附錄三外文翻譯外文資料SHT1X/SHT7XHUMIDITYTEMPERATURESENSORRELATIVEHUMIDITYANDTEMPERATURESENSORSDEWPOINTFULLYCALIBRATED,DIGITALOUTPUTEXCELLENTLONGTERMSTABILITYNOEXTERNALCOMPONENTSREQUIREDULTRALOWPOWERCONSUMPTIONSURFACEMOUNTABLEOR4PINFULLYINTERCHANGEABLESMALLSIZEAUTOMATICPOWERDOWNSHT1X/SHT7XPRODUCTSUMMARYTHESHTXXISASINGLECHIPRELATIVEHUMIDITYANDTEMPERATUREMULTISENSORMODULECOMPRISINGACALIBRATEDDIGITALOUTPUTAPPLICATIONOFINDUSTRIALCMOSPROCESSESWITHPATENTEDMICROMACHININGCMOSENSTECHNOLOGYENSURESHIGHESTRELIABILITYANDEXCELLENTLONGTERMSTABILITYTHEDEVICEINCLUDESACAPACITIVEPOLYMERSENSINGELEMENTFORRELATIVEHUMIDITYANDABANDGAPTEMPERATURESENSORBOTHARESEAMLESSLYCOUPLEDTOA14BITANALOGTODIGITALCONVERTERANDASERIALINTERFACECIRCUITONTHESAMECHIPTHISRESULTSINSUPERIORSIGNALQUALITY,AFASTRESPONSETIMEANDINSENSITIVITYTOEXTERNALDISTURBANCESEMCATAVERYCOMPETITIVEPRICEEACHSHTXXISINDIVIDUALLYCALIBRATEDINAPRECISIONHUMIDITYCHAMBERWITHACHILLEDMIRRORHYGROMETERASREFERENCETHECALIBRATIONCOEFFICIENTSAREPROGRAMMEDINTOTHEOTPMEMORYTHESECOEFFICIENTSAREUSEDINTERNALLYDURINGMEASUREMENTSTOCALIBRATETHESIGNALSFROMTHESENSORSTHE2WIRESERIALINTERFACEANDINTERNALVOLTAGEREGULATIONALLOWSEASYANDFASTSYSTEMINTEGRATIONITSTINYSIZEANDLOWPOWERCONSUMPTIONMAKESITTHEULTIMATECHOICEFOREVENTHEMOSTDEMANDINGAPPLICATIONSTHEDEVICEISSUPPLIEDINEITHSURFACEMOUNTABLELCCLEADLESSCHIPCARRIERORASAPLUGGABLE4PINSINGLEINLINETYPEPACKAGECUSTOMERSPECIFICPACKAGINGOPTIONSMAYBEAVAILABLEONREQUESTAPPLICATIONS_HVAC_AUTOMOTIVE_CONSUMERGOODS_WEATHERSTATIONS_HUMIDIFIERS_DEHUMIDIFIERS_TESTMEASUREMENT_DATALOGGING_AUTOMATION_WHITEGOODS_MEDICAL2INTERFACESPECIFICATIONSFIGURE2TYPICALAPPLICATIONCIRCUIT21POWERPINSTHESHTXXREQUIRESAVOLTAGESUPPLYBETWEEN24AND55VAFTERPOWERUPTHEDEVICENEEDS11MSTOREACHITS“SLEEP”STATENOCOMMANDSSHOULDBESENTBEFORETHATTIMEPOWERSUPPLYPINSVDD,GNDMAYBEDECOUPLEDWITHA100NFCAPACITOR22SERIALINTERFACEBIDIRECTIONAL2WIRETHESERIALINTERFACEOFTHESHTXXISOPTIMIZEDFORSENSORREADOUTANDPOWERCONSUMPTIONANDISNOTCOMPATIBLEWITHI2CINTERFACES,SEEFAQFORDETAILS221SERIALCLOCKINPUTSCKTHESCKISUSEDTOSYNCHRONIZETHECOMMUNICATIONBETWEENAMICROCONTROLLERANDTHESHTXXSINCETHEINTERFACECONSISTSOFFULLYSTATICLOGICTHEREISNOMINIMUMSCKFREQUENCY222SERIALDATADATATHEDATATRISTATEPINISUSEDTOTRANSFERDATAINANDOUTOFTHEDEVICEDATACHANGESAFTERTHEFALLINGEDGEANDISVALIDONTHERISINGEDGEOFTHESERIALCLOCKSCKDURINGTRANSMISSIONTHEDATALINEMUSTREMAINSTABLEWHILESCKISHIGHTOAVOIDSIGNALCONTENTIONTHEMICROCONTROLLERSHOULDONLYDRIVEDATALOWANEXTERNALPULLUPRESISTOREG10KISREQUIREDTOPULLTHESIGNALHIGHSEEFIGURE2PULLUPRESISTORSAREOFTENINCLUDEDINI/OCIRCUITSOFMICROCONTROLLERSSEETABLE5FORDETAILEDIOCHARACTERISTICS223SENDINGACOMMANDTOINITIATEATRANSMISSION,A“TRANSMISSIONSTART”SEQUENCEHASTOBEISSUEDITCONSISTSOFALOWERINGOFTHEDATALINEWHILESCKISHIGH,FOLLOWEDBYALOWPULSEONSCKANDRAISINGDATAAGAINWHILESCKISSTILLHIGHFIGURE3“TRANSMISSIONSTART“SEQUENCETHESUBSEQUENTCOMMANDCONSISTSOFTHREEADDRESSBITSONLY“000”ISCURRENTLYSUPPORTEDANDFIVECOMMANDBITSTHESHTXXINDICATESTHEPROPERRECEPTIONOFACOMMANDBYPULLINGTHEDATAPINLOWACKBITAFTERTHEFALLINGEDGEOFTHE8THSCKCLOCKTHEDATALINEISRELEASEDANDGOESHIGHAFTERTHEFALLINGEDGEOFTHE9THSCKCLOCK224MEASUREMENTSEQUENCERHANDTAFTERISSUINGAMEASUREMENTCOMMAND00000101FORRH,00000011FORTEMPERATURETHECONTROLLERHASTOWAITFORTHEMEASUREMENTTOCOMPLETETHISTAKESAPPROXIMATELY11/55/210MSFORA8/12/14BITMEASUREMENTTHEEXACTTIMEVARIESBYUPTO15WITHTHESPEEDOFTHEINTERNALOSCILLATORTOSIGNALTHECOMPLETIONOFAMEASUREMENT,THESHTXXPULLSDOWNTHEDATALINEANDENTERSIDLEMODETHECONTROLLERMUSTWAITFORTHIS“DATAREADY”SIGNALBEFORERESTARTINGSCKTOREADOUTTHEDATAMEASUREMENTDATAISSTOREDUNTILREADOUT,THEREFORETHECONTROLLERCANCONTINUEWITHOTHERTASKSANDREADOUTASCONVENIENTTWOBYTESOFMEASUREMENTDATAANDONEBYTEOFCRCCHECKSUMWILLTHENBETRANSMITTEDTHEUCMUSTACKNOWLEDGEEACHBYTEBYPULLINGTHEDATALINELOWALLVALUESAREMSBFIRST,RIGHTJUSTIFIEDEGTHE5THSCKISMSBFORA12BITVALUE,FORA8BITRESULTTHEFIRSTBYTEISNOTUSEDCOMMUNICATIONTERMINATESAFTERTHEACKNOWLEDGEBITOFTHECRCDATAIFCRC8CHECKSUMISNOTUSEDTHECONTROLLERMAYTERMINATETHECOMMUNICATIONAFTERTHEMEASUREMENTDATLSBBYKEEPINGACKHIGHTHEDEVICEAUTOMATICALLYRETURNSTOSLEEPMODEAFTERTHEMEASUREMENTANDCOMMUNICATIONHAVEENDEDWARNINGTOKEEPSELFHEATINGBELOW01CTHESHTXXSHOULDNOTBEACTIVEFORMORETHAN10OFTHETIMEEGMAX2MEASUREMENTS/SECONDFOR12BITACCURACY225CONNECTIONRESETSEQUENCEIFCOMMUNICATIONWITHTHEDEVICEISLOSTTHEFOLLOWINGSIGNALSEQUENCEWILLRESETITSSERIALINTERFACEWHILELEAVINGDATAHIGH,TOGGLESCK9ORMORETIMESTHISMUSTBEFOLLOWEDBYA“TRANSMISSIONSTART”SEQUENCEPRECEDINGTHENEXTCOMMANDTHISSEQUENCERESETSTHEINTERFACEONLYTHESTATUSREGISTERPRESERVESITSCONTENTFIGURE4CONNECTIONRESETSEQUENCE226CRC8CHECKSUMCALCULATIONTHEWHOLEDIGITALTRANSMISSIONISSECUREDBYA8BITCHECKSUMITENSURESTHATANYWRONGDATACANBEDETECTEDANDELIMINATEDPLEASECONSULTAPPLICATIONNOTE“CRC8CHECKSUMCALCULATION”FORINFORMATIONONHOWTOCALCULATETHECRC23STATUSREGISTERSOMEOFTHEADVANCEDFUNCTIONSOFTHESHTXXAREAVAILABLETHROUGHTHESTATUSREGISTERTHEFOLLOWINGSECTIONGIVESABRIEFOVERVIEWOFTHESEFEATURESAMOREDETAILEDDESCRIPTIONISAVAILABLEINTHEAPPLICATIONNOTE“STATUSREGISTERFIGURE7STATUSREGISTERWRITEFIGURE8STATUSREGISTERREAD231MEASUREMENTRESOLUTIONTHEDEFAULTMEASUREMENTRESOLUTIONOF14BITTEMPERATUREAND12BITHUMIDITYCANBEREDUCEDTO12AND8BITTHISISESPECIALLYUSEFULINHIGHSPEEDOREXTREMELOWPOWERAPPLICATIONS232ENDOFBATTERYTHE“ENDOFBATTERY”FUNCTIONDETECTSVDDVOLTAGESBELOW247VACCURACYIS005V233HEATERANONCHIPHEATINGELEMENTCANBESWITCHEDONITWILLINCREASETHETEMPERATUREOFTHESENSORBY515C927FPOWERCONSUMPTIONWILLINCREASEBY8MA5VAPPLICATIONSBYCOMPARINGTEMPERATUREANDHUMIDITYVALUESBEFOREANDAFTERSWITCHINGONTHEHEATER,PROPERFUNCTIONALITYOFBOTHSENSORSCANBEVERIFIEDINHIGH95RHRHENVIRONMENTSHEATINGTHESENSORELEMENTWILLPREVENTCONDENSATION,IMPROVERESPONSETIMEANDACCURACYWARNINGWHILEHEATEDTHESHTXXWILLSHOWHIGHERTEMPERATURESANDALOWERRELATIVEHUMIDITYTHANWITHNOHEATING3CONVERTINGOUTPUTTOPHYSICALVALUES31RELATIVEHUMIDITYTOCOMPENSATEFORTHENONLINEARITYOFTHEHUMIDITYSENSORANDTOOBTAINTHEFULLACCURACYITISRECOMMENDEDTOCONVERTTHEREADOUTWITHTHEFOLLOWINGFORMULA1RHLINEARC1C2SORHC32TABLE6HUMIDITYCONVERSIONCOEFFICIENTSTABLE7TEMPERATURECOMPENSATIONCOEFFICIENTTHEHUMIDITYSENSORHASNOSIGNIFICANTVOLTAGEDEPENDENCYFIGURE10CONVERSIONFROMSORHTORELATIVEHUMIDITY311HUMIDITYSENSORRH/TEMPERATURECOMPENSATIONFORTEMPERATURESSIGNIFICANTLYDIFFERENTFROM25C77FTHETEMPERATURECOEFFICIENTOFTHERHSENSORSHOULDBECONSIDEREDRHTRUETC25T1T2SORHRHLINEAR32TEMPERATURETHEBANDGAPPTATPROPORTIONALTOABSOLUTETEMPERATURETEMPERATURESENSORISVERYLINEARBYDESIGNUSETHEFOLLOWINGFORMULATOCONVERTFROMDIGITALREADOUTTOTEMPERATURETEMPERATURED1D2SOTTABLE8TEMPERATURECONVERSIONCOEFFICIENTSFORIMPROVEDACCURACIESINEXTREMETEMPERATURESWITHMORECOMPUTATIONINTENSECONVERSIONFORMULASSEEAPPLICATIONNOTE“RHANDTEMPERATURENONLINEARITYCOMPENSATION33DEWPOINTSINCEHUMIDITYANDTEMPERATUREAREBOTHMEASUREDONTHESAMEMONOLITHICCHIP,THESHTXXALLOWSSUPERBDEWPOINTMEASUREMENTSSEEAPPLICATIONNOTE“DEWPOINTCALCULATION”FORMORE4APPLICATIONSINFORMATION41OPERATINGANDSTORAGECONDITIONSFIGURE11RECOMMENDEDOPERATINGCONDITIONSCONDITIONSOUTSIDETHERECOMMENDEDRANGEMAYTEMPORARILYOFFSETTHERHSIGNALUPTO3RHAFTERRETURNTONORMALCONDITIONSITWILLSLOWLYRETURNTOWARDSCALIBRATIONSTATEBYITSELFSEE43“RECONDITIONINGPROCEDURE”TOACCELERATETHISPROCESSPROLONGEDEXPOSURETOEXTREMECONDITIONSMAYACCELERATEAGEING42EXPOSURETOCHEMICALSCHEMICALVAPORSMAYINTERFEREWITHTHEPOLYMERLAYERSUSEDFORCAPACITIVEHUMIDITYSENSORSTHEDIFFUSIONOFCHEMICALSINTOTHEPOLYMERMAYCAUSEASHIFTINBOTHOFFSETANDSENSITIVITYINACLEANENVIRONMENTTHECONTAMINANTSWILLSLOWLYOUTGASTHERECONDITIONINGPROCEDUREDESCRIBEDBELOWWILLACCELERATETHISPROCESSHIGHLEVELSOFPOLLUTANTSMAYCAUSEPERMANENTDAMAGETOTHESENSINGPOLYMER43RECONDITIONINGPROCEDURETHEFOLLOWINGRECONDITIONINGPROCEDUREWILLBRINGTHESENSORBACKTOCALIBRATIONSTATEAFTEREXPOSURETOEXTREMECONDITIONSORCHEMICALVAPORS8090C176194FAT74RHFOR48HREHYDRATION44TEMPERATUREEFFECTSTHERELATIVEHUMIDITYOFAGASSTRONGLYDEPENDSONITSTEMPERATUREITISTHEREFOREESSENTIALTOKEEPHUMIDITYSENSORSATTHESAMETEMPERATUREASTHEAIROFWHICHTHERELATIVEHUMIDITYISTOBEMEASUREDIFTHESHTXXSHARESAPCBWITHELECTRONICCOMPONENTSTHATGIVEOFFHEATITSHOULDBEMOUNTEDFARAWAYANDBELOWTHEHEATSOURCEANDTHEHOUSINGMUSTREMAINWELLVENTILATEDTOREDUCEHEATCONDUCTIONCOPPERLAYERSBETWEENTHESHT1XANDTHERESTOFTHEPCBSHOULDBEMINIMIZEDANDASLITMAYBEMILLEDINBETWEENSEEFIGURE1345MEMBRANESAMEMBRANEMAYBEUSEDTOPREVENTDIRTFROMENTERINGTHEHOUSINGANDTOPROTECTTHESENSORITWILLALSOREDUCEPEAKCONCENTRATIONSOFCHEMICALVAPORSFOROPTIMALRESPONSETIMESAIRVOLUMEBEHINDTHEMEMBRANEMUSTBEKEPTTOAMINIMUMFORTHESHT1XPACKAGESENSIRIONRECOMMENDSTHESF1FILTERCAPFOROPTIMALIP67PROTECTION46LIGHTTHESHTXXISNOTLIGHTSENSITIVEPROLONGEDDIRECTEXPOSURETOSUNSHINEORSTRONGUVRADIATIONMAYAGETHEHOUSING47MATERIALSUSEDFORSEALING/MOUNTINGMANYMATERIALSABSORBHUMIDITYANDWILLACTASABUFFER,INCREASINGRESPONSETIMESANDHYSTERESISMATERIALSINTHEVICINITYOFTHESENSORMUSTTHEREFOREBECAREFULLYCHOSENRECOMMENDEDMATERIALSAREALLMETALS,LCP,POMDELRIN,PTFETEFLON,PE,PEEK,PP,PB,PPS,PSU,PVDF,PVFFORSEALINGANDGLUINGUSESPARINGLYHIGHFILLEDEPOXYFORELECTRONICPACKAGINGEGGLOBTOP,UNDERFILL,ANDSILICONEOUTGASSINGOFTHESEMATERIALSMAYALSOCONTAMINATETHESHTXXCF42STOREWELLVENTILATEDAFTERMANUFACTURINGORBAKEAT50CFOR24HTOOUTGASCONTAMINANTSBEFOREPACKING48WIRINGCONSIDERATIONSANDSIGNALINTEGRITYCARRYINGTHESCKANDDATASIGNALPARALLELANDINCLOSEPROXIMITYEGINWIRESFORMORETHAN10CMMAYRESULTINCROSSTALKANDLOSSOFCOMMUNICATIONTHISMAYBERESOLVEDBYROUTINGVDDAND/ORGNDBETWEENTHETWODATASIGNALSPLEASESEETHEAPPLICATIONNOTE“ESD,LATCHUPANDEMC”FORMOREINFORMATIONPOWERSUPPLYPINSVDD,GNDSHOULDBEDECOUPLEDWITHA100NFCAPACITORIFWIRESAREUSED49ESDELECTROSTATICDISCHARGEESDIMMUNITYISQUALIFIEDACCORDINGTOMILSTD883E,METHOD3015HUMANBODYMODELAT2KVLATCHUPIMMUNITYISPROVIDEDATAFORCECURRENTOF100MAWITHTAMB80CACCORDINGTOJEDEC17SEEAPPLICATIONNOTE“ESD,LATCHUPANDEMC”FORMOREINFORMATION5IMPORTANTNOTICES51WARNING,PERSONALINJURYDONOTUSETHISPRODUCTASSAFETYOREMERGENCYSTOPDEVICESORINANYOTHERAPPLICATIONWHEREFAILUREOFTHEPRODUCTCOULDRESULTINPERSONALINJURYFAILURETOCOMPLYWITHTHESEINSTRUCTIONSCOULDRESULTINDEATHORSERIOUSINJURYSHOULDBUYERPURCHASEORUSESENSIRIONAGPRODUCTSFORANYSUCHUNINTENDEDORUNAUTHORIZEDAPPLICATION,BUYERSHALLINDEMNIFYANDHOLDSENSIRIONAGANDITSOFFICERS,EMPLOYEES,SUBSIDIARIES,AFFILIATESANDDISTRIBUTORSHARMLESSAGAINSTALLCLAIMS,COSTS,DAMAGESANDEXPENSES,ANDREASONABLEATTORNEYFEESARISINGOUTOF,DIRECTLYORINDIRECTLY,ANYCLAIMOFPERSONALINJURYORDEATHASSOCIATEDWITHSUCHUNINTENDEDORUNAUTHORIZEDUSE,EVENIFSUCHCLAIMALLEGESTHATSENSIRIONAGWASNEGLIGENTREGARDINGTHEDESIGNORMANUFACTUREOFTHEPART52ESDPRECAUTIONSTHEINHERENTDESIGNOFTHISCOMPONENTCAUSESITTOBESENSITIVETOELECTROSTATICDISCHARGEESDTOPREVENTESDINDUCEDDAMAGEAND/ORDEGRADATION,TAKENORMALESDPRECAUTIONSWHENHANDLINGTHISPRODUCTSEEAPPLICATIONNOTE“ESD,LATCHUPANDEMC”FORMOREINFORMATION53WARRANTYSENSIRIONAGMAKESNOWARRANTY,REPRESENTATIONORGUARANTEEREGARDINGTHESUITABILITYOFITSPRODUCTFORANYPARTICULARPURPOSE,NORDOESSENSIRIONAGASSUMEANYLIABILITYARISINGOUTOFTHEAPPLICATIONORUSEOFANYPRODUCTORCIRCUITANDSPECIFICALLYDISCLAIMSANYANDALLLIABILITY,INCLUDINGWITHOUTLIMITATIONCONSEQUENTIALORINCIDENTALDAMAGES“TYPICAL”PARAMETERSCANANDDOVARYINDIFFERENTAPPLICATIONSALLOPERATINGPARAMETERS,INCLUDING“TYPICAL”MUSTBEVALIDATEDFOREACHCUSTOMERAPPLICATIONSBYCUSTOMERSTECHNICALEXPERTSSENSIRIONAGRESERVESTHERIGHT,WITHOUTFURTHERNOTICE,TOCHANGETHEPRODUCTSPECIFICATIONSAND/ORINFORMATIONINTHISDOCUMENTANDTOIMPROVERELIABILITY,FUNCTIONSANDDESIGN數(shù)字溫濕度傳感器SHT1X/SHT7X_相對濕度和溫度測量_兼有露點(diǎn)_全標(biāo)定輸出，無需標(biāo)定即可互換使用_卓越的長期穩(wěn)定性_兩線制數(shù)字接口，無需額外部件_基于請求式測量，因此低能耗_表面貼片或4針引腳安裝_超小尺寸_自動(dòng)休眠SHT1X/SHT7X產(chǎn)品概述SHTXX系列產(chǎn)品是一款高度集成的溫濕度傳感器芯片，提供全標(biāo)定的數(shù)字輸出。它采用專利的CMOSENS技術(shù)，確保產(chǎn)品具有極高的可靠性與卓越的長期穩(wěn)定性。傳感器包括一個(gè)電容性聚合體測濕敏感元件、一個(gè)用能隙材料制成的測溫元件，并在同一芯片上，與14位的A/D轉(zhuǎn)換器以及串行接口電路實(shí)現(xiàn)無縫連接。因此，該產(chǎn)品具有品質(zhì)卓越、超快響應(yīng)、抗干擾能力強(qiáng)、極高的性價(jià)比等優(yōu)點(diǎn)。每個(gè)傳感器芯片都在極為精確的濕度腔室中進(jìn)行標(biāo)定，以鏡面冷凝式濕度計(jì)為參照。校準(zhǔn)系數(shù)以程序形式儲(chǔ)存在OTP內(nèi)存中，在標(biāo)定的過程中使用。兩線制的串行接口與內(nèi)部的電壓調(diào)整，使外圍系統(tǒng)集成變得快速而簡單。微小的體積、極低的功耗，使其成為各類應(yīng)用的首選。產(chǎn)品提供表面貼片LCC或4針單排引腳封裝。特殊封裝形式可根據(jù)用戶需求而提供。應(yīng)用領(lǐng)域框圖_暖通空調(diào)HVAC_汽車_消費(fèi)品_氣象站_濕度調(diào)節(jié)器_除濕器_測試及檢測設(shè)備_數(shù)據(jù)記錄器_自動(dòng)控制_家電_醫(yī)療2接口說明圖2典型應(yīng)用電路21電源引腳SHTXX的供電電壓為2455V。傳感器上電后，要等待11MS以越過“休眠”狀態(tài)。在此期間無需發(fā)送任何指令。電源引腳（VDD，GND）之間可增加一個(gè)100NF的電容，用以去耦濾波。22串行接口兩線雙向SHTXX的串行接口，在傳感器信號(hào)的讀取及電源損耗方面，都做了優(yōu)化處理；但與I2C接口不兼容，詳情參見FAQ221串行時(shí)鐘輸入SCKSCK用于微處理器與SHTXX之間的通訊同步。由于接口包含了完全靜態(tài)邏輯，因而不存在最小SCK頻率。222串行數(shù)據(jù)DATADATA三態(tài)門用于數(shù)據(jù)的讀取。DATA在SCK時(shí)鐘下降沿之后改變狀態(tài)，并僅在SCK時(shí)鐘上升沿有效。數(shù)據(jù)傳輸期間，在SCK時(shí)鐘高電平時(shí)，DATA必須保持穩(wěn)定。為避免信號(hào)沖突，微處理器應(yīng)驅(qū)動(dòng)DATA在低電平。需要一個(gè)外部的上拉電阻（例如10K）將信號(hào)提拉至高電平（參見圖2）。上拉電阻通常已包含在微處理器的I/O電路中。詳細(xì)的IO特性，參見表5。223發(fā)送命令用一組“啟動(dòng)傳輸”時(shí)序，來表示數(shù)據(jù)傳輸?shù)某跏蓟?。它包括?dāng)SCK時(shí)鐘高電平時(shí)DATA翻轉(zhuǎn)為低電平，緊接著SCK變?yōu)榈碗娖?，隨后是在SCK時(shí)鐘高電平時(shí)DATA翻轉(zhuǎn)為高電平。圖3“啟動(dòng)傳輸“時(shí)序后續(xù)命令包含三個(gè)地址位（目前只支持“000”），和五個(gè)命令位。SHTXX會(huì)以下述方式表示已正確地接收到指令在第8個(gè)SCK時(shí)鐘的下降沿之后，將DATA下拉為低電平（ACK位）。在第9個(gè)SCK時(shí)鐘的下降沿之后，釋放DATA（恢復(fù)高電平）。表2SHT控制命令代碼命令代碼含義00011測量溫度00101測量濕度00111讀內(nèi)部狀態(tài)寄存器11110復(fù)位命令，使內(nèi)部狀態(tài)寄存器恢復(fù)默認(rèn)值，下一次命令前至少等11MS其他保留224測量時(shí)序RH和T發(fā)布一組測量命令（00000101表示相對濕度RH，00000011表示溫度T）后，控制器要等待測量結(jié)束。這個(gè)過程需要大約11/55/210MS，分別對應(yīng)8/12/14BIT測量。確切的時(shí)間隨內(nèi)部晶振速度，最多有15變化。SHTXX通過下拉DATA至低電平并進(jìn)入空閑模式，表示測量的結(jié)束?？刂破髟谠俅斡|發(fā)SCK時(shí)鐘前，必須等待這個(gè)“數(shù)據(jù)備妥”信號(hào)來讀出數(shù)據(jù)。檢測數(shù)據(jù)可以先被存儲(chǔ)這樣控制器可以繼續(xù)執(zhí)行其它任務(wù)在需要時(shí)再讀出數(shù)據(jù)。接著傳輸2個(gè)字節(jié)的測量數(shù)據(jù)和1個(gè)字節(jié)的CRC奇偶校驗(yàn)。UC需要通過下拉DATA為低電平，以確認(rèn)每個(gè)字節(jié)。所有的數(shù)據(jù)從MSB開始，右值有效（例如對于12BIT數(shù)據(jù)，從第5個(gè)SCK時(shí)鐘起算作MSB；而對于8BIT數(shù)據(jù)，首字節(jié)則無意義）。用CRC數(shù)據(jù)的確認(rèn)位，表明通訊結(jié)束。如果不使用CRC8校驗(yàn)，控制器可以在測量值LSB后，通過保持確認(rèn)位ACK高電平，來中止通訊。在測量和通訊結(jié)束后，SHTXX自動(dòng)轉(zhuǎn)入休眠模式。警告為保證自身溫升低于01，SHTXX的激活時(shí)間不要超過15（例如，對應(yīng)12BIT精度測量，每秒最多進(jìn)行3次測量）。225通訊復(fù)位時(shí)序如果與SHTXX通訊中斷，下列信號(hào)時(shí)序可以復(fù)位串口當(dāng)DATA保持高電平時(shí)，觸發(fā)SCK時(shí)鐘9次或更多。在下一次指令前，發(fā)送一個(gè)“傳輸啟動(dòng)”時(shí)序。這些時(shí)序只復(fù)位串口，狀態(tài)寄存器內(nèi)容仍然保留。圖4通訊復(fù)位時(shí)序226CRC8校驗(yàn)數(shù)字信號(hào)的整個(gè)傳輸過程由8BIT校驗(yàn)來確保。任何錯(cuò)誤數(shù)據(jù)將被檢測到并清除。詳情可參閱應(yīng)用說明“CRC8校驗(yàn)”。圖6測量時(shí)序概覽TS啟動(dòng)傳輸23狀態(tài)寄存器SHTXX的某些高級(jí)功能可以通過狀態(tài)寄存器實(shí)現(xiàn)。下面的章節(jié)概括介紹了這些功能。詳情可參閱應(yīng)用說明“狀態(tài)寄存器”。圖7狀態(tài)寄存器讀圖8狀態(tài)寄存器寫231測量分辨率默認(rèn)的測量分辨率分別為14BIT（溫度）、12BIT（濕度），也可分別降至12BIT和8BIT。通常在高速或超低功耗的應(yīng)用中采用該功能。232電量不足“電量不足”功能可監(jiān)測到VDD電壓低于247V的狀態(tài)。精度為005V。233加熱元件芯片上集成了一個(gè)可通斷的加熱元件。接通后，可將SHTXX的溫度提高大約5（9）。功耗增加8MA5V。應(yīng)用于比較加熱前后的溫度和濕度值，可以綜合驗(yàn)證兩個(gè)傳感器元件的性能。在高濕95RH環(huán)境中，加熱傳感器可預(yù)防結(jié)露，同時(shí)縮短響應(yīng)時(shí)間，提高精度。警告加熱SHTXX后溫度升高、相對濕度降低，較之加熱前，示值略有差異。3輸出轉(zhuǎn)換為物理量31相對濕度為了補(bǔ)償濕度傳感器的非線性以獲取準(zhǔn)確數(shù)據(jù)，建議使用如下公式1修正讀數(shù)RHLINEARC1C2SORHC32表6濕度轉(zhuǎn)換系數(shù)表7溫度補(bǔ)償系數(shù)濕度傳感器對電壓基本上沒有依賴性。圖10從SORH轉(zhuǎn)換到相對濕度311相對濕度對于溫度依賴性的補(bǔ)償由于實(shí)際溫度與測試參考溫度2577的顯著不同，應(yīng)考慮濕度傳感器的溫度修正系數(shù)RHTRUETC25T1T2SORHRHLINEAR32溫度由能隙材料PTAT正比于絕對溫度研發(fā)的溫度傳感器具有極好的線性?？捎萌缦鹿綄?shù)字輸出轉(zhuǎn)換為溫度值TEMPERATURED1D2SOT表8溫度轉(zhuǎn)換系數(shù)33露點(diǎn)由于濕度與溫度經(jīng)由同一塊芯片測量，SHTXX系列產(chǎn)品可以同時(shí)實(shí)現(xiàn)高質(zhì)量的露點(diǎn)測量?？蓞㈤啈?yīng)用說明“露點(diǎn)計(jì)算”。4應(yīng)用信息41工作與貯存條件圖11建議的工作條件超出建議的工作范圍可能導(dǎo)致最大3的RH信號(hào)暫時(shí)性漂移。當(dāng)恢復(fù)到正常工作條件后，傳感器會(huì)緩慢自恢復(fù)到校正狀態(tài)?？蓞㈤?3小節(jié)的“恢復(fù)處理”以加