19-0410; Rev 0; 6/95 MAAILAA +15kV ESD-Protected, Slew-Rate-Limited, Low-Power, General Description The MAX481E, MAX483E, MAX485E, MAX487E-MAX491E, and MAX1487E are low-power transceivers for RS-485 and RS-422 communications in harsh environments. Each driver output and receiver input is protected against + 15kV electro- static discharge (ESD) shocks, without latchup. These parts contain one driver and one receiver. The MAX483E, MAX487E, MAX488E, and MAX489E feature reduced slew- rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, thus allowing error-free data transmission up to 250kbps. The driver slew rates of the MAX481E, MAX485E, MAX490E, MAX491E, and MAX1487E are not limited, allowing them to transmit up to 2.5Mbps. These transceivers draw as little as 120UA supply current when unloaded or when fully loaded with disabled drivers (see Selection Table). Additionally, the MAX481E, MAX483E, and MAX487E have a Jow-current shutdown mode in which they consume only 0.1pA. All parts operate from a single +5V supply. Drivers are short-circuit current limited, and are protected against excessive power dissipation by thermal shutdown circuitry that places their outputs into a high-impedance state. The receiver input has a fail-safe feature that guaran- tees a logic-high output if the input is open circuit. The MAX487E and MAX1487E feature quarter-unit-load receiver input impedance, allowing up to 128 transceivers on the bus. The MAX488E-MAX491E are designed for full- duplex communications, while the MAX481, MAX483E, MAX485E, MAX487E, and MAX1487E are designed for half- duplex applications. For applications in a less demanding environment, see the pin- and function-compatible MAX481, MAX483, MAX485, MAX487-MAX491, and MAX1487. Applications Low-Power RS-485 Transceivers Low-Power RS-422 Transceivers Level Translators Transceivers for EMl-Sensitive Applications Industrial-Control Local Area Networks RS-485/RS-422 Transceivers Features ESD Protection: +15kVHuman Body Model Available in MAX Package (the smallest 8-pin SO) Slew-Rate Limited for Error-Free Data Transmission (MAX483E/487E/488E/489E) # Low Quiescent Current: 120A (MAX483E/487E/488E/489E) 230pA (MAX1487E) 300pA (MAX481E/485E/490E/491E) @ -7V to +12V Common-Mode Input Voltage Range Three-State Outputs 30ns Propagation Delays, 5ns Skew (MAX481E/485E/490E/491E/1 487E) @ Full-Duplex and Half-Duplex Versions Available Allows up to 128 Transceivers on the Bus (MAX487E/MAX1487E) @ Current Limiting and Thermal Shutdown for Driver Overload Protection * Ordering Information PART TEMP.RANGE _ PIN-PACKAGE MAX481ECPA OC to +70C 8 Plastic DIP MAX481ECSA . O to +70C 8S0 MAX481ECUA 0C to +70C 8 UMAX MAX481EEPA -40C to +85C 8 Plastic DIP MAX481EESA -40C to +85C 8SO Ordering Information continued on last page. Selection Table PART HALF/FULL | DATA RATE | SLEW-RATE | LOW-POWER ao RIVER CUnEENY Thy ASM TTERS PIN NUMBER DUPLEX (Mbps) LIMITED | SHUTDOWN | enapiE (uA) ON BUS COUNT MAX481E Half 25 No Yes Yes 300 32 8 MAX483E Half 0.25 Yes Yes Yes 420 32 8 MAX485E Half 25 No No Yes 300 32 8 MAX487E Half 0.25 Yes Yas Yes 120 128 8 MAX488E Full 0.25 Yes No No 420 32 8 MAX489E Fun 025. Yes No Yes 120 32 14 MAX490E Ful 25 No No No 300 32 8 MAX491E Full 25 No No Yes 300 32 14 MAX1487E Half 25 No No Yes 230 128 8 MA AXIAA Maxim Integrated Products 2-19 Call toll free 1-800-998-8800 for free samples or literature. AL8VLXVIW/3 1 6PXVW-AL8PXVW/AS8YXVW/ACSEXUW/ALSexXUNMAX481 E/MAX483E/MAX485E/MAX487E-MAX491 E/MAX1487E +15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers ABSOLUTE MAXIMUM RATINGS Supply Voltage (VOC) 0... ec cect c teeter teeter 12v 8-Pin SO (derate 5.88MW/C above +70C)......0.. 471mW Control Input Voltage (RE, DE) . ..-0.5V to (Voc + 0.5V) 14-Pin SO (derate 8. 33mMW/C above +70C) 00. 667mW Driver input Voltage (DI)....... -0.5V to (Vcc + 0.5V) 8-Pin uMAX (derate 4. 1mMW/C above +70C) ........... 830mWw Driver Output Voltage (A,B)... eee -8V to +12.5V Operating Temperature Ranges Receiver Input Voltage (A, B).. cn BV to 412.5V MAX4_ C_ _/MAX1487EC_A Le OC ta +70C Receiver Output Voltage (RO)....................-0.5V to (Vcc + 0.5V) MAX4__E_ _/MAX1487EE_A. . 40C to +85C Continuous Power Dissipation (Ta = +70C} Storage Temperature Range 65C to + 160C 8-Pin Plastic DIP (derate 9.09mW/C above +70C)....727mMW Lead Temperature (soldering, 108C) ........ ce +300C 14-Pin Plastic DIP (derate 10.00mW/C above +70C) ..800mW Stresses beyond those listed under Absolute Maximum Ratings may Cause permanent damage lo the device. These are stress ralings only, and functional operation of the device al these or any other conditions beyond those indicated in the operational sections of the specifications 1s not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability DC ELECTRICAL CHARACTERISTICS (Vcc = 5V 5%, Ta = TMIN to TMAx, unless otherwise noted.) (Notes 1, 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX | UNITS Differential Driver Output (no load) Voo1 5 Vv Differential Driver Output Vooe R = SOQ (RS-422) 2 V (with toad) R = 27Q (RS-485), Figure 8 1.5 5 Change in Magnitude of Driver Ditferential Output Voltage for AVoD R = 279 or 50Q, Figure 8 02 Vv Compiementary Output States Driver Common-Mode Ouiput Voltage . Voc R = 27Q or 508, Figure 8 3 Vv Change in Magnitude of Driver Common-Mode Output Voltage AVOD R = 27Q or 5082, Figure 8 02 v for Complementary Output States Input High Voltage VIH DE, Di, RE 2.0 v Input Low Voltage Vit DE, Di, RE 0.8 v Input Current Hint DE, DI, RE +2 uA DE = OV. = 1. Voc = OV or .25V, Vin = 12V 0 mA Input Current all devices except _- ; 8} lina | MAX487E/MAX1487E Vin = -V 0.8 MAX487E/MAX 1487E, Vin = 12V 0.25 mA DE = OV, Vcc = OVor 5.25V | Vin = -7V -0.2 Receiver Differential Threshold Voltage Vin | -7VSVoms 12V 0.2 da Vv Receiver Input Hysteresis AVTH Vom = OV 70 mv Receiver Output High Voltage VoH lo = -4AMA, Vio = 200mV 3.5 Vv Receiver Output Low Vaitage VoL lo = 4mA, Vip = -200mV 0.4 Vv Three-State (high impedance) Output Current at Receiver lozR 0.4V s Vo s 2.4V +1 yA -7V $ Vom 12V, all devices except 12 kg MAX487E/MAX 1487E Receiver Input Resistance Rin - -7V < Vom $ 12V, MAX487E/MAX1487E 48 kg? 2-20 MAXUM+15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers DC ELECTRICAL CHARACTERISTICS (continued) (Vcc = 5V +5%, Ta = TIN to TMAX, unless otherwise noted.) (Notes 1,.2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX | UNITS MAX488E/MAX489E, DE, Di, RE = 0V or Voc 120-280 MAX490E/MAX491E, DE, Di, RE = OV or Vec 300500 No-Load Supply Current MAXABTE/MAXABSE. DE = Voc 500 900 (Note 3) pe lec | RE = OVor Voc DE =0V 300. 500 | pA MAX1487E, DE = Voc 300500 RE = OV or Vec DE = OV 230 400 MAX483E 350 650 MAX483E/MAX487E, | DE = Vcc RE = 0VorVcc MAX487E 250 400 DE = OV 120 250 Supply Current in Shutdown ISHDN MAX481E/483E/487E, DE = OV, RE = Vcc 0.1 10 HA Driver Short-Circuit Current, Vo = High loso1 -7V = Vo <12V (Note 4) 35 250 mA Driver Short-Circuit Current, Vo = Low losp2 -#V Vo $12V (Note 4) 35 250 mA Receiver Short-Circuit Current losr OV<Vo<Vec 7 95 mA ESD Protection A,B, Y and Z pins, tested using Human Body Model 15 kV SWITCHING CHARACTERISTICSMAX481E/MAX485E, MAX490E/MAX491E, MAX1487E (Vcc = 5V +5%, Ta = TMIN to Tmax, unless otherwise noted.) (Notes 1, 2) MAAXLAA PARAMETER SYMBOL CONDITIONS MIN TYP MAX | UNITS . tPLH Figures 10 and 12, Roirr = 54Q, 10 60 Driver Input to Output PHL Cut = CL2 = 100pF 10 50 ns Driver Output Skew to Output tskEw | Figures 10 and 12, Roire = 54Q. CL1 = C2 = 100pF 10 ns Figures 10 and 12,} MAX481E, MAX485E, MAX1487E 3 40 Driver Rise or Fall Time tr, te Roire = 54Q, ns Ci1 = CL2 = 100pF| MAX490EC/E, MAX491EC/E 5 25 Driver Enable to Output High 12H Figures 11 and 13, CL = 100pF, $2 clased 70 ns Driver Enable to Output Low tZL Figures 11 and 13, CL = 100pF, S1 closed 70 ns Driver Disable Time from Low tz Figures 11 and 13, Cy = 15pF, S1 closed 70 ns Driver Disable Time from High tHzZ Figures 11 and 13, CL = 15pF, S2 closed 70 ns Figures 10 and 14.) MAX481E, MAX485E, MAX1487El 20 60 200 Receiver Input to Qutput tPLH, fPHL | Roier = 54Q, - ns C1 = C2 = 100pF] MAX490EC/E, MAX491 EC/E 20 60 150 bpp H > PPHL | Differential tp | Figures 10 and 14, Roire = 549, P ns Receiver Skew Cus = Cia = 100pF Receiver Enable to Outout Low {ZL Figures 9 and 15, Ca = 15pF, S1 closed 20 50 ns Receiver Enable to Output High ZH Figures 9 and 15, Cat = 15pF, $2 closed 20 50 ns Receiver Disable Time from Low Lz Figures 9 and 15, Cat = 15pF, $1 closed 20 50 ns Receiver Disable Time from High tHz Figures 9 and 15, Car = 15pF, S2 closed 20 50 ns Maximum Data Rate IMAX 25 Mbps Time to Shutdown tsHDN =| MAX481 (Note 5) 50 200 600 ns 2-21 ALS lL XVW/Al6PXVN-AL8PX VA/ASBPXUW/ACEPXVW/ALSPXUWNMAX48 1 E/MAX483E/MAX485E/MAX487E-MAX491 E/MAX1487E +15kV ESD-Protected, Siew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers SWITCHING CHARACTERISTICSMAX481E/MAX485E, MAX490E/MAX491E, MAX1487E (continued) (Vec = 5V +5%, Ta = TMIN to Tmax, unless otherwise noted.) (Notes 1, 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX | UNITS Driver Enable from Shutdown to | . _ Output High (MAX481E) (ZH(SHDN) | Figures 1t and 13, CL = 100pF, S2 closed 100 ns Driver Enable from Shutdown to Output Low (MAX48 1) tZL(SHDN) | Figures 11 and 13, CL = 100pF, S1 closed 100 ns Receiver Enable from Shutdown Figures 9 and 15, CL = 15pF, $2 closed, to Output High (MAX481E) IZH(SHON) | ag = 2V 1000 | ns Receiver Enable from Shutdown t Figures 9 and 15, Ci = 15pF, S1 closed, 1000 to Output Low (MAX481E) 2ZUSHON) | Ba = 2V ns SWITCHING CHARACTERISTICS-MAX483E, MAX487E/MAX488E/MAX489E (Voc = 5V +5%. Ta = TMIN to Tmax, unless otherwise noted.) (Notes 1, 2} PARAMETER SYMBOL CONDITIONS MIN TYP MAX | UNITS IPLH Figures 10 and 12, RoiFr = 54Q, 250 2000 Onver input to Output PHL Cut = CL = 100pF 250 2000 ns Figures 10 and 12, RpIFF = 5422, Driver Output Skew to Output ISKEW CLt = Cle = 100pF 800 ns - . Figures 10 and 12, Roire = 54Q, Driver Rise or Fall Time tA, IF Cut = CL2 = 100pF 250 2000 ns Driver Enable to Output High {ZH Figures 11 and 13, CL = 100pF, S2 closed 250 2000 ns Driver Enable to Output Low {ZL Figures 11 and 13, CL = 100pF, S1 closed 250 2000 ns Driver Disable Time from Low Lz Figures 11 and 13, Cy = 15pF, S1 clased 300 3000 ns Driver Disable Time from High tHz Figures 11 and 13, C, = 15pF, S2 closed 300 3000 ns 'PLH_ | Figures 10 and 14, Rolfe = 5492 250 2000 R Input t t . : eceiver Input to Outpu TPuL Cut = Cie = 100pE 350 3000 ns I tpuH - tee | Differential Figures 10 and 14, RoiFF = 549 t : , 100 Receiver Skew SkD Ci1 = Cia = 100pF ns Receiver Enable to Qutput Low {27 Figures 9 and 15, Cat = 15pF, S1 closed 50 ns Receiver Enable to Output High WH Figures 9 and 15, Ca_ = 15pF, S2 closed 50 ns Receiver Disable Time from Low tLz Figures 9 and 15. Cri = 15pF, $1 closed 50 ns Receiver Disable Time from High HZ Figures 9 and 15, Cri = 15pF, S2 closed 50 ns Maximum Data Rate {MAX tPLH, tPHL < 50% of data period 250 kbps Time to Shutdown tSHDN MAX483E/MAX487E (Note 5) 50 600 ns Driver Enable from Shutdown to ' MAX483E/MAX487E, Figures 11 and 13, 000 ns Output High ZH(SHDN}| Cc = 100pF, $2 closed Driver Enable fram Shutdown to \ MAX483E/MAX487E, Figures 11 and 13, 2000 ns Output Low ZL(SHDN) CL = 100pF, St closed Receiver Enable from Shutdown MAX483E/MAX487E, Figures 9 and 15, to Output High ZH{SHON) CL = 15pF, S2 closed 2500 ns Receiver Enable from Shutdown ZL(SHON) MAX483E/MAX487E, Figures 9 and 15, 2500 ns to Output Low CL = 15pF, S1 closed 2-22 MAXIMA+15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers NOTES FOR ELECTRICAL/SWITCHING CHARACTERISTICS Note 1: All currents into device pins are positive, all currents out of device pins are negative. All vollages are referenced to device ground unless otherwise specified Note 2: All typical specifications are given for Vcc = 5V and Ta = +25'"C Note 3: Supply current specification is valid for loaded transmitters when DE = OV Note 4: Applies to peak current See Typical Operating Characteristics Note : The MAX48 1E/MAX483E/MAX487E are put into shutdown by bringing RE high and DE tow. If the inputs are in this state for less than 5Ons, the parts are guaranteed not to enter shutdowr: If the inputs are in this state for at least GOOns, the parts are guaranteed to nave entered shutdown, See Low-Power Shutdown Mode section, Pin Description PIN MAX481E/MAX483E MAX488E MAX489E NAME FUNCTION MAX485E/MAX487E MAX490E MAX491E MAX1487E DIP/SO uMAX DIP/SO BMAX DIP/SO RO Receiver Output If A > B by 200mV, RO wiil be high. ' 3 2 4 2 IfA < B by 200mvV, RO will be low 5 4 3 aE Receiver Oulput Enable RO is enabled when RE is . 7 i . iow; RO 1s high impedance when RE is high. Driver Output Enable. The driver outputs, Y and Z, are enabled by bringing DE high. They are high imped- 3 5 - _ 4 DE ance when DE is low If the driver outputs are enabled, the parts function as line drivers. While they are high impedance, they function as line receivers if RE is low Driver Input. A low on DI forces output Y low and out- 4 6 3 5 5 DI put Z high. Similarly, a high on DI forces output Y high and autput Z low 5 7 4 6,7 GND Ground - - 5 9 Y Noninverting Driver Output _ 6 10 Zz Inventing Driver Output . Noninverting Receiver Input and Noninverting Driver 6 & _ _ A oO utput _ 8 2 12 A Noninverting Receiver Input 7 1 _ _ _ B Inverting Recewer Inputand Inverting Driver Output _ 7 1 W B Inverting Receiver Input is} 2 | 3 14 Vec Pasitive Supply: 4 75V < Vcc $ & 25V _ _ _ _ 1,8, 13 N.C No Connectnat internally connected MAAXIAMA 2-23 FZ8v1XVW/4L6VXVW-3L8PXVW/ASSPXVUW/ACSPXVA/ALSePXVNMAX48 1 E/MAX483E/MAX485E/MAX487E-MAX491 E/MAX1487E +15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers TOP VIEW a ao [1 a] vex MAXIM _ | MAX4B IE RE [2 7 | B = WWF MAXARIE | oe oe [3 | Ta, - MAXAB5E e MAX487E bl oi [4] [5] uno ro [1] ae 8} Vec MAX1487E jor =~ 7,8 B at [2] Rt , Rt DIP/SO oe FH Lia jeeee ing ! 4 RO bi L4 5 Ly ax [2] * o 5 ono _ Veo [2] maxdare = [7] ono = iz (3) iraxaase | [e} _ NOTE PIN LABELS Y AND Z ON TIMING, TEST, AND WAVEFORM DIAGRAMS REFER TO PINS A AND 6 WHEN DE 1S HIGH Re [4] MAx487E 5) oe TYPICAL OPERATING CIRCUIT SHOWN WITH DIP/SO PACKAGE MAX1487E MAX Figure 1 MAX48 1E/MAX483E/MAX485E/MAX 1487E Pin Configuration and Typical Operating Circuit TOP VIEW s clone ) e CC veo 1] <f raya Zs MAAXIM t Vee | = MAX4BBE l ro [2 | Ly] 8 MAX490E of] {6]2 5 3 aw [a] ls rely 14 - IS. n, = DIP/SO . ~ BA a wt nee LY maxim bE)? [om AL2] maxasee = [2] 8 vee [a] MAXAIOE FE wo mG } Ro [| rs | 01 ae = GND uMAX NOTE TYPICAL OPERATING CIRCUIT SHOWN WITH DIP/SO PACKAGE Figure 2. MAX488E/MAX490E Pin Configuration and Typical Operating Circuit Vec DE Veo RE OP VIEW [4 ia shows MAXIMA |_| 7 - MAX4B9E nc G] 4) ves sy MAX49IE ro [2 lia] Nc 3 i WO Al Lag re [3 | fia] a 7 oe [4] ii}e 1204 DI LS 10} Z 2 Eh jsfa ibm DOO He ono [6 | lo Jy 8 cno [7] junc Nc 813) TTT DIP/SO ke = GND DE Figure 3. MAX489E/MAX49 IE Pin Configuration and Typical Operating Circuit 2-24+15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers Function Tables (MAX481 E/MAX483E/MAX485E/MAX487E/MAX1487E) Table 1. Transmitting INPUTS OUTPUTS RE DE DI Zz Y x 1 1 0 1 x 1 0 1 0 0 0 x High-Z High-Z 1 0 x High-Z* High-Z* L X = Don't care High-Z = High impedance * Shutdown mode for MAX481E/MAX483E/MAX487E Applications Information The MAX481E/MAX483E/MAX485E/MAX487E-MAX491E and MAX1487E are low-power transceivers for RS-485 and RS-422 communications. These E versions of the MAX481, MAX483, MAX485, MAX487-MAX491, and MAX1487 provide extra protection against ESD. The rugged MAX481E, MAX483E, MAX485E, MAX497E- MAX491E, and MAX1487E are intended for harsh envi- ronments where high-speed communication is important. These devices eliminate the need for transient suppres- sor diodes and the associated high capacitance loading. The standard (non-"E") MAX481, MAX483, MAX485, MAX487-MAX491, and MAX1487 are recommended for applications where cost is critical. The MAX481E, MAX485E, MAX490E, MAX491E, and MAX1487E can transmit and receive at dala rates up to 2.5Mbps, while the MAX483E, MAX487E, MAX488E, and MAX48GE are specified for data rates up to 250kbps. The MAX488E-MAX491E are full-duplex transceivers, while the MAX481E, MAX483E, MAX487E, and MAX1487E are half-duplex. In-addition, driver enable (DE) and receiver enable (RE) pins are included on the MAX481E. MAX483E, MAX485E, MAX487E, MAX489E, MAX491E, and MAX1487E. When disabled, the driver and receiver outputs are high impedance. +15kV ESD Protection As with all Maxim devices, ESD-protection structures are incorporated on all pins to protect against electro- static discharges encountered during handling and assembly. The driver outputs and receiver inpuls have extra protection against static electricity. Maxim's engi- MA AXIMA Table 2. Receiving (INPUTS OUTPUT RE DE AB AO 0 0 > +02V 1 0 0 < -0.2V 0 0 0 Inputs open { 1 0 x High-2* X = Don't care High-Z = High impedance * Shutdown mode for MAX48 1E/MAX483E/MAX487E neers developed state-of-the-art structures to protect these pins against ESD of +15kV without damage. The ESD structures withstand high ESD in ali states: normal operation, shutdown, and powered down. After an ESD event, Maxim's MAX481E, MAX483E, MAX485E, MAX487E-MAX491E, and MAX1487E keep working without latchup. ESD protection can be tested in various ways; the transmitter outputs and receiver inputs of this product family are characterized for protection to +15kV using the Human Body Model. Other ESD test methodologies include IEC 10004-2 con- tact discharge and IEC 1000-4-2 air-gap discharge (for- merly 1EC801-2). ESD Test Conditions ESD performance depends on a variety of conditions. Contact Maxim for a reliability report that documents test set-up, test methodology, and test results. Human Body Model Figure 4 shows the Human Body Model. and Figure 5 shows the current waveform it generates when dis- charged into a low impedance. This model consists of a 100pF capacitor charged to the ESD voltage of inter- est, which is then discharged into the test device through a 1.5kQ resistor. 1EC1000-4-2 The IEC 1000-4-2 standard covers ESD testing and per- formance of finished equipment: tt does not specifically refer to integrated circuits (Figure 6). 2-25 3L8P LXVW/ALGYXVN-ALEPXVW/ASEPXVW/SACSPXVW/ALSeXUW+15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers Ry 1M Re 150082 AN o CHARGE CURRENT DISCHARGE LIMIT RESISTOR RESISTANCE HIGH DEVICE VOLTAGE Cs L STORAGE UNDER oc 1OOpF PF CAPACITOR TEST SOURCE Ip 100% lr PEAK-TO-PEAK RINGING 90% | } (NOT DRAWN TO SCALE) AMPERES 36 8% 10% JR i 6 0 th TIME a ft I CURRENT WAVEFORM Figure 4. Hurnarn Body ESD Test Mode! Figure 5. Human Body Model Current Wavetorm R: SOM10 100M Rn 3302 _\\\0 o- CHARGE CURRENT DISCHARGE LIMIT RESISTOR RESISTANCE HIGH- we) DEVICE VOLTAGE Gg t- STORAGE UNDER ne 15OpF 77 CAPACITOR TEST SOURCE lg WO0%p -4------}--------}-----.- 50% } - = 10% FE t) = 0 ?ns to 1ns tm} tg t 30ns <q G0ns _4 Figure 6. IEC 1000-4-2 ESD Test Model Figure 7. 1EC1000-4-2 ESD Generator Current Waveform C RECEIVER TEST POINT OUTPUT Cu + spe | MAX481 E/MAX483E/MAX485E/MAX487E-MAX49 1 E/MAX1487E Figure 8 Driver DC Test Load 2-26 Figure 9. Receiver Inning Test Load MA AXIAA+15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers 50082 S| ro OUTPUT UNDER TEST Figure 10. Driver/Receiver Timing Test Crcuit Figure 11. Driver Timing Test Load aw Di TOY ae 15V yo 5 ~~ Mei tera + 42V5 oe = ' Vy a ft Y 4 Tt ~ i Wei __ Mors 2V vay) viz Vout a oe a. ty | i att pues trea b a. bf 15v te ye RI v2 ey) fat tr stony 21 Ne c Van 23V OUTPUT NORMALLY LOW Vol +05V ? OUTPUT NORMALLY HIGH 23V Vii -0 SV cy ____ to el tastony, tH tay | [- Figure 12 Driver Propagation Delays Figure 13. Driver Enable and Disable Times (except MAX488E and MAX490E) Von RO NS Yb ne OUTPUT 1 of ~ at bry tp. + ov Vip ee, AB WAR INPUT _3y . Ua RE 15V Se 1.5V ov S EEEEEEEEEEEEEEEEEEEeeeeetl et Ur SHON. t21 tz] |< Vc. -+4 RG 15V QUTPUT NORMALLY LOW Voy +0 5V OUTPUT NORMALLY HIGH RQ 15V Von - O.5V Wo Tm Ue SHDN MH tH | |-*- Figure 14. Receiver Propagation Delays MAAXIAA Figure 15. Receiver Enabie and Disable Times (except MAX486E anid MAX490E) 2-27 3Z8Pv lL XVW/4lL6PXVWN-ALEVXVW/ASEPXVW/AECSPXVW/ALSVXUNMAX48 1 E/MAX483E/MAX485E/MAX48 7E-MAX491 E/MAX1487E +15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers The major difference between tests done using the Human Body Model and IEC 1000-4-2 is higher peak current in IEC 1000-4-2, because series resistance is lower in the JEC1000-4-2 model Hence, tne ESD with- stand voltage measured to IEC1000-4-2 is generally lower than that measured using the Human Body Model. Figure 7 shows the current waveform for the 8kV IEC 1000-4-2 ESD contact-discharge test. The air-gap test involves approaching the device with a charged probe. The contact-discharge method con- nects the probe to the device before the probe is ener- gized. Machine Model The Machine Model for ESD tests all pins using a 200pF storage capacitor and zero discharge resis- tance. Its objective is to emulate the stress caused by contact that occurs with handling and assembly during manufacturing. Of course, all pins require this protec- tion during manufacturingnot just inputs and outputs. Therefore, after PC board assembly, the Machine Model is tess relevant to 1/O ports. MAX487E/MAX1487E: 128 Transceivers on the Bus The 48kQ, 1/4-unit-load receiver input impedance of the MAX487E and MAX1487E allows up to 128 transceivers on a bus, compared to the t-unit load (12kQ input impedance) of standard RS-485 drivers (32 transceivers maximum) Any combination of MAX487E/MAX1487E and other RS-485 transceivers with a total of 32 unit loads or less can be put on the bus. The MAX481E, MAX483E, MAX485E, and MAX488E-MAX491E have standard 12k82 receiver input impedance MAX483E/MAX487E/MAX488E/MAX489E: Reduced EMI and Reflections The MAX483E and MAX487E-MAX489E are slew-rate limited, minimizing EMI] and reducing reflections caused by improperly terminated cables. Low-Power Shutdown Mode (MAX481 E/MAX483E/MAX487E) A low-power shutdown mode is initialed by bringing both RE high and DE low. The devices will not shut down unless both the driver and receiver are disabled. In shutdown, the devices typically draw only 0.1pA of supply current. RE and DE may be driven simultaneously; the parts are guaranteed not to enter shutdown if RE is high and DE is low for iess than 50ns. If the inputs are in this state for al least 600ns, the parts are guaranteed to enter shutdown. For the MAX481E, MAX483E, and MAX487E, the t71H and tz_ enable times assume the part was not in the low-power shutdown state (the MAX485E, MAX488E- MAX491E, and MAX 1487E can not be shut down), The tZH(SHDN) and {ZL(SHDN) enable times assume the parts were shut down (see Electrical Characteristics) It takes the drivers and receivers longer to become enabled from the low-power shutdown state (tZ1(SHDN), {ZL(SHDN)) than from the operating mode (t2H. tzL). (The parls are in operating mode if the RE, DE inputs equal a logical 0,1 or 1,1 or 0.0.) Driver Output Protection Excessive outpul current and power dissipation caused by faults or by bus contention are prevented by two mechanisms. A foldback current limit on the output stage provides immediate protection against short cir- cuits over the whole common-mode voltage range (see Typical Operating Characteristics). \n addition, a ther- mal shutdown circuit forces the driver outputs into a high-impedance state il the die temperature rises excessively. Typical Applications The MAX481E, MAX483E, MAX485E. MAX487E- MAX491E, and MAX1487E transceivers are designed for bidirectional dala communications on multipoint bus transmission lines. Figures 16 and 17 show typical net- work application circuits. These parts can also be used as line repeaters, with cable lengths longer than 4000 feet. To minimize reflections, the line should be terminated at both ends in its characteristic impedance. and stub lengths off the main line should be kept as short as poss- ble. The slew-rale-limited MAX483E and MAX487E.- MAX489E are more tolerant of imperfect termination Bypass the Voc pin with 0.1pF Isolated RS-485 For isolated RS-485 applications, see the MAX253 and MAX 1480 data sheets. 2-28 _ MAAXLIN+15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers 12082 42082 Ol DE MA AXIAA MAX481E MAX463E MAX485E MAX487E MAX 1487E Figure 16 MAX481E/MAX483E/MAX485E/MAX487E/MAX 1487E Typical Haif-Duplex RS-485 Network O1 OE RE RO MAXIAN MAX486E MAXA89E MAX490E MAXA9IE ol DE RE RO NOTE: RE AND DE ON MAX489/MAX491 ONLY Figure 17 MAX488E-MAX491E Full-Dupiex AS-485 Network MA AXLMA. 2-29 3Z8P LX VW/4L6PXVN-JZLEPXVW/ASEPXVW/ACSEXVW/ALSPXVNMAX481 E/MAX483E/MAX485E/MAX487E-MAX491 E/MAX1487E +15kV ESD-Protected, Siew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers Ordering Information (continued) [ PART TEMP.RANGE _ PIN-PACKAGE PART TEMP.RANGE __ PIN-PACKAGE MAX483ECPA O'Cto+70C 8B Plastic DIP MAX489ECPD OC to +70C 14 Plastic DIP MAX483ECSA oCto+70"C 8S0 MAX489ECSD O'Cto+70C 140 MAX483ECUA OC to +70C BMAX MAX489EEPD 40C to +85C 14 Plastic DIP | MAX483EEPA 40C 10 4+85C_-B Plastic DIP MAX489EESD 40C 10 485C 14 SO MAX483EESA 40D to 485C B SO MAX490ECPA OG 1o 470C 8 Plastic DIP | MAX485ECPA OC to+70C Plastic DIP MAX490ECSA aCto+70C 8 SO MAX485ECSA OCw4+70C 850 MAX490ECUA O'C to +70C 8 UMAX | MAX485ECUA so ta + 70C) CB MAX MAX490EEPA -40C to+85C 8 Plastic DIP | MAX485EEPA 40C to 485C Plastic DIP MAX490EESA 40C 10 485C. SO MAX485EESA 40C 10+85CB SO MAX491ECPD OCto+70C 14 Plastic DIP MAX487ECPA UC to 470C _B Plastic DIP MAX491ECSD | oC to 470C 140 MAX4B7ECSA OCto+70G. BSO MAX491EEPD -40C 10 485C 14 Plastic DIP MAX487ECUA O'Cto+70C. & UMAX MAX491EESD 40C to +85C 14 SO MAX487EEPA 40C to +85C 28 Plastic DIP MAX1487ECPA OC to 470C _-& Plastic DIP MAX487EESA -a0C 10 +B5'C SO MAX1487ECSA O"'C to +70" BSO ~MAX488ECPA o'Cto 470C 8 Plastic DIP MAX1487ECUA -40C 10 485C BMAX MAX4BBECSA OCtor70G BSO MAX 1487EEPA 40C 0 485C _8 Plastic DIP ~ MAX488ECUA OC to+70"C BMAX MAX1487EESA -45'C to 4125'S B SO MAX4B8EEPA 49C to 485C. & Plastic DIP MAX4BBEESA AC BSC SO Chip Topographies MAX481E/483E/485E/487E/1487E MAX488E/489E/490E/491E Vec Vec toned no +) mp NG. N.C. (MAX488E/490E} _| Lg RE (MAX489E/491E) N.C. (MAX488E/490E) | DE (MAX489E/491E} (3.251mm}) (3.254mm) Y Y Ee SUBSTRATE CONNECTED TO GND. [yg hl (2.159mm)} TRANSISTOR COUNT: 295 (2.159mm} MAAXLAA 2-30