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IntroductionAcircuitordevicethatchangesthephaseofasignalby180,asrequiredforfeedingapush-pullamplifierstagewithoutusingacouplingtransformer,orforchangingthepolarityofapulse;atriodeiscommonlyusedasaphaseinverter.Alsoknownasinverter.Thefollowingisanintroductionto74LS04andothersimilarICchips.CatalogIntroductionI74LS04VS.74LS141.1BriefIntroduction1.2Differencebetween74LS04and74LS14II74LS04VS.74LS08III74LS04VS.74HC04IV74LS04VS.54LS04FAQOrdering&QuantityI74LS04VS.74LS141.1BriefIntroductionBoth74LS04and74LS14arenotgatesofthe74series.74LS04isaHexInverter.74LS14isaHexSchmidttrigger.The74LS04gatecircuithasathresholdvoltage.Whentheinputvoltagerisesfromthelowleveltothethresholdvoltage,ordecreasesfromthehighleveltothethresholdvoltage,theconditionofthecircuitwillchange.74LS14isaSchmidttrigger.Itisaspecialgatecircuit,whichisnotcompatiblewiththesimplegatecircuit.Schmidttriggerhastwothresholdvoltages(positivethresholdvoltageandnegativethresholdvoltage).1.2Differencebetween74LS04and74LS14◾Output:Theoutputof74LS04and74LS14arethesame.Ifthesamemanufacturer,theoutputparametersarethesame.◾Input:Thedifferencebetweenthetwoisthattheinputisnotthesame.74LS04inputisTTLlevel,while74LS14inputisSchmidtinput(withhysteresischaracteristics).Becausetheinputisdifferent,theapplicationofthetwochipsisalsodifferent.74LS04ismostlyusedfornoncontrolofgeneraldataontheboard,while74LS14isgenerallyusedforsignalshapingorsignalbufferingofcriticalsignals.Inmostcases,74LS14canreplace74LS04.II74LS04VS.74LS08The74LS08devicecontains4independent2-inputANDgates.Thelogicfunctionexpressionof74LS08is:Y=ABorY=/(A+B),positivelogic.74LS08iscommonlyusedindigitalcircuitsystems.74LS0474LS08VCC(Min)(V)4.754.75VCC(Max)(V)5.255.25LogiclevelTTLTTLPin/Package14PDIP,14SO,14SOIC,14SSOPPDIP14,SOIC14,SOP14,SSOP14III74LS04VS.74HC0474HC04isahexinverterofCMOScircuit,andtheworkingvoltageis2V-6V.Both74LS04and74HC04areinverters,butLSstandsforlow-powerSchottkyandHCishigh-speedCOMS.LSisslightlyfasterthanHC.LSadoptsTTLlevel.HCisCMOSlevel.74HC04iseasytounderstand.Inputlowlevel,outputhighlevel.Inputhighlevel,outputlowlevel.74LS04containssixindependentgateseachofwhichperformsthelogicINVERTfunction.Theoutputsignalsofthesixinvertersareoppositetotheinputsignals.Theinvertercanreversethephaseoftheinputsignalby180degrees.Thiscircuitisusedinanalogcircuits,suchasaudioamplifier,clockoscillator,etc.IV74LS04VS.54LS0454LS04containssixindependentinverters.Itischaracterizedforoperationoverthefullmilitarytemperaturerangeof-55℃to125℃.74LS0454LS04TechnologyFamilyLSLSVCC(Min)(V)4.754.5VCC(Max)(V)5.255.5Bits(#)66Voltage(Nom)(V)55F@NomVoltage(Max)(Mhz)3535ICC@NomVoltage(Max)(mA)0.0330.033tpd@NomVoltage(Max)(ns)2222IOL(Max)(mA)88IOH(Max)(mA)-0.4-0.4SchmittTriggerNoNoRatingCatalogMilitaryOperatingTemperatureRange(C)0to70-55to125Pin/Package14PDIP,14SO,14SOIC,14SSOP14CDIP,14CFP,20LCCCFAQWhatis74LS04?74LS04isamemberof74XXYYICseries.The74-seriesaredigitallogicintegratedcircuits.74LS04IChassixNOTgates.TheseNOTgatesperformInvertingfunction.HencenameHEXINVERTINGGATES.Whatisthefunctionofic74ls04?74LS04HexNOTGateIC.74LS04isa2inputquadruple8-bitNOTgateIC.InverterinlogicconvertersisanelectronicsdevicewhosebasicfunctionsaretoinverttheincominglogicweatheritisHIGHorLOW.TheyarealsoknownasNOTgates.Whatisahexinverter?Ahexinverterisatypeofanintegratedcircuitthatcontainssixinverters.Manysophisticateddigitaldevicesuseinverters,includingmultiplexers,decoders,andstatemachines.Aninvertercircuitsmainfunctionistooutputthevoltagerepresentingtheoppositeleveltoitsinput.WhyisNOTgatecalledaninverter?ANOTgate,oftencalledaninverter,isanicedigitallogicgatetostartwithbecauseithasonlyasingleinputwithsimplebehavior.ANOTgateperformslogicalnegationonitsinput.Inotherwords,iftheinputistrue,thentheoutputwillbefalse.

IntroductionAcircuitordevicethatchangesthephaseofasignalby180,asrequiredforfeedingapush-pullamplifierstagewithoutusingacouplingtransformer,orforchangingthepolarityofapulse;atriodeiscommonlyusedasaphaseinverter.Alsoknownasinverter.Thefollowingisanintroductionto74LS04andothersimilarICchips.CatalogIntroductionI74LS04VS.74LS141.1BriefIntroduction1.2Differencebetween74LS04and74LS14II74LS04VS.74LS08III74LS04VS.74HC04IV74LS04VS.54LS04FAQOrdering&QuantityI74LS04VS.74LS141.1BriefIntroductionBoth74LS04and74LS14arenotgatesofthe74series.74LS04isaHexInverter.74LS14isaHexSchmidttrigger.The74LS04gatecircuithasathresholdvoltage.Whentheinputvoltagerisesfromthelowleveltothethresholdvoltage,ordecreasesfromthehighleveltothethresholdvoltage,theconditionofthecircuitwillchange.74LS14isaSchmidttrigger.Itisaspecialgatecircuit,whichisnotcompatiblewiththesimplegatecircuit.Schmidttriggerhastwothresholdvoltages(positivethresholdvoltageandnegativethresholdvoltage).1.2Differencebetween74LS04and74LS14◾Output:Theoutputof74LS04and74LS14arethesame.Ifthesamemanufacturer,theoutputparametersarethesame.◾Input:Thedifferencebetweenthetwoisthattheinputisnotthesame.74LS04inputisTTLlevel,while74LS14inputisSchmidtinput(withhysteresischaracteristics).Becausetheinputisdifferent,theapplicationofthetwochipsisalsodifferent.74LS04ismostlyusedfornoncontrolofgeneraldataontheboard,while74LS14isgenerallyusedforsignalshapingorsignalbufferingofcriticalsignals.Inmostcases,74LS14canreplace74LS04.II74LS04VS.74LS08The74LS08devicecontains4independent2-inputANDgates.Thelogicfunctionexpressionof74LS08is:Y=ABorY=/(A+B),positivelogic.74LS08iscommonlyusedindigitalcircuitsystems.74LS0474LS08VCC(Min)(V)4.754.75VCC(Max)(V)5.255.25LogiclevelTTLTTLPin/Package14PDIP,14SO,14SOIC,14SSOPPDIP14,SOIC14,SOP14,SSOP14III74LS04VS.74HC0474HC04isahexinverterofCMOScircuit,andtheworkingvoltageis2V-6V.Both74LS04and74HC04areinverters,butLSstandsforlow-powerSchottkyandHCishigh-speedCOMS.LSisslightlyfasterthanHC.LSadoptsTTLlevel.HCisCMOSlevel.74HC04iseasytounderstand.Inputlowlevel,outputhighlevel.Inputhighlevel,outputlowlevel.74LS04containssixindependentgateseachofwhichperformsthelogicINVERTfunction.Theoutputsignalsofthesixinvertersareoppositetotheinputsignals.Theinvertercanreversethephaseoftheinputsignalby180degrees.Thiscircuitisusedinanalogcircuits,suchasaudioamplifier,clockoscillator,etc.IV74LS04VS.54LS0454LS04containssixindependentinverters.Itischaracterizedforoperationoverthefullmilitarytemperaturerangeof-55℃to125℃.74LS0454LS04TechnologyFamilyLSLSVCC(Min)(V)4.754.5VCC(Max)(V)5.255.5Bits(#)66Voltage(Nom)(V)55F@NomVoltage(Max)(Mhz)3535ICC@NomVoltage(Max)(mA)0.0330.033tpd@NomVoltage(Max)(ns)2222IOL(Max)(mA)88IOH(Max)(mA)-0.4-0.4SchmittTriggerNoNoRatingCatalogMilitaryOperatingTemperatureRange(C)0to70-55to125Pin/Package14PDIP,14SO,14SOIC,14SSOP14CDIP,14CFP,20LCCCFAQWhatis74LS04?74LS04isamemberof74XXYYICseries.The74-seriesaredigitallogicintegratedcircuits.74LS04IChassixNOTgates.TheseNOTgatesperformInvertingfunction.HencenameHEXINVERTINGGATES.Whatisthefunctionofic74ls04?74LS04HexNOTGateIC.74LS04isa2inputquadruple8-bitNOTgateIC.InverterinlogicconvertersisanelectronicsdevicewhosebasicfunctionsaretoinverttheincominglogicweatheritisHIGHorLOW.TheyarealsoknownasNOTgates.Whatisahexinverter?Ahexinverterisatypeofanintegratedcircuitthatcontainssixinverters.Manysophisticateddigitaldevicesuseinverters,includingmultiplexers,decoders,andstatemachines.Aninvertercircuitsmainfunctionistooutputthevoltagerepresentingtheoppositeleveltoitsinput.WhyisNOTgatecalledaninverter?ANOTgate,oftencalledaninverter,isanicedigitallogicgatetostartwithbecauseithasonlyasingleinputwithsimplebehavior.ANOTgateperformslogicalnegationonitsinput.Inotherwords,iftheinputistrue,thentheoutputwillbefalse.

DescriptionDS18B20isatemperaturesensorofMaxim.Thesingle-chipmicrocomputercancommunicatewithDS18B20through1-Wireprotocolandfinallyreadthetemperature.Thehardwareinterfaceofthe1-Wirebusisverysimple,justconnectthedatapinofDS18B20toanIOportofthemicrocontroller.ThisVideoIntroducesDS18B20withDatasheetCatalogDescriptionDocumentandMediaDS18B20PinoutParametersAdvantageFeaturesApplicationsDS18B20CircuitSchematicDS18B20TemperatureSensorDataDS18B20BlockDiagramHowtousetheDS18B20SensorWheretouseDS18B20SensorProductManufacturerFAQOrdering&QuantityDocumentandMediaComponentDatasheetDS18B20DatasheetDS18B20PinoutPinNameFunctionSOSOPTO-921,2,6,7,82,3,5,6,7-N.C.NoConnection383VDDOptionalVDD.VDDmustbegroundedforoperationinparasitepowermode.412DQDataInput/Output.Open-drain1-Wireinterfacepin.Alsoprovidespowertothedevicewhenusedinparasitepowermode(seethePoweringtheDS18B20section.)541GNDGroundParametersAccuracy(C)0.5ChannelsOneInterface1-WireMultiDroppableYesOper.Temp.(C)-55to+125Package/PinsSOIC(N)/8,TO92/3,UMAX/8ParasitePwr.YesPartNumberDS18B20SensorTypeLocalTemp.Resolution(bits)9,10,11,12Temp.Thresh.Programmable(NV)AdvantageTheDS18B20digitalthermometerprovides9-bitto12-bitCelsiustemperaturemeasurementsandhasanalarmfunctionwithnonvolatileuser-programmableupperandlowertriggerpoints.TheDS18B20communicatesovera1-Wirebusthatbydefinitionrequiresonlyonedataline(andground)forcommunicationwithacentralmicroprocessor.Inaddition,theDS18B20canderivepowerdirectlyfromthedataline(parasitepower),eliminatingtheneedforanexternalpowersupply.EachDS18B20hasaunique64-bitserialcode,whichallowsmultipleDS18B20stofunctiononthesame1-Wirebus.Thus,itissimpletouseonemicroprocessortocontrolmanyDS18B20sdistributedoveralargearea.ApplicationsthatcanbenefitfromthisfeatureincludeHVACenvironmentalcontrols,temperaturemonitoringsystemsinsidebuildings,equipment,ormachinery,andprocessmonitoringandcontrolsystems.FeaturesUnique1-WireInterfaceRequiresOnlyOnePortPinforCommunicationReduceComponentCountwithIntegratedTemperatureSensorandEEPROMMeasuresTemperaturesfrom-55Cto+125C(-67Fto+257F)0.5CAccuracyfrom-10Cto+85CProgrammableResolutionfrom9Bitsto12BitsNoExternalComponentsRequiredParasiticPowerModeRequiresOnly2PinsforOperation(DQandGND)SimplifiesDistributedTemperature-SensingApplicationswithMultidropCapabilityEachDeviceHasaUnique64-BitSerialCodeStoredinOn-BoardROMFlexibleUser-DefinableNonvolatile(NV)AlarmSettingswithAlarmSearchCommandIdentifiesDeviceswithTemperaturesOutsideProgrammedLimitsAvailablein8-PinSO(150mils),8-PinSOP,and3-PinTO-92PackagesApplicationsConsumerProductsIndustrialSystemsThermallySensitiveSystemsThermometersThermostaticControlsDS18B20CircuitSchematicDS18B20TemperatureSensorDataDS18B20canachievethehighest12-bittemperaturestoragevaluethroughprogramming.Thetemperaturestoragevalueisstoredintheregisterinacomplementformat.Thereare2bytesintotal,LSBisthelowbyteandMSBisthehighbyte.Amongthem,MSbisthehighbitofthebyte,andLSbisthelowbitofthebyte.Forbinarynumbers,themeaningofthetemperaturerepresentedbyeachofthemisexpressed.Amongthem,Srepresentsthesignbit,andthelower11bitsareallpowersof2,whichareusedtorepresentthefinaltemperature.ThetemperaturemeasurementrangeofDS18B20isfrom-55degreesto+125degrees.Themanifestationoftemperaturedatahaspositiveandnegativetemperatures.Eachnumberintheregisterisdistributedlikethescaleofacaliper.Thelowestbitofthebinarynumberchanges1,whichrepresentsthemappingrelationshipofatemperaturechangeof0.0625degrees.Whenthetemperatureis0℃,thecorrespondinghexadecimalnumberis0x0000.Whenthetemperatureis125℃,thecorrespondinghexadecimalnumberis0x07D0.Whenthetemperatureisminus55℃,thecorrespondinghexadecimalnumberis0xFC90.Conversely,whenthenumberis0x0001,thetemperatureis0.0625℃.DS18B20BlockDiagramHowtousetheDS18B20SensorThesensorworkswiththemethodof1-Wirecommunication.Itrequiresonlythedatapinconnectedtothemicrocontrollerwithapullupresistorandtheothertwopinsareusedforpowerasshownbelow.Thepull-upresistorisusedtokeepthelineinhighstatewhenthebusisnotinuse.Thetemperaturevaluemeasuredbythesensorwillbestoredina2-byteregisterinsidethesensor.Thisdatacanbereadbytheusingthe1-wiremethodbysendinginasequenceofdata.Therearetwotypesofcommandsthataretobesenttoreadthevalues,oneisaROMcommandandtheotherisfunctioncommand.TheaddressvalueofeachROMmemoryalongwiththesequenceisgiveninthedatasheetbelow.Youhavetoreadthroughittounderstandhowtocommunicatewiththesensor.IfyouareplanningtointerfaceitwithArduino,thenyouneednotworryaboutallthese.Youcandevelopthereadilyavailablelibraryandusethein-builtfunctionstoaccessthedata.WheretouseDS18B20SensorTheDS18B20isa1-wireprogrammableTemperaturesensorfrommaximintegrated.Itiswidelyusedtomeasuretemperatureinhardenvironmentslikeinchemicalsolutions,minesorsoiletc.Theconstrictionofthesensorisruggedandalsocanbepurchasedwithawaterproofoptionmakingthemountingprocesseasy.Itcanmeasureawiderangeoftemperaturefrom-55Cto+125withadecentaccuracyof5C.EachsensorhasauniqueaddressandrequiresonlyonepinoftheMCUtotransferdatasoitaverygoodchoiceformeasuringtemperatureatmultiplepointswithoutcompromisingmuchofyourdigitalpinsonthemicrocontroller.ProductManufacturerMaximIntegratedprovideseaseofdesign,andspeedstimetomarket,throughanalogintegration.ThecompanysanalogICsofferextrafeaturesandfunctionalitycarefullydesignedtostreamlinecircuitandsimplifydesign.LooktoMaximforsolutionsforconsumerelectronics,personalcomputersandperipherals,mobiledevices,wirelessandfibercommunications,testequipment,instrumentation,videodisplays,andautomotiveapplications.Maximsanalogandmixed-signalsolutionsincludedataconverters,interfacecircuits,power,RFwirelesscircuits,clocksandoscillators,microcontrollers(MCUs),operationalamplifiers(opamps),andsensors.FAQWhatisDS18B20temperaturesensor?TheDS18B20isa1-wireprogrammabletemperaturesensorfrommaximintegrated.Itiswidelyusedtomeasuretemperatureinhardenvironmentslikeinchemicalsolutions,minesorsoiletc.Theconstrictionofthesensorisruggedandalsocanbepurchasedwithawaterproofoptionmakingthemountingprocesseasy.HowdoestheDS18B20work?Itworksontheprincipleofdirectconversionoftemperatureintoadigitalvalue.IsDS18B20athermistor?Athermistorisathermalresistor-aresistorthatchangesitsresistancewithtemperature....Thermistorshavesomebenefitsoverotherkindsoftemperaturesensorssuchasanalogoutputchips(LM35/TMP36)ordigitaltemperaturesensorchips(DS18B20)orthermocouples.HowaccurateisDS18B20?TheDS18B20readswithanaccuracyof0.5Cfrom-10Cto+85Cand2Caccuracyfrom-55Cto+125C.Whatisds1820?TheDS18B20isonetypeoftemperaturesensoranditsupplies9-bitto12-bitreadingsoftemperature....Thecommunicationofthissensorcanbedonethroughaone-wirebusprotocolwhichusesonedatalinetocommunicatewithaninnermicroprocessor.HowdoIconnectmyDS18B20tomyRaspberryPi?OnceyouveconnectedtheDS18B20,powerupyourPiandlogin,thenfollowthesestepstoenabletheOne-Wireinterface:1.Atthecommandprompt,entersudonano/boot/config.txt,thenaddthistothebottomofthefile:2.dtoverlay=w1-gpio.3.ExitNano,andrebootthePiwithsudoreboot.WhatistheworkingprincipleofDS18B20?TheDS18B20DigitalThermometerprovides9to12-bit(configurable)temperaturereadingswhichindicatethetemperatureofthedevice.Itcommunicatesovera1-Wirebusthatbydefinitionrequiresonlyonedataline(andground)forcommunicationwithacentralmicroprocessor.Inadditionitcanderivepowerdirectlyfromthedataline(parasitepower),eliminatingtheneedforanexternalpowersupply.ThecorefunctionalityoftheDS18B20isitsdirect-to-digitaltemperaturesensor.Theresolutionofthetemperaturesensorisuser-configurableto9,10,11,or12bits,correspondingtoincrementsof0.5C,0.25C,0.125C,and0.0625C,respectively.Thedefaultresolutionatpower-upis12-bit.WheretouseDS18B20Sensor?TheDS18B20isa1-wireprogrammableTemperaturesensorfrommaximintegrated.Itiswidelyusedtomeasuretemperatureinhardenvironmentslikeinchemicalsolutions,minesorsoiletc.Theconstrictionofthesensorisruggedandalsocanbepurchasedwithawaterproofoptionmakingthemountingprocesseasy.Itcanmeasureawiderangeoftemperaturefrom-55Cto+125withadecentaccuracyof5C.EachsensorhasauniqueaddressandrequiresonlyonepinoftheMCUtotransferdatasoitaverygoodchoiceformeasuringtemperatureatmultiplepointswithoutcompromisingmuchofyourdigitalpinsonthemicrocontroller.HowconnectDS18B20toArduino?FirstplugthesensoronthebreadboardtheconnectitspinstotheArduinousingthejumpersinthefollowingorder:pin1toGND;pin2toanydigitalpin(pin2inourcase);pin3to+5Vor+3.3V,attheendputthepull-upresistor.OnanATMega328P,whyisaDS18B20temperaturesensorreturningincorrecttemperaturevalues?Severalpossibilities:1.Ifitisjustreadingalittlehigh,itmightbecausedbyselfheating.Addaheatsinkand/ormakemeasurementslessfrequently.2.Especiallyifthevaluesarereallywhacky,itmightbecodewitherrorsormis-wiring.Useapublishedsketchtocheckoperation.3.TheDS18B20mightbedefective.Tryanother.4.Itsaccurateto0.5C.Areyouexpectingittobemoreaccurate(likedowntotheLSBofthereadvalue)?IDescriptionFirst,thisblogwillintroducethe1wiredigitaltemperaturesensorDS18B20.Wemainlyintroduceitsstructure,characteristicsandworkingprinciplehere.Second,wewillintroduceatemperaturemeasurementsystembasedonDS18B20andAT89S52microcontroller.Herewemainlyintroduceitshardwarestructureandassembler.Third,therewillbepartofthesourceprogramthatisdetailedanalyed.Finally,theblogalsoexplainshowitperformstemperaturemeasurementintheagriculturalfield.Thetemperaturemeasuringdevicehasaseriesofadvantages.Suchas:highdisplayaccuracy,lowprice,simplestructure,convenientexpansionandwideapplication.DS18B20TemperatureSensorTutorialCatalogIDescriptionIIIntroductionIIIDS18B20Overview3.1DS18B20Advantages3.2DS18B20Features3.3DS18B20InternalStructureIVDS18B20MCUTemperatureMeasurementDevice4.1CompositionofSystemHardware4.2DesignofInterfaceVSoftwareDesignVIApplicationinAgriculturalProduction6.1TemperatureofMildew6.2TemperatureofAgriculturalProducts6.3TemperatureDetectioninGreenhouses6.4TemperatureofSoilVIIConclusionFAQOrdering&QuantityIIIntroductionWhatistemperature?Whataretherolesoftemperature?Temperatureisaphysicalquantitythatcharacterizesthedegreeofcoolingofanobject,anditisalsoabasicenvironmentalparameter.Inagro-industrialproductionanddailylife,themeasurementandcontroloftemperaturealwaysoccupyanextremelyimportantposition.Atpresent,atypicaltemperaturemeasurementandcontrolsystemconsistsofthefollowingparts:Analogtemperaturesensor;A/Dconversioncircuit;MCU.However,theanalogsignaloutputbytheanalogtemperaturesensorhastobeconverted.Itcaninterfacewithmicroprocessorssuchassingle-chipmicrocomputersonlyafterobtainingdigitalsignalsthroughtheA/Dconversionlink.Therefore,thehardwarecircuitstructureiscomplicatedandthecostishigh.ButDS18B20canhelpsolvethisproblem.Thenew1wiredigitaltemperaturesensorrepresentedbyDS18B20integratestemperaturemeasurementandA/Dconversion,anddirectlyoutputsdigitalquantities.Thestructureoftheinterfacecircuitwiththesingle-chipmicrocomputerissimple,anditiswidelyusedintheoccasionswithlongdistanceandmanynodes.Therefore,DS18B20hasstrongpromotionandapplicationvalue.IIIDS18B20Overview3.1DS18B20AdvantagesDS18B20type1wireintelligenttemperaturesensorproducedbyDALLASSemiconductorCompany.Itbelongstoanewgenerationofintelligenttemperaturesensorsadaptedtomicroprocessors.Comparedwiththetraditionalthermistor,ithasthefollowingadvantages:Itcandirectlyreadthemeasuredtemperature;Thereadingmodeof9-12digitscanberealizedthroughsimpleprogrammingaccordingtoactualrequirements;Itcanalsocomplete9-bitand12-bitdigitalquantitieswithin93.75msand750ms,respectively,withamaximumresolutionof0.0625C;ToreadorwritetheinformationofDS18B20,onlyoneportline(1wireinterface)isrequiredtoreadandwrite.3.2DS18B20FeaturesUnique1-WireInterfaceRequiresOnlyOnePortPinforCommunicationReduceComponentCountwithIntegratedTemperatureSensorandEEPROMMeasuresTemperaturesfrom-55Cto+125C(-67Fto+257F)0.5CAccuracyfrom-10Cto+85CProgrammableResolutionfrom9Bitsto12BitsNoExternalComponentsRequiredParasiticPowerModeRequiresOnly2PinsforOperation(DQandGND)SimplifiesDistributedTemperature-SensingApplicationswithMultidropCapabilityEachDeviceHasaUnique64-BitSerialCodeStoredinOn-BoardROMFlexibleUser-DefinableNonvolatile(NV)AlarmSettingswithAlarmSearchCommandIdentifiesDeviceswithTemperaturesOutsideProgrammedLimitsAvailablein8-PinSO(150mils),8-PinSOP,and3-PinTO-92Packages3.3DS18B20InternalStructureDS18B20adopts3-pinPR-35packageor8-pinSOICpackage.ItsDS18B20externalshapeandpindiagramareshowninFigure1.TheDS18B20internalstructureblockdiagramisshownasinFigure2.Thestructureof64-bitflashROMisshowninFigure3.Figure1.DS18B20PinoutFigure2.DS18B20InternalStructureFigure3.64bFlashROMStructureIVDS18B20MCUTemperatureMeasurementDevice4.1CompositionofSystemHardwareTheDS18B20single-chipmicrocomputerintelligenttemperaturemeasurementdeviceismainlycomposedofDS18B20temperaturesensor,AT89S52,displaymoduleandpowermodule,asshowninFigure4.Themaintechnicalindicatorsoftheproductare:MeasuringRange(℃):-55.0~+125.0MeasurementAccuracy(℃):0.1ResponseTime(s):1.5Figure4.SystemStructureDiagramThesystemusesDS18B20asatemperaturesensor.Theone-chipcomputerAT89S52ofATMELCompanyservesastheprocessor.Temperaturedisplayandlight-emittingdiodeastemperaturecontroloutputunit.Thewholesystemstrivestohaveasimplestructureandperfectfunctions.Theworkingprincipleofthesystemisasfollows:AfterDS18B20carriesonthefieldtemperaturemeasurement,themeasureddataissenttotheP3.5portofAT89S52.Thetemperaturevalueisdisplayedafterbeingprocessedbythemicrocontroller.Then,thistemperaturevalueiscomparedwiththeupperlimitofthesetalarmtemperature.Ifitishigherthanthesetupperlimit,theyellowLEDlightsup.ThemaincircuitdiagramofthesystemisshownasinFig.5.Figure5.DS18B20TemperatuerMeasurementDevice4.2DesignofInterfaceThereare2waystoconnectDS18B20tothehardwareofthemicrocontroller:Vccisconnectedtoexternalpowersupply,GNDisgrounded,andI/OisconnectedtotheI/Olineofthemicrocontroller;Useparasiticpowersupply,UDDandGNDaregroundedatthistime,andI/OisconnectedtoMCUI/O.Regardlessofthe1stor2ndpowersupplymode,theI/Olinemustbeconnectedtoapull-upresistorofabout4.7k.Figure6showsatypicalconnectionbetweenDS18B20andamicroprocessor.InFigure6(a),DS18B20adoptsparasiticpowersupply,anditsVDDandGNGterminalsarebothgrounded;InFigure6(b),theDS18B20usesanexternalpowersupply,anditsVDDterminalusesa3~5.5Vpowersupply.ThissystemadoptsthewiringmodeshowninFigure6(b),thatis,theworkingmodeofexternalpowersupply.TheactualconnectionpictureofthesystemisshowninFigure6.Figure6.PhysicalDiagramofSystemConnectionVSoftwareDesignItisworthnotingthatDS18B20hasveryhighrequirementsontwoaspects:timingandelectricalparameters.Therefore,theworkflowofthemainCPUaccessingtheDS18B20throughthesingle-businterfacemustfollowastrictoperatingsequence:first,initializetheDS18B20;second,sendROMcommands;andthen,sendfunctioncommands.Wecantakealookatthefollowingpartofthesourceprogramisasfollows:ORG0000HAJMPMAIN;StatementofMCUmemoryallocation!TEMPER_LEQU29H;usedtosavethelower8bitsofthereadtemperatureTEMPER_HEQU28H;usedtosavetheupper8bitsofthereadtemperatureFLAG1EQU38H;WhethertheDS18B20flagisdetectedPNFLAGEQU68H;DatapositiveandnegativeflagA_BITEQU20H;thesingledigitofthedigitaltubestoresthememorylocationB_BITEQU21H;ThetendigitsofthedigitaltubestorethememorylocationC_BITEQU22H;ThedecimalplacesofthedigitaltubestorethememorylocationT_INTEGEREQU26H;TheintegerpartafterFORMAT,whichintegratestwobytesoftemperatureintoonebyteT_DFEQU27H;ThedecimalfractionafterFORMAT,thedecimalfractionofnibbletemperature(therearelowfourdigits)MAIN:LCALLGET_TEMPER;CallthetemperaturereadingsubroutineLCALLT_FORMAT;Formattheread2bytetemperatureLCALLALARM;callthealarmsubroutineLCALLDISPLAY;callthedigitaltubedisplaysubroutineLCALLD1S;testafteradelayof0.5secondsAJMPMAIN;thisistheDS18B20resetinitializationsubroutineINIT_1820:SETBP3.5NOPCLRP3.5;thehostsendsoutaresetlowpulsewithadelayof537microsecondsMOVR1,#2TSR1:MOVR0,#250DJNZR0,$DJNZR1,TSR1SETBP3.5;thenpullupthedatalineNOPNOPNOPMOVR0,#25HTSR2:JNBP3.5,TSR3;waitingforDS18B20responseDJNZR0,TSR2;delayLJMPTSR4TSR3:SETBFLAG1;SettheflagbittoindicatethatDS1820existsLJMPTSR5TSR4:CLRFLAG1;cleartheflagbit,indicatingthatDS1820doesnotexistLJMPTSR7TSR5:MOVR0,#120TSR6:DJNZR0,TSR6;timingrequiresaperiodofdelayTSR7:SETBP3.5RET;readthetemperaturevalueafterconversionGET_TEMPER:;SETBP3.5LCALLINIT_1820;firstresetDS18B20JBFLAG1,TSS2RET;DeterminewhetherDS1820exists?IfDS18B20doesnotexistThenreturnTSS2:MOVA,#0CCH;skipROMmatchingLCALLWRITE_1820MOVA,#44H;IssuetemperatureconversioncommandLCALLWRITE_1820LCALLDISPLAYLCALLINIT_1820;resetbeforereadingtemperatureMOVA,#0CCH;SkipROMmatchingLCALLWRITE_1820MOVA,#0BEH;IssuereadtemperaturecommandLCALLWRITE_1820LCALLREAD_18200;savethereadtemperaturedatato28H/29HRET;WriteDS18B20subroutine(withspecifictimingrequirements)WRITE_1820:MOVR2,#8;atotalof8bitsofdata;CLRCWR1:CLRP3.5MOVR3,#6DJNZR3,$RRCAMOVP3.5,CMOVR3,#23DJNZR3,$SETBP3.5NOPDJNZR2,WR1SETBP3.5RET;readtheprogramofDS18B20,readtwobytesoftemperaturedatafromDS18B20READ_18200:MOV36H,#2;SetthehighandlowtemperatureReadfromDS18B20MOVR1,#29H;thelowbitisstoredin29H(TEMPER_L),thehighbitDeposit28H(TEMPER_H)RE00:MOVR2,#8;Thereare8bitsofdataRE01:;CLRCSETBP3.5NOPNOPCLRP3.5NOPNOPNOPSETBP3.5MOVR3,#9RE10:DJNZR3,RE10MOVC,P3.5MOVR3,#23RE20:DJNZR3,RE20RRCADJNZR2,RE01MOV@R1,ADECR1DJNZ36H,RE00RET;-----Integratethetwo-bytetemperaturereadout(pleaserefertotheinformationaboutthe2-bytetemperatureformatreadoutbyDS18B20)----------T_FORMAT:;AlarmsubroutineALARM:;DisplaysubroutineDISPLAY:;1MSdelay(calculatedby12MHZ)D1MS:MOVR7,#250llmm:nopnopDJNZR7,llmmRET;1MSdelay(calculatedby12MHZ)D1S:MovR6,#4LOOP2:movR5,#125;------------250LOOP1:LCALLD1mSDJNZR5,LOOP1DJNZR6,LOOP2RET;7-segmentdigitaltube0-9digitcommonanodedisplaycodeNUMTAB:DB0C0H,0f9H,0a4H,0b0H,99H,92H,82H,0f8H,80H,90H,0ffHXIAOSHU:DB00H,01H,01H,02H,03H,03H,04H,04H,05H,06H,06H,07H,08H,08H,09H,09HENDVIApplicationinAgriculturalProductionThistemperaturemeasurementsystemcandirectlyoutputdigitalquantities.Inaddition,ithasthecharacteristicsofsimplestructure,convenientuseandlowprice.Therefore,itcanbewidelyusedinagriculturalproduction.6.1TemperatureofMildewModerngrainwarehousescanusethissystemtomonitorthetemperatureofhundredsofpoints.Inthisway,youcaneasilygraspthetemperaturechangesatvariouspointsatdifferenttimes,increasestoragecapacity,andeffectivelyreducetheoccurrenceofmildew.6.2TemperatureofAgriculturalProductsAtpresent,low-temperaturerefrigerationmeasuresarewidelyadoptedforthepreservationoffruitsandvegetables.Thesystemcanbeinstalledinthetemperaturemeasurementpositionoftherefrigeratorcompartment.Inthisway,thetemperaturevaluecanbeconvenientlyobservedatanytimetocheckwhethertheoptimalpreservationtemperatureisreached.6.3TemperatureDetectioninGreenhousesThesystemisusedinplasticgreenhousesforgreenhousevegetablecultivationandflowerproduction.Inthisway,automatictemperaturedisplaycanberealized,andlaborandtimefortemperaturemeasurementcanbesaved.6.4TemperatureofSoilIntheprocessofplantingcropswithstrictrequirementsonsoiltemperature,thesystemcantestthechangesinsoiltemperatureasneededtofacilitatethegraspofaccuratetemperaturevalues.VIIConclusionThesingle-chiptemperaturemeasurementsystemtakesfulladvantageofthesimplicityofthehardwarestructureofDS18B20andAT89S52,using8-segmentdigitaltubedisplay,lowpriceandwideapplication.Accordingtoactualneeds,wecanalsouseLCDasadisplaydeviceorformadistributedtemperaturemeasurementandcontrolsystem.Althoughthedesigniseasytoexpand,italsohasitsshortcomings.Thesimplicityofthehardwarestructurecomesattheexpenseofsoftware.Therefore,specialattentionshouldbepaidtotheworkingsequencerequirementsofDS18B20duringprogramming.Inshort,thesystemcanbewidelyusedintemperaturemeasurementinagriculturalproduction.FAQWhatisDS18B20temperaturesensor?TheDS18B20isa1-wireprogrammabletemperaturesensorfrommaximintegrated.Itiswidelyusedtomeasuretemperatureinhardenvironmentslikeinchemicalsolutions,minesorsoiletc.Theconstrictionofthesensorisruggedandalsocanbepurchasedwithawaterproofoptionmakingthemountingprocesseasy.HowdoestheDS18B20work?Itworksontheprincipleofdirectconversionoftemperatureintoadigitalvalue.IsDS18B20athermistor?Athermistorisathermalresistor-aresistorthatchangesitsresistancewithtemperature....Thermistorshavesomebenefitsoverotherkindsoftemperaturesensorssuchasanalogoutputchips(LM35/TMP36)ordigitaltemperaturesensorchips(DS18B20)orthermocouples.HowaccurateisDS18B20?TheDS18B20readswithanaccuracyof0.5Cfrom-10Cto+85Cand2Caccuracyfrom-55Cto+125C.Whatisds1820?TheDS18B20isonetypeoftemperaturesensoranditsupplies9-bitto12-bitreadingsoftemperature....Thecommunicationofthissensorcanbedonethroughaone-wirebusprotocolwhichusesonedatalinetocommunicatewithaninnermicroprocessor.HowdoIconnectmyDS18B20tomyRaspberryPi?OnceyouveconnectedtheDS18B20,powerupyourPiandlogin,thenfollowthesestepstoenabletheOne-Wireinterface:1.Atthecommandprompt,entersudonano/boot/config.txt,thenaddthistothebottomofthefile:2.dtoverlay=w1-gpio.3.ExitNano,andrebootthePiwithsudoreboot.WhatistheworkingprincipleofDS18B20?TheDS18B20DigitalThermometerprovides9to12-bit(configurable)temperaturereadingswhichindicatethetemperatureofthedevice.Itcommunicatesovera1-Wirebusthatbydefinitionrequiresonlyonedataline(andground)forcommunicationwithacentralmicroprocessor.Inadditionitcanderivepowerdirectlyfromthedataline(parasitepower),eliminatingtheneedforanexternalpowersupply.ThecorefunctionalityoftheDS18B20isitsdirect-to-digitaltemperaturesensor.Theresolutionofthetemperaturesensorisuser-configurableto9,10,11,or12bits,correspondingtoincrementsof0.5C,0.25C,0.125C,and0.0625C,respectively.Thedefaultresolutionatpower-upis12-bit.WheretouseDS18B20Sensor?TheDS18B20isa1-wireprogrammableTemperaturesensorfrommaximintegrated.Itiswidelyusedtomeasuretemperatureinhardenvironmentslikeinchemicalsolutions,minesorsoiletc.Theconstrictionofthesensorisruggedandalsocanbepurchasedwithawaterproofoptionmakingthemountingprocesseasy.Itcanmeasureawiderangeoftemperaturefrom-55Cto+125withadecentaccuracyof5C.EachsensorhasauniqueaddressandrequiresonlyonepinoftheMCUtotransferdatasoitaverygoodchoiceformeasuringtemperatureatmultiplepointswithoutcompromisingmuchofyourdigitalpinsonthemicrocontroller.HowconnectDS18B20toArduino?FirstplugthesensoronthebreadboardtheconnectitspinstotheArduinousingthejumpersinthefollowingorder:pin1toGND;pin2toanydigitalpin(pin2inourcase);pin3to+5Vor+3.3V,attheendputthepull-upresistor.OnanATMega328P,whyisaDS18B20temperaturesensorreturningincorrecttemperaturevalues?Severalpossibilities:1.Ifitisjustreadingalittlehigh,itmightbecausedbyselfheating.Addaheatsinkand/ormakemeasurementslessfrequently.2.Especiallyifthevaluesarereallywhacky,itmightbecodewitherrorsormis-wiring.Useapublishedsketchtocheckoperation.3.TheDS18B20mightbedefective.Tryanother.4.Itsaccurateto0.5C.Areyouexpectingittobemoreaccurate(likedowntotheLSBofthereadvalue)?

MW300

IDescriptionThisblogintroducesandanalyzes4simpleandeasy74LS00NandGatecircuitdiagrams.Itsincluding:SquareWaveGeneratorCircuit,PulseGeneratorCircuit,LEDLightCircuit.Andintheend,wewillanalyzethecircuitthatturnsthetimerintoacountdowntimerindetail.ThisVideoisAnIntroductionof7400LogicDevicesCatalogIDescriptionIISquareWaveGeneratorCircuitIIIPulseGeneratorCircuitIVLEDLightCircuitVTurnTimerintoCountdownTimer5.1SchemeDesign5.2ImplementationofSchemeDesignOrdering&QuantityIISquareWaveGeneratorCircuitLetstakealookatthefigurebelow.Itsasquarewavegeneratorcircuit.Thiscircuitcontainsa74LS00NandGateintegratedcircuit.Figure1.SquareWaveGeneratorCircuitDiagramAmongthiscircuitdiagram:NANDgates1,2andexternalRCtimeconstantcomponentsformanoscillatorcircuitNANDgate3isabufferoutputstage.AslongasthecapacityofCischanged,squarewaveoutputsofdifferentfrequenciescanbeobtained.IIIPulseGeneratorCircuitFigure2.PulseSignalGeneratorCircuitDiagramThecircuitdiagramisshowninFigure2anditsasimplepulsesignalgeneratorcircuit.ThesignalgeneratormainlyusestwoTTLintegratedcircuits(74LS00and74LS221).Sowhychoosethesetwocircuits?Thatisbecause,thesetwocircuitscanbeusedtogenerateapulsesignalof=4s.Besides,itusesfewercomponentsandisconvenientfordebuggingandmaintenance.IVLEDLightCircuitThiscircuitismadewithNE555,74LS00,74LS154,74LS193andLEDlights,andtheproductionprocessisverysimple.Whenweturnonthepower,hereishowitworksis:WhentheoutputQ0ofthe74LS154decoderislow,the74LS193isapositivecounter.Atthistime,theLEDsareindividuallylitfromD1...D16;WhentheoutputQ15ofthe74LS154decoderislow,the74LS193isacountdowncounter.Atthistime,theLEDsareindividuallylitfromD16...D1.Figure3.LEDLightCircuitDiagramFromtheabovewecanseethat:theLEDlightsturnonfromD1toD16,andthenbacktoD1fromD16,andsoon.VTurnTimerintoCountdownTimerGenerally,therearetwodesignideasforturningatimerintoacountdowntimer:First,changethecountingchipinthetimer;Second,resetthefunctionofthechip.Besides,thereisactuallyanotherwaytoachievethisgoal:Byappliyingthe74LS00and74LS20chipstoreversetheresultsonthedisplay,soastoachievethepurposeofcountingdown.5.1SchemeDesignTheresultdisplayedbyeachdigitofthetimerisanincrementalvalue,suchas0.1.2.3.4.5.6.7.8.9.Yet,thecountdowntimerdisplaysadecreasingvalue,suchas9.8.7.6.5.4.3.2.1.0.Aslongasthedisplayresultconversioniscompletedwithasuitablelogiccircuit,thetimercanbeturnedintoacountdowntimer.Atfirst,weneedtofindthelogicalrelationshipbetweenthetimerdisplayresultandthecountdowntimerdisplayresult.Table1belowliststheBCDcodescorrespondingtoeachdisplayresultofthetimerandcountdowntimer.Fromthistable,youcaneasilyfindtheBCDcodesofthetimerandcountdowntimer:ThelowestbitQ1andY1areopposite;WhileQ2andY2arethesame;RelationshipbetweenQ3andY3:Y3ofthecountdowntimeristheexclusiveORoftimerQ3andQ2;RelationshipbetweenQ4andY4:TheY4bitofthecountdowntimeristheoppositevalueoftheORofQ4,Q3,andQ2ofthetimer,whichisalsoequaltothenon-re-ANDofQ4,Q3,andQ2.Table1.CorrespondingBCDCodeDisplayedby(Down)TimerTheabovelogicalexpressionis:Therefore,aslongasyouchooseacircuitthatcancompletetheabovelogicconversionrelationship,youcanrealizethedesignfromatimertoacountdowntimer.Thefigure?showsatwo-digittimercircuit.Afteraddingtheaboveconversioncircuit,itbecomesthefigure3showsthecountdowncircuit.Figure4.TimerCircuitDisplaying2DigitsFigure5.CountdownCircuitDiagram5.2ImplementationofSchemeDesignTwokindsofchips74LS00and74LS20areuesdhere.Theformerarefourtwo-inputNANDgates,whichareusedtocompletetheconversionofY1andgeneratethenegationofQ4,Q3,andQ2.Thelatteraretwofour-inputNANDgates,whichareusedtoobtainY4fromthenon-reANDofQ4,Q3,andQ2.Insummary,wecanfollowthelogicalrelationshipasfollows:ThelogicdiagramisshowninFigure6.Figure6.LogicDiagramKnowingthattheXORgateoperationcanbecompleted,theY3conversioncanbecompleted.Theconnectioncircuitdiagramoftheabove-mentionedY4,Y3,Y1conversionspecificphysicalobjectsisshowninFigure7.Figure7.Y4,Y3,Y1ConversionSpecificPhysicalConnectionDiagramFigure8showstheactualpictureofthecountdowntimer.Figure8.CountdownTimerSofar,thetimerhasbecomeacountdowntimer.Throughthisdesignmethod,thereisnoneedtochangetheoriginalcountercircuit,isitparticularlytrouble-free?I.IntroductionTDA7294isaveryinnovativeDMOShigh-powerintegratedamplifiercircuitlaunchedbythefamousEuropeanSGS-THOMSONSTMicroelectronicstomainlandChinainthe1990s.Itsweepsawaytheraw,cold,andhardtonesofthepreviouslinearintegratedpoweramplifiersandthickfilmintegration,andiswidelyusedintheHI-FIfield:suchashometheater,activespeakers,etc.Thedesignofthischipfocusesontone,andhastheadvantagesofbipolarsignalprocessingcircuitandpowerMOS.Ithasthecharacteristicsofhighvoltageresistance,lownoise,lowdistortion,andveryaffinityforreplayingsound;andhasasilentstandbyfunction,short-circuitcurrentandoverheatprotectionfunctionstomakeitsperformancemoreperfect.ThisarticlewillintroduceseveralpoweramplifiercircuitdesignsbasedonTDA7294.CatalogI.IntroductionII.OCLCircuitIII.BTLCircuitIV.ConstantCurrentPowerAmplifierV.Hi-FiIntegratedPowerAmplifierVI.ActiveSubwooferAmplifierAddsStandbyFunctionVII.HighFidelityPowerAmplifierVIII.ClassABPowerAmplifierIX.Two-channelPowerAmplifierX.100WPowerAmplifierCircuitOrdering&QuantityII.OCLCircuitTheOCLcircuitdiagramisshowninFigure1.Thiscircuitisadual-channel70WpoweramplifiercomposedoftwoTDA7294.Therearefewexternalcomponentsandsimplecircuit.Whenthepowersupplyvoltageis35V,70Wcontinuousoutputpowercanbeobtainedonan8ohmload.Itisverysuitableforplaybackinanenvironmentbelow30squaremeters.Ifthespeakerimpedanceislessthan8ohms,thepowersupplyvoltageshouldbereducedaccordingly.Figure1OCLCircuitDiagramIII.BTLCircuitTheBTLcircuitisshowninFigure2.ItusestwoTDA7294bridgestoformaBTLpoweramplifiercircuit.Theoutputpowercanreachmorethan150W.Itissuitableforplacesthatrequirehighpowersuchasdancehalls.4TDA7294arerequiredforstereo.Whenthepowersupplyvoltageis25V,acontinuousoutputpowerof150Wcanbeobtainedonan8ohmload.Whenthepowersupplyis35V,acontinuousoutputpowerof180Wcanbeobtainedona16ohmload.WhenuseTDA7294asBTLpoweramplifier,theloadmustnotbelessthan8ohms.Figure2BTLCircuitDiagramIV.ConstantCurrentPowerAmplifierThispoweramplifiercircuitissomewhatdifferentfromtheprevioustwostructures.Itsfeedbackcircuitiscurrentsampling,voltagesummationandnegativefeedback.Thiskindofcircuitstructureistheconstantcurrentpoweramplifierthatpeopleoftensay.Thespecificanalysisofthecircuitwillnotbedetailed,onlythemoreprominentadvantagescomparedwiththetraditionalconstantvoltagepoweramplifierwillbeintroduced.(1)Theoutputcurrentofthepoweramplifierhasnothingtodowiththeloadimpedance.Eveniftheloadisshort-circuited,itwillnotcausetheamplifiertooverheat.(2)Theoutputpowerincreaseswiththeincreaseofloadimpedance.Pushingthespeakerloadwithinacertainpowerreservecanensurethebassstrengthandhighfrequencyresolutionoftheoriginalmusicsignal.(3)Theforceactingonthevoicecoilofthespeakeronlydependsonthecurrent.Theuseoffluid-controlledoscillationtopromotethespeakermustbefasterthanthevoltage-controlledoscillation,sothattheinputandoutputimpedanceofthespeakervibrationsystemcanbeeasilymatched.Theconstantcurrentpoweramplifiercircuitisactuallyacontrolledcurrentsourcecontrolledbytheinputsignalvoltage.Itsinternalfeedbackcircuitiscurrentsampling,voltagesummingnegativefeedback,andithasthecharacteristicsofhighinputandoutputimpedance.Theinputimpedanceishigh,whichisexactlywhatthepreviousstageconstantvoltageamplifiercircuitneeds,whichisbeneficialforthesignalvoltagetobesenttotheinputendofthepoweramplifierwithoutloss.Thehighoutputimpedancecanreducetheshuntoftheinternalresistancetothesignal,whichisconducivetoaddingtheoutputsignalcurrenttotheload.InFigure3,thepowersupplyvoltageisselectedas35V,anditsmagnificationisdeterminedbytheratioofthespeakertoR6.Figure3ConstantcurrentpoweramplifiercircuitdiagramV.Hi-FiIntegratedPowerAmplifierThefamousEuropeanSGS-THOMSONSTMicroelectronicshaslaunchedaHi-Fihigh-powerDMOSintegratedamplifiercircuitTDA7294.ThecircuitisshowninFigure4.Itintegratesthebestdesignofmodernpoweramplifiercircuit,combinestheadvantagesofbipolarsignalprocessingcircuitandpowerMOS,hasthecharacteristicsoflownoiseandlowdistortion;standbyandmutecircuitcompletelyeliminatestheimpactnoisecausedbypoweronandoff,andeliminatesspeakerprotectioncircuitoverheating,short-circuitcurrentprotectionandotherfunctionsmakeitsperformancemoreexcellent.ThisdeviceissuitableforhometheaterandHi-Fiamplifiers.Themainparametersare:VS(powersupplyvoltage)10~40V(maximumvoltagewithoutsignal50V);Io(peakoutputcurrent)10A;Po(RMScontinuousoutputpower)70Wwhenvs=35V8;vs=70Wwhen27V4;(effectivevalueofmusicoutputpower)100WwhenVS=38V8;100WwhenVS=29V4.Figure4Hi-FiIntegratedPowerAmplifierCircuitDiagramTheclosed-loopgainofthecircuitinFigure4is30dB.IncreasingR3canincreasethegain,andviceversa,buttheamplifiergainshouldbe24dB.TheamplifierhasthebestperformancewhenR1=R3.R7,C4andR5+R6,C3determinethestandbyandmutetimeconstants.Thelargerthevalue,thelongerthetime.Whenthecontrolterminalisconnectedtolowpotentialground,itismuteandstandby;whenthecontrolterminalisconnectedtoVS,because(R5+R6)R7,pin⑩risestoahigherpotentialthanpin⑨,andturnstoalowpotentialfirstwhenshuttingdown,whichmakesthestandbyandshutdownprocessesgooninasilentstate,ensuringthattheamplifieristurnedonandoffwithoutnoise.Figure5BTLPoweramplifierfinishedboardForhigh-powerprofessionalapplicationsfiledssuchasdancehalls,youcanchoosetheBTLpoweramplifierfinishedboardshowninFigure5.BothTDA7294areequippedwiththeirownprofessionalradiators.Whenvs=25V8,themaximumcontinuousoutputpowerreaches150W;when35V16,Themaximumcontinuousoutputpowerreaches170W.WeusedTDA7294standardapplicationcircuitandMarantzPM80andYAMAHAA-592tomakealisteningcomparison.Theformerisamid-pricedHi-FimachinewithaClassA,ClassAandBstatusswitch,andthelatterisa439.16dollarsclasswithAc-3inputAVpoweramplifier,audiosourceismusicfaxE60CD,speakerisTannerNo.5.ItturnsoutthatthesoundorientationofTDA7294hasadistinctiveEuropeanstyle,soft,mellow,delicate,andfullofbouncingfeeling.ItissimilartotheMarantzPM-80inClassAandBstatus,butthesoundfieldofPM-80isdeeperwhenworkinginpureClassA.ComparedwithYAMAHAA-592,thedifferenceislarger.ThelowfrequencyofA-592seemstobeslightlyimproved.Itsoundspowerful,butitisharderandthelinesareblurry.TDA7294issweetandnatural,withhigherresolution,reallylikelandscapepaintingdonewithsplashesofinkandfine-brushflowersandbirds(atechniqueofchineseink-painting),eachhasitsinfinitecharm.VI.ActiveSubwooferAmplifierAddsStandbyFunctionThiscircuitisanimprovementontheaudiocircuitusingtheintegratedcircuitTDA7294.ThecircuitdiagramisshowninFigure6.TDA729410pinhasamutefunction.WhentheexternalDCprovideshighlevel,theintegratedblockisintheworkingstate;whenthelowlevelisapplied,theintegratedblockisinthecut-offstate.Atthistime,thecircuitconsumeslittlepowerandIC114pinhasnooutput,thatis,standbyform.Thegeneralcircuitistoprovideahighleveltopin10tomakeitintheconductingstate,infact,thedevelopmentofthispinfunctioncanmeetsomespecialworkrequirements.Thiscircuitisbasedonthistoincreasethestandbyfunctionoftheactivesubwooferpoweramplifier,anditscircuitisreliableandresponsive.Figure6ActivesubwooferamplifieraddsstandbyfunctioncircuitdiagramVII.HighFidelityPowerAmplifierThecircuitisshowninFigure7.ThedrivestageadoptsTDA7294.Theinternaldrivestageandoutputstageofthechipusefieldeffecttubes,whicharepoweredby40V,andtheoutputpowercanreach70W(RL=8;THD=0.005%).Ithasadelicatetoneandanexcellentsenseofhearing.PoweroutputVT1,VT2adoptsShankenhigh-powerpairtube2SA1394,2SC3858.Thecircuitprincipleisasfollows:ThesignalisinputtotheTDA7294non-invertinginputpin③throughC1andR1.R7andR3,C3,C4ofICpin②formanegativefeedbacknetwork,theclosedloopgainofthisamplifierisabout34times.The⑨and⑩pinsarethestandbyandmuteterminalsrespectively.SincetheRCnetworktimeconstantofthe⑩pinislargerthanthatofthe⑨pin,theswitchingmachinesareallperformedundermutesatge,avoidingtheswitchingimpactsound,andC7isabootstrapcapacitor.Figure7High-fidelitypoweramplifierpromotedbyTDA7294Productionpoints:(1)InsulatingmicasheetsshouldbeaddedbetweenthemetalcapandtheheatsinkofTDA7294(themetalcapisconnectedtothepin⑧).(2)Thepowertransformerusesring-shaped300Wdouble20V,four50V/10000Ffiltercapacitors,two50V/100F,andtwo100V/0.1F.Thepowersupplypartshouldbetestedseparately,firstwithoutconnectingthepoweramplifier,measurewhetherthepositiveandnegativeoutputvoltageofthepowersupplyaresymmetrical,theerrorshouldbewithin0.6V.(3)Whentestingthemachine,forsafetyreasons,youshouldfirstusealowervoltagetest(suchas25V)withoutaddingasignal,andmeasuretheDCvoltageoftheoutputterminaltotheground.Normally,itshouldbewithin20mV.(4)R8,R9,R10,D1formthefinalbiascircuit.ThisbiasmakestheoutputtubesVT1andVT2notcutoffduringoperation,sothequiescentcurrentcanbesmall(about5mA).(5)Thepowertubeshouldbestrictlymatched(within3%)andgenuineproductsshouldbeselected.TheoutputresistanceR14isa5Wnon-inductivetype,andtheinductorLisformedbytightlywinding10turnsonR14withadiameterof1.5mmenameledwire.TDA7294uses60mmTimes,85mmTimes,20mm12-slotheatsink,andtheoutputpairtubeneedsaprofessionalheatsink.Thesectionswithhighcurrentontheprintedboardneedtobetin-rolled,whichisextremelybeneficialforthetransparencyandstrengthofthesound.Figure8PoweramplifierPCBpromotedbyTDA7294VIII.ClassABPowerAmplifierTDA7294integratedcircuitcanbeusedasahigh-fidelityaudioclassABpoweramplifier.Itcandrive4ohmor8ohmspeakers,andwhenconnectedtoan8ohmspeaker,itwillprovide50wattsofoutputpowerand0.1%THD.Figure9ClassABpoweramplifiercircuitdiagramYoumustinstallalargeenoughradiatorforTDA7294.Pin10isamuteinput,andpin9providesastandbymode.Muteshouldalwaysoccurwhenselectingstandbymode.TheIChasinternalthermalprotection,whichcausesmutereductionat145C,andtheamplifierentersstandbyat150C.TheTDA7294integratedcircuitheatsinkisinternallyconnectedtothenegativepowerrail.Ifthemoduleisinstalledinagroundedmetalenclosure,thentheICmustbeinsulatedfromtheheatsink.Ifnot,thenegativepowerrailwillbeshortedtoground.IX.Two-channelPowerAmplifierTDA7294high-powerintegratedcircuitICisspeciallydesignedforassemblinghigh-performanceaudioamplifiers.TwoTDA7294piecescanbeusedtomakeapowerfuldual-channelhigh-fidelitypoweramplifier.ThecircuitprincipleisshowninFigure10.TheoverallcircuitiscomposedoftwoTDA7294corecomponents,andtheperipheryincludessomeresistorsandcapacitors.Thecircuitsofthetwochannelsarealmostidenticalindesign.TheyallusethestandardcircuitofficiallyreleasedbyTDA7294,connectedtoanon-invertingamplifiercircuit,withavoltagegainof30.5dB,anoutputpowerofupto70Wperchannel,andadualpowersupplysymmetricalpowersupplyvoltage35V.Amongthem,Cl5andCl6areinputcouplingcapacitors.0.47Fisusedintheoriginalcircuit.Here,ifyouincreaseitto1F,youcanimprovethelow-frequencyresponseofthecircuit.Itisrecommendedtousepolypropylenespecialaudiocapacitors,suchasWIMAsMKT4seriescapacitors,itcangreatlyimprovethesoundresolution.R3andR4areinputresistances,whichdeterminetheinputimpedanceofTDA7294inthein-phaseamplificationstate.Here,22kisrelativelymoderate.Toolargeavaluecanreducetheburdenonthefront-endsignalsource,butitmayaffectthestabilityofTDA7294andmaketheoutputmidpointvoltagedriftincreased,toosmallvaluewillaffecttheresponseabilitytolowfrequency.ThetheoreticalvalueofthefeedbackresistorsR7andR8shouldbeequaltotheinputresistorsR3andR4,whichcanensurethebiascurrentbalanceoftheTDA7294inputdifferentialcircuitandreducesignaldistortion.ThefeedbackgroundresistanceR5,R6cooperateswithR7,R8tosetthecircuitgain.Here,thefeedbackDCblockingcapacitorsCl3andCl4areusedtoformACnegativefeedback,inhibitDCvoltageoutput,andprotectthespeaker.Figure10Two-channelpoweramplifiercircuitdiagramTDA7294hasastartmutefunction,andcooperateswithanexternalcircuittoachieveanon-impactsoundeffectwhenthepoweristurnedonandoff.R9,R1O,R11,Rl2,Cl7,Cl8andVD5,VD6intheschematicdiagramformanexternalmutecontrolcircuit.Delaytheenergizationofpins9and10ofTDA7294toachievethefunctionofsoftstart.Thepowersupplyrectifierfiltercircuitisalsoverysimple.Thefullbridgerectifiercircuitiscomposedof4EuropeanspeedrectifierdiodesVD1-VD4.CapacitorsC1andC2arethemainfiltercapacitors.Large-capacityandhigh-currentaudiofiltercapacitorsarerequired,suchasELNAsFORAUDIOseriesorBHCAerovoxindustrialgradecapacitors.DesignPCBisgenerallyabottleneckinamateurproduction,sothatmanyexcellentschematicdiagramshavenotbeentransformedintofinishedPCBsthatcanbeactuallyassembled.Here,thepopularProtel99sedesignsoftwareisusedtodrawtheprintedcircuitboardagainsttheschematicdiagram10,asshowninFigure11.The2mmthickFR-4board-baseddouble-sidedPCBisused,andthecopperfoilisthickenedto70mm,whichissuitableforhighcurrentpoweramplifiers.ThewholePCBtraceadoptsone-pointgroundingmethod,whicheffectivelyeliminatesgroundwireinterferencenoise.Insomehigh-currenttraces,tinplatingisalsoadoptedtoincreasetheadditionalcurrentcarryingcapacity.Thepowerinputandpoweroutputstructureuseshigh-currentscrewterminalstoensuresufficientover-currentcapabilityanddurabilityofrepeatedwiring.Figure11PrintedcircuitboardX.100WPowerAmplifierCircuitFigure12100WpoweramplifiercircuitdiagramcomposedofTDA7294Figure12isa100WpoweramplifiercomposedofamonolithicaudiopoweramplifierintegratedcircuitTDA7294.TDA7294includespre-opamplifier,finalpoweramplifier,temperatureprotection,shortcircuitprotection,mutecontrolandothercircuits.ThefinalstageadoptsbipolarDMOSpowertransistor,whichhasthecharacteristicsofhighoutputpower,bandwidth,lowdistortion,andgoodversatility.Theintegratedcircuitalsohasperfectanti-overload,anti-shortcircuitandtemperatureprotectioncircuitfunctions.Whenthechiptemperatureistoohigh,itautomaticallycutsofftheaudiosignaltoprotectthechipfromburningThepoweramplifiercircuitcomposedofTDA7294hasthecharacteristicsofsimpleperipheralcircuitandeasyproduction.Thecircuitinputimpedanceis20k,theinputsensitivityis750mV,thevoltagegainis32dB,thepowersupplyvoltagerangeis(25~40)V,andthequiescentcurrentis50mA.Whentheloadimpedanceis8,theoutputpoweris100W;whentheloadimpedanceis4,theoutputpowercanreach180W.Inactualproduction,TDA7294shouldbeequippedwithenoughheatsinks.Thesupportingpowercircuitshouldhavesufficientcapacity.Ifyouneedtoincreasethecircuitvoltagegain,youcanappropriatelychangetheratioofR3toR2,voltagegainA=201g(R3/R2)(dB).However,itisnotadvisabletoone-sidedlypursuethevoltagegainofthisstage.Excessivevoltagegaincaneasilycausecircuitself-excitation.Thesolutionistoincreasethevoltagegainofthepre-stage.I.DescriptionTDA2030Aisoneofthehigh-fidelityintegratedpoweramplifiers,andmanypoweramplifiercircuitsusethisintegrationmethod.TDA2030isalsoaHI-FIpoweramplifierintegratedblockusedbymanycomputeractivespeakers.Ithassimpleconnectionmethodandaffordableprice.Theratedpoweris14W.Thepowersupplyvoltageis6~18V.Theoutputcurrentislarge,theharmonicdistortionandthecrossoverdistortionaresmall(14V/4ohm,THD=0.5%).Ithasexcellentshortcircuitandoverheatprotectioncircuit.Thefollowingdescribesitsconnectionandapplicationcircuit.CatalogI.DescriptionII.Connection2.1SinglePowerConnection2.2DualPowerConnectionIII.ApplicationCircuit3.1OTLFormPowerAmplifier3.2OCLFormPowerAmplifier3.3BTLFormPowerAmplifier3.440WPowerAmplifierCircuit3.5High-fidelityActiveSpeakerCircuit3.625WBridgeLowFrequencyPowerAmplifierCircuitOrdering&QuantityII.ConnectionItsconnectionmethodisdividedintosinglepowersupplyanddualpowersupply:2.1SinglePowerConnectionFigure1TDA2030singlepowerconnectiondiagram2.2DualPowerConnectionFigure2TDA2030dualpowerconnectiondiagramIII.ApplicationCircuit3.1OTLFormPowerAmplifierOTLformpoweramplifier:singlepowersupply,outputcouplingcapacitor.TheR5(150k)andR4(4.7k)resistorsinthecircuitshowninFigure3determinetheclosed-loopgainoftheamplifier.ThesmallertheR4resistor,thegreaterthegain,buttoolargegaincaneasilycausesignaldistortion.Twodiodesareconnectedbetweenthepowersupplyandtheoutputterminaltopreventtheinductiveloadofthespeakerfromkickingbackandaffectingthesoundquality.ThecapacitorofC3(0.22uF)andtheresistanceofR6(1)areusedtocompensatetheinductiveload(speaker)toeliminateself-excitation.Thecircuitusesa36Vsinglepowersupplyandtheoutputpowerisabout20W.Figure3OTLtypepoweramplifiermadewithTDA2030A3.2OCLFormPowerAmplifierTheformoftheOCLpoweramplifieradoptsdualpowersuppliesandhasnooutputcouplingcapacitor.AsshowninFigure4,sincethelowfrequencyresponseoftheoutputcouplingcapacitorisimproved,itisahigh-fidelitycircuit.Thedualpowersupplyusesatransformerwiththemiddlepointoftheprimarycoilgroundedandtheupperandlowervoltagesaresymmetricalandequal.Afterrectificationandfiltering,a18Vdualpowersupplyisformed,andtheoutputpoweris20W.Figure4OCLtypepoweramplifiermadewithTDA20303.3.BTLFormPowerAmplifierThemainfeatureofBTLis:itiscomposedoftwoidenticalpoweramplifiers,andtheinputsignalsareinversetoeachother.Thein-phaseinputandtheinvertedinputoftheamplifierareactuallyusedtoensurethattheinputsignalsareinversetoeachother.Atthesametime,theamplitudesofthetwoinputsignalsshouldbethesame,sothatthebasicrequirementsoftheBTLcircuitformcanbemet.ThecircuitdiagramisshowninFigure5,whereR7(1k)andR8(33)resistorsdividethesignalandtheattenuationfactorisexactlythesameastheamplificationfactorofU1.TheattenuatedsignalisaddedtotheinvertinginputterminalofU2throughR5.Infact,twoopampscompleteasignalamplification,andtheactualmeasuredoutputlevelis1.5timeshigherthanthatofanintegratedcircuit.Thatis,theoriginaloutputpoweroftheopampis20W,andtheoutputpowerisnowabout50W.However,duetothecharacteristicsoftheBTLcircuit,whenchoosinganintegratedcircuit,usetwooperationalamplifiercircuitswiththesameparametersasmuchaspossibletoadjusttheinputsignalamplitude.Youcanuseanoscilloscopetoobservetheamplitudeofthetwoinputsignalsbyinputtingasinewave.Atthistime,adjustR7tomakethetwoinputsignalsTheamplitudeisthesametoensurethatthenonlinearsymmetrydistortionisminimizedwhileincreasingthepower.Figure5BTLtypepoweramplifiermadewithTDA2030A3.440WPowerAmplifierCircuitFigure6isa40WpoweramplifiercircuitmadebyTDA2030poweramplifierintegratedblockandBD907/908:Figure640WpoweramplifiercircuitmadebyTDA20303.5High-fidelityActiveSpeakerCircuitAhigh-fidelityactivespeakercircuitdesignedwithTDA2030,thecircuitdiagramisshowninFigure7.Usingdualpowersupply,addedhighandlowbassandvolumeadjustment.WhendesigningthePCB,thegroundwireshouldnotpassthroughthecomponentpinsasmuchaspossibletoreduceDCnoise.Figure7Highfidelityactivespeakercircuitdiagram3.625WBridgeLowFrequencyPowerAmplifierCircuitFigure825WbridgelowfrequencypoweramplifiercircuitThecircuitinFigure8usestwoTDA2030sconnectedtoformabridgecircuit,withthesamecircuitstructureandparametersonbothsides.Theintegratedcircuitontherightiscontrolledbytheintegratedcircuitontheleftthrougha22knegativefeedbackresistor,andviceversa.Thediode1N4001isusedtopreventthespeakerinductiveloadfromgeneratingovervoltageanddamagingthedevice.Theamplificationfactorofthecircuitcanbeadjustedbychangingthenegativefeedbackvoltageratiobetweentheoutputterminal(pin4)andtheinvertinginputterminal(pin2).

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IDescriptionThisblogintroducesthepoweramplifierwithNE5532andLM1875Tasthecorecomponents.Thepoweramplifierwearediscussinghereisahigh-fidelitytwo-channelstereosubwooferpoweramplifier.Here,wewilldiscussitsmethodsandprocedures,schematicdesign,assemblyanddebugging,andspeakerproduction.Hopethisblogcanprovideagoodreferenceforbeginners.Figure1.LM1875CatalogIDescriptionIILM1875TandNE5532Overview2.1PowerAmplifierLM1875T2.2Pre-amplificationComponentNE5532IIICompositionofPowerSupplyIVAssemblyandDebuggingSpeaker4.1ElectricalInspection4.2BoxProductionVIntheEndOrdering&QuantityIILM1875TandNE5532OverviewFirst,weintroducethecorecomponentsthatwewilluse.Andthen,thebasiccharacteristicsofthesecomponents.Audiopoweramplifierisgenerallycomposedofthefollowingthreeparts:powersupply,pre-amplifierandpost-amplifier.Here,wewillusehigh-efficiencyHI-FIpowerintegratedchipLM1875Tasthecoreoriginal.LM1875Tadoptsapositiveandnegative15Vdualpowersupply,theleft,andrightchannelsworkinOCLmode,andthebassworksinBTLmode.AsfarasthecharacteristicsofLM1875Tareconcerned,ithasthecharacteristicsofgoodsoundquality,goodfrequencyresponse,lowcostandrelativelysimplecircuit.Inaddition,thepre-amplifierpartusestheNE5532integratedoperationalamplifier.2.1PowerAmplifierLM1875TLM1875Thasexcellentperformance.Manyluxury-lookingactivespeakers,mid-rangepoweramplifiers,andsubwoofersonthemarketuseLM1875T.ThepoweramplifiercircuitcomposedofLM1875Tchiphasthefollowingcharacteristics:Theoutputpowerislarge,themaximumpowercanreachabout20W;Thestaticcurrentissmall,theloadcapacityisstrong,andthedynamiccurrentislarge,whichcandrive4~8speakers;Thecircuitissimple,easytomanufactureandlowcost;Withaninternalprotectioncircuit,itisahigh-fidelitypoweramplifiercomponentwithstableperformance.Theblogdesignofthisarticleisadual-channelstereosubwooferpoweramplifier,butLM1875Tisamono-channelpoweramplifierintegratedcircuit,sothedual-channelOCLworkingmodeusesoneLM1875Tforeachchannel.SincethebassworksinBTLmode,wehavetousetwopieces.LM1875Thas5pins.Theyarepositivepowersupply,negativepowersupply,positiveinput,reverseinput,andoutput.ThecircuitisshowninFigure2.Figure2.LM1875Circuit2.2Pre-amplificationComponentNE5532Beforethepoweramplifiercircuit,itisgenerallynecessarytoaddapreamplifier.Thepurposeofthisistoamplifythevoltageofvariousinputweakelectricalsignals.Inordertoensurethattheoutputelectricalsignalhashighfidelity,thepre-amplifierisNE5532.NE5532isahigh-performance,low-noise,dualoperationalamplifierintegratedcircuit.Comparedwithmanystandardopamps,NE5532hasbettersoundperformance,excellentoutputdrivecapability,relativelyhighsmallsignalbandwidth,andlargepowersupplyvoltagerange.Therefore,itisverysuitableforhigh-qualityandprofessionalaudioequipment,instruments,controlcircuitsandtelephonechannelamplifiers.Whenusedforaudioamplification,thetoneiswarmandhighfidelity.ThefunctionalblockdiagramofNE5532isshownasinFig.3.Figure3.NE5532FunctionalBlockDiagramIIICompositionofPowerSupplyLM1875Tadoptsapositiveandnegative15Vdualpowersupply.TheoperatingvoltageofNE5532isalso15V.Weneedtostepdownthemainspowerto15Vthroughastep-downtransformer,thenrectifyitthroughtherectifierbridgeKBL406,filteritthroughalargecapacitor,anddirectlysupplyittothepoweramplifier.Inthisway,largeroutputpowerisobtained.After7815and7915,theregulatedoutput15VisusedasthepowersupplyofthepreamplifierNE5532.ThecompositionofthepowersupplyisshowninFigure4.Figure4.PowerCircuitFigure5.PowerAmplifierCircuitBoardIVAssemblyandDebuggingSpeakerWhenstartingthecircuitinstallation,firstcheckthecircuitboardagainstthecircuitdiagram.Forexample,checkwhetherthemaincomponentsareinstalledcorrectly,andwhetherthesolderjointshavemissingsolderingorfalsesoldering.Thenturnonthepowertodebugthecircuit,andmakespeakersafterthedebuggingiscompleted.TheactualproductionisshowninFigure6.Figure6.PhysicalShootingPic4.1ElectricalInspectionUseanACsignalgeneratortoaddatinysinusoidalsignaltothesignalinput.Then,usetheoscilloscopetomeasurethethreeoutputsignalsofthepoweramplifierboard.Atthistime,observewhetherthesinemeetstherequirementsandwhethertheparametersinthetestarerelativelystable.Then,connecttwofull-rangespeakerstotheleftandrightchannels,andconnectawoofertothebassoutputport.Atthistime,addthesongsignaltocarefullycheckwhetherthethreespeakersareworkingproperlyandthesoundisgood.Iftheabovestepsarewellexpressed,thenproceedtothenextstep.4.2BoxProductionThekeytomakingspeakersistheselection,sizeandothersteps.Intheexperiment,weusedthelaminatesinthelaboratoryforsplicingandassembly.First,drawasketch.Thepaintingisdividedonthreedifferentsubstrates,andthenmadeintotwopartsrespectively.Afterdrilling,polishing,splicingandbonding,thecompletedcircuitpartsareinstalledintheirrespectiveparts.Then,wedividetheentirepoweramplifierintothreeparts.Twosatellitespeakers,aswellasawooferandpoweramplifierboard.Thesethreepartstogetherformacomplete2.1subwooferpoweramplifier.Here,thereisaplacethatneedsspecialattention.Whenmakingthebasspartofthecabinet,theimpactofvibrationshouldbefullyconsidered.Therefore,wehavetodesigndampingcomponents.VIntheEndAftertheinstallationisnormal,connectthemusicsignalsourceandlistentothemusiceffect.Thesoundreproducedbythiscircuithasastrongsenseofhierarchy,aclearsenseoforientation,andanobvioussenseofspaceanddistance.Inaddition,thesoundimageorientationisclear,thewidthisoutstanding,andthesounddynamicrangeislarge,givingpeoplearealfeeling.IntroductionLM3886isahigh-performanceaudiopoweramplifier.ItexhibitsextremelylowTHD+Nvaluesof0.03%attheratedoutputintotheratedloadovertheaudiospectrum,andprovidesexcellentlinearitywithanIMD(SMPTE)typicalratingof0.004%.Itisverysuitablefortheenthusiastswhopursuebothbeautifulsoundqualityandstrongvolume.ThisarticleintroducesseveralpracticalapplicationsofLM3886inhometheatersystems.ThisisatechnicalexaminationvediooftheLM3886Amplifier.CatalogIntroductionCatalogIHighQualityDual-channelPowerAmplifierIIPowerfulBTLPowerAmplifierIIISubwooferSpeakerOrdering&QuantityIHighQualityDualChannelPowerAmplifierLM3886outputsnearly70Wpoweratratedvoltageandthepeakpoweris150W.Thedualchannelpoweramplifieradoptssimpleandtypicalcircuit,whichcanreplaceavarietyofHI-FIpoweramplifier,andissuitablefortheleftandrightmainchannelofpoweramplifierinhomecinema.ThewholecircuitisinstalledonthesamePCB.EachofthetwoLM3886sisequippedwithaspecialaluminumradiator(length140,thickness50,height75(mm)),whicharefixedonbothsidesofthePCBtofacilitateheatdissipation.Thepowertransformercanchoosedouble24~28V,3~5A.IIPowerfulBTLPowerAmplifierApureBTLbridgeamplifieriscomposedofanoperationalamplifierNE5532,anLM3886in-phaseamplifierandanLM3886invertingamplifier,whichcaneasilyoutputmorethan200Wundistortedpower.Itcanbeusedindancehalls,karaoke,theatersandotheroccasions.Thiscircuitcankeepthesoundqualitynaturalandsmoothwhenplayingatlowvolume.BTLPoweramplifiercircuitisshowninFigure1.Onecircuitboardforeachchannel,withindependentrectification.Thesizeoftworadiatorsis140mminlength,50mminthicknessand100mminheight.Figure1.BTLPowerAmplifierCircuitIIISubwooferSpeakerFigure2isthecircuitofahouseholdsubwooferspeaker.Figure2.circuitofsubwooferspeakerInthepicture,theLinkwitzactivecompensatoraccuratelycontrolsthecenterfrequencyf1ofthecompensationpeakanditsQvalue,sothattheclosedbox(seeFigure3)withanaturalcornerfrequencyabout50Hzandthefrequencyresponsecurve(seeFigure4)extendsdownflatly.Thelowend-3dBpointreaches25Hz.Figure3.ClosedboxFigure4.frequencyresponsecurveInFigure4,curveAisnaturalfrequencyresponse;Biscompensationcurve;andCissystemfrequencyresponse.Theturningfrequencyofthelow-passfilteriscontinuouslyadjustablefrom80Hzto200Hz,sothattheactivesubwoofercanmatchthereadersdualchannelspeakerwithdifferentfrequencylimits.TheloudspeakerusessilverfluteYD310-43.Thebasindiameteris310mm.Themagnetdiameteris158mm.Theresonancefrequencyis25Hz.Q=0.35.Thecontinuouspoweris50W,andthesensitivityisashighas95dB.ComparedwiththeHiviS8unitwithasensitivityof88dB,thesensitivitydifferencebetweenthetwois7dB.Fortheclosedbox,theoutputsoundpressureofYindiYD310-43whenitinput50WisequivalenttotheoutputofHiviS8unitwhenitinput200W.YindicanalsobereplacedbytheBlueWhaleYD310-8XA.Insteadofthebassreflexwithpoortransientperformanceandlowsensitivity,itisbettertousethesimplestclosedbox.Theboxshallbesolidandairtight,filledwithglassfibercottonoracryliccottonforwarmthabsorption,andthesmallcavityatthebottomoftheboxshallbeusedtoinstallthecircuitpart.Forthesakeofsimpleinstallation,allcircuitsareinstalledonthePCB.ThePCB,radiator,switchandI/Oconnectorarefixedonthemetalpanel,andthenfixedonthespeakerwith6screws.Then,itcanworkafterconnectingtohornandtransformer.Connectthesubwooferactivespeakerwiththehomestereospeakertoforma3Dplaybacksystem.

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ⅠIntroductionAlinefollowingcardesignedwithLM393VoltageComparatorcapableoftrackingonaspecificrunway.Thelinefollowingcarmainlyincludesasolarpowersupplypartandatrackingcontrolpart.Thecontrolcircuitpartmainlyincludesabattery,aswitch,firstandsecondlightsensitivecircuits,aDCmotor,acomparisoncircuit,andamotordrivecircuit.ThisblogtestshowsthatthelinefollowingcarcontrolledbytheLM393voltagecomparatorhasthecharacteristicsofhighcontrolaccuracy,faststartandstop,etc.,andsolvestheproblemsofthecomplicatedcontrolcircuitstructureofthelinefollowingcarandthelargedeviationofthedrivingtrajectory.CatalogⅠIntroductionⅡWhatisLM393?ⅢWhatisALineFollowingCar?3.1SolarPowerDesign3.2LineFollowingDesignⅣCircuitDesignofLineFollowingCarⅤTestⅥConclusionOrdering&QuantityⅡWhatisLM393?TheLM393offersexceptionalvalueforcost-sensitiveapplicationswithaloweroffsetvoltage,highersupplyvoltagecapability,lowersupplycurrent,lowerinputbiascurrent,shorterpropagationdelay,aswellasimproved2kVESDperformanceandinputrobustnesswithdedicatedESDclamps.TheLM393devicesconsistoftwoindependentvoltagecomparatorsthataredesignedtooperatefromasinglepowersupplyoverawiderangeofvoltages.Thequiescentcurrentisindependentofthesupplyvoltage,andtheoutputscanbeconnectedtootheropen-collectoroutputstoachieveawiredANDrelationship.Figure1.LM393ⅢWhatisALineFollowingCar?Alinefollowingcarisacarthatcantravelalongapresettrajectory.Intheprocessofdrivingthelinefollowing,howtomakethecarcanaccuratelyfollowthetrajectorywithoutlargedeviationsisthefundamentalapplicationofthelinefollowingcar.However,theexistinglinefollowingcargenerallyusestheinfraredreflectionmethodtofeedbackthedrivingtrajectoryofthecar,thecontrolcircuitstructureismorecomplicated,andtheinfraredreflectioniseasilyaffected,sonotonlythecostishigher,butalsothedrivingtrajectoryofthecarispronetodeviation,soitoftendoesnotmatchthedesigntrajectory.UsingLM393voltagecomparatorasthemaincontrolchipofthetrackingcarwillbeabetterway.UsetheresistancechangeofthephotoresistorunderthelightintensityandtheLM393voltagecomparatortocontroltheleftandrightdrivingwheelsofthecartorealizethetrackingdriveofthecar,andcooperatewiththedisplaycircuittounderstandthestatusofthecar.TheprincipleblockdiagramoflinefollowingcarbasedonLM393voltagecomparatorisshowninFigure3.Figure2.LineFollowingCarⅣCircuitDesignofLineFollowingCarThecircuitdesignoflinefollowingcarbasedonLM393voltagecomparatormainlyincludessolarpowersupplyandcartrackingdesign.Themaincomponentsofthelinefollowingcarincludeabatterybox,acontrolcircuitboardattachedtothebottomofthebatteryboxbydouble-sidedadhesive,andseveralwheelassembliesinstalledonbothsidesofthecontrolcircuitboardandasolarbatterypanelinstalledabovethebatterybox.Figure3.BlockDiagramofLineFollowingCar3.1SolarPowerDesignThelinefollowingcaradoptsbatterypowersupplyandstorage.Thesolarbatteryboardprovidespowerforthebattery,thatis,thebatteryinthecarischargedfirst,andonlywhenthebatteryhasenoughpoweroutputvoltage,therequiredvoltagecanbeoutputattheoutputendofthebatterytodrivethetracingcar.ThedesignofthepowersupplypartmentionedinthisblogusesasinglelithiumbatterychargingmanagementchipTP4057withaninputvoltageof4V9V(typicalvalue5V),whichcanbeusedtochangetheresistancetocontrolthechargingcurrent,anditsadjustmentrangeis100mm500mAandthecut-offvoltageis4.2V.Thechargingcircuithassimpleperipherals,noexternalswitchtubeisrequired,andhasfunctionssuchaschargingindicationandfullindication,anti-reversebatterypositiveandnegativepolereverseconnectionprotection,andpowersupplyundervoltageprotection.Inadditiontousingsolarpanelstopowerthecircuit,itcanalsoworkwithUSBpowerandadapterpower.Figure4.SchematicDiagramofChargingCircuit3.2LineFollowingDesignThecartrackingadoptstheLM393voltagecomparatorasthecontrolcenteroftheentiretrackingcircuit.LM393isadualvoltagecomparatorintegratedcircuit,whichiscomposedoftwoindependentprecisionvoltagecomparators.Itsfunctionistocomparetwoinputvoltagesandchangetheleveloftheoutputvoltageaccordingtothelevelofthetwoinputvoltages.TheschematicdiagramusingtheLM393voltagecomparatorasthetrackingcontrolcircuitisshowninFigure5.ThiscarchoosesredLEDlightasitslightsource.Whenthelightsourceshinesonwhiteobjectsandblackobjects(thepredeterminedtrajectoryofthecarisblack),thereflectivityisdifferent.Thelightisreflectedontothephotoresistorthroughtheground.WhentheredLEDlightisprojectedonthewhiteareaandtheblacktrackline,theresistanceofthephotoresistorwillbesignificantlydifferentbecauseofthedifferentreflectance;Bydetectingtheresistancechangeofthephotoresistor,itcanbejudgedwhetherthecarisdrivingontheblacktrackline.ThiscarchoosesredLEDlightasitslightsource.Whenthelightsourceshinesonwhiteobjectsandblackobjects(thepredeterminedtrajectoryofthecarisblack),thereflectivityisdifferent.Thelightisreflectedontothephotoresistorthroughtheground.WhentheredLEDlightisprojectedonthewhiteareaandtheblacktrackline,theresistanceofthephotoresistorwillbesignificantlydifferentbecauseofthedifferentreflectance;Bydetectingtheresistancechangeofthephotoresistor,itcanbejudgedwhetherthecarisdrivingontheblacktrackline.Figure5.SchematicDiagramofTracingIftheresistanceofthephotoresistorchanges,itmeansthatthewhiteareahasbeendetected,andthecarhasdeviated;atthistime,themotoroftheleftorrightwheelofthecarisdeceleratedorevenstoppedtomakethecarreturntotheblacktrack.ThetrackcarrunsonasimilarS-shapedroutetoachievethelinefollowingfunction.Whenthereisanimbalance(forexample,onewheelispressedontheblacktrackline),themotorononesideisstoppedimmediately,andthemotorontheothersideisacceleratedtorotate,sothatthecarcancorrectthedirectionandreturntothecorrectdirection.Thewholeprocessisaclosedloopcontrol,soyoucanquicklyandsensitivelycontrolthemovementofthelinefollowingcar.Atthesametime,thephotoresistorcandetecttheintensityoftheexternallight.Thestrongertheexternallightis,thesmallertheresistancevalueofthephotoresistoris.TheleftandrightwheeldriveofthistrackingcarusesaDCmotorwithareductiongear.TheDCmotordrivesthecartoslowdown,otherwisethecarwillruntoofastifthespeedistoohigh.Moreover,thetorqueistoosmalltorunevenwithoutdeceleration.Themotorusedinthislinefollowingcarhasintegratedareductiongeartogreatlyreducethedifficultyofproductionanddebugging.Comparedwiththeuseofasingle-chipmicrocomputerasthecontrolcircuit,thecontrolcircuitcomposedoftheLM393voltagecomparatorhasasimplerstructure,isconvenientforassemblyanddebugging,andhasalowercost.ⅤTestFirstofall,placethecaronthewhitebackgroundtestfieldoftheblacktrackline(theblackrunwayisthecarspresettrack),andturnontheswitchesS1,S2,solarpanels(orbatteries)toprovideelectricity,sothatthevoltagecomparatorcontrolsthestartoftwoDCmotorstodrivethewheelassembliesonbothsidesofthecar.OurDIYlinefollowingcarbegantodrivealongthedesignedtrack(blackrunway)!Duringthedrivingofthecar,thelight-emittingdiodesD2andD3ontheleftandrightsidesofthecarbothemitredlightsources.Becausethelightsourceirradiatestheblackrunwayandthewhiterunwaywithdifferentreflectivity,andthephotoresistorcandetecttheexternallightintensity,thestrongertheexternallight,thesmallerthephotoresistorresistance,theweakertheexternallight,thegreatertheresistance.Therefore,whentheredLEDlightisprojectedontotheblackandwhiterunway,becauseofthedifferentreflectance,theresistanceofthephotoresistorwillbesignificantlydifferent.Figure6.RedLEDWhenthelightsourceisreflectedbytherunwaytothephotoresistorsR14andR15,thecomparatorcandeterminewhetherthecarisdrivingontheblacktracklineorthewhiteareaaccordingtothechangesintheresistanceofthephotoresistorsonbothsides.Andthroughthediodesandphotoresistorsontheleftandrightsides,wecanalsodeterminewhichsidethecarisdeflectingatthistime.Whenanimbalanceoccurs(forexample,thesideofthecarispressedagainstthewhitearea),theDCmotorononesideisimmediatelystopped,andtheDCmotorontheothersideisacceleratedtorotate,sothatthecarcancorrectthedrivingdirectionandreturntothecorrectdrivingdirection(blacktrackon-line.Actually,wecanseethattheleftandrightdrivingwheelsofthecarrotateinturnandstopdrivingthecarforward;thereisaprocessofdeviation,correction,deviation,andcorrection;butitalwaysadvancesalongtheestablishedblacktrajectory.ⅥConclusionThesolartrackingcardiscussedinthisblog:Passedthetestandsuccessfullyrealizedthecarslinefollowing;Canbepoweredbysolarenergyorbattery;Strongstabilityandanti-interferenceability,highcontrolaccuracy,faststartandstop;Solvedtheproblemsofcomplicatedcontrolcircuitoflinefollowingcarandlargedeviationofdrivingtrajectory.UsingonlytheLM393voltagecomparatorasthecontrollercircuitallowsustoassembleanddebugconvenientlyandatalowercost.Theuseofnon-singlechipcontrolisafeatureofthislinefollowingcar.Figure7.LM393Insummary,thelinefollowingcarbasedonLM393controlissuitablefortechnologicalinnovationandtechnologypromotion.Afterreadingtheblog,haveyoubetterunderstandLM393?Finally,ifyouhaveanyquestionsaboutLM393,pleasedonothesitatetoleaveamessageinthecommentsectionbelow!

IDescriptionLM1875isapoweramplifierintegratedblockchip.Itssuperiorperformanceandattractivetonehavebeenacceptedbymanyenthusiasts,anditwasalltherageinthe1990s.LM1875adoptsTO-220packagestructure,whichisshapedlikeamid-powertube,smallinsize,simpleinperipheralcircuits,andlargeinoutputpower.Theintegratedcircuitintroducedinthisblogisequippedwithoverload,overheatingandinductiveloadreversepotentialsafetyprotection,whichisoneoftheidealchoicesforhigh-endaudio.Figure1.LM1875CatalogIDescriptionIILM1875ParametersIIILM1875CircuitPrincipleIVLM1875CircuitAssemblyandDebuggingVIntheEndOrdering&QuantityIILM1875ParametersVoltageRange16~60VQuiescentCurrent50MmAOutputPower25WHarmonicDistortion0.02%,whenf=1kHz,RL=8,P0=20WRatedGain26dB,whenf=1kHzWorkingVoltage25VConversionRate18V/SIIILM1875CircuitPrincipleThiscircuitiscomposedofanattenuatedtonecontrolcircuitcontrolledseparatelyforhighandlowsounds,LM1875amplifiercircuitandpowersupplycircuit.Amongthem,thesoundqualitycontrolpartusesanattenuatedtonecircuitcontrolledseparatelyforhighandlowsounds.Thespecificcomponentsareasfollows:R02,R03,C02,C01,W02formabasscontrolcircuit;C03,C04,W03formatreblecontrolcircuit;R04istheisolationresistance;W01isthevolumecontroller,whichadjuststhevolumeoftheamplifier;C05isanisolationcapacitortopreventthedownstreamLM1875DCpotentialelementfromaffectingtheprevioustonecircuit.TheamplifyingcircuitmainlyadoptsLM1875,whichiscomposedof1875,R08,R09,C066,etc.ThemagnificationofthecircuitisdeterminedbytheratioofR08toR09;C06isusedtostabilizethedriftoftheLM1875s4thpinDCzeropotential,butithasacertainimpactonthesoundquality;C07andR10functiontopreventtheamplifierfromgeneratinglow-frequencyself-excitation.InAddtion,theloadimpedanceofthisamplifieris416.Figure2.LM1875CircuitWhataboutthepowersupplycircuitofthepoweramplifier?Pleasetakealookatthepicturebelow.Inordertoensurethesoundqualityofthepoweramplifierboard,weneedtopayattentiontothefollowingwhendesigningthecircuit:Theoutputpowerofthepowertransformershallnotbelessthan80W;Theoutputvoltageis2*25V;Thefiltercapacitorusestwo4700UF/25Velectrolyticcapacitorsinparallel;Positiveandnegativepowersuppliesshare44700UF/25Vcapacitors;Thetwo104basecapacitorsarehigh-frequencyfiltercapacitors;Onlyiftheaboverequirementsaremet,theamplifiercanmaintainbettersoundquality.Figure3.LM1875CircuitIVLM1875CircuitAssemblyandDebuggingThisblogwillintroducethenecessarytoolsforcircuitassembly,howtoprepareforsoldering,andfinallyhowtodebugthecircuit.Ofcourse,ifyoustillfeellikeyouarestillcannotgetenough,intheendyoucanevenfollowourtipstotryanextrainterestingexperimentwiththiscircuit.ToolsThatYouNeedA20Welectricsolderingiron,preferablywithadjustabletemperature;Amultimeter;Apairofneedlenosepliers;Ascrewdriver;Somesolderwireandpineperfume.HowtoPrepareforWeldingWeldingsequence:①Weldingjumpers;②Weldingresistance;③Weldingcapacitor;④Weldedrectifiertube;⑤Weldingpotentiometer;⑥WeldLM1875.NotesFixtheLM1875withscrewsontheheatsinkbeforeweldingLM1875,otherwisethescrewswillbedifficulttodriveinwhentheheatsinkisinstalledattheend;ThepartofLM1875incontactwiththeheatsinkmustbecoatedwithasmallamountofheatdissipationgreasetofacilitateheatdissipation;Payattentiontotheweldingqualitywhenwelding.Forbeginners,youcanpracticeafewmoretimesontheoldcircuitboard,andthenformallysolder.HowtoDebugCorrectlyThedebuggingofthispoweramplifierboardisverysimple.Afterthecircuitboardissolderedwithelectroniccomponents,wemustcarefullycheckthecircuitboardforsolderingerrors.Specialattentionshouldbepaidtoelectronicpartswithpolarity,suchaselectrolyticcapacitorsandbridgerectifiers.Oncetheweldingisreversed,thereisariskofburningthecomponents.Whenthetransformerisconnected,theoutputterminaloftheamplifierisnotconnectedtothespeaker,butconnectedtoamultimeter(preferablydigitaldisplay,andthemultimeterissettoDC*2V).Inaddition,payattentiontothereadingofthemultimeterwhenpoweringonthepoweramplifierboard.Undernormalcircumstances,thereadingshouldbewithin30mV,otherwiseweshouldimmediatelycutoffthepowertocheckthecircuitboard.Ifthereadingoftheelectricmeteriswithinthenormalrange,itindicatesthatthefunctionofthepoweramplifierboardisbasicallynormal.Atthistime,weconnectedthespeaker,theninputthemusicsignal,andthenpoweronthetestmachine.Underthecorrectproceduresandspecifications,turnthevolumepotentiometer,thevolumeshouldchange,andturnthehighandlowknobs,thetoneofthespeakerwillchange.Figure4.LM1875ExperimentWorthTryingFirst,wewillshort-circuitC6andmeasuretheDCpotentialattheoutputofLM1875withamultimetertoseeifitiswithin30MV.Then,connectthespeakerandtestfortwohours.UseamultimetertomeasuretheDCpotentialattheoutputoftheLM1875toseeiftheDCpotentialiswithin30MV.IftheDCpotentialiswithin30MV,thecapacitorC6canbeomitted.Inthiscase,theamplifierboardbecomesapureDCpoweramplifier.VIntheEndSofar,thepoweramplifierboardhasbeensuccessfullyinstalledandadjusted.Lookingatthispieceofworkthatyoucanbeproudofandenjoyingthewonderfulmusic,areyousatisfied?DescriptionThe2N7000isaN-ChannelEnhancementModeFieldEffectTransistor,a.k.a.MOSFETforvoltagecontrolledsmallsignalswitching.2N7000NChannelEnhancementModeMOSFETSwitchCircuitBasicsCatalogDescription2N7000Pinout2N7000Parameters2N7000Features2N7000Applications2N7000Advantage2N7000SwitchingWaveformsandTestCircuit2N7000PackageInformation2N7000PopularitybyRegion2N7000AlternativesHowtouse2N7000Wheretouse2N7000ProductManufacturerFAQOrdering&Quantity2N7000PinoutPinNumberPinNameDescription1SourceCurrentflowsoutthroughSource2GateControlsthebiasingoftheMOSFET3DrainCurrentflowsinthroughDrain2N7000ParametersConfigurationSINGLEWITHBUILT-INDIODEContinuousDrainCurrent(ID)200mADrainCurrent-Max(ID)0.2ADraintoSourceResistance5RDraintoSourceVoltage(Vdss)60VDrain-sourceOnResistance-Max5DSBreakdownVoltage-Min60VElementConfigurationSingleFeedbackCap-Max(Crss)5pFFETTechnologyMETAL-OXIDESEMICONDUCTORGatetoSourceVoltage(Vgs)30VHeight5.33mmJEDEC-95CodeTO-92JESD-30CodeO-PBCY-T3LeadFreeLeadFreeLength5.21mmManufacturerMicrochipTechnologyIncManufacturerPartNumber2N7000-GP003MaxPowerDissipation1WNumberofChannels1NumberofElements1NumberofTerminals3OperatingModeENHANCEMENTMODEOperatingTemperature-Max150COperatingTemperature-Min-55CPackageTO-92-3PartLifeCycleCodeActivePolarity/ChannelTypeN-CHANNELReachComplianceCodeCompliantREACHSVHCNoSVHCRiskRank5.56SurfaceMountNOTerminalFormTHROUGH-HOLETerminalPositionBOTTOMTransistorApplicationSWITCHINGTransistorElementMaterialSILICONVoltageRating(DC)60VWeight0.00776ozWidth4.19mm2N7000FeaturesFreefromsecondarybreakdownLowpowerdriverequirementEaseofparallelingLowCISSandfastswitchingspeedsExcellentthermalstabilityIntegralsource-draindiodeHighinputimpedanceandhighgain2N7000ApplicationsMotorcontrolsConvertersAmplifiersSwitchesPowersupplycircuitsDrivers(relays,hammers,solenoids,lamps,memories,displays,bipolartransistors,etc.)The2N7000hasbeenreferredtoasaFETlingtonandasanabsolutelyidealhackerpart.ThewordFETlingtonisareferencetotheDarlington-transistor-likesaturationcharacteristic.Atypicaluseofthesetransistorsisasaswitchformoderatevoltagesandcurrents,includingasdriversforsmalllamps,motors,andrelays.Inswitchingcircuits,theseFETscanbeusedmuchlikebipolarjunctiontransistors,buthavesomeadvantages:highinputimpedanceoftheinsulatedgatemeansalmostnogatecurrentisrequiredconsequentlynocurrent-limitingresistorisrequiredinthegateinputMOSFETs,unlikePNjunctiondevices(suchasLEDs)canbeparalleledbecauseresistanceincreaseswithtemperature,althoughthequalityofthisloadbalanceislargelydependentontheinternalchemistryofeachindividualMOSFETinthecircuitThemaindisadvantagesoftheseFETsoverbipolartransistorsinswitchingarethefollowing:susceptibilitytocumulativedamagefromstaticdischargepriortoinstallationcircuitswithexternalgateexposurerequireaprotectiongateresistororotherstaticdischargeprotectionNon-zeroohmicresponsewhendriventosaturation,ascomparedtoaconstantjunctionvoltagedropinabipolarjunctiontransistor2N7000AdvantageTheSupertex2N7000isanenhancement-mode(normallyoff)transistorthatutilizesaverticalDMOSstructureandSupertexswell-provensilicon-gatemanufacturingprocess.Thiscombinationproducesadevicewiththepowerhandlingcapabilitiesofbipolartransistors,andthehighinputimpedanceandpositivetemperaturecoefficientinherentinMOSdevices.CharacteristicofallMOSstructures,thisdeviceisfreefromthermalrunawayandthermally-inducedsecondarybreakdown.SupertexsverticalDMOSFETsareideallysuitedtoawiderangeofswitchingandamplifyingapplicationswhereverylowthresholdvoltage,highbreakdownvoltage,highinputimpedance,lowinputcapacitance,andfastswitchingspeedsaredesired.2N7000SwitchingWaveformsandTestCircuit2N7000PackageInformation3-LeadTO-92PackageOutline(N3)FrontView3-LeadTO-92PackageOutline(N3)SideView3-LeadTO-92PackageOutline(N3)BottomView2N7000PopularitybyRegion2N7000AlternativesManufacturerManufacturerPartNo.LifecycleStatusIndicatorMicrochipSupertex2N7000-GVolumeProductionHowtouse2N7000AMosfethasthreeterminals:Drain,SourceandGate.ThecurrentalwaysentersthroughtheDrainandleavesthroughtheSource.TheGatepinactsasaswitchtoturntheMosfetonoroff.IftheGateisconnectedtoground,theMosfetisswitchedoff,i.e.thereisnoconnectionbetweentheDrainandtheSource(open).IftheGateissuppliedwithitssourcevoltage(VGS)thentheMOSFETwillbeON,i.e.theDrainandSourcepinswillbeconnectedtogether(Closed).Thus,bycontrollingthevoltage(VGS),wecanswitchtheMOSFET,makingtheMOSFETavoltage-controlleddevice.Thegate-sourcevoltage(VGS)isacriticalparameterwhenusingthetransistor.Forthistransistor,theVGSis20V,sowhenwesupplythisvoltage,theMOSFETwillbecompletelyclosed.Anyvaluebetween20VcausestheMOSFETtopartiallyclose,creatingapartialconnection.TheloadswitchedbytheMOSFETcanreach60V(VDS)andcanconsumeupto200mA(ID).GivenbellowisaverysimplecircuitunderneaththatusesthisMOSFETtocontrola24V2Aloadmotor.Thecurrentandvoltagevaluescanalsobeobservedwhentheswitchisclosedandopen.AsweknowthatthevoltageofthegridsourceofthisMosfetis20V,weused20VtoturnontheMOSFET.Whenthegateswitchisopen,theMosfetsgatepinmustbeconnectedtogroundtocuttheload,soweuseda10KresistortoturnofftheMOSFETafterturningiton.TheRGresistorisacurrentlimitingresistorthatlimitstherequiredgridcurrent.IftheloadcontrolledbytheMOSFETisaninductiveloadlikethemotorwehaveusedhere,thenitismandatorytouseaflywheeldiodetosafelydischargetheloadaccumulatedbytheinductivecoil.Wheretouse2N70002N7000isasmallN-channelMOSFET.MOSFETsareelectronicpowerswitches,justliketransistors,butwithahighercurrentandvoltagerating.The2N7000MOSFETcanbeusedtoswitchloadsthatoperateonlessthan60V(VDS)and200mA(ID).ThismosfetcomesinacompactTO-92packageandhasathresholdvoltageof3V,soifyouarelookingforasmallmosfettoswitchaload,thisICmightberightforyou.ProductManufacturerMicrochipTechnologyInc.isaleadingproviderofmicrocontrollerandanalogsemiconductors,providinglow-riskproductdevelopment,lowertotalsystemcostandfastertimetomarketforthousandsofdiversecustomerapplicationsworldwide.HeadquarteredinChandler,Arizona,Microchipoffersoutstandingtechnicalsupportalongwithdependabledeliveryandquality.FAQWhatisa2n7000Mosfet?2N7000isasmallsignalN-channelMOSFET.MOSFETsarepowerelectronicswitchesjustliketransistors,butwithahighercurrentandvoltagerating.The2N7000MOSFETcanbeusedtoswitchloadswhichoperatesonlessthan60V(VDS)and200mA(ID).Whatisamaximumoperatingvoltageforthe2n7002transistor?The2N7002isalogiclevelMOSFETwithalowon-stateresistance.Themosfethasalowgatetosourcethresholdvoltageof2.1Vtypicallythismakesthemosfetsuitableevenfor3.3Vapplicationcircuits.WhatisMosfetgatethresholdvoltage?ThethresholdvoltagerepresentsthevoltageatwhichtheMOSFETstartstoturnon,whilstthemaximumgate-sourcevoltageisthemaximumgate-sourcevoltagethattheMOSFETcanwithstandsafely.WhatisanchannelMosfet?TheN-ChannelMOSFEThasanN-channelregionlocatedinbetweenthesourceanddrainterminals.Itisafour-terminaldevicehavingtheterminalsasgate,drain,source,body.InthistypeofFieldEffectTransistor,thedrainandsourceareheavilydopedn+regionandthesubstrateorbodyareofP-type.

DescriptionThe2N7002isalogiclevelMOSFETwithalowon-stateresistance.Themosfethasalowgatetosourcethresholdvoltageof2.1Vtypicallythismakesthemosfetsuitableevenfor3.3Vapplicationcircuits.Sincethemosfethaslowonstateresistanceithashighefficiencyduringwhenthemosfetinon.Duetothispropertyitcanmaintainhighswitchingperformanceandhenceusedwidelyinpowermanagementapplications.ThemosfetalsocomesinaSMDpackagehencecanbeusedforcompactapplications.Oneconsiderabledisadvantageofthemosfetisitslowdraincurrent;itcanprovideacontinuouscurrentof200mAandpeakscurrentsupto1Aatmaximumthresholdvoltage.Anythingmorethanthatwilldamagethemosfet.CatalogDescriptionPinConfigurationFeaturesDucumentsandMediaPackageOutlineApplicationsAlternativesProductManufacturerOrdering&QuantityPinConfigurationPinNo.PinNameDescription1GateControlsthebiasingoftheMOSFET2SourceCurrentflowsoutthroughSource3DrainCurrentflowsinthroughDrainFeaturesSuitableforlogiclevelgatedrivesourcesSurface-mountedpackageVeryfastswitchingTrenchMOSFETtechnologyDocumentsandMediaDatasheet2N7002N-ChannellogiclevelMOSFETDatasheetPackageOutlineApplicationsLowcurrentandLowVoltageswitchingapplicationsDC-DCconverterseMobilityapplicationsApplicationwherelowon-stateresistanceisrequired.PowermanagementapplicationsAlternativesNTR4003,FDC666,FDC5582N7002EquivalentP-Channel:BSS84,FDN358POtherN-ChannelMOSFETs:BS170N,IRF3205,2N7000,IRF1010E,IRF540NProductManufacturerNXPSemiconductorsN.V.(NXP)isaholdingcompany.TheCompanyoperatesasasemiconductorcompany.TheCompanyprovideshighperformancemixedsignalandstandardproductsolutions.TheCompanyssegmentsareHighPerformanceMixedSignal(HPMS),StandardProducts(SP),andCorporateandOther.Itsproductsolutionsareusedinarangeofend-marketapplications,includingautomotive,personalsecurityandidentification,wirelessandwirelineinfrastructure,mobilecommunications,multi-marketindustrial,consumerandcomputing.Itengageswithglobaloriginalequipmentmanufacturers(OEMs)andsellsproductsinallgeographicregions.NXPsHPMSsegmentincludesbusinesslines,suchasAutomotive,SecureIdentificationSolutions(SIS),SecureConnectedDevices(SCD),andSecureInterfacesandInfrastructure(SII).TheCompanysSPsegmentsuppliesarangeofstandardsemiconductorcomponents,suchassmallsignaldiscretesandpowerdiscretes.DescriptionTheweatherinthepasttwodayshassuddenlycooleddown,andIforgottoinstallaswitchonthebedside,andIdontwanttogetoutofbedtoturnoffthelightbecauseofthecold.Atthistime,itwouldbenicetohaveanintelligentcontrolswitch.ThisblogintroducesasmartswitchcontrollerbasedonATMEGA328P-PU.Thecontroller,withoutchangingtheexistingswitchesandcircuits,canautomaticallyturnoffthelightsafterapowerfailure.Atthesametime,thewirelesscontrollightswitchfunctioncanalsoberealizedthroughtheBluetoothmodule,andthelightcanbeturnedonandoffwhilelyingdown,andthereisnoneedtogetoutofbed.ATMEGA328P-PUCatalogDescriptionIIntroductionIIATmega328P-PUBasedSystemPricipleIIIATmega328P-PUBasedSystemHardwareDesign3.1Centralcontrolmodule3.2Lightdetectioncircuit3.3BluetoothmoduleIVATmega328P-PUBasedStructureDesignVATmega328P-PUBasedSystemSoftwareDesignVIConclusionComponentDatasheetFAQOrdering&QuantityIIntroductionThesmartswitchlightcontrollerbasedonATmega328P-PUintroducedinthisblogconsistsofthefollowingmodules:LightDetectionModule:Perceivethechangeofindoorlightintensity;BluetoothModule:controlandrealizeautomaticlightswitch;SteeringGearandMechanicalLinkageMechanism:Itcanalsoautomaticallyturnoffthelights.Thecontrollerusestheorganiccombinationofmechatronics,whichisreliableandeasytocontrol.IIATmega328P-PUBasedSystemPricipleTheintelligentswitchlightcontrollersystemismainlycomposedoflightdetectionmodule,Bluetoothmodule,steeringgearandArduinocontrolsystem.Thesystemcontrolprocessisasfollows:Thelightdetectionmoduleperceivestheenvironmentfrombrighttodark;ThelightdetectionmodulesendsthesensedinformationtotheArduino;Arduinoturnsoffthelightingequipmentbycontrollingthesteeringgearaccordingtothisinformation;Or,tocompletetheoperationofturningoffthelights,youcanalsodirectlycontrolitthroughthemobilephoneAPPBluetooth.ThesystemprinciplediagramoftheintelligentswitchlightcontrollerisshowninFigure1.Figure1.SystemschematicdiagramIIIATmega328P-PUBasedSystemHardwareDesign3.1CentralcontrolmoduleThemostwidelyusedmicrocontrollersforthecentralcontrolmoduleareAVRand51microcontrollers.Fromtheperspectiveoffunctionandupgradepotential,theAVR8-bitmicrocontrollerATMEGA328P-PUwasselectedasthecentralcontrolmodule.So,whataretheadvantagesofATMEGA328P-PUcontrolmodule?Whychooseit?ATMEGA328P-PU,asacentralcontrolmodule,hasflexibleI/Oportresourcesandpowerfulfunctions.Itnotonlyhaslowpowerconsumptionbutisreliable,andcanmeettheneedsofsubsequentequipmentupdates.Figure2showstheminimumsystemdiagramofATMEGA328P.Figure2.ATMEGA328Pminimumsystem3.2LightdetectioncircuitHere,thelightdetectioncircuitisafour-wiresystem.TheAOportisananalogsignaloutputport,whichconvertstheexternallightintensityintoacontinuousoutputvoltagevalue.Whenthebrightnessofthelightchanges,howdoestheDOportactasadigitalsignaloutputport?Whentheambientlightbrightnessdoesnotreachthesetthreshold,theDOterminaloutputsahighlevel;Whenthebrightnessoftheambientlightexceedsthesetthreshold,theDOterminaloutputsalowlevel.Becausethesignaloutputbythecircuitisstableandreliable,thecontrollerselectsthedigitalsignaloutputbytheDOportastheinputsignalofthecontrolmodule.Inthisway,thesensitivityandreliabilityofthesystemcanbeimproved.IlluminationdetectioncircuitdiagramshowninFigure3.Figure3.Illuminationdetectioncircuitdiagram3.3BluetoothmoduleThisblogusestheHC-05master-slaveintegratedBluetoothmodule.ItscircuitdiagramisshownasinFig.4.Figure4.BluetoothdetectioncircuitThemoduleadoptsCSRmainstreamBluetoothchip,BluetoothV2.0protocolstandard,andcanworkwith3.3Vlowvoltage.Itischeap,smallinsize,stableinsignal,lowinpower,andcanbeusedinconjunctionwithmobileAPPtorealizewirelesscontrolofthesystem.Inthisdesign,Bluetoothonlyactsasaslave,receivinginstructionsfromthemobilephone.IVATmega328P-PUBasedStructureDesignTakethedormitoryasanexampletodesignthecontrollerfortheswitch(asshowninFigure5).Figure5.PowerswitchAftermeasurement,whentheswitchisintheequilibriumposition,thatis,betweentheclosedandopenpositions,ifthelight-offpositionispressedmorethan2mm,thebuttonwillturnoffthepower.Whenthelight-onpositionispresseddownmorethan2mm,thebuttonwillturnonthepower.Wecandesignalinkmechanismconnectedwiththesteeringgeartomake:Whenthesteeringgearrotatesto180,theconnectingrodpositionisthehighest;Whenthesteeringgearrotatesto0,theconnectingrodpositionislowest.Then,settheinitialpositionofthesteeringgearto90,sothatthebuttonisatthevalueofthebalanceposition.Atthistime,coincidethemiddlepositionoftheT-shapedfixingbracketwiththemiddlepositionofthebutton.Inaddition,inordertofacilitatetherealizationoffunctions,thecentralpositioncanbesetasachute.Figure6showsthedesignandinstallation.Figure7showsthatthecontrollerisdesignedasarectangularbox.Figure8showsthelayoutofeachmodule.Figure9showsthephysicalobjectandinstallationdiagramofthesmartswitchcontroller.Figure6.DesignandinstallationdrawingofconnectingrodpartFigure7.OverallviewofthecontrollerFigure8.SchematicdiagramofeachmoduleinstallationFigure9.PhysicalimageofsmartswitchcontrollerVATmega328P-PUBasedSystemSoftwareDesignThesoftwarepartcompletestheprocessingofthesignalsreceivedbythelightdetectionmoduleandtheBluetoothmodule,andthencontrolsthemechanicalstructuretoswitchthelights.Figure10showsthesystemsoftwareflowchart.Thelightdetectionmodule(theschematicdiagramofthelightdetectionmoduleisshowninFigure11)isusedtodetectchangesinbrightnessanddarknessofthesurroundingenvironment.Whenthesurroundingenvironmentisalwaysinalightstate,thelightdetectioncircuitwillcontinuouslysendalow-levelsignal0tothecentralcontrolmodule;Whenthesurroundingenvironmenthasbeeninadarkstate,thelightdetectioncircuitwillcontinuouslysendahighlevelsignal1tothecentralcontrolmodule.Whenthesurroundingenvironmentchangesfromnolighttolight(judgingthedaybreak),inthiscase,thesystemdoesnotact.Whenthesurroundingenvironmentchangesfromlighttonolight(judgedasamomentofpowerfailure),thelightdetectioncircuitwillstarttosendahighlevelsignal1tothecentralcontrolmodule.Atthemomentoftransition,thecentralcontrolmodulewillcontrolthesystemtoexecuteaworkcycle.Afterturningoffthelight,thesystemwillautomaticallyresetandwaitforthenextchangefromlighttonolight.Becausetheportmemoryofthecentralcontrolmoduleislimited,andthelightdetectioncircuitcontinuouslytransmitsdatatotheport.Thiswillcausethecentralcontrolmoduletorestartinashorttimeduetoexhaustionofmemory,makingthesystemunstableandunreliable.Therefore,aportclearingfunctionisspeciallywrittenwhencompilingthesystemtoensurethattheexpireddatasentbythelightdetectioncircuitisclearedintime.Therebyimprovingthestabilityandreliabilityofthesystem.Figure10.SystemsoftwareflowchartAftertalkingaboutthelightdetectionmodule,howdoestheBluetoothmoduleprocessthereceivedsignaltocontroltheswitch?WecanusemobilephoneAPPandBluetoothmoduletocontrolthesystemtoturnonandoffthelightsthroughwirelesstransmission.WhenthemobilephonesendsthecommandcharacterAtothecentralcontrolmodulethroughtheBluetoothmodule,thesystemwillexecuteacycleofturningoffthelights,andthenautomaticallyreset;Inthesameway,whenthemobilephonesendsthecommandcharacterBtothecentralcontrolmodulethroughtheBluetoothmodule,thesystemexecutesalight-oncommandforaworkingcycle,andthenautomaticallyresets.Figure11.SchematicdiagramofthelightmoduleVIConclusionThesmartswitchlightcontrollerdiscussedinthisbloghassignificantadvantages:*Donotchangethecircuitoftheoriginalpush-typepowerswitch.Therefore,itisnotonlysafe,butalsoeasytodisassembleandassemble;*TurnonandoffthelightsviaBluetoothwirelesscontrol.Therefore,ithasstrongoperability;*Aftercompletingtheswitchlampworkcycle,realizeautomaticreset.Inaddition,whilerealizingautomation,wecanalsomoveourfingerstoeasilyswitchlightsonthebed;*ATmega328P-PUhasgreatdevelopmentpotential.Thereasonforusingitistomeettheneedsofexpandingfunctionsinthefuture.suchas:CooperatewithWIFImodule:canrealizeultra-remotecontrol;Cooperatewithtimer:itcanrealizethefunctionofturningonthelightsatatime.Insummary,theintelligentswitchlightcontrollerbasedonATmega328P-PUweintroducedissimpleandreasonableinstructure,easytoinstall,safe,convenientandefficienttooperate.WiththesmartswitchlightcontrollerofATmega328P-PU,whenwelazilylieonthebedandplaywiththemobilephone,weusethemobilephonetocontrolthelightswitch.Atnight,weareafraidthatweforgettoturnoffthelightswhenwefallasleep,andwedontneedtogetoutofbed.Itcanalsoautomaticallyturnoffthelightswhenitgetsdark.ComponentDatasheetATMEGA328PDatasheetFAQWhatismeantbyATMEGA328P?ATMEGA328Pishighperformance,lowpowercontrollerfromMicrochip.ATMEGA328Pisan8-bitmicrocontrollerbasedonAVRRISCarchitecture.ItisthemostpopularofallAVRcontrollersasitisusedinARDUINOboards.WhatisthedifferencebetweenATMEGA328andATMEGA328P?ATMEGA328PandATMEGA328arethesameeverysensearchitecturally.ATMEGA328PjustconsumeslowerpowerthanATMEGA328,whichmeansthatthe328Pismanufacturedinafinerprocessthanthe328.WhyATMEGA328isusedinArduino?TheATMEGA328/Pisalow-powerCMOS8-bitmicrocontrollerbasedontheAVRenhancedRISC(reducedinstructionsetcomputer)architecture.InOrdertomaximizeperformanceandparallelism,theAVRusesHarvardarchitecturewithseparatememoriesandbusesforprogramanddata.HowdoyoucodeATMEGA328P?IsATMEGA328Pamicrocontroller?TheATMEGA328isasingle-chipmicrocontrollercreatedbyAtmelinthemegaAVRfamily(laterMicrochipTechnologyacquiredAtmelin2016).IthasamodifiedHarvardarchitecture8-bitRISCprocessorcore.CantheATMEGA328PmicrocontrollerbeusedwithouttheArduinoboard?Yes.YoucanuseATMega328Pwithoutarduinoboard....YoucanusearduinoboardwiththeIC.ProgramtheICandthentakeitoutanduseitinyourcircuit.Youwillhavetouse16MHZOscillatorwithcapacitors.HowdoIprogramAtmega328Pwithoutbootloader?ProgrammingAVRWithArduinoAsISPWithoutBootloaderandExternalCrystalStep1:ThingsYouNeed....Step2:UploadArduinoISPCodeonArduinoBoard....Step3:OpenCommandPrompt(inWindowsOS)...Step4:RequiredDownloads.....Step5:InstallationofWinAVR(onlyHelpforWindowsOSIsCoveredforNow)

DescriptionTheCD405xBanalogmultiplexersanddemultiplexersaredigitally-controlledanalogswitcheshavinglowONimpedanceandverylowOFFleakagecurrent.ThesemultiplexercircuitsdissipateextremelylowquiescentpoweroverthefullVDDVSSandVDDVEEsupplyvoltageranges,independentofthelogicstateofthecontrolsignals.TheCD4051Bisasingle8-Channelmultiplexerhavingthreebinarycontrolinputs,A,B,andC,andaninhibitinput.Thethreebinarysignalsselect1of8channelstobeturnedon,andconnectoneofthe8inputstotheoutput.CatalogDescriptionPinoutConfigurationandFunctionCD4051BlockDiagramDocumentsandMediaFeaturesApplicationCD4051TypicalApplicationCircuitsOrdering&QuantityPinoutConfigurationandFunctionCD4051BlockDiagramThelogicdiagramofCD4051iscomposedofthreeparts:logiclevelconversioncircuit,8select1decodingcircuitand8CMOSswitchunits.A,BandCare3-bitbinaryaddressinputterminals,and8combinationsof3-bitbinarycanbeusedforselection8channels;INHistheaddressinputprohibitionterminal,whenitishigh,theaddressinputterminalisinvalid,thatis,nochannelisstrobed.TheinputlevelsofA,B,CandINHarecompatiblewithTTL.CD4051has8input\outputterminals,1output/inputterminal,digitalcircuitpowersupply+Eand-E1,analogcircuitpowersupply+Eand-E2.ThemainfunctionofthelogiclevelconversioncircuitistoinputtheaddressA,B,CandaddressinputinhibitterminalINHinputTTLlogiclevelisconvertedintoCMOSlevel,sothattheswitchunitcanbecontrolledbyTTLlevel.Themainfunctionofthe8-to-1addressdecodingcircuitistoconverttheaddressinputsignalfromthelogiclevelconversioncircuitintothecorrespondingswitchunitstrobesignalandturnonthecorrespondingswitchunit.DocumentsandMediaDatasheetCD405xBCMOSSingle8-ChannelAnalogMultiplexer/DemultiplexerwithLogic-LevelConversiondatasheet(Rev.I)FeaturesWideRangeofDigitalandAnalogSignalLevelsDigital:3Vto20VAnalog:20VP-PLowONResistance,125Ω(Typical)Over15VP-PSignalInputRangeforVDDVEE=18VHighOFFResistance,ChannelLeakageof100pA(Typical)atVDDVEE=18VLogic-LevelConversionforDigitalAddressingSignalsof3Vto20V(VDDVSS=3Vto20V)toSwitchAnalogSignalsto20VP-P(VDDVEE=20V)MatchedSwitchCharacteristics,rON=5Ω(Typical)forVDDVEE=15VVeryLowQuiescentPowerDissipationUnderAllDigital-ControlInputandSupplyConditions,0.2W(Typical)atVDDVSS=VDDVEE=10VBinaryAddressDecodingonChip5V,10V,and15VParametricRatings100%TestedforQuiescentCurrentat20VMaximumInputCurrentof1Aat18VOverFullPackageTemperatureRange,100nAat18Vand25CBreak-Before-MakeSwitchingEliminatesChannelOverlapApplicationAnalogandDigitalMultiplexingandDemultiplexingA/DandD/AConversionSignalGatingFactoryAutomationTelevisionsAppliancesConsumerAudioProgrammableLogicCircuitsSensorsCD4051TypicalApplicationCircuits1.CD4051,CH3130multi-channeldemodulatorcircuitdiagramThiscircuitismainlycomposedof8-channelanalogswitchCD4051andvoltagefollowerCH3130,etc.TheinputsignaloftheprohibitionterminalINHofanalogswitchCD4051isusedtocontrolthegatingofvoltagefollowerCH3130,therebyperformdemodulationtomultipleanalogsignals.2.CD4051constructs32-channelcircuitBecausetheCD4051hasonlyeightinputports,fourCD4051sareneededtobuilda32-waymultiplexer,labeledINH1,INH2,INH3,andINH4.The32-waymultiplexershouldhave5controlports,ofwhichthefirstthreearetheinputportsofCD4051andthelasttwoarecontrolports.(BecauseCD4051hasthreeinputports),labelthemasD1,D2,D3,D4,D5(0000011111,00000channel0,11111channel31).Thebasicideaistorealizethechoiceof32channelports(0-7,8-15,16-23,24-31)byselecting4CD4051s.IfyouchoosethethirdCD4051,youcanchoose16-23(10000-10111)channelport.However,theselectionofCD4051isachievedbycontrollingtheINHlevelofeachCD4051.Forexample,ifyouwanttoturnonthethirdCD4051,makeitsINHhigh(atthistimeD5=1,D4=0,thenINH3=D5!D4).Therefore,thechoiceofINHisachievedbycontrollingthelogicalrelationshipbetweenD5andD4.WhereINH1=!D5!D4;INH2=!D5D4;INH3=D5!D4;INH4=D5D4.DescriptionLM317isaadjustable3-terminalpositive-voltageregulator,thisbolgcoversLM317regulatoralternative,datasheet,applications,featuresandotherinformationonhowtouseandwheretousethisdevice.ABasicIntroductiontoLM317VoltageRegulatorCatalogDescriptionLM317PinoutLM317FeaturesLM317ApplicationsLM317CircuitLM317ParametersLM317CADModelLM317AdvantageLM317ElectricalCharacteristicsLM317PackageLM317AlternativesLM317EquivalentsWheretouseLM317HowtouseLM317LM317ManufacturerComponentDatasheetFAQOrdering&QuantityLM317PinoutPinNumberPinNameDescription1AdjustThispinsadjuststheoutputvoltage2OutputVoltage(Vout)Theregulatedoutputvoltagesetbytheadjustpincanbeobtainedfromthispin3InputVoltage(Vin)TheinputvoltagewhichhastoberegulatedisgiventothispinLM317FeaturesOutputvoltagerangeadjustablefrom1.25Vto37VOutputcurrentgreaterthan1.5AInternalshort-circuitcurrentlimitingThermaloverloadprotectionOutputsafe-areacompensationLM317ApplicationsATCAsolutionsDLP:3Dbiometrics,hyperspectralimaging,opticalnetworking,andspectroscopyDVRandDVSDesktopPCsDigitalsignageandstillcamerasECGelectrocardiogramsEVHEVchargers:levels1,2,and3ElectronicshelflabelsEnergyharvestingEthernetswitchesFemtobasestationsFingerprintandirisbiometricsHVAC:heating,ventilating,andairconditioningHigh-speeddataacquisitionandgenerationHydraulicvalvesIPphones:wiredandwirelessIntelligentoccupancysensingMotorcontrols:brushedDC,brushlessDC,lowvoltage,permanentmagnet,andsteppermotorsPoint-to-pointmicrowavebackhaulsPowerbanksolutionsPowerlinecommunicationmodemsPoweroverethernet(PoE)PowerqualitymetersPowersubstationcontrolsPrivatebranchexchanges(PBX)ProgrammablelogiccontrollersRFIDreadersRefrigeratorsSignalorwaveformgeneratorsSoftware-definedradios(SDR)Washingmachines:high-endandlow-endX-rays:baggagescanners,medical,anddentalLM317CircuitLM317ParametersOutputoptionsAdjustableOutputIout(Max)(A)1.5Vin(Max)(V)40Vin(Min)(V)3Vout(Max)(V)37Vout(Min)(V)1.25Noise(uVrms)38Iq(Typ)(mA)5ThermalresistanceJA(C/W)24Approx.price(US$)1ku|0.14Loadcapacitance(Min)(F)0RatingCatalogRegulatedoutputs(#)1FeaturesAccuracy(%)5PSRR@100KHz(dB)38Dropoutvoltage(Vdo)(Typ)(mV)2000Operatingtemperaturerange(C)0to125IhsManufacturerTEXASINSTRUMENTSINCBrandNameTexasInstrumentsLM317CADModelPackagePinsDownloadDDPAK/TO-263(KTT)3ViewoptionsSOT-223(DCY)4ViewoptionsTO-220(KCS)3ViewoptionsTO-220(KCT)3ViewoptionsLM317ElectricalCharacteristicsOverrecommendedrangesofoperatingvitualjunctiontemperature(unlessotherwisenoted)LM317PackageDDPAK/TO-263(KTT)SOT-223(DCY)TO-220(KCS)TO-220(KCT)LM317AlternativesSharethesamefunctionalityandpinoutbutisnotanequivalenttothecompareddevice:LM7805,LM7806,LM7809,LM7812,LM7905,LM7912,LM117V33,XC6206P332MR.LM317EquivalentsLT1086,LM1117(SMD),PB137,LM337(NegativeVariableVoltageregulator)WheretouseLM317WhenitcomestovariablevoltageregulationrequirementsLM317wouldmostlikelybethefirstchoice.Apartfromusingitasavariablevoltageregulator,itcanalsobeusedasafixedvoltageregulator,currentlimiter,Batterycharger,ACvoltageregulatorandevenasanadjustablecurrentregulator.OnenotabledrawbackofthisICisthatithasavoltagedropofabout2.5acrossitduringregulation,soifyoulookingtoavoidthatproblemlookintotheotherequivalentICsgivenabove.So,ifyouarelookingforavariablevoltageregulatortodelivercurrentupto1.5AthenthisregulatorICmightbetherightchoiceforyourapplication.HowtouseLM317LM317isa3-terminalregulatorICanditisverysimpletouse.Ithasmanyapplicationcircuitsinitsdatasheet,butthisICisknownforbeingusedasavariablevoltageregulator.So,letslookintohowtousethisICasavariablevoltageregulator.AssaidearliertheIChas3pins,inwhichtheinputvoltageissuppliedtopin3(VIN)thenusingapairofresistors(potentialdivider)wesetavoltageatpin1(Adjust)whichwilldecidetheoutputvoltageoftheICthatisgivenoutatpin2(VOUT).Nowtomakeitactasavariablevoltageregulatorwehavetosetvariablevoltagesatpin1whichcanbedonebyusingapotentiometerinthepotentialdivider.Thebelowcircuitisdesignedtotake12V(youcansupplyupto24V)asinputandregulateitfrom1.25Vto10V.TheResistorR1(1K)andthepotentiometer(10k)togethercreatesapotentialdifferenceatadjustpinwhichregulatestheoutputpinaccordingly.TheformulaetocalculatetheOutputvoltagebasedonthevalueofresistorsisVOUT=1.25(1+(R2/R1))Now,letsverifythisformulafortheabovecircuit.ThevalueofR1is1000ohmsandthevalueofR2(potentiometer)is5000becauseitisa10kpotentiometerplacedat50%(50/100of1000is5000).Vout=1.25(1+(5000/1000))=1.256=7.5VAndthesimulationshows7.7Vwhichisprettymuchclose.Youcanvarytheoutputvoltagebysimplyvaryingthepotentiometer.Inourcircuit,amotorisconnectedasaloadwhichconsumesaround650mAyoucanconnectanyloadupto1.5A.Thesameformulaecanalsobeusedtocalculatethevalueofresistorforyourequiredoutputvoltage.Oneeasywaytodothisistousethisonlinecalculatortorandomlysubstitutethevalueofresistorsyouhaveandcheckwhichoutputvoltageyouwillget.LM317ManufacturerTexasInstrumentsInc.(TI)isanAmericantechnologycompanythatdesignsandmanufacturessemiconductorsandvariousintegratedcircuits,whichitsellstoelectronicsdesignersandmanufacturersglobally.ItsheadquartersareinDallas,Texas,UnitedStates.TIisoneofthetoptensemiconductorcompaniesworldwide,basedonsalesvolume.TexasInstrumentssfocusisondevelopinganalogchipsandembeddedprocessors,whichaccountsformorethan80%oftheirrevenue.TIalsoproducesTIdigitallightprocessing(DLP)technologyandeducationtechnologyproductsincludingcalculators,microcontrollersandmulti-coreprocessors.Todate,TIhasmorethan43,000patentsworldwide.ComponentDatasheetLM317DatasheetFAQWhatislm317usedfor?TheLM317servesawidevarietyofapplicationsincludinglocal,oncardregulation.Thisdevicecanalsobeusedtomakeaprogrammableoutputregulator,orbyconnectingafixedresistorbetweentheadjustmentandoutput,theLM317canbeusedasaprecisioncurrentregulator.Whatisthemaximuminputvoltageoflm317?TheLM317isanadjustablevoltagelinearregulatorthatcanoutput1.2537Vatupto1.5Acurrentwithaninputvoltagerangeof340V.Whatisthedifferencebetweenlm317andlm317t?Member.Thereisnofunctionaldifferenceastheyareoneinthesame.TheTattheendjustindicatesthatitsinaTO-220package.Theyusuallytagonextrathingsafterthepartnametoreferencethingslikepackage,temprange,etc.Islm317atransistor?TheLM317isanadjustablethree-terminalpositive-voltageregulatorcapableofsupplyingmorethan1.5Aoveranoutput-voltagerangeof1.25Vto32V....Byusingaheat-sinkedpasstransistorsuchasa2N3055(Q1)wecanproduceseveralampsofcurrentfarabovethe1.5ampsoftheLM317.Howdoesanlm317work?Thecircuitconsistsofalow-sideresistorandhigh-sideresistorconnectedinseriesformingaresistivevoltagedividerwhichisapassivelinearcircuitusedtoproduceanoutputvoltagewhichisafractionofitsinputvoltage.WhatisIClm317?TheLM317deviceisanadjustablethree-terminalpositive-voltageregulatorcapableofsupplyingmorethan1.5Aoveranoutput-voltagerangeof1.25Vto37V.Itrequiresonlytwoexternalresistorstosettheoutputvoltage.Thedevicefeaturesatypicallineregulationof0.01%andtypicalloadregulationof0.1%.HowdoIknowifmylm317isworking?Testinglm317t.Ifyoulooktotheic,thelegstowardsyou,therightoneistheinputpin.youmustseeadifferenceofminimum1.2Vbetweenthetwopins,otherwisetheICisfaulty.furthermore,thefirsttestistoseeifyouhaveinputvoltage!Whatistheworkingpricipleoflm317?LM317worksonaverysimpleprinciple.Itisavariablevoltageregulatori.e.supportsdifferentoutputvoltagelevelsforaconstantappliedinputvoltagesupply.HowtomakeasimplevoltageregulatorcircuitusingLM317?