芯片资料 MAX485

_______________GeneralDescriptionTheMAX481E,MAX483E,MAX485E,MAX487E–MAX491E,andMAX1487Earelow-powertransceiversforRS-485andRS-422communicationsinharshenvironments.Eachdriveroutputandreceiverinputisprotectedagainst±15kVelectro-staticdischarge(ESD)shocks,withoutlatchup.Thesepartscontainonedriverandonereceiver.TheMAX483E,MAX487E,MAX488E,andMAX489Efeaturereducedslew-ratedriversthatminimizeEMIandreducereflectionscausedbyimproperlyterminatedcables,thusallowingerror-freedatatransmissionupto250kbps.ThedriverslewratesoftheMAX481E,MAX485E,MAX490E,MAX491E,andMAX1487Earenotlimited,allowingthemtotransmitupto2.5Mbps.Thesetransceiversdrawaslittleas120µAsupplycurrentwhenunloadedorwhenfullyloadedwithdisableddrivers(seeSelectionTable).Additionally,theMAX481E,MAX483E,andMAX487Ehavealow-currentshutdownmodeinwhichtheyconsumeonly0.5µA.Allpartsoperatefromasingle+5Vsupply.Driversareshort-circuitcurrentlimited,andareprotectedagainstexcessivepowerdissipationbythermalshutdowncircuitrythatplacestheiroutputsintoahigh-impedancestate.Thereceiverinputhasafail-safefeaturethatguaran-teesalogic-highoutputiftheinputisopencircuit.TheMAX487EandMAX1487Efeaturequarter-unit-loadreceiverinputimpedance,allowingupto128transceiversonthebus.TheMAX488E–MAX491Earedesignedforfull-duplexcommunications,whiletheMAX481E,MAX483E,MAX485E,MAX487E,andMAX1487Earedesignedforhalf-duplexapplications.ForapplicationsthatarenotESDsen-sitiveseethepin-andfunction-compatibleMAX481,MAX483,MAX485,MAX487–MAX491,andMAX1487.________________________ApplicationsLow-PowerRS-485TransceiversLow-PowerRS-422TransceiversLevelTranslatorsTransceiversforEMI-SensitiveApplicationsIndustrial-ControlLocalAreaNetworks____________________________Features'ESDProtection:±15kV—HumanBodyModel'Slew-RateLimitedforError-FreeDataTransmission(MAX483E/487E/488E/489E)'LowQuiescentCurrent:120µA(MAX483E/487E/488E/489E)230µA(MAX1487E)300µA(MAX481E/485E/490E/491E)'-7Vto+12VCommon-ModeInputVoltageRange'Three-StateOutputs'30nsPropagationDelays,5nsSkew(MAX481E/485E/490E/491E/1487E)'Full-DuplexandHalf-DuplexVersionsAvailable'Allowsupto128TransceiversontheBus(MAX487E/MAX1487E)'CurrentLimitingandThermalShutdownforDriverOverloadProtectionMAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E±15kVESD-Protected,Slew-Rate-Limited,Low-Power,RS-485/RS-422Transceivers________________________________________________________________MaximIntegratedProducts1MAX481EMAX483EMAX485EMAX487EMAX488EMAX489EMAX490EMAX491EMAX1487EPARTNUMBERHALF/FULLDUPLEXDATARATE(Mbps)SLEW-RATELIMITEDLOW-POWERSHUTDOWNRECEIVER/DRIVERENABLEQUIESCENTCURRENT(μA)NUMBEROFTRANSMITTERSONBUSPINCOUNTHalfHalfHalfHalfFullFullFullFullHalf2.50.252.50.250.250.252.52.52.5NoYesNoYesYesYesNoNoNoYesYesNoYesNoNoNoNoNoYesYesYesYesNoYesNoYesYes3001203001201201203003002303232321283232323212888888148148______________________________________________________________SelectionTable19-0410;Rev3;7/96______________OrderingInformationOrderingInformationcontinuedonlastpage.8SO0°Cto+70°CMAX481ECSA8PlasticDIP0°Cto+70°CMAX481ECPAPIN-PACKAGETEMP.RANGEPART8SO-40°Cto+85°CMAX481EESA8PlasticDIP-40°Cto+85°CMAX481EEPAForfreesamples&thelatestliterature:–MAX491E/MAX1487E±15kVESD-Protected,Slew-Rate-Limited,Low-Power,RS-485/RS-422Transceivers2_______________________________________________________________________________________SupplyVoltage(VCC).............................................................12VControlInputVoltage(–R—E–,DE)...................-0.5Vto(VCC+0.5V)DriverInputVoltage(DI).............................-0.5Vto(VCC+0.5V)DriverOutputVoltage(Y,Z;A,B)..........................-8Vto+12.5VReceiverInputVoltage(A,B).................................-8Vto+12.5VReceiverOutputVoltage(RO)....................-0.5Vto(VCC+0.5V)ContinuousPowerDissipation(TA=+70°C)8-PinPlasticDIP(derate9.09mW/°Cabove+70°C)....727mW14-PinPlasticDIP(derate10.00mW/°Cabove+70°C)..800mW8-PinSO(derate5.88mW/°Cabove+70°C).................471mW14-PinSO(derate8.33mW/°Cabove+70°C)...............667mWOperatingTemperatureRangesMAX4__C__/MAX1487EC_A.............................0°Cto+70°CMAX4__E__/MAX1487EE_A...........................-40°Cto+85°CStorageTemperatureRange.............................-65°Cto+160°CLeadTemperature(soldering,10sec).............................+300°CDCELECTRICALCHARACTERISTICS(VCC=5V±5%,TA=TMINtoTMAX,unlessotherwisenoted.)(Notes1,2)Stressesbeyondthoselistedunder“AbsoluteMaximumRatings”maycausepermanentdamagetothedevice.Thesearestressratingsonly,andfunctionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedintheoperationalsectionsofthespecificationsisnotimplied.Exposuretoabsolutemaximumratingconditionsforextendedperiodsmayaffectdevicereliability.ABSOLUTEMAXIMUMRATINGSPARAMETERSYMBOLMINTYPMAXUNITSDriverCommon-ModeOutputVoltageVOC3VChangeinMagnitudeofDriverDifferentialOutputVoltageforComplementaryOutputStatesΔVOD0.2VChangeinMagnitudeofDriverCommon-ModeOutputVoltageforComplementaryOutputStatesΔVOD0.2VInputHighVoltage