LM386 Low Voltage Audio Power Amplifier …

1 GAIN1 GAIN815 k15 k15 k50 k3+ INPUT65 VSVOUTGND4- INPUT250 kBYPASS7 ProductFolderOrderNowTechnicalDocumentsT ools &SoftwareSupport &CommunityAn IMPORTANTNOTICEat the end of this datasheetaddressesavailability,warranty, changes,use in safety-criticalapplications,intellectual propertymattersand MAY2004 REVISEDMAY2017LM386 Low VoltageAudioPowerAmplifier11 Features1 BatteryOperation MinimumExternalParts WideSupplyVoltageRange:4 V 12 V or5 V 18 V Low QuiescentCurrentDrain:4 mA VoltageGainsfrom20 to 200 Ground-ReferencedInput Self-CenteringOutputQuiescentVoltage Low (AV= 20, VS= 6 V, RL= 8 ,PO= 125 mW,f = 1 kHz) Availablein 8-PinMSOPP ackage2 Applications AM-FMRadioAmplifiers PortableTapePlayerAmplifiers Intercoms TV SoundSystems Line Drivers UltrasonicDrivers SmallServoDrivers PowerConverters3 DescriptionThe LM386M-1and LM386MX-1are poweramplifiersdesignedforusein gainis internallyset to 20 to keepexternalpart countlow, but the additionof an externalresistorandcapacitorbetweenpins1 and8 willincreasethe gain to any valuefrom20 to groundreferencedwhilethe outputautomaticallybiasesto one-halfthe only24 mWwhenoperatingfroma 6-V supply,makingthe LM386M-1and LM386MX-1idealfor (1)PARTNUMBERPACKAGEBODYSIZE(NOM)LM386N- 1 PDIP(8) (8) (8) (8) (8) (8) (1) For all availablepackages,see the orderableaddendumatthe end of the MAY2004.

2 LM386 SubmitDocumentationFeedbackCopyright 2004 2017,TexasInstrumentsIncorporatedTableof Contents1 Pin Configurationand Applicationand Deviceand Mechanical,Packaging,and RevisionHistoryNOTE:Pagenumbersfor previousrevisionsmay differfrompagenumbersin the (March2017)to RevisionCPage ChangeddevicesLM386M-1/LM386MX-1To: LM386in the datasheettitle ..1 ChangedFrom:LM386N-4To: SpeakerImpedancein ChangedFrom:5 to 12 To: 5 V to 12 V for SupplyVoltagein ChangedkW To: k in ChangedkW To: k in ChangedFrom:5 to 12 To: 5 V to 12 V for SupplyVoltagein ChangedFrom:5 to 12 To: 5 V to 12 V for SupplyVoltagein ChangedFrom:5 to 12 To: 5 V to 12 V for SupplyVoltagein ChangedFrom:5 to 12 To: 5 V to 12 V for SupplyVoltagein ChangedFrom:5 to 12 To: 5 V to 12 V for SupplyVoltagein ChangedFrom:5 to 12 To: 5 V to 12 V for SupplyVoltagein (May2004)to RevisionBPage AddedLM386MX-1deviceto the AddedDeviceInformation,Applicationand Implementation,PowerSupplyRecommendation ,Layout,and Deviceand INPUT+ MAY2004 REVISEDMAY2017 ProductFolderLinks.

3 LM386 SubmitDocumentationFeedbackCopyright 2004 2017,TexasInstrumentsIncorporated5 Pin Configurationand FunctionsD Package8-PinMSOPTop ViewPin Gainsettingpin INPUT2 IInvertinginput+INPUT3 INoninvertinginputGND4 PGroundreferenceVOUT5 OOutputVS6 PPowersupplyvoltageBYPASS7 OBypassdecouplingpathGAIN8 Gainsettingpin(1)Stressesbeyondthoselist edunderAbsoluteMaximumRatingsmay causepermanentdamageto the stressratingsonly,whichdo not implyfunctionaloperationof the deviceat theseor any otherconditionsbeyondthoseindicatedunder RecommendedOperatingConditions. Exposureto absolute-maximum-ratedconditionsfor extendedperiodsmay (unlessotherwisenoted)(1)MINMAXUNITS upplyVoltage,VCCLM386N-1/-3, ,VI ,Tstg 65150 C(1)JEDEC documentJEP155statesthat 500-VHBM allowssafe manufacturingwith a standardESDcontrolprocess.(2)JEDEC documentJEP157statesthat 250-VCDM allowssafe manufacturingwith a (ESD)ElectrostaticdischargeHuman-bodymod el(HBM),per ANSI/ESDA/JEDECJS-001(1) 1000 VCharged-devicemodel(CDM),per JEDEC specificationJESD22-C101(2) 10004LM386 SNAS545C MAY2004.

4 LM386 SubmitDocumentationFeedbackCopyright 2004 2017, (unlessotherwisenoted)MINNOMMAXUNITVCCS upplyVoltage412 VLM386N-4518 VSpeakerImpedance4 VIAnaloginputvoltage C(1)For moreinformationabouttraditionaland new thermalmetrics,see (1)LM386LM386LM386 UNITD (SOIC)DGK(VSSOP)P (PDIP)888R C/WR JC(top)Junction-to-case(top) C/WR C/W C/W (unlessotherwisenoted)PARAMETERTESTCONDI TIONSMINTYPMAXUNITVSO peratingSupplyVoltageLM386N-1,-3, LM386M-1,LM386MM-1412 VLM386N-4518 IQQuiescentCurrentVS= 6 V, VIN= 048mAPOUTO utputPowerVS= 6 V, RL= 8 , THD= 10%(LM386N-1,LM386M-1,LM386MM-1)250325mW VS= 9 V, RL= 8 , THD= 10%(LM386N-3)500700VS= 16 V, RL= 32 , THD= 10%(LM386N-4)700100 AVVoltageGainVS= 6 V, f = 1 kHz26dB10 F fromPin 1 to 846 BWBandwidthVS= 6 V, Pins1 and 8 Open300kHzTHDT otalHarmonicDistortionVS= 6 V, RL= 8 , POUT= 125 mWf = 1 kHz,Pins1 and 8 6 V, f = 1 kHz,CBYPASS= 10 FPins1 and 8 Open,Referredto Output50dBRINI nputResistance50k IBIASI nputBiasCurrentVS= 6 V, Pins2 and 3 MAY2004 REVISEDMAY2017 ProductFolderLinks: LM386 SubmitDocumentationFeedbackCopyright 2004 2017, SupplyCurrentvs SupplyVoltageFigure2.

5 PowerSupplyRejectionvs FrequencyFigure3. OutputVoltagevs SupplyVoltageFigure4. VoltageGainvs FrequencyFigure5. TotalHarmonicDistortionvs FrequencyFigure6. TotalHarmonicDistortionvs PowerOut6LM386 SNAS545C MAY2004 : LM386 SubmitDocumentationFeedbackCopyright 2004 2017,TexasInstrumentsIncorporatedTypical Characteristics(continued)Figure7. DeviceDissipationvs OutputPowerFigure8. DeviceDissipationvs OutputPowerFigure9. DeviceDissipationvs OutputPower7 ParameterMeasurementInformationAll parametersare measuredaccordingto the conditionsdescribedin theSpecificationssection.+ MAY2004 REVISEDMAY2017 ProductFolderLinks: LM386 SubmitDocumentationFeedbackCopyright 2004 2017,TexasInstrumentsIncorporated8 LM386is a monolow voltageamplifierthat can be usedin a varietyof can driveloadsfrom4 to 32 . The gainis internallyset to 20 but it can be modifiedfrom20 to 200 by placinga resistorandcapacitorbetweenpins 1 and 8. This devicecomesin threedifferent8-pinpackagesas PDIP,SOICand VSSOPto fit in an resistorthat sets the gain of this deviceto 20.

6 The gain can be modifiedfrom20 settingcan be foundin this is an Op Ampit can be usedin differentconfigurationsto fit in internalgainsettingresistorallowsthe LM386to be usedin a very low part additiona seriesresistorcan beplacedbetweenpins 1 and 5 to modifythe gain and frequencyresponsefor F 250 F ++- LM386 Copyright 2017, Texas Instruments Incorporated8LM386 SNAS545C MAY2004 : LM386 SubmitDocumentationFeedbackCopyright 2004 2017,TexasInstrumentsIncorporated9 Applicationand ImplementationNOTEI nformationin the followingapplicationssectionsis not partof the TI componentspecification,and TI doesnot warrantits accuracyor s customersareresponsiblefor determiningsuitabilityof componentsfor test theirdesignimplementationto showndifferentsetupsthat showhow the LM386can be implementedin a varietyof 20 Figure10 showsthe minimumpart countapplicationthat can be gain is internallyset to LM386withGain= DesignParametersDESIGNPARAMETEREXAMPLEVA LUELoadImpedance4 to 32 SupplyVoltage5 V to 12 makethe LM386a moreversatileamplifier,two pins (1 and 8) are providedfor gain 1 and 8openthe resistorsets the gain at 20 (26 dB).

7 If a capacitoris put frompin 1 to 8, bypassingthe resistor,the gain will go up to 200 (46 dB). If a resistoris placedin serieswith the capacitor,the gain can be setto any valuefrom20 to also be doneby capacitivelycouplinga resistor(or FET)frompin 1to be placedin parallelwith the internalfeedbackresistorsto tailorthe gain andfrequencyresponsefor example,we can compensatepoorspeakerbassresponsebyfrequ encyshapingthe donewitha seriesRC frompin 1 to 5 (parallelingthe internal15-k resistor).For 6 dB effectivebassboost:R ~= 15 k , the lowestvaluefor goodstableoperationis R = 10k if pin 8 is pins 1 and 8 are bypassedthenR as low as 2 k can be restrictionis becausethe amplifieris only compensatedfor MAY2004 REVISEDMAY2017 ProductFolderLinks: LM386 SubmitDocumentationFeedbackCopyright 2004 2017, schematicshowsthat bothinputsare biasedto groundwith a 50 k basecurrentof the inputtransistorsis about250 nA, so the inputsare at whenleft the dc sourceresistancedrivingthe LM386is higherthan250 k it will contributevery little additionaloffset( mV at the input,50 mV atthe output).

8 If the dc sourceresistanceis less than10 k , thenshortingthe unusedinputto groundwill keeptheoffsetlow ( mV at the input,50 mV at the output).For dc sourceresistancesbetweenthesevalueswecan eliminateexcessoffsetby puttinga resistorfromthe unusedinputto ground,equalin valueto the dc courseall offsetproblemsare eliminatedif the inputis LM386with highergains(bypassingthe resistorbetweenpins 1 and 8) it is necessaryto bypassthe unusedinput,preventingdegradationof gainand donewith a Fcapacitoror a shortto grounddependingon the dc sourceresistanceon the SupplyCurrentvs SupplyVoltageVIN10 F 250 F ++- LM386 +10 F VSBYPASSC opyright 2017, Texas Instruments Incorporated10LM386 SNAS545C MAY2004 : LM386 SubmitDocumentationFeedbackCopyright 2004 2017, 200 Figure12. LM386withGain= DesignParametersDESIGNPARAMETEREXAMPLEVA LUELoadImpedance4 to 32 SupplyVoltage5 V to 12 DetailedDesignProcedurecan be foundin SupplyCurrentvs SupplyVoltageVIN10 F 250 F ++ kCopyright 2017, Texas Instruments Incorporated10 F MAY2004 REVISEDMAY2017 ProductFolderLinks: LM386 SubmitDocumentationFeedbackCopyright 2004 2017, 50 Figure14.

9 LM386withGain= DesignParametersDESIGNPARAMETEREXAMPLEVA LUELoadImpedance4 to 32 SupplyVoltage5 V to 12 DetailedDesignProcedurecan be foundin SupplyCurrentvs SupplyVoltage3 V 15mA32617851050 F ++- LM386 +10 F VS47 F F F RLELDEMACF-S-2158f = 1 kHzCopyright 2017, Texas Instruments Incorporated12LM386 SNAS545C MAY2004 : LM386 SubmitDocumentationFeedbackCopyright 2004 2017, DesignParametersDESIGNPARAMETEREXAMPLEVA LUELoadImpedance4 to 32 SupplyVoltage5 V to 12 DetailedDesignProcedurecan be foundin SupplyCurrentvs SupplyVoltageVIN10 F 250 F ++-LM386VS10 F10 k1 VOBYPASSC opyright 2017, Texas Instruments MAY2004 REVISEDMAY2017 ProductFolderLinks: LM386 SubmitDocumentationFeedbackCopyright 2004 2017, DesignParametersDESIGNPARAMETEREXAMPLEVA LUELoadImpedance4 to 32 SupplyVoltage5 V to 12 DetailedDesignProcedurecan be foundin VoltageGainvs Frequency342618510 k+-LM386VS1 k50 F+30 kf = 1 FRLVOC opyright 2017, Texas Instruments Incorporated14LM386 SNAS545C MAY2004 : LM386 SubmitDocumentationFeedbackCopyright 2004 2017, SquareWaveOscillatorTable6.

10 DesignParametersDESIGNPARAMETEREXAMPLEVA LUELoadImpedance4 to 32 SupplyVoltage5 V to 12 DetailedDesignProcedurecan be foundin SupplyCurrentvs SupplyVoltage342685+- LM386 BYPASSR110 kVSCCVOL10 kC12200 F10 F+71+10 FFROMDETECTOR8 F++47250 FFERRITEBEADC opyright 2017, Texas Instruments MAY2004 REVISEDMAY2017 ProductFolderLinks: LM386 SubmitDocumentationFeedbackCopyright 2004 2017, RadioPowerAmplifierFigure22. AM DesignParametersDESIGNPARAMETEREXAMPLEVA LUELoadImpedance4 to 32 SupplyVoltage5 V to 12 DetailedDesignProcedurecan be foundin SupplyCurrentvs SupplyVoltage10 PowerSupplyRecommendationsThe LM386is specifiedfor operationup to 12 V or 18 V. The powersupplyshouldbe well regulatedand thevoltagemustbe withinthe is recommendedto placea capacitorto GNDcloseto the to ground planeConnection to Power 5 VTop layer tracesTop layer ground to ground planeConnection to Power 5 VTop layer tracesTop layer ground plane16LM386 SNAS545C MAY2004 : LM386 SubmitDocumentationFeedbackCopyright 2004 2017,TexasInstrumentsIncorporated11 requiredcomponentsas closeas possibleto the shorttracesfor the outputto the analogtracesfar fromthe digitalsignaltracesand LayoutExamplefor MinimumPartsGain= 20 dB on PDIP packageFigure25.