packageisspecificallydependentonPCBtracearea,tracematerial,andthenumberoflayersandthermalvias.ForimprovedthermalresistanceandpowerdissipationfortheLLPpackage,refertoApplicationNoteAN-1187.
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LM2675TypicalPerformanceCharacteristics
NormalizedOutputVoltage
LineRegulation
0128030301280304
Efficiency
Drain-to-SourceResistance
0128030501280306
SwitchCurrentLimit
Operating
QuiescentCurrent
0128030701280308
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LM2675TypicalPerformanceCharacteristics
Standby
QuiescentCurrent
(Continued)
ON/OFFThreshold
Voltage
01280309
01280310
ON/OFFPinCurrent(Sourcing)
SwitchingFrequency
0128031101280312
FeedbackPinBiasCurrent
PeakSwitchCurrent
0128031301280314
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LM2675TypicalPerformanceCharacteristics
DropoutVoltage—3.3VOption
(Continued)
DropoutVoltage—5.0VOption
0128031501280316
BlockDiagram
01280317
*ActiveInductorPatentNumber5,514,947†ActiveCapacitorPatentNumber5,382,918
FIGURE1.
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LM2675TypicalPerformanceCharacteristics
ContinuousModeSwitchingWaveforms
VIN=20V,VOUT=5V,ILOAD=1A
L=47µH,COUT=68µF,COUTESR=50mΩ
(CircuitofFigure2)
DiscontinuousModeSwitchingWaveformsVIN=20V,VOUT=5V,ILOAD=300mA
L=15µH,COUT=68µF(2x),COUTESR=25mΩ
0128031801280319
A:VSWPinVoltage,10V/div.B:InductorCurrent,0.5A/div
C:OutputRippleVoltage,20mV/divAC-Coupled
A:VSWPinVoltage,10V/div.B:InductorCurrent,0.5A/div
C:OutputRippleVoltage,20mV/divAC-Coupled
HorizontalTimeBase:1µs/div
LoadTransientResponseforContinuousMode
VIN=20V,VOUT=5V,ILOAD=1A
L=47µH,COUT=68µF,COUTESR=50mΩ
HorizontalTimeBase:1µs/div
LoadTransientResponseforDiscontinuousMode
VIN=20V,VOUT=5V,
L=47µH,COUT=68µF,COUTESR=50mΩ
0128032001280321
A:OutputVoltage,100mV/div,AC-Coupled.B:LoadCurrent:200mAto1ALoadPulse
A:OutputVoltage,100mV/div,AC-Coupled.B:LoadCurrent:100mAto400mALoadPulse
HorizontalTimeBase:50µs/divHorizontalTimeBase:200µs/div
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LM2675TestCircuitandLayoutGuidelines
01280322
CIN-22µF,50VTantalum,Sprague“199DSeries”COUT-47µF,25VTantalum,Sprague“595DSeries”D1-3.3A,50VSchottkyRectifier,IR30WQ05FL1-68µHSumida#RCR110D-680LCB-0.01µF,50VCeramic
FIGURE2.StandardTestCircuitsandLayoutGuides
FixedOutputVoltageVersions
01280323
CIN-22µF,50VTantalum,Sprague“199DSeries”COUT-47µF,25VTantalum,Sprague“595DSeries”D1-3.3A,50VSchottkyRectifier,IR30WQ05FL1-68µHSumida#RCR110D-680LR1-1.5kΩ,1%
CB-0.01µF,50VCeramic
Fora5Voutput,selectR2tobe4.75kΩ,1%
whereVREF=1.21V
Usea1%resistorforbeststability.
FIGURE3.StandardTestCircuitsandLayoutGuides
AdjustableOutputVoltageVersion
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LM2675LM2675SeriesBuckRegulatorDesignProcedure(FixedOutput)
PROCEDURE(FixedOutputVoltageVersion)
Tosimplifythebuckregulatordesignprocedure,National
SemiconductorismakingavailablecomputerdesignsoftwaretobeusedwiththeSIMPLESWITCHERlineofswitching
regulators.LM267XMadeSimpleversion6.0isavailableonWindows®3.1,NT,or95operatingsystems.Given:
VOUT=RegulatedOutputVoltage(3.3V,5V,or12V)VIN(max)=MaximumDCInputVoltageILOAD(max)=MaximumLoadCurrent1.InductorSelection(L1)
A.SelectthecorrectinductorvalueselectionguidefromFigure4,Figure5orFigure6(outputvoltagesof3.3V,5V,or12Vrespectively).Forallothervoltages,seethedesignprocedurefortheadjustableversion.
B.Fromtheinductorvalueselectionguide,identifythe
inductanceregionintersectedbytheMaximumInputVoltagelineandtheMaximumLoadCurrentline.Eachregionis
identifiedbyaninductancevalueandaninductorcode(LXX).C.Selectanappropriateinductorfromthefourmanufacturer’spartnumberslistedinFigure8.Eachmanufacturermakesadifferentstyleofinductortoallowflexibilityinmeetingvariousdesignrequirements.Listedbelowaresomeofthe
differentiatingcharacteristicsofeachmanufacturer’sinductors:Schott:ferriteEPcoreinductors;thesehaveverylowleakagemagneticfieldstoreduceelectro-magneticinterference(EMI)andarethelowestpowerlossinductors
Renco:ferritestickcoreinductors;benefitsaretypicallylowestcostinductorsandcanwithstandE•Tandtransientpeak
currentsaboveratedvalue.BeawarethattheseinductorshaveanexternalmagneticfieldwhichmaygeneratemoreEMIthanothertypesofinductors.
Pulse:poweredirontoroidcoreinductors;thesecanalsobelowcostandcanwithstandlargerthannormalE•Tandtransientpeakcurrents.ToroidinductorshavelowEMI.
Coilcraft:ferritedrumcoreinductors;thesearethesmallestphysicalsizeinductors,availableonlyasSMTcomponents.BeawarethattheseinductorsalsogenerateEMI—butlessthanstickinductors.
Completespecificationsfortheseinductorsareavailablefromtherespectivemanufacturers.Atablelistingthemanufacturers’phonenumbersislocatedinFigure9.2.OutputCapacitorSelection(COUT)
A.SelectanoutputcapacitorfromtheoutputcapacitortableinFigure10.Usingtheoutputvoltageandtheinductancevaluefoundintheinductorselectionguide,step1,locatetheappropriatecapacitorvalueandvoltagerating.
2.OutputCapacitorSelection(COUT)
A.Usethe5.0VsectionintheoutputcapacitortableinFigure10.Chooseacapacitorvalueandvoltageratingfromthelinethatcontainstheinductancevalueof33µH.Thecapacitanceandvoltageratingvaluescorrespondingtothe33µHinductorarethe:Given:VOUT=5VVIN(max)=12VILOAD(max)=1A1.InductorSelection(L1)
A.Usetheinductorselectionguideforthe5VversionshowninFigure5.
EXAMPLE(FixedOutputVoltageVersion)
B.FromtheinductorvalueselectionguideshowninFigure5,theinductanceregionintersectedbythe12Vhorizontallineandthe1Averticallineis33µH,andtheinductorcodeisL23.C.Theinductancevaluerequiredis33µH.FromthetableinFigure8,gototheL23lineandchooseaninductorpartnumberfromanyofthefourmanufacturersshown.(Inmostinstances,boththroughholeandsurfacemountinductorsareavailable.)
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LM2675LM2675SeriesBuckRegulatorDesignProcedure(FixedOutput)
PROCEDURE(FixedOutputVoltageVersion)
Thecapacitorlistcontainsthrough-holeelectrolyticcapacitorsfromfourdifferentcapacitormanufacturersandsurfacemounttantalumcapacitorsfromtwodifferentcapacitormanufacturers.Itisrecommendedthatboththemanufacturersandthemanufacturer’sseriesthatarelistedinthetablebeused.Atablelistingthemanufacturers’phonenumbersislocatedinFigure11.
3.CatchDiodeSelection(D1)
A.Innormaloperation,theaveragecurrentofthecatchdiodeistheloadcurrenttimesthecatchdiodedutycycle,1-D(Distheswitchdutycycle,whichisapproximatelytheoutputvoltagedividedbytheinputvoltage).Thelargestvalueofthecatchdiodeaveragecurrentoccursatthemaximumloadcurrentandmaximuminputvoltage(minimumD).Fornormaloperation,thecatchdiodecurrentratingmustbeatleast1.3timesgreater
thanitsmaximumaveragecurrent.However,ifthepowersupplydesignmustwithstandacontinuousoutputshort,thediodeshouldhaveacurrentratingequaltothemaximumcurrentlimitoftheLM2675.Themoststressfulconditionforthisdiodeisashortedoutputcondition.
B.Thereversevoltageratingofthediodeshouldbeatleast1.25timesthemaximuminputvoltage.
C.Becauseoftheirfastswitchingspeedandlowforward
voltagedrop,Schottkydiodesprovidethebestperformanceandefficiency.ThisSchottkydiodemustbelocatedclosetotheLM2675usingshortleadsandshortprintedcircuittraces.4.InputCapacitor(CIN)
4.InputCapacitor(CIN)
SurfaceMount:
68µF/10VSprague594DSeries.100µF/10VAVXTPSSeries.ThroughHole:
68µF/10VSanyoOS-CONSASeries.220µF/35VSanyoMV-GXSeries.220µF/35VNichiconPLSeries.220µF/35VPanasonicHFQSeries.
(Continued)
EXAMPLE(FixedOutputVoltageVersion)
3.CatchDiodeSelection(D1)
A.RefertothetableshowninFigure12.Inthisexample,a1A,20VSchottkydiodewillprovidethebestperformance.Ifthecircuitmustwithstandacontinuousshortedoutput,ahighercurrentSchottkydiodeisrecommended.
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LM2675LM2675SeriesBuckRegulatorDesignProcedure(FixedOutput)
PROCEDURE(FixedOutputVoltageVersion)
AlowESRaluminumortantalumbypasscapacitorisneededbetweentheinputpinandgroundtopreventlargevoltage
transientsfromappearingattheinput.ThiscapacitorshouldbelocatedclosetotheICusingshortleads.Inaddition,theRMScurrentratingoftheinputcapacitorshouldbeselectedtobeatleast1⁄2theDCloadcurrent.Thecapacitormanufacturerdatasheetmustbecheckedtoassurethatthiscurrentratingisnotexceeded.ThecurvesshowninFigure14showtypicalRMScurrentratingsforseveraldifferentaluminumelectrolyticcapacitorvalues.Aparallelconnectionoftwoormore
capacitorsmayberequiredtoincreasethetotalminimumRMScurrentratingtosuittheapplicationrequirements.
Foranaluminumelectrolyticcapacitor,thevoltageratingshouldbeatleast1.25timesthemaximuminputvoltage.Cautionmustbeexercisedifsolidtantalumcapacitorsareused.Thetantalumcapacitorvoltageratingshouldbetwicethemaximuminputvoltage.ThetablesinFigure15showtherecommended
applicationvoltageforAVXTPSandSprague594Dtantalumcapacitors.Itisalsorecommendedthattheybesurgecurrenttestedbythemanufacturer.TheTPSseriesavailablefromAVX,andthe593Dand594DseriesfromSpragueareallsurge
currenttested.Anotherapproachtominimizethesurgecurrentstressesontheinputcapacitoristoaddasmallinductorinserieswiththeinputsupplyline.
Usecautionwhenusingceramiccapacitorsforinputbypassing,becauseitmaycausesevereringingattheVINpin.5.BoostCapacitor(CB)
(Continued)
EXAMPLE(FixedOutputVoltageVersion)
TheimportantparametersfortheinputcapacitoraretheinputvoltageratingandtheRMScurrentrating.Withamaximuminputvoltageof12V,analuminumelectrolyticcapacitorwithavoltageratinggreaterthan15V(1.25xVIN)wouldbeneeded.Thenexthighercapacitorvoltageratingis16V.
TheRMScurrentratingrequirementfortheinputcapacitorinabuckregulatorisapproximately1⁄2theDCloadcurrent.Inthisexample,witha1Aload,acapacitorwithaRMScurrentratingofatleast500mAisneeded.ThecurvesshowninFigure14canbeusedtoselectanappropriateinputcapacitor.Fromthecurves,locatethe16VlineandnotewhichcapacitorvalueshaveRMScurrentratingsgreaterthan500mA.
Forathroughholedesign,a330µF/16Velectrolyticcapacitor(PanasonicHFQseries,NichiconPL,SanyoMV-GXseriesorequivalent)wouldbeadequate.Othertypesorother
manufacturers’capacitorscanbeusedprovidedtheRMSripplecurrentratingsareadequate.Additionally,foracomplete
surfacemountdesign,electrolyticcapacitorssuchastheSanyoCV-CorCV-BSandtheNichiconWForURandtheNICComponentsNACZseriescouldbeconsidered.
Forsurfacemountdesigns,solidtantalumcapacitorscanbeused,butcautionmustbeexercisedwithregardtothecapacitorsurgecurrentratingandvoltagerating.Inthisexample,
checkingFigure15,andtheSprague594Dseriesdatasheet,aSprague594D15µF,25Vcapacitorisadequate.5.BoostCapacitor(CB)
ThiscapacitordevelopsthenecessaryvoltagetoturntheswitchForthisapplication,andallapplications,usea0.01µF,50Vgateonfully.Allapplicationsshouldusea0.01µF,50Vceramicceramiccapacitor.capacitor.
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LM2675LM2675SeriesBuckRegulatorDesignProcedure(FixedOutput)
InductorValueSelectionGuides(ForContinuousModeOperation)
(Continued)
01280326
01280328
FIGURE4.LM2675-3.3
FIGURE6.LM2675-12
01280327
01280329
FIGURE5.LM2675-5.0
FIGURE7.LM2675-ADJ
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LM2675LM2675SeriesBuckRegulatorDesignProcedure(FixedOutput)
Ind.
InductanceCurrentRef.
(µH)(A)
Desg.L4L5L6L7L9L10L11L12L13L14L15L18L19L20L21L22L23L24L27L28L29L30
68473322220150100684733222201501006847332222015010068
0.320.370.440.520.320.390.480.580.700.830.990.550.660.820.991.171.401.701.001.201.471.78
Schott
ThroughHole
SurfaceMount
HoleRL-1284-68-43RL-1284-47-43RL-1284-33-43RL-1284-22-43RL-5470-3RL-5470-4RL-5470-5RL-5470-6RL-5470-7RL-1284-33-43RL-1284-22-43RL-5471-2RL-5471-3RL-5471-4RL-5471-5RL-5471-6RL-5471-7RL-1283-22-43RL-5471-2RL-5471-3RL-5471-4RL-5471-5
Renco
Through
SurfaceMountRL1500-68RL1500-47RL1500-33RL1500-22
PulseEngineeringThroughHole
SurfaceMount
(Continued)
CoilcraftSurfaceMount
6714394067144310671483106714842067148320671484306714833067148440671439606714433067143970671443406714398067144350671439906714436067144000671443806714834067148450671483506714846067144040671444206714405067144430671440606714444067144070671444506714408067144460671440906714447067148370671484806714411067144490671441206714450067144130671445106714414067144520
PE-53804PE-53804-SDO1608-683PE-53805PE-53805-SDO1608-473PE-53806PE-53806-SDO1608-333PE-53807PE-53807-SDO1608-223
RL1500-220PE-53809PE-53809-SDO3308-224RL1500-150PE-53810PE-53810-SDO3308-154RL1500-100PE-53811PE-53811-SDO3308-104RL1500-68RL1500-47RL1500-33RL1500-22
PE-53812PE-53812-SDO3308-683PE-53813PE-53813-SDO3308-473PE-53814PE-53814-SDO3308-333PE-53815PE-53815-SDO3308-223
RL1500-220PE-53818PE-53818-SDO3316-224RL1500-150PE-53819PE-53819-SDO3316-154RL1500-100PE-53820PE-53820-SDO3316-104RL1500-68
———————
PE-53821PE-53821-SDO3316-683PE-53822PE-53822-SDO3316-473PE-53823PE-53823-SDO3316-333PE-53824PE-53824-SDO3316-223PE-53827PE-53827-SPE-53828PE-53828-SPE-53829PE-53829-SPE-53830PE-53830-S
DO5022P-224DO5022P-154DO5022P-104DO5022P-683
FIGURE8.InductorManufacturers’PartNumbers
CoilcraftInc.
CoilcraftInc.,EuropePulseEngineeringInc.PulseEngineeringInc.,Europe
RencoElectronicsInc.SchottCorp.
PhoneFAXPhoneFAXPhoneFAXPhoneFAXPhoneFAXPhoneFAX
(800)322-2645(708)639-1469+441236730595+441236730627(619)674-8100(619)674-8262+3539324107+3539324459(800)645-5828(516)586-5562(612)475-1173(612)475-1786
FIGURE9.InductorManufacturers’PhoneNumbers
www.national.com14
LM2675LM2675SeriesBuckRegulatorDesignProcedure(FixedOutput)
OutputCapacitor
OutputVoltage(V)
Inductance
(µH)
SurfaceMountSprague594DSeries(µF/V)
2233
3.3
47681001502233
5.0
4768100150223347
12
68100150220
120/6.3120/6.368/10120/6.3120/6.3120/6.3100/1668/1068/10100/16100/16100/16120/2068/2547/2047/2047/2047/2047/20
AVXTPSSeries(µF/V)100/10100/10100/10100/10100/10100/10100/1010010100/10100/10100/10100/10(2x)68/2068/2068/2068/2068/2068/2068/20
SanyoOS-CONSASeries(µF/V)100/1068/1068/10100/10100/10100/10100/1068/1068/10100/10100/10100/1068/2068/2047/2047/2047/2047/2047/20
ThroughHoleSanyoMV-GX
Series(µF/V)330/35220/35150/35120/35120/35120/35330/35220/35150/35120/35120/35120/35330/35220/35150/35120/35120/35120/35120/35
NichiconPLSeries(µF/V)330/35220/35150/35120/35120/35120/35330/35220/35150/35120/35120/35120/35330/35220/35150/35120/35120/35120/35120/35
(Continued)
PanasonicHFQSeries(µF/V)330/35220/35150/35120/35120/35120/35330/35220/35150/35120/35120/35120/35330/35220/35150/35120/35120/35120/35120/35
FIGURE10.OutputCapacitorTable
NichiconCorp.PanasonicAVXCorp.Sprague/VishaySanyoCorp.
PhoneFAXPhoneFAXPhoneFAXPhoneFAXPhoneFAX
(847)843-7500(847)843-2798(714)373-7857(714)373-7102(803)448-9411(803)448-1943(207)324-4140(207)324-7223(619)661-6322(619)661-1055
FIGURE11.CapacitorManufacturers’PhoneNumbers
15www.national.com
LM2675LM2675SeriesBuckRegulatorDesignProcedure(FixedOutput)
1ADiodes
VR20V30V
SurfaceMountSK12B120SK13B130MBRS13040V
SK14B140MBRS14010BQ04010MQ04015MQ040
50V
SK15B15010BQ050
MBR15011DQ05SR105
SK3530WQ05F
MBR35031DQ05SR305
ThroughHole1N5817SR1021N581811DQ03SR1031N581911DQ04SR104
SK3430BQ04030WQ04FMBRS340MBRD340
1N5822MBR34031DQ04SR304
SK3330WQ03F
3ADiodesSurfaceMountSK32
ThroughHole1N5820SR3021N582131DQ03
(Continued)
FIGURE12.SchottkyDiodeSelectionTable
InternationalRectifierCorp.Motorola,Inc.GeneralInstrumentsCorp.Diodes,Inc.
PhoneFAXPhoneFAXPhoneFAXPhoneFAX
(310)322-3331(310)322-3332(800)521-6274(602)244-6609(516)847-3000(516)847-3236(805)446-4800(805)446-4850
FIGURE13.DiodeManufacturers’PhoneNumbers
01280330
FIGURE14.RMSCurrentRatingsforLowESRElectrolyticCapacitors(Typical)
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LM2675LM2675SeriesBuckRegulatorDesignProcedure(FixedOutput)
AVXTPS
RecommendedApplicationVoltage
3.35101215
Sprague594D
RecommendedApplicationVoltage
2.53.35812182429
FIGURE15.
VoltageRating
46.3101620253550
VoltageRating
6.310202535
(Continued)
+85˚CRating
+85˚CRating
LM2675SeriesBuckRegulatorDesignProcedure(AdjustableOutput)
PROCEDURE(AdjustableOutputVoltageVersion)Tosimplifythebuckregulatordesignprocedure,National
SemiconductorismakingavailablecomputerdesignsoftwaretobeusedwiththeSIMPLESWITCHERlineofswitching
regulators.LM267XMadeSimpleversion6.0isavailableforuseonWindows3.1,NT,or95operatingsystems.Given:
VOUT=RegulatedOutputVoltageVIN(max)=MaximumInputVoltageILOAD(max)=MaximumLoadCurrent
F=SwitchingFrequency(Fixedatanominal260kHz).1.ProgrammingOutputVoltage(SelectingR1andR2,asshowninFigure3)
Usethefollowingformulatoselecttheappropriateresistorvalues.
Given:VOUT=20VVIN(max)=28VILOAD(max)=1A
F=SwitchingFrequency(Fixedatanominal260kHz).1.ProgrammingOutputVoltage(SelectingR1andR2,asshowninFigure3)
SelectR1tobe1kΩ,1%.SolveforR2.
EXAMPLE(AdjustableOutputVoltageVersion)
whereVREF=1.21V
SelectavalueforR1between240Ωand1.5kΩ.ThelowerR2=1k(16.53−1)=15.53kΩ,closest1%valueis15.4kΩ.resistorvaluesminimizenoisepickupinthesensitivefeedbackR2=15.4kΩ.pin.(Forthelowesttemperaturecoefficientandthebeststabilitywithtime,use1%metalfilmresistors.)
17www.national.com
LM2675LM2675SeriesBuckRegulatorDesignProcedure(AdjustableOutput)
(Continued)
PROCEDURE(AdjustableOutputVoltageVersion)2.InductorSelection(L1)
EXAMPLE(AdjustableOutputVoltageVersion)
2.InductorSelection(L1)
A.CalculatetheinductorVolt•microsecondconstantE•T(V•A.CalculatetheinductorVolt•microsecondconstant(E•T),µs),fromthefollowingformula:
whereVSAT=internalswitchsaturationvoltage=0.25VandVD=diodeforwardvoltagedrop=0.5V
B.UsetheE•TvaluefromthepreviousformulaandmatchitwiththeE•TnumberontheverticalaxisoftheInductorValueSelectionGuideshowninFigure7.
C.Onthehorizontalaxis,selectthemaximumloadcurrent.D.IdentifytheinductanceregionintersectedbytheE•TvalueandtheMaximumLoadCurrentvalue.Eachregionisidentifiedbyaninductancevalueandaninductorcode(LXX).
E.Selectanappropriateinductorfromthefourmanufacturer’spartnumberslistedinFigure8.Forinformationonthedifferenttypesofinductors,seetheinductorselectioninthefixedoutputvoltagedesignprocedure.
3.OutputCapacitorSelection(COUT)
B.E•T=21.6(V•µs)
C.ILOAD(max)=1A
D.FromtheinductorvalueselectionguideshowninFigure7,theinductanceregionintersectedbythe21.6(V•µs)horizontallineandthe1Averticallineis68µH,andtheinductorcodeisL30.
E.FromthetableinFigure8,locatelineL30,andselectaninductorpartnumberfromthelistofmanufacturerspartnumbers.
3.OutputCapacitorSeIection(COUT)
A.SelectanoutputcapacitorfromthecapacitorcodeselectionA.UsetheappropriaterowofthecapacitorcodeselectionguideinFigure16.Usingtheinductancevaluefoundintheguide,inFigure16.Forthisexample,usethe15–20Vrow.Theinductorselectionguide,step1,locatetheappropriatecapacitorcapacitorcodecorrespondingtoaninductanceof68µHisC20.codecorrespondingtothedesiredoutputvoltage.
B.Selectanappropriatecapacitorvalueandvoltagerating,usingthecapacitorcode,fromtheoutputcapacitorselectiontableinFigure17.Therearetwosolidtantalum(surfacemount)capacitormanufacturersandfourelectrolytic(throughhole)
capacitormanufacturerstochoosefrom.Itisrecommendedthatboththemanufacturersandthemanufacturer’sseriesthatarelistedinthetablebeused.Atablelistingthemanufacturers’phonenumbersislocatedinFigure11.
B.FromtheoutputcapacitorselectiontableinFigure17,
chooseacapacitorvalue(andvoltagerating)thatintersectsthecapacitorcode(s)selectedinsectionA,C20.
ThecapacitanceandvoltageratingvaluescorrespondingtothecapacitorcodeC20arethe:SurfaceMount:
33µF/25VSprague594DSeries.33µF/25VAVXTPSSeries.ThroughHole:
33µF/25VSanyoOS-CONSCSeries.120µF/35VSanyoMV-GXSeries.120µF/35VNichiconPLSeries.120µF/35VPanasonicHFQSeries.
Othermanufacturersorothertypesofcapacitorsmayalsobeused,providedthecapacitorspecifications(especiallythe100kHzESR)closelymatchthecharacteristicsofthecapacitorslistedintheoutputcapacitortable.Refertothecapacitormanufacturers’datasheetforthisinformation.
www.national.com18
LM2675LM2675SeriesBuckRegulatorDesignProcedure(AdjustableOutput)
(Continued)
PROCEDURE(AdjustableOutputVoltageVersion)4.CatchDiodeSelection(D1)
A.Innormaloperation,theaveragecurrentofthecatchdiodeistheloadcurrenttimesthecatchdiodedutycycle,1-D(Distheswitchdutycycle,whichisapproximatelyVOUT/VIN).Thelargestvalueofthecatchdiodeaveragecurrentoccursatthemaximuminputvoltage(minimumD).Fornormaloperation,thecatchdiodecurrentratingmustbeatleast1.3timesgreaterthanitsmaximumaveragecurrent.However,ifthepowersupplydesignmustwithstandacontinuousoutputshort,thediodeshouldhaveacurrentratinggreaterthanthemaximumcurrentlimitoftheLM2675.Themoststressfulconditionforthisdiodeisashortedoutputcondition.
B.Thereversevoltageratingofthediodeshouldbeatleast1.25timesthemaximuminputvoltage.
C.Becauseoftheirfastswitchingspeedandlowforward
voltagedrop,Schottkydiodesprovidethebestperformanceandefficiency.TheSchottkydiodemustbelocatedclosetotheLM2675usingshortleadsandshortprintedcircuittraces.5.InputCapacitor(CIN)
AlowESRaluminumortantalumbypasscapacitorisneededbetweentheinputpinandgroundtopreventlargevoltage
transientsfromappearingattheinput.ThiscapacitorshouldbelocatedclosetotheICusingshortleads.Inaddition,theRMScurrentratingoftheinputcapacitorshouldbeselectedtobeatleast1⁄2theDCloadcurrent.Thecapacitormanufacturerdatasheetmustbecheckedtoassurethatthiscurrentratingisnotexceeded.ThecurvesshowninFigure14showtypicalRMScurrentratingsforseveraldifferentaluminumelectrolyticcapacitorvalues.Aparallelconnectionoftwoormore
capacitorsmayberequiredtoincreasethetotalminimumRMScurrentratingtosuittheapplicationrequirements.
Foranaluminumelectrolyticcapacitor,thevoltageratingshouldbeatleast1.25timesthemaximuminputvoltage.Cautionmustbeexercisedifsolidtantalumcapacitorsareused.Thetantalumcapacitorvoltageratingshouldbetwicethemaximuminputvoltage.ThetablesinFigure15showtherecommended
applicationvoltageforAVXTPSandSprague594Dtantalumcapacitors.Itisalsorecommendedthattheybesurgecurrenttestedbythemanufacturer.TheTPSseriesavailablefromAVX,andthe593Dand594DseriesfromSpragueareallsurge
currenttested.Anotherapproachtominimizethesurgecurrentstressesontheinputcapacitoristoaddasmallinductorinserieswiththeinputsupplyline.
Usecautionwhenusingceramiccapacitorsforinputbypassing,becauseitmaycausesevereringingattheVINpin.6.BoostCapacitor(CB)
5.InputCapacitor(CIN)
TheimportantparametersfortheinputcapacitoraretheinputvoltageratingandtheRMScurrentrating.Withamaximuminputvoltageof28V,analuminumelectrolyticcapacitorwithavoltageratingofatleast35V(1.25xVIN)wouldbeneeded.TheRMScurrentratingrequirementfortheinputcapacitorinabuckregulatorisapproximately1⁄2theDCloadcurrent.Inthisexample,witha1Aload,acapacitorwithaRMScurrentratingofatleast500mAisneeded.ThecurvesshowninFigure14canbeusedtoselectanappropriateinputcapacitor.Fromthecurves,locatethe35VlineandnotewhichcapacitorvalueshaveRMScurrentratingsgreaterthan500mA.
Forathroughholedesign,a330µF/35Velectrolyticcapacitor(PanasonicHFQseries,NichiconPL,SanyoMV-GXseriesorequivalent)wouldbeadequate.Othertypesorother
manufacturers’capacitorscanbeusedprovidedtheRMSripplecurrentratingsareadequate.Additionally,foracomplete
surfacemountdesign,electrolyticcapacitorssuchastheSanyoCV-CorCV-BS,andtheNichiconWForURandtheNICComponentsNACZseriescouldbeconsidered.
Forsurfacemountdesigns,solidtantalumcapacitorscanbeused,butcautionmustbeexercisedwithregardtothecapacitorsurgecurrentratingandvoltagerating.Inthisexample,
checkingFigure15,andtheSprague594Dseriesdatasheet,aSprague594D15µF,50Vcapacitorisadequate.
EXAMPLE(AdjustableOutputVoltageVersion)
4.CatchDiodeSelection(D1)
A.RefertothetableshowninFigure12.Schottkydiodesprovidethebestperformance,andinthisexamplea1A,40VSchottkydiodewouldbeagoodchoice.Ifthecircuitmust
withstandacontinuousshortedoutput,ahighercurrent(atleast2.2A)Schottkydiodeisrecommended.
6.BoostCapacitor(CB)
ThiscapacitordevelopsthenecessaryvoltagetoturntheswitchForthisapplication,andallapplications,usea0.01µF,50Vgateonfully.Allapplicationsshouldusea0.01µF,50Vceramicceramiccapacitor.capacitor.
19www.national.com
LM2675LM2675SeriesBuckRegulatorDesignProcedure(AdjustableOutput)
(Continued)
Case
Style(Note7)SMandTHSMandTHSMandTHSMandTHSMandTHSMandTHSMandTHSMandTHSMandTHSMandTH
TH
OutputVoltage(V)1.21–2.502.50–3.753.75–5.05.0–6.256.25–7.57.5–10.010.0–12.512.5–15.015.0–20.020.0–30.030.0–37.0
TH-ThroughHole
Inductance(µH)
22————C8C9C14C15C18C21C23
33———C4C4C10C11C16C19C22C24
47——C4C7C7C11C12C17C20C22C24
68—C1C5C6C6C12C12C17C20C22C25
100C1C2C6C6C6C13C13C17C20C22C25
150C2C3C6C6C6C13C13C17C20C22C25
220C3C3C6C6C6C13C13C17C20C22C25
Note7:SM-SurfaceMount,
FIGURE16.CapacitorCodeSelectionGuide
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LM2675LM2675SeriesBuckRegulatorDesignProcedure(AdjustableOutput)
(Continued)
OutputCapacitor
Cap.Ref.Desg.#C1C2C3C4C5C6C7C8C9C10C11C12C13C14C15C16C17C18C19C20C21C22C23C24C25
SurfaceMountSprague594DSeries(µF/V)120/6.3120/6.3120/6.368/10100/16100/1668/10100/16100/16100/16100/16100/16100/16100/1647/2047/2047/2068/2533/2533/2533/3533/35(Note9)(Note9)(Note9)
AVXTPSSeries(µF/V)100/10100/10100/10100/10100/10100/10100/10100/10100/16100/16100/16100/16100/16100/1668/2068/2068/20(2x)33/2533/2533/25(2x)22/2522/35(Note9)(Note9)(Note9)
SanyoOS-CONSASeries(µF/V)100/10100/10100/3568/10100/10100/1068/10100/10100/1668/1668/1668/16100/16100/1647/2047/2047/2047/25(Note8)33/25(Note8)33/25(Note8)(Note9)(Note9)(Note9)(Note9)(Note9)
ThroughHole
SanyoMV-GX
Series(µF/V)220/35150/35120/35220/35150/35120/35150/35330/35330/35220/35150/35120/35120/35220/35220/35150/35120/35220/35150/35120/35150/35120/35220/50150/50150/50
NichiconPLSeries(µF/V)220/35150/35120/35220/35150/35120/35150/35330/35330/35220/35150/35120/35120/35220/35220/35150/35120/35220/35150/35120/35150/35120/35100/50100/5082/50
PanasonicHFQSeries(µF/V)220/35150/35120/35220/35150/35120/35150/35330/35330/35220/35150/35120/35120/35220/35220/35150/35120/35220/35150/35120/35150/35120/35120/50120/5082/50
Note8:TheSCseriesofOs-Concapacitors(othersareSAseries)
Note9:ThevoltageratingsofthesurfacemounttantalumchipandOs-Concapacitorsaretoolowtoworkatthesevoltages.
FIGURE17.OutputCapacitorSelectionTable
21www.national.com
LM2675ApplicationInformation
TYPICALSURFACEMOUNTPCBOARDLAYOUT,FIXEDOUTPUT(4XSIZE)
01280336
CIN-15µF,50V,SolidTantalumSprague,“594Dseries”COUT-68µF,16V,SolidTantalumSprague,“594Dseries”D1-1A,40VSchottkyRectifier,SurfaceMountL1-33µH,L23,CoilcraftDO3316CB-0.01µF,50V,Ceramic
TYPICALSURFACEMOUNTPCBOARDLAYOUT,ADJUSTABLEOUTPUT(4XSIZE)
01280337
CIN-15µF,50V,SolidTantalumSprague,“594Dseries”COUT-33µF,25V,SolidTantalumSprague,“594Dseries”D1-1A,40VSchottkyRectifier,SurfaceMountL1-68µH,L30,CoilcraftDO3316CB-0.01µF,50V,CeramicR1-1k,1%
R2-UseformulainDesignProcedure
FIGURE18.PCBoardLayout
Layoutisveryimportantinswitchingregulatordesigns.Rap-idlyswitchingcurrentsassociatedwithwiringinductancecangeneratevoltagetransientswhichcancauseproblems.Forminimalinductanceandgroundloops,thewiresindicatedbyheavylines(inFigure2andFigure3)shouldbewideprintedcircuittracesandshouldbekeptasshortas
possible.Forbestresults,externalcomponentsshouldbelocatedasclosetotheswitcherICaspossibleusinggroundplaneconstructionorsinglepointgrounding.
Ifopencoreinductorsareused,specialcaremustbetakenastothelocationandpositioningofthistypeofinduc-tor.Allowingtheinductorfluxtointersectsensitivefeedback,ICgroundpath,andCOUTwiringcancauseproblems.
22
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LM2675ApplicationInformation
(Continued)
Whenusingtheadjustableversion,specialcaremustbetakenastothelocationofthefeedbackresistorsandtheassociatedwiring.PhysicallylocatebothresistorsneartheIC,androutethewiringawayfromtheinductor,especiallyanopencoretypeofinductor.LLPPACKAGEDEVICES
TheLM2675isofferedinthe16leadLLPsurfacemountpackagetoallowforincreasedpowerdissipationcomparedtotheSO-8andDIP.
TheDieAttachPad(DAP)canandshouldbeconnectedtoPCBGroundplane/island.ForCADandassemblyguide-linesrefertoApplicationNoteAN-1187athttp://power.national.com.
23www.national.com
LM2675PhysicalDimensions
unlessotherwisenoted
inches(millimeters)
8-Lead(0.150\"Wide)MoldedSmallOutlinePackage,JEDEC
OrderNumberLM2675M-3.3,LM2675M-5.0,
LM2675M-12orLM2675M-ADJNSPackageNumberM08A
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LM2675PhysicalDimensions
inches(millimeters)unlessotherwisenoted(Continued)
8-Lead(0.300\"Wide)MoldedDual-In-LinePackage
OrderNumberLM2675N-3.3,LM2675N-5.0,
LM2675N-12orLM2675N-ADJNSPackageNumberN08E
25www.national.com
LM2675SIMPLESWITCHERPowerConverterHighEfficiency1AStep-DownVoltageRegulatorPhysicalDimensions
inches(millimeters)unlessotherwisenoted(Continued)
16-LeadLLPSurfaceMountPackage
NSPackageNumberLDA16A
Nationaldoesnotassumeanyresponsibilityforuseofanycircuitrydescribed,nocircuitpatentlicensesareimpliedandNationalreservestherightatanytimewithoutnoticetochangesaidcircuitryandspecifications.Forthemostcurrentproductinformationvisitusatwww.national.com.LIFESUPPORTPOLICY
NATIONAL’SPRODUCTSARENOTAUTHORIZEDFORUSEASCRITICALCOMPONENTSINLIFESUPPORTDEVICESORSYSTEMSWITHOUTTHEEXPRESSWRITTENAPPROVALOFTHEPRESIDENTANDGENERALCOUNSELOFNATIONALSEMICONDUCTORCORPORATION.Asusedherein:
1.Lifesupportdevicesorsystemsaredevicesorsystemswhich,(a)areintendedforsurgicalimplantintothebody,or(b)supportorsustainlife,andwhosefailuretoperformwhenproperlyusedinaccordancewithinstructionsforuseprovidedinthelabeling,canbereasonablyexpectedtoresultinasignificantinjurytotheuser.BANNEDSUBSTANCECOMPLIANCE
NationalSemiconductorcertifiesthattheproductsandpackingmaterialsmeettheprovisionsoftheCustomerProductsStewardshipSpecification(CSP-9-111C2)andtheBannedSubstancesandMaterialsofInterestSpecification(CSP-9-111S2)andcontainno‘‘BannedSubstances’’asdefinedinCSP-9-111S2.
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Email:new.feedback@nsc.comTel:1-800-272-9959
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Email:jpn.feedback@nsc.comTel:81-3-5639-7560
2.Acriticalcomponentisanycomponentofalifesupportdeviceorsystemwhosefailuretoperformcanbereasonablyexpectedtocausethefailureofthelifesupportdeviceorsystem,ortoaffectitssafetyoreffectiveness.
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