LM3661AM资料

LM3361ALowVoltage󰁋PowerNarrowBandFMIFSystemAugust1989

LM3361ALowVoltage󰁋PowerNarrowBandFMIFSystem

GeneralDescription

TheLM3361AcontainsacompletenarrowbandFMde-modulationsystemoperabletolessthan2Vsupplyvoltage󰀟Blockswithinthedeviceincludeanoscillator󰀷mixer󰀷FMIFlimitingamplifier󰀷FMdemodulator󰀷opamp󰀷scancontrol󰀷andmuteswitch󰀟TheLM3361AissimilartotheMC3361withthefollowingimprovements󰀌theLM3361Ahashighervoltageswingbothattheopampandaudiooutputs󰀟ItalsohaslowernominaldraincurrentandasquelchcircuitthatdrawssignificantlylesscurrentthantheMC3361󰀟Devicepinoutfunctionsareidenticalwithsomeslightlydifferentop-eratingcharacteristics󰀟

Features

YYYYYY

Functionsatlowsupplyvoltage(lessthan2V)

Highlysensitive(b3dBlimitingat2󰀟0mVinputtypical)Highaudiooutput(increased6dBoverMC3361)Lowdraincurrent(2󰀟8mAtyp󰀟󰀷VCCe3󰀟6V)MinimaldraincurrentincreasewhensquelchedLowexternalpartscount

BlockDiagramandTestCircuit

TL󰁋H󰁋5586–1

OrderNumberLM3661AM

orLM3361AN

SeeNSPackageNumber

M16AorN16E

C1995NationalSemiconductorCorporation

TL󰁋H󰁋5586

T1-TOKORMC-2A6597HMCF-MURATACFU455E

RRD-B30M115󰁋PrintedinU󰀟S󰀟A󰀟

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AbsoluteMaximumRatings

IfMilitary󰁋Aerospacespecifieddevicesarerequired󰀷pleasecontacttheNationalSemiconductorSalesOffice󰁋Distributorsforavailabilityandspecifications󰀟PackageDissipation(Note1)1500mWPowerSupplyVoltage(VS)RFInputVoltage(VSl3󰀟6V)MuteFunction(pin14)

12V1Vrms

b0󰀟7to5Vp

SolderingInformationDual-In-LinePackageSoldering(10seconds)SmallOutlinePackage

VaporPhase(60seconds)Infrared(15seconds)

260󰀂C215󰀂C220󰀂C

OperatingAmbientTemperatureRange0󰀂Ctoa70󰀂C

b55󰀂Ctoa150󰀂CStorageTemperatureRange

SeeAN-450‘‘SurfaceMountingMethodsandTheirEffect

onProductReliability’’forothermethodsofsolderingsur-facemountdevices󰀟

ParametersGuaranteedByElectricalTesting

(Testckt󰀟󰀷TAe25󰀂C󰀷VSe3󰀟6V󰀷fOe10󰀟7MHz󰀷Dfeg3kHz󰀷fMODe1kHz󰀷50Xsource)

Parameter

SupplyVoltageRangeSupplyCurrentSquelchOffSquelchOn

RFInputforb3dBLimitingRecoveredAudioatAudioOutputAudioOutDCOpAmpGainOpAmpOutputDCOpAmpInputBiasCurrentScanVoltage

Pin12high(2V)Pin12Low(0V)

MuteSwitchImpedance󰀷Pin12e0VSwitchS1frompos󰀟1topos󰀟2

VSISISRFInputAudioOutputV9V11󰁋VINV10

(V10bV11)󰁋1MXV13V13DV14󰁋DI14

2001󰀟2400󰀟4

Measure

Min2󰀟0

Typ3󰀟62󰀟83󰀟62󰀟03501󰀟5550󰀟72003󰀟415

750󰀟51󰀟8Max9󰀟05󰀟06󰀟06󰀟0

UnitsVmAmAmVmVRMSVDCdBVDCnAVDCVDCX

3󰀟0

30

DesignParametersNotTestedorGuaranteed

MixerConversionGain(Note2)MixerInputResistanceMixerInputCapacitanceDetectorOutputImpedanceSquelchHysterisis

MuteOffImpedance(measurepin14withpin12SquelchThreshold

DetectorCenterFrequencySlope

Typ463󰀟62󰀟2500100100󰀟650󰀟15

V󰁋VkXpFXmVMXVDCV󰁋kHz

󰀁

2V)

Note1󰀟Foroperationabove25󰀂Cambienttemperature󰀷thedevicemustbederatedbasedon150󰀂CmaximumjunctiontemperatureandathermalresistanceiJAof80󰀂C󰁋W󰀟

Note2󰀟Mixergainissupplydependentandeffectsoverallsensitivityaccordingly(SeeTypicalPerformanceCharacteristics)󰀟

Coils󰀍

TokoAmerica

1250FeehanvilleDriveMountProspect󰀷IL60056(312)297-0070

Filters󰀍

Murata

2200LakeParkDriveSmyrna󰀷GA30080(404)436-1300

2

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TypicalPerformanceCharacteristics(TestCircuits)

TL󰁋H󰁋5586–2

3

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4

TL󰁋H󰁋5586–3InternalSchematic

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ApplicationsInformation(SeeInternalSchematic)

OSCILLATOR

TheColpittstypeoscillatorisinternallybiasedwitharegu-latedcurrentsourcewhichassuresproperoperationoverawidesupplyrange󰀟Thecollector󰀷base󰀷andemittertermi-nalsareatpins4󰀷1󰀷and2respectively󰀟Thecrystal󰀷whichisusedintheparallelresonantmode󰀷maybereplacedwithanappropriateinductoriftheapplicationdoesnotrequirethestabilityofacrystaloscillator󰀟Inthiscase󰀷theresonantfrequencywillbedeterminedbytheinductorinparallelwiththeseriescombinationofC1andC2󰀟

tic󰀷alsoincreasesdistortion(seeTypicalPerformanceCharacteristics)󰀟Forproperoperation󰀷thevoltageswingonpin8shouldbeadequatetodrivetheupperrankofthemultiplierintoswitching(about100mVrms)󰀟Thisvoltagelevelisdependentontheinternal10pFcapacitorandthetankRpvoltagedividernetwork󰀟Afterdetectionandde-em-phasis󰀷theaudiooutputatpin9isbufferedbyanemitterfollower󰀟OPAMP

Theopampinvertinginput(pin10)whichisinternallyrefer-encedto0󰀟7V󰀷receivesdcbiasfromtheoutputatpin11throughtheexternalfeedbacknetwork󰀟BecauseofthelowD󰀟C󰀟bias󰀷maximumswingontheopampoutputwith10%distortionis500mVrms󰀟Thiscanbeincreasedwhenoper-atingonsuppliesover2󰀟3VbyaddingaresistorfromtheopampinputtogroundwhichraisesthequiescentD󰀟C󰀟attheoutputallowingmoreswing(seefigurebelowforselectionofaddedresistor)󰀟Theopampisnormallyutilizedaseitherabandpassfiltertoextractaspecificfrequencyfromtheaudiooutput󰀷suchasaringordialtone󰀷orasahighpassfiltertodetectnoiseduetonoinputatthemixer󰀟Thelatterconditionwillgenerateasignalattheopampoutput󰀷whichwhenappliedtopin12canmutetheexternalaudioamp󰀟Formaxswing󰀌VOUTe(VSbVBE)󰁋2(frominternalcircuit)

so(VSbVBE)󰁋2e0󰀟71aR2

ethereforeR3

TL󰁋H󰁋5586–4

soCte(C1)(C2)󰁋(C1aC2)andfOe󰀟159󰁋0L(Ct)MIXER

Themixerisdoublebalancedtoreducespuriousresponses󰀟TheupperpairsareswitchedbytheoscillatorwhiletheRFinputisappliedtothelowerpair(pin16)󰀟R43setsthemixerinputimpedanceat3󰀟6kX󰀟Themixeroutputimpedanceof1󰀟8kXwillproperlymatchtheinputimpedanceofaceramicfilterwhichisusedasabandpassfiltercouplingthemixeroutputtotheIFlimitingamplifier󰀟

IFLIMITER

TheIFamplifierconsistsofsixdifferentialgainstages󰀷withtheinputimpedancesetbyR2at1󰀟8kXtoproperlytermi-natetheceramicfilterdrivingtheIF󰀟TheIFalone(withoutmixer)hasab3dBlimitingsensitivityofapproximately50mV󰀟Thesystembandwidthislimitedtoabout5MHzduetohighimpedancesintheIFwhicharenecessarytomeetlowpowerrequirements󰀟TheIFoutputisconnectedtotheex-ternalquadcoilatpin8viaaninternal10pFcapacitor󰀟FMDEMODAUDIOOUT

AconventionalquadraturedetectorisusedtodemodulatetheFMsignal󰀟TheQofthequadcoil󰀷whichisdeterminedbytheexternalresistorplacedacrossit󰀷hasmultipleeffectsontheaudiooutput󰀟IncreasingtheQincreasesoutputlevelbutbecauseofnonlinearitiesinthetankphasecharacteris-

󰀣

VSbVBE

b1

1󰀟4

󰀣

R2R3

J

J

TL󰁋H󰁋5586–5

IncreasingOPAmpSwing

SQUELCHTRIGGERCIRCUIT

Thesquelchtriggercircuitisconfiguredsuchthatalowbiasontheinput(pin12)willforcepin13high(200mVbelowsupply)󰀷whereitcansupportatleasta1mAload󰀷andpin14tobealowimpedance󰀷typically15Xtoground󰀟Con-nectingpin14toahighimpedancegroundreferencepointintheaudiopathbetweenpin9andtheaudioampwillmutetheaudiooutput󰀟Pullingpin12abovemutethreshold(0󰀟65V)willforcepin13toanimpedanceofabout60kXtogroundandpin14willbeanopencircuit󰀟Thereis100mVofhysterisisatpin12whicheffectivelypreventsjitter󰀟

5

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LM3361ALowVoltage󰁋PowerNarrowBandFMIFSystemPhysicalDimensionsinches(millimeters)

MoldedSmallOutlinePackage(M)

OrderNumberLM3361AMNSPackageNumberM16A

MoldedDual-In-LinePackage(N)

OrderNumberLM3361ANNSPackageNumberN16E

LIFESUPPORTPOLICY

NATIONAL’SPRODUCTSARENOTAUTHORIZEDFORUSEASCRITICALCOMPONENTSINLIFESUPPORTDEVICESORSYSTEMSWITHOUTTHEEXPRESSWRITTENAPPROVALOFTHEPRESIDENTOFNATIONALSEMICONDUCTORCORPORATION󰀟Asusedherein󰀌1󰀟Lifesupportdevicesorsystemsaredevicesorsystemswhich󰀷(a)areintendedforsurgicalimplantintothebody󰀷or(b)supportorsustainlife󰀷andwhosefailuretoperform󰀷whenproperlyusedinaccordancewithinstructionsforuseprovidedinthelabeling󰀷canbereasonablyexpectedtoresultinasignificantinjurytotheuser󰀟

NationalSemiconductorCorporation1111WestBardinRoad2󰀟Acriticalcomponentisanycomponentofalifesupportdeviceorsystemwhosefailuretoperformcanbereasonablyexpectedtocausethefailureofthelifesupportdeviceorsystem󰀷ortoaffectitssafetyoreffectiveness󰀟

NationalSemiconductorEuropeFax󰀌(a49)0-180-5308586NationalSemiconductorHongKongLtd󰀟13thFloor󰀷StraightBlock󰀷NationalSemiconductorJapanLtd󰀟Tel󰀌81-043-299-2309