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logic symbolThis symbol is in accordance with ANSI/IEEE Std 91-1984 and IECPublication 617-12.2VCC 1.5 V2VCC + 1.5 V26147138C1+C1C2+C213451110129GND150 VVCC16VCCC1+C1C2+C2T1INT2INR1OUTR2OUTT1OUTT2OUTR1INR2INVS+VSMAX232, MAX232IDUAL EIA-232 DRIVER/RECEIVERSLLS047G FEBRUARY 1989 REVISED AUGUST 19981POST OFFICE BOX 655303 DALLAS, TEXAS 75265?Operates With Single 5-V Power Supply?LinBiCMOS Process Technology?Two Drivers and Two Receivers?30-V Input Levels?Low Supply Current . . . 8 mA Typical?Meets or Exceeds TIA/EIA-232-F and ITURecommendation V.28?Designed to be Interchangeable WithMaxim MAX232?ApplicationsTIA/EIA-232-FBattery-Powered SystemsTerminalsModemsComputers?ESD Protection Exceeds 2000 V PerMIL-STD-883, Method 3015?Package Options Include PlasticSmall-Outline (D, DW) Packages andStandard Plastic (N) DIPs descriptionThe MAX232 device is a dual driver/receiver thatincludes a capacitive voltage generator to supplyEIA-232 voltage levels from a single 5-V supply.Each receiver converts EIA-232 inputs to 5-VTTL/CMOS levels. These receivers have a typicalthreshold of 1.3 V and a typical hysteresis of 0.5 V,and can accept 30-V inputs. Each driverconverts TTL/CMOS input levels into EIA-232levels. The driver, receiver, and voltage-generatorfunctions are available as cells in the TexasInstruments LinASIC library.The MAX232 is characterized for operation from0C to 70C. The MAX232I is characterized foroperation from 40C to 85C.AVAILABLE OPTIONSPACKAGED DEVICESTASMALLOUTLINE(D)SMALLOUTLINE(DW)PLASTIC DIP(N)0C to 70CMAX232DMAX232DWMAX232N40C to 85CMAX232IDMAX232IDWMAX232INThis device is available taped and reeled by adding an R to the part number (i.e., MAX232DR).Copyright 1998, Texas Instruments IncorporatedPRODUCTION DATA information is current as of publication date.Products conform to specifications per the terms of Texas Instrumentsstandard warranty. Production processing does not necessarily includetesting of all parameters.Please be aware that an important notice concerning availability, standard warranty, and use in critical applications ofTexas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.LinASIC and LinBiCMOS are trademarks of Texas Instruments Incorporated.1234 5678161514131211109C1+VS+C1C2+C2VST2OUTR2INVCCGNDT1OUTR1INR1OUTT1INT2INR2OUTD, DW, OR N PACKAGE(TOP VIEW)MAX232, MAX232IDUAL EIA-232 DRIVER/RECEIVERSLLS047G FEBRUARY 1989 REVISED AUGUST 19982POST OFFICE BOX 655303 DALLAS, TEXAS 75265absolute maximum ratings over operating free-air temperature range (unless otherwise noted)Input supply voltage range, VCC (see Note 1) 0.3 V to 6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Positive output supply voltage range, VS+ VCC 0.3 V to 15 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Negative output supply voltage range, VS 0.3 V to 15 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Input voltage range, VI: Driver 0.3 V to VCC + 0.3 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Receiver 30 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Output voltage range, VO: T1OUT, T2OUT VS 0.3 V to VS+ + 0.3 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R1OUT, R2OUT 0.3 V to VCC + 0.3 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Short-circuit duration: T1OUT, T2OUT Unlimited. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Package thermal impedance, JA (see Note 2): D package113C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DW package105C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N package78C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Storage temperature range, Tstg 65C to 150C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds 260C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, andfunctional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is notimplied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.NOTE 1:All voltage values are with respect to network ground terminal.2.The package thermal impedance is calculated in accordance with JESD 51, except for through-hole packages, which use a trace lengthof zero.recommended operating conditionsMINNOMMAXUNITSupply voltage, VCC4.555.5VHigh-level input voltage, VIH (T1IN,T2IN)2VLow-level input voltage, VIL (T1IN, T2IN)0.8VReceiver input voltage, R1IN, R2IN30VOperating free air temperature TAMAX232070COperating free-air temperature,TAMAX232I4085CMAX232, MAX232IDUAL EIA-232 DRIVER/RECEIVERSLLS047G FEBRUARY 1989 REVISED AUGUST 19983POST OFFICE BOX 655303 DALLAS, TEXAS 75265electrical characteristics over recommended ranges of supply voltage and operating free-airtemperature range (unless otherwise noted)PARAMETERTEST CONDITIONSMINTYPMAXUNITVOHHigh-level output voltageT1OUT, T2OUTRL = 3 k to GND57VVOHHigh-level out ut voltageR1OUT, R2OUTIOH = 1 mA3.5VVOLLow level output voltageT1OUT, T2OUTRL = 3 k to GND75VVOLLow-level output voltageR1OUT, R2OUTIOL = 3.2 mA0.4VVIT+Receiver positive-going inputthreshold voltageR1IN, R2INVCC = 5 V,TA = 25C1.72.4VVITReceiver negative-going inputthreshold voltageR1IN, R2INVCC = 5 V,TA = 25C0.81.2VVhysInput hysteresis voltageR1IN, R2INVCC = 5 V0.20.51VriReceiver input resistanceR1IN, R2INVCC = 5,TA = 25C357kroOutput resistanceT1OUT, T2OUTVS+ = VS = 0,VO = 2 V300IOSShort-circuit output currentT1OUT, T2OUTVCC = 5.5 V,VO = 010mAIISShort-circuit input currentT1IN, T2INVI = 0200AICCSupply currentVCC = 5.5 V,TA = 25CAll outputs open,810mAAll typical values are at VCC = 5 V, TA = 25C.The algebraic convention, in which the least positive (most negative) value is designated minimum, is used in this data sheet for logic voltagelevels only.Not more than one output should be shorted at a time.switching characteristics, VCC = 5 V, TA = 25CPARAMETERTEST CONDITIONSMINTYPMAXUNITtPLH(R)Receiver propagation delay time, low- to high-level outputSee Figure 1500nstPHL(R)Receiver propagation delay time, high- to low-level outputSee Figure 1500nsSRDriver slew rateRL = 3 k to 7 k,See Figure 230V/sSR(tr)Driver transition region slew rateSee Figure 33V/sMAX232, MAX232IDUAL EIA-232 DRIVER/RECEIVERSLLS047G FEBRUARY 1989 REVISED AUGUST 19984POST OFFICE BOX 655303 DALLAS, TEXAS 75265PARAMETER MEASUREMENT INFORMATION 10 nsVCCR1INorR2INR1OUTorR2OUTRL = 1.3 kSee Note CCL = 50 pF(see Note B)TEST CIRCUIT 10 nsInputOutputtPHLtPLH1.5 VVOLVOH0 V3 V10%90%50%500 nsWAVEFORMS1.5 V90%50%10%NOTES:A.The pulse generator has the following characteristics: ZO = 50 , duty cycle 50%.B.CL includes probe and jig capacitance.C.All diodes are 1N3064 or equivalent.PulseGenerator(see Note A)Figure 1. Receiver Test Circuit and Waveforms for tPHL and tPLH MeasurementsMAX232, MAX232IDUAL EIA-232 DRIVER/RECEIVERSLLS047G FEBRUARY 1989 REVISED AUGUST 19985POST OFFICE BOX 655303 DALLAS, TEXAS 75265PARAMETER MEASUREMENT INFORMATIONT1IN or T2INT1OUT or T2OUTCL = 10 pF(see Note B)TEST CIRCUIT 10 ns 10 nsInputOutputtPHLtPLHVOLVOH0 V3 V10%90%50%5 sWAVEFORMS90%50%10%RL90%10%90%10%tTLHtTHLEIA-232 OutputSR ?0.8 (VOHVOL)tTLHor0.8 (VOLVOH)tTHLNOTES:A.The pulse generator has the following characteristics: ZO = 50 , duty cycle 50%.B.CL includes probe and jig capacitance.PulseGenerator(see Note A)Figure 2. Driver Test Circuit and Waveforms for tPHL and tPLH Measurements (5-s input)EIA-232 Output3 V3 V3 V3 V3 k10%1.5 V90%WAVEFORMS20 s1.5 V90%10%VOHVOLtTLHtTHL 10 ns 10 nsTEST CIRCUITCL = 2.5 nFPulseGenerator(see Note A)InputOutputSR ?6 VtTHLor tTLHNOTE A: The pulse generator has the following characteristics: ZO = 50 , duty cycle 50%.Figure 3. Test Circuit and Waveforms for tTHL and tTLH Measurements (20-s input)MAX232, MAX232IDUAL EIA-232 DRIVER/RECEIVERSLLS047G FEBRUARY 1989 REVISED AUGUST 19986POST OFFICE BOX 655303 DALLAS, TEXAS 75265APPLICATION INFORMATIONVS+VS26147138C1+C1C2+C213451110129GND150 VVCC165 VEIA-232 OutputEIA-232 OutputEIA-232 InputEIA-232 Input+1 F8.5 V 8.5 V1 F1 F1 FFrom CMOS or TTLTo CMOS or TTLFigure 4. Typical Operating CircuitIMPORTANT NOTICETexas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinueany product or service without notice, and advise customers to obtain the latest version of relevant informationto verify, before placing orders, that information being relied on is current and complete. All products are soldsubject to the terms and conditions of sale supplied at the time of order acknowledgement, including thosepertaining to warranty, patent infringement, and limitation of liability.TI warrants performance of its semiconductor products to the specifications applicable at the time of sale inaccordance with TIs standard warranty. Testing and other quality control techniques are utilized to the extentTI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarilyperformed, except those mandated by government requirements.CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OFDEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICALAPPLICATIONS”). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, ORWARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHERCRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TOBE FULLY AT THE CUSTOMERS RISK.In order to minimize risks associated with the customers applications, adequate design and operatingsafeguards must be provided by the customer to minimize inherent or procedural hazards.TI assumes no liability for applications assistance or customer product design. TI does not warrant or representthat any license, either express or implied, is granted under any patent right, copyright, mask work right, or otherintellectual property right of TI covering or relating to any combination, machine, or process in which suchsemiconductor products or services might be or are used. TIs publication of information regarding any thirdpartys products or services does not constitute TIs approval, warranty or endorsement thereof.Copyright 1998, Texas Instruments IncorporatedFor free samples & the latest literature: , or phone 1-800-998-8800_General DescriptionThe MAX481, MAX483, MAX485, MAX487MAX491, andMAX1487 are low-power transceivers for RS-485 and RS-422 communication. Each part contains one driver and onereceiver. The MAX483, MAX487, MAX488, and MAX489feature reduced slew-rate drivers that minimize EMI andreduce reflections caused by improperly terminated cables,thus allowing error-free data transmission up to 250kbps.The driver slew rates of the MAX481, MAX485, MAX490,MAX491, and MAX1487 are not limited, allowing them totransmit up to 2.5Mbps.These transceivers draw between 120A and 500A ofsupply current when unloaded or fully loaded with disableddrivers. Additionally, the MAX481, MAX483, and MAX487have a low-current shutdown mode in which they consumeonly 0.1A. All parts operate from a single 5V supply.Drivers are short-circuit current limited and are protectedagainst excessive power dissipation by thermal shutdowncircuitry that places the driver outputs into a high-imped-ance state. The receiver input has a fail-safe feature thatguarantees a logic-high output if the input is open circuit.The MAX487 and MAX1487 feature quarter-unit-loadreceiver input impedance, allowing up to 128 MAX487/MAX1487 transceivers on the bus. Full-duplex communi-cations are obtained using the MAX488MAX491, whilethe MAX481, MAX483, MAX485, MAX487, and MAX1487are designed for half-duplex applications._ApplicationsLow-Power RS-485 TransceiversLow-Power RS-422 TransceiversLevel TranslatorsTransceivers for EMI-Sensitive ApplicationsIndustrial-Control Local Area Networks_Featureso In MAX Package: Smallest 8-Pin SOo Slew-Rate Limited for Error-Free DataTransmission (MAX483/487/488/489)o 0.1A Low-Current Shutdown Mode(MAX481/483/487)o Low Quiescent Current:120A (MAX483/487/488/489)230A (MAX1487)300A (MAX481/485/490/491)o -7V to +12V Common-Mode Input Voltage Rangeo Three-State Outputso 30ns Propagation Delays, 5ns Skew (MAX481/485/490/491/1487)o Full-Duplex and Half-Duplex Versions Availableo Operate from a Single 5V Supplyo Allows up to 128 Transceivers on the Bus(MAX487/MAX1487)o Current-Limiting and Thermal Shutdown forDriver Overload Protection_Ordering InformationOrdering Information continued at end of data sheet.* Contact factory for dice specifications.MAX481/MAX483/MAX485/MAX487MAX491/MAX1487Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers_Maxim Integrated Products1MAX481?MAX483?MAX485?MAX487?MAX488?MAX489?MAX490?MAX491?MAX1487PART?NUMBERHALF/FULL?DUPLEXDATA RATE?(Mbps)SLEW-RATE?LIMITEDLOW-POWER?SHUTDOWNRECEIVER/?DRIVER?ENABLEQUIESCENT?CURRENT?(A)NUMBER OF?TRANSMITTERS?ON BUSPIN?COUNTHalf?Half?Half?Half?Full?Full?Full?Full?Half2.5?0.25?2.5?0.25?0.25?0.25?2.5?2.5?2.5No?Yes?No?Yes?Yes?Yes?No?No?NoYes?Yes?No?Yes?No?No?No?No?NoYes?Yes?Yes?Yes?No?Yes?No?Yes?Yes300?120?300?120?120?120?300?300?23032?32?32?128?32?32?32?32?1288?8?8?8?8?14?8?14?8_Selection Table19-0122; Rev 5; 2/96PARTTEMP. RANGEPIN-PACKAGEMAX481CPA0C to +70C8 Plastic DIPMAX481CSA0C to +70C8 SOMAX481CUA0C to +70C8 MAXMAX481C/D0C to +70CDice*MAX481/MAX483/MAX485/MAX487MAX491/MAX1487Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers2_ABSOLUTE MAXIMUM RATINGSSupply Voltage (VCC).12VControl Input Voltage (RE, DE).-0.5V to (VCC+ 0.5V)Driver Input Voltage (DI).-0.5V to (VCC+ 0.5V)Driver Output Voltage (A, B).-8V to +12.5VReceiver Input Voltage (A, B).-8V to +12.5VReceiver Output Voltage (RO).-0.5V to (VCC+0.5V)Continuous Power Dissipation (TA= +70C)8-Pin Plastic DIP (derate 9.09mW/C above +70C) .727mW14-Pin Plastic DIP (derate 10.00mW/C above +70C).800mW8-Pin SO (derate 5.88mW/C above +70C).471mW14-Pin SO (derate 8.33mW/C above +70C).667mW8-Pin MAX (derate 4.1mW/C above +70C).830mW8-Pin CERDIP (derate 8.00mW/C above +70C).640mW14-Pin CERDIP (derate 9.09mW/C above +70C).727mWOperating Temperature RangesMAX4_ _C_ _/MAX1487C_ A .0C to +70CMAX4_ _E_ _/MAX1487E_ A.-40C to +85CMAX4_ _MJ_/MAX1487MJA .-55C to +125CStorage Temperature Range.-65C to +160CLead Temperature (soldering, 10sec).+300CDC ELECTRICAL CHARACTERISTICS(VCC= 5V 5%, TA= TMINto TMAX, unless otherwise noted.) (Notes 1, 2)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functionaloperation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure toabsolute maximum rating conditions for extended periods may affect device reliability.VVIN= -7VVIN= 12VVIN= -7VVIN= 12VInput Current(A, B)IIN2VTHk48-7V VCM 12V, MAX487/MAX1487RINReceiver Input Resistance-7V VCM 12V, all devices exceptMAX487/MAX1487R = 27 (RS-485), Figure 40.4V VO 2.4VR = 50 (RS-422)IO = 4mA, VID= -200mVIO= -4mA, VID= 200mVVCM= 0V-7V VCM 12VDE, DI, REDE, DI, REMAX487/MAX1487, DE = 0V, VCC= 0V or 5.25VDE, DI, RER = 27 or 50, Figure 4R = 27 or 50, Figure 4R = 27 or 50, Figure 4DE = 0V;VCC= 0V or 5.25V,all devices exceptMAX487/MAX1487CONDITIONSk12A1IOZRThree-State (high impedance)Output Current at ReceiverV0.4VOLReceiver Output Low Voltage3.5VOHReceiver Output High VoltagemV70VTHReceiver Input HysteresisV-0.20.2Receiver Differential ThresholdVoltage-0.2mA0.25mA-0.81.01.55VOD2Differential Driver Output(with load)V2V5VOD1Differential Driver Output (no load)A2IIN1Input CurrentV0.8VILInput Low VoltageV2.0VIHInput High VoltageV0.2VODChange in Magnitude of DriverCommon-Mode Output Voltagefor Complementary Output StatesV0.2VODChange in Magnitude of DriverDifferential Output Voltage forComplementary Output StatesV3VOCDriver Common-Mode OutputVoltageUNITSMINTYPMAXSYMBOLPARAMETERMAX481/MAX483/MAX485/MAX487MAX491/MAX1487Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers_3SWITCHING CHARACTERISTICSMAX481/MAX485, MAX490/MAX491, MAX1487(VCC= 5V 5%, TA= TMINto TMAX, unless otherwise noted.) (Notes 1, 2)DC ELECTRICAL CHARACTERISTICS (continued)(VCC= 5V 5%, TA= TMINto TMAX, unless otherwise noted.) (Notes 1, 2)mA7950V VO VCCIOSRReceiver Short-Circuit CurrentmA35250-7V VO12V (Note 4)IOSD2Driver Short-Circuit Current,VO= LowmA35250-7V VO12V (Note 4)IOSD1Driver Short-Circuit Current,VO= HighMAX1487,RE= 0V or VCC250400350650ns103060tPHLDriver Rise or Fall TimeFigures 6 and 8, RDIFF= 54, CL1= CL2= 100pFnsMAX490M, MAX491MMAX490C/E, MAX491C/E2090150MAX481, MAX485, MAX1487MAX490M, MAX491MMAX490C/E, MAX491C/EMAX481, MAX485, MAX1487Figures 6 and 8, RDIFF= 54,CL1= CL2= 100pFMAX481 (Note 5)Figures 5 and 11, CRL= 15pF, S2 closedFigures 5 and 11, CRL= 15pF, S1 closedFigures 5 and 11, CRL= 15pF, S2 closedFigures 5 and 11, CRL= 15pF, S1 closedFigures 6 and 10, RDIFF= 54,CL1= CL2= 100pFFigures 6 and 8,RDIFF= 54,CL1= CL2= 100pFFigures 6 and 10,RDIFF= 54,CL1= CL2= 100pFCONDITIONSns510tSKEWns50200600tSHDNTime to ShutdownMbps2.5fMAXMaximum Data Ratens2050tHZReceiver Disable Time from Highns103060tPLH2050tLZReceiver Disable Time from Lowns2050tZHDriver Input to OutputReceiver Enable to Output Highns2050tZLReceiver Enable to Output Low2090200nsns134070tHZtSKDDriver Disable Time from High|tPLH- tPHL|DifferentialReceiver Skewns4070tLZDriver Disable Time from Lowns4070tZLDriver Enable to Output Low31540ns51525ns31540tR, tF2090200Driver Output Skew to OutputtPLH, tPHLReceiver Input to Output4070tZHDriver Enable to Output HighUNITSMINTYPMAXSYMBOLPARAMETERCONDITIONSUNITSMINTYPMAXSYMBOLPARAMETER230400300500MAX481/MAX485,RE= 0V or VCC500900MAX490/MAX491,DE, DI, RE= 0V or VCC300500MAX488/MAX489,DE, DI, RE= 0V or VCC120250DE = VCC300500DE = 0VDE = VCCDE = 0VAMAX481/483/487, DE = 0V, RE= VCC0.110ISHDNSupply Current in Shutdown 120250ICCNo-Load Supply Current(Note 3)DE = 5VDE = 0VMAX483MAX487MAX483/MAX487,RE= 0V or VCCFigures 7 and 9, CL= 100pF, S2 closedFigures 7 and 9, CL= 100pF, S1 closedFigures 7 and 9, CL= 15pF, S1 closedFigures 7 and 9, CL= 15pF, S2 closedAMAX481/MAX483/MAX485/MAX487MAX491/MAX1487Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers4_SWITCHING CHARACTERISTICSMAX483, MAX487/MAX488/MAX489(VCC= 5V 5%, TA= TMINto TMAX, unless otherwise noted.) (Notes 1, 2)SWITCHING CHARACTERISTICSMAX481/MAX485, MAX490/MAX491, MAX1487 (continued)(VCC= 5V 5%, TA= TMINto TMAX, unless otherwise noted.) (Notes 1, 2)3001000Figures 7 and 9, CL= 100pF, S2 closedFigures 7 and 9, CL= 100pF, S1 closedFigures 5 and 11, CL= 15pF, S2 closed,A - B = 2VCONDITIONSns40100tZH(SHDN)Driver Enable from Shutdown toOutput High (MAX481)nsFigures 5 and 11, CL= 15pF, S1 closed,B - A = 2VtZL(SHDN)Receiver Enable from Shutdownto Output Low (MAX481)ns40100tZL(SHDN)Driver Enable from Shutdown toOutput Low (MAX481)ns3001000tZH(SHDN)Receiver Enable from Shutdownto Output High (MAX481)UNITSMINTYPMAXSYMBOLPARAMETERtPLHtSKEWFigures 6 and 8, RDIFF= 54,CL1= CL2= 100pFtPHLFigures 6 and 8, RDIFF= 54,CL1= CL2= 100pFDriver Input to OutputDriver Output Skew to Outputns100800nsns2000MAX483/MAX487, Figures 7 and 9,CL= 100pF, S2 closedtZH(SHDN)Driver Enable from Shutdown toOutput High 2502000ns2500MAX483/MAX487, Figures 5 and 11,CL= 15pF, S1 closedtZL(SHDN)Receiver Enable from Shutdownto Output Low ns2500MAX483/MAX487, Figures 5 and 11,CL= 15pF, S2 closedtZH(SHDN)Receiver Enable from Shutdownto Output High ns2000MAX483/MAX487, Figures 7 and 9,CL= 100pF, S1 closedtZL(SHDN)Driver Enable from Shutdown toOutput Low ns50200600MAX483/MAX487 (Note 5) tSHDNTime to Shutdown tPHLtPLH, tPHL B by 200mV, RO will be high;If A +0.2V? -0.2V?Inputs open?X1?0?1?High-Z*X = Dont care?High-Z = High impedance?* Shutdown mode for MAX481/MAX483/MAX487INPUTSOUTPUTSREDEDIZYX?X?0?11?1?0?01?0?X?X0?1?High-Z?High-Z*1?0?High-Z?High-Z*X = Dont care?High-Z = High impedance?* Shutdown mode for MAX481/MAX483/MAX487Low-Power Shutdown Mode(MAX481/MAX483/MAX487)A low-power shutdown mode is initiated by bringingboth REhigh and DE low. The devices will not shutdown unless both the driver and receiver are disabled.In shutdown, the devices typically draw only 0.1A ofsupply current.REand DE may be driven simultaneously; the parts areguaranteed not to enter shutdown if REis high and DEis low for less than 50ns. If the inputs are in this statefor at least 600ns, the parts are guaranteed to entershutdown.For the MAX481, MAX483, and MAX487, the tZHandtZLenable times assume the part was not in the low-power shutdown state (the MAX485/MAX488MAX491and MAX1487 can not be shut down). The tZH(SHDN)and tZL(SHDN)enable times assume the parts were shutdown (see Electrical Characteristics).It takes the drivers and receivers longer to becomeenabled from the low-power shutdown state(tZH(SHDN), tZL(SHDN) than from the operating mode(tZH, tZL). (The parts are in operating mode if the RE,DE inputs equal a logical 0,1 or 1,1 or 0, 0.)Driver Output Protection Excessive output current and power dissipation causedby faults or by bus contention are prevented by twomechanisms. A foldback current limit on the outputstage provides immediate protection against short cir-cuits over the whole common-mode voltage range (seeTypical Operating Characteristics). In addition, a ther-mal shutdown circuit forces the driver outputs into ahigh-impedance state if the die temperature risesexcessively.Propagation DelayMany digital encoding schemes depend on the differ-ence between the driver and receiver propagationdelay times. Typical propagation delays are shown inFigures 1518 using Figure 14s test circuit.The difference in receiver delay times, | tPLH- tPHL|, istypically under 13ns for the MAX481, MAX485,MAX490, MAX491, and MAX1487 and is typically lessthan 100ns for the MAX483 and MAX487MAX489.The driver skew times are typically 5ns (10ns max) forthe MAX481, MAX485, MAX490, MAX491, andMAX1487, and are typically 100ns (800ns max) for theMAX483 and MAX487MAX489.MAX481/MAX483/MAX485/MAX487MAX491/MAX1487Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers_1110dB/div0Hz5MHz500kHz/div10dB/div0Hz5MHz500kHz/divFigure 12. Driver Output Waveform and FFT Plot of MAX481/MAX485/MAX490/MAX491/MAX1487 Transmitting a 150kHzSignalFigure 13. Driver Output Waveform and FFT Plot of MAX483/MAX487MAX489 Transmitting a 150kHz SignalMAX481/MAX483/MAX485/MAX487MAX491/MAX1487Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers12_TTL IN?tR, tF 6nsDR100pFB100pFARECEIVER?OUTR = 54ZY500mV/div20ns/divABRO2V/divVCC = 5V?TA = +25C500mV/div20ns/divABRO2V/divVCC = 5V?TA = +25C500mV/div400ns/divABRO2V/divVCC = 5V?TA = +25C500mV/div400ns/divABRO2V/divVCC = 5V?TA = +25CFigure 14. Receiver Propagation Delay Test CircuitFigure 15. MAX481/MAX485/MAX490/MAX491/MAX1487Receiver tPHLFigure 16. MAX481/MAX485/MAX490/MAX491/MAX1487Receiver tPLHFigure 17. MAX483, MAX487MAX489 Receiver tPHLFigure 18. MAX483, MAX487MAX489 Receiver tPLHLine Length vs. Data RateThe RS-485/RS-422 standard covers line lengths up to4000 feet. For line lengths greater than 4000 feet, seeFigure 23.Figures 19 and 20 show the system differential voltagefor the parts driving 4000 feet of 26AWG twisted-pairwire at 110kHz into 120 loads.Typical ApplicationsThe MAX481, MAX483, MAX485, MAX487MAX491, andMAX1487 transceivers are designed for bidirectional datacommunications on multipoint bus transmission lines.Figures 21 and 22 show typical network applicationscircuits. These parts can also be used as linerepeaters, with cable lengths longer than 4000 feet, asshown in Figure 23.To minimize reflections, the line should be terminated atboth ends in its characteristic impedance, and stublengths off the main line should be kept as short as possi-ble. The slew-rate-limited MAX483 and MAX487MAX489are more tolerant of imperfect termination.MAX481/MAX483/MAX485/MAX487MAX491/MAX1487Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers_13DIVY-VZRO5V0V1V0V-1V5V0V2s/divDIVY-VZRO5V0V1V0V-1V5V0V2s/divDIRODEREABRERERERORORODIDIDIDEDEDEDDDRRRBBBAAA120120DRMAX481?MAX483?MAX485?MAX487?MAX1487Figure 19. MAX481/MAX485/MAX490/MAX491/MAX1487System Differential Voltage at 110kHz Driving 4000ft of CableFigure 20. MAX483, MAX487MAX489 System DifferentialVoltage at 110kHz Driving 4000ft of CableFigure 21. MAX481/MAX483/MAX485/MAX487/MAX1487 Typical Half-Duplex RS-485 NetworkMAX481/MAX483/MAX485/MAX487MAX491/MAX1487Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers14_Figure 22. MAX488MAX491 Full-Duplex RS-485 Network120120RDROREDEDIABY120120DIDIDIRORORODEDEDEREREREZZZZYYYAAABBBDDDRRRMAX488?MAX489?MAX490?MAX491NOTE: RE AND DE ON MAX489/MAX491 ONLY.Figure 23. Line Repeater for MAX488MAX491120120DATA INDATA OUTRDROREDEDIABZYMAX488MAX491NOTE: RE AND DE ON MAX489/MAX491 ONLY.Isolated RS-485For isolated RS-485 applications, see the MAX253 andMAX1480 data sheets.MAX481/MAX483/MAX485/MAX487MAX491/MAX1487Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers_15_Ordering Information (continued)_Chip TopographiesMAX481/MAX483/MAX485/MAX487/MAX1487N.C. RO0.054?(1.372mm)0.080?(2.03