MAX481E/MAX483E/MAX485E/ MAX487E-MAX491E/MAX1487E LE AVAILAB 15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers 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 120A supply current when unloaded or when fully loaded with disabled drivers (see Selector Guide). Additionally, the MAX481E, MAX483E, and MAX487E have a low-current shutdown mode in which they consume only 0.5A. 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 guarantees 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 Functional Diagrams MAX481E, MAX483E, MAX485E, MAX487E, and MAX1487E are designed for half-duplex applications. For applications that are not ESD sensitive see the pinand function-compatible MAX481, MAX483, MAX485, MAX487-MAX491, and MAX1487. Next-Generation Device Features For Fault-Tolerant Applications: MAX3430: 80V Fault-Protected, Fail-Safe, 1/4Unit Load, +3.3V, RS-485 Transceiver MAX3080-MAX3089: Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited, RS-485/RS-422 Transceivers For Space-Constrained Applications: MAX3460-MAX3464: +5V, Fail-Safe, 20Mbps, Profibus, RS-485/RS-422 Transceivers MAX3362: +3.3V, High-Speed, RS-485/RS-422 Transceiver in a SOT23 Package MAX3280E-MAX3284E: 15kV ESD-Protected, 52Mbps, +3V to +5.5V, SOT23, RS-485/RS-422 True Fail-Safe Receivers MAX3030E-MAX3033E: 15kV ESD-Protected, +3.3V, Quad RS-422 Transmitters For Multiple Transceiver Applications: MAX3293/MAX3294/MAX3295: 20Mbps, +3.3V, SOT23, RS-485/RS-422 Transmitters For Fail-Safe Applications: MAX3440E-MAX3444E: 15kV ESD-Protected, 60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers For Low-Voltage Applications: MAX3483E/MAX3485E/MAX3486E/MAX3488E/ MAX3490E/MAX3491E: +3.3V Powered, 15kV ESD-Protected, 12Mbps, Slew-Rate-Limited, True RS-485/RS-422 Transceivers Ordering Information Applications Low-Power RS-485 Transceivers Low-Power RS-422 Transceivers PART MAX481ECPA TEMP RANGE 0C to +70C PIN-PACKAGE 8 Plastic DIP MAX481ECSA 0C to +70C Level Translators MAX481EEPA -40C to +85C 8 Plastic DIP Transceivers for EMI-Sensitive Applications MAX481EESA -40C to +85C 8 SO Industrial-Control Local Area Networks MAX483ECPA 0C to +70C MAX483ECSA 0C to +70C MAX483EEPA -40C to +85C 8 Plastic DIP MAX483EESA -40C to +85C 8 SO Pin Configurations appear at end of data sheet. Functional Diagrams continued at end of data sheet. UCSP is a trademark of Maxim Integrated Products, Inc. 8 SO 8 Plastic DIP 8 SO Ordering Information continued at end of data sheet. Selector Guide appears at end of data sheet. For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maximintegrated.com. 19-0410; Rev 4; 10/03 MAX481E/MAX483E/MAX485E/ MAX487E-MAX491E/MAX1487E 15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC) .............................................................12V ---- Control Input Voltage (RE , DE)...................-0.5V to (VCC + 0.5V) Driver Input Voltage (DI).............................-0.5V to (VCC + 0.5V) Driver Output Voltage (Y, Z; A, B) ..........................-8V to +12.5V Receiver Input Voltage (A, B).................................-8V to +12.5V Receiver Output Voltage (RO)....................-0.5V to (VCC + 0.5V) Continuous Power Dissipation (TA = +70C) 8-Pin Plastic DIP (derate 9.09mW/C above +70C) ....727mW 14-Pin Plastic DIP (derate 10.00mW/C above +70C) ..800mW 8-Pin SO (derate 5.88mW/C above +70C).................471mW 14-Pin SO (derate 8.33mW/C above +70C)...............667mW Operating Temperature Ranges MAX4_ _C_ _/MAX1487EC_ A .............................0C to +70C MAX4_ _E_ _/MAX1487EE_ A...........................-40C to +85C Storage Temperature Range .............................-65C to +160C Lead Temperature (soldering, 10sec) .............................+300C Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is 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 Differential Driver Output (no load) VOD1 Differential Driver Output (with load) VOD2 Change in Magnitude of Driver Differential Output Voltage for Complementary Output States Driver Common-Mode Output Voltage Change in Magnitude of Driver Common-Mode Output Voltage for Complementary Output States MIN R = 50 (RS-422) TYP MAX UNITS 5 V 2 R = 27 (RS-485), Figure 8 1.5 5 R = 27 or 50, Figure 8 0.2 V VOC R = 27 or 50, Figure 8 3 V VOD R = 27 or 50, Figure 8 0.2 V Input Low Voltage VIL Input Current IIN1 VIN = 12V 1.0 IIN2 DE = 0V; VCC = 0V or 5.25V, all devices except MAX487E/MAX1487E VIN = -7V -0.8 MAX487E/MAX1487E, DE = 0V, VCC = 0V or 5.25V VIN = 12V 0.25 VIN = -7V -0.2 Input Current (A, B) Receiver Differential Threshold Voltage V VOD ---- DE, DI, RE ---- DE, DI, RE ---- DE, DI, RE Input High Voltage VIH VTH 2.0 V 0.8 V 2 A mA -7V VCM 12V -0.2 0.2 mA V Receiver Input Hysteresis VTH VCM = 0V Receiver Output High Voltage VOH IO = -4mA, VID = 200mV Receiver Output Low Voltage VOL IO = 4mA, VID = -200mV 0.4 V Three-State (high impedance) Output Current at Receiver IOZR 0.4V VO 2.4V 1 A Receiver Input Resistance 2 CONDITIONS 70 mV 3.5 V -7V VCM 12V, all devices except MAX487E/MAX1487E 12 k -7V VCM 12V, MAX487E/MAX1487E 48 k RIN Maxim Integrated MAX481E/MAX483E/MAX485E/ MAX487E-MAX491E/MAX1487E 15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers DC ELECTRICAL CHARACTERISTICS (continued) (VCC = 5V 5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER No-Load Supply Current (Note 3) SYMBOL ICC TYP MAX MAX488E/MAX489E, ---- DE, DI, RE = 0V or VCC CONDITIONS MIN 120 250 MAX490E/MAX491E, ---- DE, DI, RE = 0V or VCC 300 500 UNITS MAX481E/MAX485E, ---- RE = 0V or VCC DE = VCC 500 900 DE = 0V 300 500 MAX1487E, ---- RE = 0V or VCC DE = VCC 300 500 DE = 0V 230 400 MAX483E 350 650 MAX487E 250 120 0.5 400 250 10 A MAX483E/MAX487E, ---- RE = 0V or VCC DE = VCC A Supply Current in Shutdown ISHDN DE = 0V ---- MAX481E/483E/487E, DE = 0V, RE = VCC Driver Short-Circuit Current, VO = High IOSD1 -7V VO 12V (Note 4) 35 250 mA Driver Short-Circuit Current, VO = Low IOSD2 -7V VO 12V (Note 4) 35 250 mA IOSR 0V VO VCC A, B, Y and Z pins, tested using Human Body Model 7 95 mA kV Receiver Short-Circuit Current ESD Protection 15 SWITCHING CHARACTERISTICS--MAX481E/MAX485E, MAX490E/MAX491E, MAX1487E (VCC = 5V 5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER SYMBOL CONDITIONS Driver Input to Output tPLH tPHL Figures 10 and 12, RDIFF = 54, CL1 = CL2 = 100pF Driver Output Skew to Output tSKEW Figures 10 and 12, RDIFF = 54, CL1 = CL2 = 100pF Driver Rise or Fall Time tR, tF Figures 10 and 12, MAX481E, MAX485E, MAX1487E RDIFF = 54, CL1 = CL2 = 100pF MAX490EC/E, MAX491EC/E Driver Enable to Output High Driver Enable to Output Low Driver Disable Time from Low Driver Disable Time from High Receiver Input to Output | tPLH - tPHL | Differential Receiver Skew Receiver Enable to Output Low Receiver Enable to Output High Receiver Disable Time from Low Receiver Disable Time from High Maximum Data Rate Time to Shutdown Maxim Integrated tZH tZL tLZ tHZ MIN TYP MAX 10 10 40 40 5 60 60 10 3 20 40 5 20 25 45 45 45 45 70 70 70 70 20 60 200 20 60 150 Figures 10 and 14, RDIFF = 54, CL1 = CL2 = 100pF 5 tZL tZH tLZ tHZ Figures 9 and 15, CRL = 15pF, S1 closed Figures 9 and 15, CRL = 15pF, S2 closed Figures 9 and 15, CRL = 15pF, S1 closed Figures 9 and 15, CRL = 15pF, S2 closed 20 20 20 20 50 50 50 50 200 600 MAX481E (Note 5) ns ns ns ns ns ns tSKD fMAX tSHDN ns ns Figures 11 and 13, CL = 100pF, S2 closed Figures 11 and 13, CL = 100pF, S1 closed Figures 11 and 13, CL = 15pF, S1 closed Figures 11 and 13, CL = 15pF, S2 closed Figures 10 and 14, MAX481E, MAX485E, MAX1487E tPLH, tPHL RDIFF = 54, CL1 = CL2 = 100pF MAX490EC/E, MAX491EC/E UNITS 2.5 50 ns ns ns ns ns Mbps ns 3 MAX481E/MAX483E/MAX485E/ MAX487E-MAX491E/MAX1487E 15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers SWITCHING CHARACTERISTICS--MAX481E/MAX485E, MAX490E/MAX491E, MAX1487E (continued) (VCC = 5V 5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Driver Enable from Shutdown to tZH(SHDN) Output High (MAX481E) Figures 11 and 13, CL = 100pF, S2 closed 45 100 ns Driver Enable from Shutdown to tZL(SHDN) Output Low (MAX481E) Figures 11 and 13, CL = 100pF, S1 closed 45 100 ns Receiver Enable from Shutdown tZH(SHDN) to Output High (MAX481E) Figures 9 and 15, CL = 15pF, S2 closed, A - B = 2V 225 1000 ns Receiver Enable from Shutdown tZL(SHDN) to Output Low (MAX481E) Figures 9 and 15, CL = 15pF, S1 closed, B - A = 2V 225 1000 ns UNITS SWITCHING CHARACTERISTICS--MAX483E, MAX487E/MAX488E/MAX489E (VCC = 5V 5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER Driver Input to Output tPHL CONDITIONS Figures 10 and 12, RDIFF = 54, CL1 = CL2 = 100pF MIN 250 TYP 800 MAX 2000 250 800 2000 20 800 ns ns Driver Output Skew to Output tSKEW Figures 10 and 12, RDIFF = 54, CL1 = CL2 = 100pF Driver Rise or Fall Time tR, tF Figures 10 and 12, RDIFF = 54, CL1 = CL2 = 100pF 250 2000 ns Driver Enable to Output High tZH Figures 11 and 13, CL = 100pF, S2 closed 250 2000 ns Driver Enable to Output Low tZL Figures 11 and 13, CL = 100pF, S1 closed 250 2000 ns Driver Disable Time from Low tLZ Figures 11 and 13, CL = 15pF, S1 closed 300 3000 ns Driver Disable Time from High tHZ Figures 11 and 13, CL = 15pF, S2 closed 300 3000 ns Figures 10 and 14, RDIFF = 54, CL1 = CL2 = 100pF 250 2000 250 2000 Receiver Input to Output I tPLH - tPHL I Differential Receiver Skew tPLH tPHL tSKD Figures 10 and 14, RDIFF = 54, CL1 = CL2 = 100pF 100 ns ns Receiver Enable to Output Low tZL Figures 9 and 15, CRL = 15pF, S1 closed 25 50 ns Receiver Enable to Output High tZH Figures 9 and 15, CRL = 15pF, S2 closed 25 50 ns Receiver Disable Time from Low tLZ Figures 9 and 15, CRL = 15pF, S1 closed 25 50 ns tHZ Figures 9 and 15, CRL = 15pF, S2 closed 25 50 Receiver Disable Time from High Maximum Data Rate fMAX tPLH, tPHL < 50% of data period 250 Time to Shutdown tSHDN MAX483E/MAX487E (Note 5) 50 Driver Enable from Shutdown to Output High Driver Enable from Shutdown to Output Low Receiver Enable from Shutdown to Output High Receiver Enable from Shutdown to Output Low 4 SYMBOL tPLH tZH(SHDN) tZL(SHDN) tZH(SHDN) tZL(SHDN) MAX483E/MAX487E, Figures 11 and 13, CL = 100pF, S2 closed MAX483E/MAX487E, Figures 11 and 13, CL = 100pF, S1 closed MAX483E/MAX487E, Figures 9 and 15, CL = 15pF, S2 closed MAX483E/MAX487E, Figures 9 and 15, CL = 15pF, S1 closed ns kbps 200 600 ns 2000 ns 2000 ns 2500 ns 2500 ns Maxim Integrated MAX481E/MAX483E/MAX485E/ MAX487E-MAX491E/MAX1487E 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 voltages are referenced to device ground unless otherwise specified. Note 2: All typical specifications are given for VCC = 5V and TA = +25C. Note 3: Supply current specification is valid for loaded transmitters when DE = 0V. Note 4: Applies to peak current. See Typical Operating Characteristics. ---- Note 5: The MAX481E/MAX483E/MAX487E are put into shutdown by bringing RE high and DE low. If the inputs are in this state for less than 50ns, the parts are guaranteed not to enter shutdown. If the inputs are in this state for at least 600ns, the parts are guaranteed to have entered shutdown. See Low-Power Shutdown Mode section. __________________________________________Typical Operating Characteristics (VCC = 5V, TA = +25C, unless otherwise noted.) 35 30 25 20 15 -15 -10 10 4.8 MAX481E-02 -20 OUTPUT CURRENT (mA) 40 RECEIVER OUTPUT HIGH VOLTAGE vs. TEMPERATURE 4.6 OUTPUT HIGH VOLTAGE (V) 45 OUTPUT CURRENT (mA) -25 MAX481E-01 50 OUTPUT CURRENT vs. RECEIVER OUTPUT HIGH VOLTAGE -5 IRO = 8mA MAX481E-03 OUTPUT CURRENT vs. RECEIVER OUTPUT LOW VOLTAGE 4.4 4.2 4.0 3.8 3.6 3.4 3.2 5 0 0 0 0.5 1.0 1.5 2.0 2.5 3.0 1.5 2.0 OUTPUT LOW VOLTAGE (V) 2.5 3.0 3.5 4.0 4.5 OUTPUT HIGH VOLTAGE (V) RECEIVER OUTPUT LOW VOLTAGE vs. TEMPERATURE 0.7 0.6 0.5 0.4 0.3 80 40 60 80 100 70 60 50 40 30 0.2 20 0.1 10 0 0 -60 -40 -20 0 20 40 60 TEMPERATURE (C) Maxim Integrated 20 MAX481E-05 IRO = 8mA 0 TEMPERATURE (C) 90 OUTPUT CURRENT (mA) OUTPUT LOW VOLTAGE (V) 0.8 -60 -40 -20 DRIVER OUTPUT CURRENT vs. DIFFERENTIAL OUTPUT VOLTAGE MAX481E-04 0.9 5.0 80 100 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 DIFFERENTIAL OUTPUT VOLTAGE (V) 5 MAX481E/MAX483E/MAX485E/ MAX487E-MAX491E/MAX1487E 15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers ____________________________Typical Operating Characteristics (continued) (VCC = 5V, TA = +25C, unless otherwise noted.) OUTPUT CURRENT vs. DRIVER OUTPUT LOW VOLTAGE 2.0 1.9 1.8 1.7 80 60 40 -80 -70 -60 -50 -40 -30 -20 20 1.5 0 0 20 60 40 0 2 4 6 8 10 12 -8 -6 -4 0 -2 2 4 TEMPERATURE (C) OUTPUT LOW VOLTAGE (V) OUTPUT HIGH VOLTAGE (V) MAX481E/MAX485E/MAX490E/MAX491E SUPPLY CURRENT vs. TEMPERATURE MAX483E/MAX487E-MAX489E SUPPLY CURRENT vs. TEMPERATURE MAX1487E SUPPLY CURRENT vs. TEMPERATURE 500 600 500 300 MAX485E; DE = 0, RE = X, MAX481E; DE = RE = 0 MAX490E/MAX491E; DE = RE = X 100 400 300 200 SUPPLY CURRENT (A) SUPPLY CURRENT (A) 500 400 MAX483E; DE = VCC, RE = X MAX487E; DE = VCC, RE = X MAX483E/MAX487E; DE = RE = 0, MAX488E/MAX489E; DE = RE = X 40 60 TEMPERATURE (C) 200 MAX1487E; DE = 0V, RE = X 0 0 20 MAX1487E; DE = VCC, RE = X 300 MAX483E/MAX487E; DE = 0, RE = VCC 0 0 400 100 100 MAX481E; DE = 0, RE = VCC -60 -40 -20 6 MAX481E-11 600 MAX481E-10 MAX481E/MAX485E; DE = VCC, RE = X 200 -10 0 80 100 600 SUPPLY CURRENT (A) 100 1.6 -60 -40 -20 6 -90 OUTPUT CURRENT (mA) 120 OUTPUT CURRENT (mA) 2.1 -100 MAX481E-07 140 MAX481E-06 R = 54 2.2 MAX481E-09 DIFFERENTIAL OUTPUT VOLTAGE (V) 2.3 OUTPUT CURRENT vs. DRIVER OUTPUT HIGH VOLTAGE MAX481E-08 DRIVER DIFFERENTIAL OUTPUT VOLTAGE vs. TEMPERATURE 80 100 -60 -40 -20 0 20 40 60 TEMPERATURE (C) 80 100 -60 -40 -20 0 20 40 60 80 100 TEMPERATURE (C) Maxim Integrated MAX481E/MAX483E/MAX485E/ MAX487E-MAX491E/MAX1487E 15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers ______________________________________________________________Pin Description PIN MAX481E/MAX483E MAX485E/MAX487E MAX1487E MAX488E MAX490E MAX489E MAX491E NAME 1 2 2 RO 2 -- 3 ---- RE FUNCTION Receiver Output: If A > B by 200mV, RO will be high; If A < B by 200mV, RO will be low. ---- Receiver Output Enable. RO is enabled when RE is ---- low; RO is high impedance when RE is high. 3 -- 4 DE Driver Output Enable. The driver outputs, Y and Z, are enabled by bringing DE high. They are high impedance 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 R E is low. 4 3 5 DI Driver Input. A low on DI forces output Y low and output Z high. Similarly, a high on DI forces output Y high and output Z low. 5 4 6, 7 GND -- 5 9 Y Noninverting Driver Output -- 6 10 Z Inverting Driver Output 6 -- -- A Noninverting Receiver Input and Noninverting Driver Output -- 8 12 A Noninverting Receiver Input 7 -- -- B Inverting Receiver Input and Inverting Driver Output -- 7 11 B Inverting Receiver Input 8 1 14 VCC Positive Supply: 4.75V VCC 5.25V -- -- 1, 8, 13 N.C. No Connect--not internally connected Maxim Integrated Ground 7 MAX481E/MAX483E/MAX485E/ MAX487E-MAX491E/MAX1487E 15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers 0.1F TOP VIEW RO 1 R 8 RO VCC 1 RE 2 7 B RE 2 DE 3 6 A DE 3 5 GND DI 4 DI 4 D R 8 VCC 7 B Rt 6 A 5 GND D MAX481E MAX483E MAX485E MAX487E MAX1487E DE DI D B Rt A RO R RE DIP/SO NOTE: PIN LABELS Y AND Z ON TIMING, TEST, AND WAVEFORM DIAGRAMS REFER TO PINS A AND B WHEN DE IS HIGH. TYPICAL OPERATING CIRCUIT SHOWN WITH DIP/SO PACKAGE. Figure 1. MAX481E/MAX483E/MAX485E/MAX487E/MAX1487E Pin Configuration and Typical Operating Circuit 0.1F VCC MAX488E MAX490E VCC 1 5 Y TOP VIEW 8 A RO 2 7 B DI 3 6 Z VCC 1 GND 4 R 5 D DI 3 Rt D 6 Z R RO 8 A RO Y 2 Rt R D 7 DI B DIP/SO 4 GND GND NOTE: TYPICAL OPERATING CIRCUIT SHOWN WITH DIP/SO PACKAGE. Figure 2. MAX488E/MAX490E Pin Configuration and Typical Operating Circuit DE 4 TOP VIEW N.C. 1 RO 2 R 13 N.C. 12 A DE 4 11 B DI 5 10 Z D GND 7 9 Y 8 N.C. 9 DI 5 MAX489E MAX491E Y Rt D 10 RO R Z 12 RO 2 R A Rt D 11 DI B NC 1, 8, 13 3 DIP/SO VCC RE 0.1F 14 14 V CC RE 3 GND 6 VCC 6, 7 GND RE GND DE Figure 3. MAX489E/MAX491E Pin Configuration and Typical Operating Circuit 8 Maxim Integrated MAX481E/MAX483E/MAX485E/ MAX487E-MAX491E/MAX1487E 15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers __________Function Tables (MAX481E/MAX483E/MAX485E/MAX487E/MAX1487E) Table 1. Transmitting Table 2. Receiving INPUTS OUTPUTS INPUTS OUTPUT RE DE DI Z Y RE DE A-B RO X 1 1 0 1 0 0 > +0.2V 1 X 1 0 1 0 0 0 < -0.2V 0 0 0 X High-Z High-Z 0 0 Inputs open 1 1 0 X High-Z* High-Z* 1 0 X High-Z* 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 environments where high-speed communication is important. These devices eliminate the need for transient suppressor 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 data rates up to 2.5Mbps, while the MAX483E, MAX487E, MAX488E, and MAX489E 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, driverenable (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 electrostatic discharges encountered during handling and assembly. The driver outputs and receiver inputs have extra protection against static electricity. Maxim's engi- Maxim Integrated X = Don't care High-Z = High impedance * Shutdown mode for MAX481E/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 all 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 IEC10004-2 contact discharge and IEC1000-4-2 air-gap discharge (formerly IEC801-2). 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 discharged into a low impedance. This model consists of a 100pF capacitor charged to the ESD voltage of interest, which is then discharged into the test device through a 1.5k resistor. IEC1000-4-2 The IEC1000-4-2 standard covers ESD testing and performance of finished equipment; it does not specifically refer to integrated circuits (Figure 6). 9 MAX481E/MAX483E/MAX485E/ MAX487E-MAX491E/MAX1487E 15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers R C 1M CHARGE CURRENT LIMIT RESISTOR HIGH VOLTAGE DC SOURCE Cs 100pF R D 1500 IP 100% 90% DISCHARGE RESISTANCE STORAGE CAPACITOR DEVICE UNDER TEST PEAK-TO-PEAK RINGING (NOT DRAWN TO SCALE) Ir AMPERES 36.8% 10% 0 0 Figure 4. Human Body ESD Test Model TIME tRL tDL CURRENT WAVEFORM Figure 5. Human Body Model Current Waveform I 100% CHARGE CURRENT LIMIT RESISTOR HIGHVOLTAGE DC SOURCE Cs 150pF R D 330 90% DISCHARGE RESISTANCE STORAGE CAPACITOR I PEAK R C 50M to 100M DEVICE UNDER TEST 10% t r = 0.7ns to 1ns t 30ns 60ns Figure 6. IEC1000-4-2 ESD Test Model Figure 7. IEC1000-4-2 ESD Generator Current Waveform Y TEST POINT RECEIVER OUTPUT CRL 15pF R VOD R 1k VCC S1 1k VOC S2 Z Figure 8. Driver DC Test Load 10 Figure 9. Receiver Timing Test Load Maxim Integrated MAX481E/MAX483E/MAX485E/ MAX487E-MAX491E/MAX1487E 15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers 3V DE CL1 Y DI A RDIFF VID OUTPUT UNDER TEST B Z RE CL CL2 S2 Figure 10. Driver/Receiver Timing Test Circuit Figure 11. Driver Timing Test Load 3V 3V DI 1.5V 0V DE 1.5V 1.5V 1.5V 0V tPHL tPLH 1/2 VO tZL(SHDN), tZL Z tLZ Y, Z VO 2.3V OUTPUT NORMALLY LOW VOL Y 1/2 VO VO VDIFF 0V -VO VCC S1 500 RO 10% VDIFF = V (Y) - V (Z) VOH -0.5V 2.3V 90% tR OUTPUT NORMALLY HIGH Y, Z 90% 0V 10% VOL +0.5V tZH(SHDN), tZH tF tHZ tSKEW = | tPLH - tPHL | Figure 12. Driver Propagation Delays Figure 13. Driver Enable and Disable Times (except MAX488E and MAX490E) 3V RE 1.5V 1.5V 0V RO A-B VOH 1.5V VOL tPHL VID -VID OUTPUT 0V 1.5V tPLH INPUT tZL(SHDN), tZL VCC RO tLZ 1.5V OUTPUT NORMALLY LOW 0V VOL + 0.5V OUTPUT NORMALLY HIGH RO VOH - 0.5V 1.5V 0V tZH(SHDN), tZH Figure 14. Receiver Propagation Delays Maxim Integrated tHZ Figure 15. Receiver Enable and Disable Times (except MAX488E and MAX490E) 11 MAX481E/MAX483E/MAX485E/ MAX487E-MAX491E/MAX1487E 15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers 10dB/div 10dB/div 0Hz 500kHz/div 5MHz Figure 16. Driver Output Waveform and FFT Plot of MAX485E/MAX490E/MAX491E/MAX1487E Transmitting a 150kHz Signal The major difference between tests done using the Human Body Model and IEC1000-4-2 is higher peak current in IEC1000-4-2, because series resistance is lower in the IEC1000-4-2 model. Hence, the ESD withstand 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 IEC1000-4-2 ESD contact-discharge test. The air-gap test involves approaching the device with a charged probe. The contact-discharge method connects the probe to the device before the probe is energized. Machine Model The Machine Model for ESD tests all pins using a 200pF storage capacitor and zero discharge resistance. Its objective is to emulate the stress caused by contact that occurs with handling and assembly during manufacturing. Of course, all pins require this protection during manufacturing--not just inputs and outputs. Therefore, after PC board assembly, the Machine Model is less relevant to I/O ports. MAX487E/MAX1487E: 128 Transceivers on the Bus The 48k, 1/4-unit-load receiver input impedance of the MAX487E and MAX1487E allows up to 128 transceivers on a bus, compared to the 1-unit load (12k 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 12k receiver input impedance. 12 0Hz 500kHz/div 5MHz Figure 17. Driver Output Waveform and FFT Plot of MAX483E/MAX487E-MAX489E Transmitting a 150kHz Signal 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. Figure 16 shows the driver output waveform and its Fourier analysis of a 150kHz signal transmitted by a MAX481E, MAX485E, MAX490E, MAX491E, or MAX1487E. Highfrequency harmonics with large amplitudes are evident. Figure 17 shows the same information displayed for a MAX483E, MAX487E, MAX488E, or MAX489E transmitting under the same conditions. Figure 17's high-frequency harmonics have much lower amplitudes, and the potential for EMI is significantly reduced. Low-Power Shutdown Mode (MAX481E/MAX483E/MAX487E) A low-power shutdown mode is initiated 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 0.5A 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 less than 50ns. If the inputs are in this state for at least 600ns, the parts are guaranteed to enter shutdown. For the MAX481E, MAX483E, and MAX487E, the t ZH and tZL enable times assume the part was not in the low-power shutdown state (the MAX485E, MAX488E- MAX491E, and MAX1487E can not be shut down). The t ZH(SHDN) and t ZL(SHDN) enable times assume the parts were shut down (see Electrical Characteristics). Maxim Integrated MAX481E/MAX483E/MAX485E/ MAX487E-MAX491E/MAX1487E 15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers 100pF B Z TTL IN tR, tF < 6ns D R R = 54 Y RECEIVER OUT A 100pF delay times. Typical propagation delays are shown in Figures 19-22 using Figure 18's test circuit. The difference in receiver delay times, tPLH - tPHL, is typically under 13ns for the MAX481E, MAX485E, MAX490E, MAX491E, and MAX1487E, and is typically less than 100ns for the MAX483E and MAX487E- MAX489E. The driver skew times are typically 5ns (10ns max) for the MAX481E, MAX485E, MAX490E, MAX491E, and MAX1487E, and are typically 100ns (800ns max) for the MAX483E and MAX487E-MAX489E. Typical Applications Figure 18. Receiver Propagation Delay Test Circuit It takes the drivers and receivers longer to become enabled 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 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 circuits over the whole common-mode voltage range (see Typical Operating Characteristics). In addition, a thermal shutdown circuit forces the driver outputs into a high-impedance state if the die temperature rises excessively. Propagation Delay Many digital encoding schemes depend on the difference between the driver and receiver propagation Maxim Integrated The MAX481E, MAX483E, MAX485E, MAX487E- MAX491E, and MAX1487E transceivers are designed for bidirectional data communications on multipoint bus transmission lines. Figures 25 and 26 show typical network 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 possible. The slew-rate-limited MAX483E and MAX487E- MAX489E are more tolerant of imperfect termination. Bypass the VCC pin with 0.1F. Isolated RS-485 For isolated RS-485 applications, see the MAX253 and MAX1480 data sheets. Line Length vs. Data Rate The RS-485/RS-422 standard covers line lengths up to 4000 feet. Figures 23 and 24 show the system differential voltage for the parts driving 4000 feet of 26AWG twisted-pair wire at 110kHz into 100 loads. 13 MAX481E/MAX483E/MAX485E/ MAX487E-MAX491E/MAX1487E 15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers A B 500mV/div 500mV/div B A RO 5V/div 5V/div RO 25ns/div 25ns/div Figure 19. MAX481E/MAX485E/MAX490E/MAX1487E Receiver tPHL Figure 20. MAX481E/MAX485E/MAX490E/MAX491E/ MAX1487E Receiver tPLH A B 500mV/div 500mV/div B A RO 5V/div 5V/div RO 200ns/div 200ns/div Figure 21. MAX483E/MAX487E-MAX489E Receiver tPHL DI 5V Figure 22. MAX483E/MAX487E-MAX489E Receiver tPLH DI 5V 0V 0V 1V 0 V A - VB 0 VB - VA -1V -1V 5V DO 5V 0V 0V 2s/div Figure 23. MAX481E/MAX485E/MAX490E/MAX491E/ MAX1487E System Differential Voltage at 110kHz Driving 4000ft of Cable 14 DO 2s/div Figure 24. MAX483E/MAX1487E-MAX489E System Differential Voltage at 110kHz Driving 4000ft of Cable Maxim Integrated MAX481E/MAX483E/MAX485E/ MAX487E-MAX491E/MAX1487E 15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers 120 120 DE B B DI D D DI DE B A A B A A R R RO RE RO RE R R D D MAX481E MAX483E MAX485E MAX487E MAX1487E DE DI RO RE DI RO RE DE Figure 25. MAX481E/MAX483E/MAX485E/MAX487E/MAX1487E Typical Half-Duplex RS-485 Network A R RO RE Y 120 120 D B Z Z B DE DI DE DI 120 D Y 120 Z Y B A Y Z R A DE RE RO A R D D DI B R RE RO DI DE RE RO MAX488E MAX489E MAX490E MAX491E NOTE: RE AND DE ON MAX489E/MAX491E ONLY. Figure 26. MAX488E-MAX491E Full-Duplex RS-485 Network Maxim Integrated 15 MAX481E/MAX483E/MAX485E/ MAX487E-MAX491E/MAX1487E 15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers Ordering Information (continued) PART TEMP RANGE PIN-PACKAGE TEMP RANGE PIN-PACKAGE MAX485ECPA 0C to +70C 8 Plastic DIP MAX489EEPD PART -40C to +85C 14 Plastic DIP MAX485ECSA 0C to +70C 8 SO MAX489EESD -40C to +85C 14 SO MAX485EEPA -40C to +85C 8 Plastic DIP MAX490ECPA 0C to +70C 8 Plastic DIP MAX485EESA -40C to +85C 8 SO MAX490ECSA 0C to +70C 8 SO MAX487ECPA 0C to +70C 8 Plastic DIP MAX490EEPA -40C to +85C 8 Plastic DIP MAX487ECSA 0C to +70C 8 SO MAX490EESA -40C to +85C 8 SO MAX487EEPA -40C to +85C 8 Plastic DIP MAX491ECPD 0C to +70C MAX487EESA -40C to +85C 8 SO MAX491ECSD 0C to +70C MAX488ECPA 0C to +70C 8 Plastic DIP MAX491EEPD -40C to +85C 14 Plastic DIP -40C to +85C 14 SO 14 Plastic DIP 14 SO MAX488ECSA 0C to +70C 8 SO MAX491EESD MAX488EEPA -40C to +85C 8 Plastic DIP MAX1487ECPA 0C to +70C MAX488EESA -40C to +85C 8 SO MAX1487ECSA 0C to +70C MAX489ECPD 0C to +70C 14 Plastic DIP MAX1487EEPA -40C to +85C 8 Plastic DIP MAX489ECSD 0C to +70C 14 SO MAX1487EESA -40C to +85C 8 SO 8 Plastic DIP 8 SO Selector Guide HALF/FULL DUPLEX DATA RATE (Mbps) SLEWRATE LIMITED LOW-POWER SHUTDOWN MAX481E Half 2.5 No Yes MAX483E Half 0.25 Yes Yes Yes 120 32 8 MAX485E Half 2.5 No No Yes 300 32 8 MAX487E Half 0.25 Yes Yes Yes 120 128 8 MAX488E Full 0.25 Yes No No 120 32 8 MAX489E Full 0.25 Yes No Yes 120 32 14 MAX490E Full 2.5 No No No 300 32 8 MAX491E Full 2.5 No No Yes 300 32 14 MAX1487E Half 2.5 No No Yes 230 128 8 PART NUMBER Chip Information TRANSISTOR COUNT: 295 RECEIVER/ QUIESCENT NUMBER OF DRIVER CURRENT TRANSMITTERS ENABLE (A) ON BUS Yes 300 32 PIN COUNT 8 Package Information For the latest package outline information, go to www.maxim-ic.com/packages. Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. 16 (c) Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 Maxim Integrated The Maxim logo and Maxim Integrated are trademarks of Maxim Integrated Products, Inc.