affectrrrr333

PrecisionLowDrift2.
048V/2.
500VSOT-23VoltageReferenceADR380/ADR381Rev.
CInformationfurnishedbyAnalogDevicesisbelievedtobeaccurateandreliable.
However,noresponsibilityisassumedbyAnalogDevicesforitsuse,norforanyinfringementsofpatentsorotherrightsofthirdpartiesthatmayresultfromitsuse.
Specificationssubjecttochangewithoutnotice.
NolicenseisgrantedbyimplicationorotherwiseunderanypatentorpatentrightsofAnalogDevices.
Trademarksandregisteredtrademarksarethepropertyoftheirrespectiveowners.
OneTechnologyWay,P.
O.
Box9106,Norwood,MA02062-9106,U.
S.
A.
Tel:781.
329.
4700www.
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comFax:781.
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31132001–2010AnalogDevices,Inc.
Allrightsreserved.
FEATURESInitialaccuracy:±5mV/±6mVmaximumInitialaccuracyerror:±0.
24%/±0.
24%LowTCVOUT:25ppm/°CmaximumLoadregulation:70ppm/mALineregulation:25ppm/VWideoperatingranges2.
4Vto18VforADR3802.
8Vto18VforADR381Lowpower:120μAmaximumHighoutputcurrent:5mAWidetemperaturerange:40°Cto+85°CTiny3-leadSOT-23packagewithstandardpinoutAPPLICATIONSBattery-poweredinstrumentationPortablemedicalinstrumentsDataacquisitionsystemsIndustrialprocesscontrolsystemsHarddiskdrivesAutomotivePINCONFIGURATIONVIN1VOUT2GND3ADR380/ADR381TOPVIEW(NottoScale)02175-001Figure1.
3-LeadSOT-23(RTSuffix)GENERALDESCRIPTIONTheADR380andADR381areprecision2.
048Vand2.
500Vbandgapvoltagereferencesfeaturinghighaccuracy,highstability,andlowpowerconsumptioninatinyfootprint.
Patentedtemperaturedriftcurvaturecorrectiontechniquesminimizenonlinearityofthevoltagechangewithtemperature.
Thewideoperatingrangeandlowpowerconsumptionmakethemidealfor3Vto5Vbattery-poweredapplications.
TheADR380andADR381aremicropower,lowdropoutvoltage(LDV)devicesthatprovideastableoutputvoltagefromsuppliesaslowas300mVabovetheoutputvoltage.
Theyarespecifiedovertheindustrial(40°Cto+85°C)temperaturerange.
TheADR380/ADR381areavailableinthetiny3-leadSOT-23package.
Table1.
ADR38xProductsPartNumberNominalOutputVoltage(V)ADR3802.
048ADR3812.
500ADR380/ADR381Rev.
C|Page2of16TABLEOFCONTENTSFeatures1Applications.
1PinConfiguration.
1GeneralDescription.
1RevisionHistory2Specifications.
3ADR380ElectricalCharacteristics.
3ADR381ElectricalCharacteristics.
4AbsoluteMaximumRatings.
5ThermalResistance.
5ESDCaution.
5TypicalPerformanceCharacteristics6Terminology.
10TheoryofOperation11DevicePowerDissipationConsiderations.
11InputCapacitor.
11OutputCapacitor.
11ApplicationsInformation.
12StackingReferenceICsforArbitraryOutputs12ANegativePrecisionReferenceWithoutPrecisionResistors12PrecisionCurrentSource12PrecisionHighCurrentVoltageSource13OutlineDimensions.
14OrderingGuide14REVISIONHISTORY10/10—Rev.
BtoRev.
CDeletedFigure32.
14ChangestoOrderingGuide141/09—Rev.
AtoRev.
BUpdatedFormat.
UniversalChangestoTable7.
5ChangestoStackingReferenceICsforArbitraryOutputsSection,Figure28,andFigure2912UpdatedOutlineDimensions.
14ChangestoOrderingGuide147/04—Rev.
0toRev.
AUpdatedFormat.
UniversalChangestoOrderingGuide.
16UpdatedOutlineDimensions.
16ADR380/ADR381Rev.
C|Page3of16SPECIFICATIONSADR380ELECTRICALCHARACTERISTICSVIN=5.
0V,TA=25°C,unlessotherwisenoted.
Table2.
ParameterSymbolConditionsMinTypMaxUnitOutputVoltageVOUT2.
0432.
0482.
053VInitialAccuracyErrorVOERR5+5mV0.
24+0.
24%TemperatureCoefficientTCVOUT40°C15V10secVIN≤15VIndefiniteStorageTemperatureRange65°Cto+150°COperatingTemperatureRange40°Cto+85°CJunctionTemperatureRange65°Cto+150°CLeadTemperature(Soldering,60Sec)300°CθJAisspecifiedfortheworst-caseconditions,thatis,adevicesolderedinacircuitboardforsurface-mountpackages.
Table7.
PackageTypeθJAUnit3-LeadSOT-23(RT)333°C/WESDCAUTION1Absolutemaximumratingsapplyat25°C,unlessotherwisenoted.
StressesabovethoselistedunderAbsoluteMaximumRatingsmaycausepermanentdamagetothedevice.
Thisisastressratingonly;functionaloperationofthedeviceattheseoranyotherconditionsabovethoseindicatedintheoperationalsectionofthisspecificationisnotimplied.
Exposuretoabsolutemaximumratingconditionsforextendedperiodsmayaffectdevicereliability.
ADR380/ADR381Rev.
C|Page6of16TYPICALPERFORMANCECHARACTERISTICSTEMPERATURE(°C)2.
042VOUT(V)2.
0442.
0462.
0482.
0502.
0522.
054SAMPLE1SAMPLE2SAMPLE33510–15–40856002175-002Figure2.
ADR380OutputVoltagevs.
TemperatureTEMPERATURE(°C)2.
494VOUT(V)2.
4962.
4982.
5002.
5022.
5042.
506SAMPLE1SAMPLE2SAMPLE3–40–151035608502175-003Figure3.
ADR381OutputVoltagevs.
TemperaturePPM(°C)051015202530TOTALNUMBEROFDEVICES=130TEMPERATURE+25°C–40°C+85°C+25°CFREQUENCY–11–9–7–5–3–113579111315171902175-004Figure4.
ADR380OutputVoltageTemperatureCoefficientPPM(°C)0FREQUENCY102030405060TOTALNUMBEROFDEVICESINSAMPLE=450TEMPERATURE+25°C–40°C+85°C+25°C–11–13–15–9–7–5–3–11357911131502175-005Figure5.
ADR381OutputVoltageTemperatureCoefficientINPUTVOLTAGE(V)2.
55.
07.
510.
012.
515.
0+85°C–40°C+25°C0SUPPLYCURRENT(A)2040801001201406002175-006Figure6.
ADR380SupplyCurrentvs.
InputVoltageINPUTVOLTAGE(V)2.
55.
07.
510.
012.
515.
0+85°C+25°C0SUPPLYCURRENT(A)20408010012014060–40°C02175-007Figure7.
ADR381SupplyCurrentvs.
InputVoltageADR380/ADR381Rev.
C|Page7of16VIN=5VVIN=3VTEMPERATURE(°C)0LOADREGULATION(ppm/mA)10204050607030ILOAD=0mATO5mA–40–151035608502175-008Figure8.
ADR380LoadRegulationvs.
TemperatureTEMPERATURE(°C)0LOADREGULATION(ppm/mA)10204050607030–40–1510356085VIN=5VVIN=3.
5VILOAD=5mA02175-009Figure9.
ADR381LoadRegulationvs.
TemperatureVIN=2.
5VTO15VTEMPERATURE(°C)0LINEREGULATION(ppm/V)12453–40–151035608502175-010Figure10.
ADR380LineRegulationvs.
TemperatureVIN=2.
8VTO15VTEMPERATURE(°C)0LINEREGULATION(ppm/V)12453–40–151035608502175-011Figure11.
ADR381LineRegulationvs.
Temperature–40°CLOADCURRENT(mA)0DIFFERENTIALVOLTAGE(V)0.
20.
40.
60.
8+85°C+25°C01234502175-012Figure12.
ADR380MinimumInput/OutputDifferentialVoltagevs.
LoadCurrentLOADCURRENT(mA)0DIFFERENTIALVOLTAGE(V)0.
20.
40.
60.
8012345–40°C+85°C+25°C02175-013Figure13.
ADR381MinimumInput/OutputDifferentialVoltagevs.
LoadCurrentADR380/ADR381Rev.
C|Page8of16HYSTERESIS(ppm)0FREQUENCY102030405060TEMPERATURE+25°C–40°C+85°C+25°C–260–200–140–80–204010016022028034040002175-014Figure14.
ADR381VOUTHysteresisTIME(1s/DIV)2V/DIV102175-015Figure15.
ADR381TypicalNoiseVoltage,0.
1Hzto10HzTIME(10ms/DIV)100V/DIV102175-016Figure16.
ADR381TypicalNoiseVoltage,10Hzto10kHzTIME(10s/DIV)1V/DIV0.
5V/DIVCBYPASS=0FVOUTLINEINTERRUPTION0.
5V/DIV12VIN02175-017Figure17.
ADR381LineTransientResponseTIME(10s/DIV)1V/DIV0.
5V/DIVCBYPASS=0.
1FVOUTLINEINTERRUPTION0.
5V/DIV1202175-018Figure18.
ADR381LineTransientResponseCL=0FTIME(200s/DIV)1V/DIVVOUTVLOADONLOADOFFILOAD=1mA2V/DIV1202175-019Figure19.
ADR381LoadTransientResponsewithCL=0μFADR380/ADR381Rev.
C|Page9of16CL=1nFTIME(200s/DIV)1V/DIVVOUTVLOADONLOADOFFILOAD=1mA2V/DIV1202175-020Figure20.
ADR381LoadTransientResponsewithCL=1nFCL=100nFTIME(200s/DIV)1V/DIVVOUTVLOADONLOADOFFILOAD=1mA2V/DIV1202175-021Figure21.
ADR381LoadTransientResponsewithCL=100nFRL=500TIME(200s/DIV)2V/DIVVOUTVIN5V/DIV1202175-022Figure22.
ADR381Turn-On/Turn-OffResponseat5V101001k10k100k1MZOUT(10/DIV)CL=40pFCL=0.
1FCL=1FCBYPASS=0.
1FFREQUENCY(Hz)02175-023Figure23.
ADR381OutputImpedancevs.
FrequencyHOURS0–150DRIFT(ppm)–100–5050100150CONDITIONS:VIN=6VINACONTROLLEDENVIRONMENT50°C±1°C0100200300400500600700800900100002175-024Figure24.
ADR380Long-TermDriftHOURS0–150DRIFT(ppm)–100–5050100150CONDITIONS:VIN=6VINACONTROLLEDENVIRONMENT50°C±1°C0100200300400500600700800900100002175-025Figure25.
ADR381Long-TermDriftADR380/ADR381Rev.
C|Page10of16TERMINOLOGYTemperatureCoefficientThechangeofoutputvoltageovertheoperatingtemperaturechangeandnormalizedbytheoutputvoltageat25°C,expressedinppm/°C.
Theequationfollows:610)()()(]Cppm/[**°=°12OUT1OUT2OUTOUTTTC)(25VTVTVTCVwhere:VOUT(25°C)=VOUTat25°C.
VOUT(T1)=VOUTatTemperature1.
VOUT(T2)=VOUTatTemperature2.
LineRegulationThechangeinoutputvoltageduetoaspecifiedchangeininputvoltage.
Itincludestheeffectsofself-heating.
Lineregulationisexpressedineitherpercentpervolt,parts-per-millionpervolt,ormicrovoltspervoltchangeininputvoltage.
LoadRegulationThechangeinoutputvoltageduetoaspecifiedchangeinloadcurrent.
Itincludestheeffectsofself-heating.
Loadregulationisexpressedineithermicrovoltspermilliampere,parts-per-millionpermilliampere,orohmsofdcoutputresistance.
Long-TermStabilityAtypicalshiftinoutputvoltageover1000hoursatacontrolledtemperature.
Figure24andFigure25showasampleofpartsmeasuredatdifferentintervalsinacontrolledenvironmentof50°Cfor1000hours.
610)()()(]ppm[)()(*=Δ=Δ0UTO1OUT0OUTUTO1UTO0OUTOUTtVtVtVVtVtVVwhere:VOUT(t0)=VOUTatTime0.
VOUT(t1)=VOUTafter1000hoursofoperationatacontrolledtemperature.
Notethat50°Cwaschosenbecausemostapplicationsrunatahighertemperaturethan25°C.
ThermalHysteresisThechangeofoutputvoltageafterthedeviceiscycledthroughtemperaturefrom+25°Cto40°Cto+85°Candbackto+25°C.
Thisisatypicalvaluefromasampleofpartsputthroughsuchacycle.
6____10)C25(]ppm[*°°=°=C)(25VVVVVC)(25VVOUTTCOUTOUTHYSOUTTCOUTUTOHYSOUTwhere:VOUT(25°C)=VOUTat25°C.
VOUT_TC=VOUTat25°Cafteratemperaturecyclefrom+25°Cto40°Cto+85°Candbackto+25°C.
ADR380/ADR381Rev.
C|Page11of16THEORYOFOPERATIONBandgapreferencesarethehighperformancesolutionforlowsupplyvoltageandlowpowervoltagereferenceapplications,andtheADR380/ADR381arenoexception.
However,theuniquenessofthisproductliesinitsarchitecture.
AsshowninFigure26,theidealzeroTCbandgapvoltageisreferencedtotheoutput,nottoground.
ThebandgapcellconsistsofthePNPpairQ51andQ52,runningatunequalcurrentdensities.
ThedifferenceinVBEresultsinavoltagewithapositiveTCthatisamplifiedbytheratioof2*R58/R54.
ThisPTATvoltage,combinedwiththeVBEofQ51andQ52,producethestablebandgapvoltage.
Reductioninthebandgapcurvatureisperformedbytheratioofthetworesistors,R44andR59.
Precisionlasertrimmingandotherpatentedcircuittechniquesareusedtofurtherenhancethedriftperformance.
GNDVOUTVINQ1R59R54Q51R60R61R48R49R44R58R53Q52–+02175-026Figure26.
SimplifiedSchematicDEVICEPOWERDISSIPATIONCONSIDERATIONSTheADR380/ADR381arecapableofdeliveringloadcurrentsto5mAwithaninputvoltagethatrangesfrom2.
8V(ADR381only)to15V.
Whenthisdeviceisusedinapplicationswithlargeinputvoltages,takecaretoavoidexceedingthespecifiedmaximumpowerdissipationorjunctiontemperaturethatmayresultinprematuredevicefailure.
Usethefollowingformulatocalculateadevice'smaximumjunctiontemperatureordissipation:JAAJDTTPθ=where:PDisthedevicepowerdissipation,TJandTAarejunctionandambienttemperatures,respectively.
θJAisthedevicepackagethermalresistance.
INPUTCAPACITORAninputcapacitorisnotrequiredontheADR380/ADR381.
Thereisnolimitforthevalueofthecapacitorusedontheinput,butacapacitorontheinputimprovestransientresponseinapplicationswheretheloadcurrentsuddenlyincreases.
OUTPUTCAPACITORTheADR380/ADR381donotneedanoutputcapacitorforstabilityunderanyloadcondition.
Usinganoutputcapacitor,typically0.
1μF,removesanyverylowlevelnoisevoltageanddoesnotaffecttheoperationofthepart.
Theonlyparameterthatdegradesbyapplyinganoutputcapacitoristurn-ontime.
(Thisvariesdependingonthesizeofthecapacitor.
)Loadtransientresponseisalsoimprovedwithanoutputcapacitor,whichactsasasourceofstoredenergyforasuddenincreaseinloadcurrent.
ADR380/ADR381Rev.
C|Page12of16APPLICATIONSINFORMATIONSTACKINGREFERENCEICsFORARBITRARYOUTPUTSSomeapplicationsmayrequiretworeferencevoltagesources,whichareacombinedsumofstandardoutputs.
Thefollowingcircuitshowshowthisstackedoutputreferencecanbeimplemented:GNDVOUTVIN3GNDVOUTVINC21FC10.
1FC30.
1FC41F3R13.
9kVOUT2VOUT12211VINU2ADR380/ADR381U1ADR380/ADR38102175-027Figure27.
StackingVoltageReferenceswiththeADR380/ADR381TwoADR380sorADR381sareused;theoutputsoftheindivid-ualreferencesaresimplycascadedtoreducethesupplycurrent.
Suchconfigurationprovidestwooutputvoltages:VOUT1andVOUT2.
VOUT1istheterminalvoltageofU1,whileVOUT2isthesumofthisvoltageandtheterminalvoltageofU2.
U1andU2canbechosenforthetwodifferentvoltagesthatsupplytherequiredoutputs.
Whilethisconceptissimple,aprecautionisinorder.
BecausethelowerreferencecircuitmustsinkasmallbiascurrentfromU2,plusthebasecurrentfromtheseriesPNPoutputtransistorinU2,theexternalloadofeitherU1orR1mustprovideapathforthiscurrent.
IftheU1minimumloadisnotwell-defined,ResistorR1shouldbeused,settoavaluethatconservativelypasses600μAofcurrentwiththeapplicableVOUT1acrossit.
NotethatthetwoU1andU2referencecircuitsarelocallytreatedasmacrocells,eachhavingitsownbypassesatinputandoutputforoptimumstability.
BothU1andU2inthiscircuitcansourcedccurrentsuptotheirfullrating.
Theminimuminputvoltage,VIN,isdeterminedbythesumoftheoutputs,VOUT2,plusthe300mVdropoutvoltageofU2.
ANEGATIVEPRECISIONREFERENCEWITHOUTPRECISIONRESISTORSInmanycurrent-outputCMOSDACapplicationswheretheoutputsignalvoltagemustbeofthesamepolarityasthereferencevoltage,itisoftenrequiredtoreconfigureacurrent-switchingDACintoavoltage-switchingDACthroughtheuseofa1.
25Vreference,anopamp,andapairofresistors.
UsingacurrentswitchingDACdirectlyrequiresanadditionalopera-tionalamplifierattheoutputtoreinvertthesignal.
Anegativevoltagereferenceisthendesirablefromthepointthatanadditionaloperationalamplifierisnotrequiredforeitherreinversion(current-switchingmode)oramplification(voltage-switchingmode)oftheDACoutputvoltage.
Ingeneral,anypositivevoltagereferencecanbeconvertedintoanegativevoltagereferencethroughtheuseofanoperationalamplifierandapairofmatchedresistorsinaninvertingconfiguration.
Thedisadvantagetothisapproachisthatthelargestsinglesourceoferrorinthecircuitistherelativematchingoftheresistorsused.
ThecircuitinFigure28avoidstheneedfortightlymatchedresistorswiththeuseofanactiveintegratorcircuit.
Inthiscircuit,theoutputofthevoltagereferenceprovidestheinputdrivefortheintegrator.
Theintegrator,tomaintaincircuitequilibrium,adjustsitsoutputtoestablishtheproperrelation-shipbetweenthereferenceVOUTandGND.
Thus,anynegativeoutputvoltagedesiredcanbechosenbysubstitutingfortheappropriatereferenceIC.
Aprecautionshouldbenotedwiththisapproach:althoughrail-to-railoutputamplifiersworkbestintheapplication,theseoperationalamplifiersrequireafiniteamount(mV)ofheadroomwhenrequiredtoprovideanyloadcurrent.
Thechoiceforthecircuit'snegativesupplyshouldtakethisissueintoaccount.
GNDVOUTVINC20.
1F3+5V–VREFVIN2A11U2–5VOP195–V+VC11FU1ADR380/ADR381R41kR3100kC31FC41FR510002175-028Figure28.
NegativePrecisionVoltageReferenceUsingNoPrecisionResistorsPRECISIONCURRENTSOURCEManytimesinlowpowerapplications,theneedarisesforaprecisioncurrentsourcethatcanoperateonlowsupplyvoltages.
AsshowninFigure29,theADR380/ADR381canbeconfiguredasaprecisioncurrentsource.
Thecircuitconfigurationillustratedisafloatingcurrentsourcewithagroundedload.
ThereferenceoutputvoltageisbootstrappedacrossRSET(R1+P1),whichsetstheoutputcurrentintotheload.
Withthisconfiguration,circuitprecisionismaintainedforloadcurrentsintherangefromthereferencesupplycurrent,typically90μAtoapproximately5mA.
GNDVOUTVIN3VIN2R11RLP1IOUTISYADJUSTU1ADR380/ADR381C31FC11FC20.
1F02175-029Figure29.
PrecisionCurrentSourceADR380/ADR381Rev.
C|Page13of16PRECISIONHIGHCURRENTVOLTAGESOURCEInsomecases,theusermaywanthigheroutputcurrentdeliveredtoaloadandstillachievebetterthan0.
5%accuracyfromtheADR380/ADR381.
Theaccuracyforareferenceisnormallyspecifiedonthedatasheetwithnoload.
However,theoutputvoltagechangeswithloadcurrent.
ThecircuitinFigure30provideshighcurrentwithoutcompromis-ingtheaccuracyoftheADR380/ADR381.
Byopampaction,VOUTfollowsVREFwithverylowdropinR1.
Tomaintaincircuitequilibrium,theopampalsodrivestheN-ChannelMOSFETQ1intosaturationtomaintainthecurrentneededatdifferentloads.
R2isoptionaltopreventoscillationatQ1.
Insuchanapproach,hundredsofmilliampsofloadcurrentcanbeachieved,andthecurrentislimitedbythethermallimitationofQ1.
VIN=VOUT+300mV.
GNDVOUTVIN3VOUT218VTO15VRLVINA1–V+VAD820U1ADR380/ADR381Q12N7002R2100R1100kC10.
001F02175-030Figure30.
ADR380/ADR381forPrecisionHighCurrentVoltageSourceADR380/ADR381Rev.
C|Page14of16OUTLINEDIMENSIONS3.
042.
902.
80COMPLIANTTOJEDECSTANDARDSTO-236-AB011909-C123SEATINGPLANE2.
642.
101.
401.
301.
202.
051.
780.
1000.
0131.
030.
890.
600.
450.
510.
371.
120.
890.
1800.
0850.
250.
54REFGAUGEPLANE0.
60MAX0.
30MIN1.
020.
950.
88Figure31.
3-LeadSmallOutlineTransistorPackage[SOT-23-3](RT-3)DimensionsshowninmillimetersORDERINGGUIDEModel1TemperatureRangePackageDescriptionPackageOptionBranding2OutputVoltageOrderingQuantityADR380ARTZ-REEL740°Cto+85°C3-LeadSOT-23RT-3R2D2.
0483,000ADR381ARTZ-R240°Cto+85°C3-LeadSOT-23RT-3R3A2.
500250ADR381ARTZ-REEL740°Cto+85°C3-LeadSOT-23RT-3R3A#2.
5003,0001Z=RoHSCompliantPart,#denotesRoHScompliantproductmaybetoporbottommarked.
2PriortoDateCode0542,theADR380ARTZ-REEL7partswerebrandedwithR2Awithoutthe#.
ADR380/ADR381Rev.
C|Page15of16NOTESADR380/ADR381Rev.
C|Page16of16NOTES2001–2010AnalogDevices,Inc.
Allrightsreserved.
Trademarksandregisteredtrademarksarethepropertyoftheirrespectiveowners.
D02175-0-10/10(C)