19-1138; Rev 0; 9/96 MAXIM Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers General Description The MAX3080-MAX30839 high-speed transceivers for RS-485/RS-422 communication contain one driver and one receiver. These devices feature fail-safe circuitry, which guarantees a logic-high receiver output when the receiver inputs are open or shorted. This means that the receiver output will be a logic high if all transmitters on a terminated bus are disabled (high impedance). The MAX3080/MAX308 1/MAX3082 feature reduced slew-rate drivers that minimize EMI and reduce reflec- tions caused by improperly terminated cables, allowing error-free data transmission up to 115kbps. The MAX3083/MAX3084/MAX3085 offer higher driver out- put slew-rate limits, allowing transmit speeds up to 500kbps. The MAX3086/MAX3087/MAX3088's driver slew rates are not limited, making transmit speeds up to 10Mbps possible. The MAX3089s slew rate is selectable between 115kbps, 500kbps, and 10Mbps by driving a selector pin with a single three-state driver. These transceivers typically draw 375yA of supply current when unloaded, or when fully loaded with the drivers disabied. All devices have a 1/8-unit-load receiver input imped- ance that allows up to 256 transceivers on the bus. The MAX3082/MAX3085/MAX3088 are intended for half- duplex communications, while the MAX3080/MAX308 1/ MAX3083/MAX3084/MAX3086/MAX3087 are intended for full-duplex communications. The MAX3089 is selec- table between half-duplex and full-duplex operation. It also features independently programmable receiver and transmitter output phase via separate pins. Features True Fail-Safe Receiver While Maintaining EIA/TIA-485 Compatibility @ Enhanced Slew-Rate Limiting Facilitates Error-Free Data Transmission (MAX3080-MAX3085/MAX3089) # 1nA Low-Current Shutdown Mode (except MAX3081/MAX3084/MAX3087) Pin-Selectable Full/Half-Duplex Operation (MAX3089) @ Phase Controls to Correct for Twisted-Pair Reversal (MAX3089) Allow Up to 256 Transceivers on the Bus Applications RS-422/RS-485 Communications Level Translators Transceivers for EMl-Sensitive Applications Industrial-Control Local Area Networks Ordering information PART TEMP. RANGE PIN-PACKAGE MAX3080CPD OC to +70C 14 Plastic DIP MAX3080CSD OC to +70C 1480 MAX3080EPD ~40C to +85C 14 Plastic DIP MAX3080ESD -40C to +85C 14S0 Ordering information continued on last page. Selection Table a 680EXVN-OSOEXVN Half/Full Data Slew Low- Receiver/ | Quiescent |Transcelvers Pin Industry- Part Duplex Rate Rate Power Driver Current On Count Standard (Mbps) Limited | Shutdown} Enable (yA) Bus Pinout MAX3080 Full 0.115 Yes Yes Yes 375 256 14 75180 MAX3081 Full 0.115 Yes No No 375 256 75179 MAX3082 Half 0.115 Yes Yes Yes 375 256 8 75176 MAX23083 Full 0.5 Yes Yes Yes 375 256 14 75180 MAX3084 Full 0.5 Yes No No 375 256 8 75179 MAX3085 Half 0.5 Yes Yes Yes 375 256 8 75176 MAX3086 Full 10 No Yes Yes 375 256 14 75180 MAX3087 Full 10 No No No 375 256 8 75179 MAX3088 Half 10 No Yes Yes 375 256 8 75176 MAX3089 | Selectable | Selectable | Selectable Yes Yes 375 256 14 75180* *Pin compatible with 75180, with additional features implemented using pins 1, 6, 8, and 13. MAAXISA Maxim Integrated Products 2-87 For free samples & the latest literature: http:/;www.maxim-ic.com, or phone 1-800-998-8800MAX3080-MAX3089 Fail-Safe, High-Speed (10Mbps), Siew-Rate-Limited RS-485/RS-422 Transceivers ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC) oes cess cesses ces ccererseeneeseeteeens +7V Continuous Power Dissipation Control input Voltage (RE, DE)............... -0.3V to (Voc + 0.3V) 8-Pin Plastic DIP (derate 9.09mW/C above +70C) ...727mW Special Input Voltage 8-Pin SO (derate 5.88mW/C above +70C)..........0.. 471imw (H/F, SRL, TXP, RXP)....cccccccsecceseseeeetereee -0.3V to (Voc + 0.3V) 14-Pin Plastic DIP (derate 10.0mW/C above +70C) ....800mW Oriver Input Voltage (DI)........ .0.3V to (Voc + 0.3V) 14-Pin SO (derate 8.33mMW/C above +70C)............. 667mWw Driver Output Voltage (A, B, Y, Z)....-cecccccsesenssceeeeeseees 13V Operating Temperature Ranges Receiver Input Voltage (A, B).........0... Receiver Input Voltage, Full Duplex (A, B). Receiver Output Voltage (RO)... -0.3V to (Voc + 0.3V) Storage Temperature Range........... Lead Temperature (soldering, 10sec tk 13V MAXB08_C oo os secccee sees tsseseseseeeeasecsteaneaneney 0C to +70C 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 (Voc = +5V +5%, Ta = Tmin to TMAX, unless otherwise noted. Typical values are at Vcc = +5V and Ta = +25C.) (Note 1) PARAMETER | SYMBOL | CONDITIONS MIN TYP MAX | UNITS DRIVER Differential Driver Output (no load) Voo1 | Figure 5 5 v . : . Figure 5, R = 50Q (RS-422) 2.0 Vv Differential Driver Output 002 Figure 5, R = 272 (RS-485) 15 Vv Change in Magnitude of Differential Output Voltage AVop Figure 5, R = S0Q or R = 270 0.2 Vv (Note 2) Driver Common-Mode Output ; _ = Voltage Voc Figure 5, R = 500 or R = 27Q 3 Vv Change In Magnitude of _ _ Common-Mode Voltage (Note 2) AVoc | Figure 5, R = 5082 or R = 27 02 Vv Input High Voltage Vint DE, DI, RE, H/F, TXP, RXP 2.0 v Input Low Voltage Vint DE, Di, RE, H/F, TXP, RXP 08 Vv . MAX3080-MAX3085, and MAX3089 with DI Input Hysteresis VHYS SRL = Voc or unconnected 100 mv lint DE, DI, RE +2 A SRL Input Current ina | HE, TXP. RXP, internal pull-down 10 ao | ? Input High Voltage ViH2 SRL Voc - 0.8 Vv Input Middle Voitage ViM2 SRL (Note 3) 0.4Vcc 0.6Vcc Vv Input Low Voltage Vit2 SRL 0.8 v SRL = Vec 75 A SRL Input Current tina SRL = GND (Note 3) 75 u Input Current (A and B) hin DE = GND, Vin = 12V 128 vA Full Duplex IN4 Vec = GND or 5.25V | Vin = -7V 75 Output Leakage (Y and Z) | DE = GND, Vin = 12V 125 yA Full Duplex 2 | Vee = GND or 5.25V [Wij = -7V 100 . ae -7Vs Vout s Voc ~250 Covent (Note 4) Output Vont [OVS Vour s12V 250} mA OV s Vour $ Voc #25 2-88 MAAXLAA(Voc = +5V 5%, Ta = Tin to TMAx, unless otherwise noted. Typical values are at Vcc = +5V and Ta = +25C.) (Note 1) Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers DC ELECTRICAL CHARACTERISTICS (continued) PARAMETER | SYMBOL | CONDITIONS | MIN TYP = MAX | UNITS RECEIVER Receiver Differential Threshold Voltage VTH -7V sVoms 12V -200 -125 -50 mv Receiver Input Hysteresis AVTH 25 mV Receiver Output High Voltage VOH lo = -4mA, Vip = -50mV Vec -1.5 Vv Receiver Output Low Voltage VoL lo = 4mA, Vip = -200mV 0.4 Vv Three-State Output Current at Receiver fozr 0.4V<Vo0 $2.4V +1 pA Receiver Input Resistance Rin -7V s Vom S$ 12V 96 kQ Receiver Output Short-Circuit Current losR OV<VrROosVcc +7 +95 mA SUPPLY CURRENT No load, DE = Vcc 430 900 RE = DI = GND pA or Vcc, SRL = Vcc DE = GND 375 600 Supply Current loc No load, DE = Vcc 475 1000 RE = Dl = GND pA or Vcc, SRL = GND DE = GND 420 800 Rupe ly Current in Shutdown IsHon | DE = GND, VAE = Voc 0.001 10 pA Note 1: All currents into the device are positive; all currents out of the device are negative. All voltages are referred to device ground unless otherwise noted. Note 2: AVop and AVoc are the changes in Vop and Voc, respectively, when the DI input changes state. Note 3: The SRL pin is internally biased to Vcc / 2 by a 100kQ/100kQ resistor divider. It is guaranteed to be Vcc / 2 if left unconnected. Note 4: Maximum current level applies to peak current just prior to foldback-current limiting; minimum current level applies during current limiting. MA AXIS 2-89 i 680EXVNW-O80EXUNMAX3080-MAX3089 Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers SWITCHING CHARACTERISTICS-MAX3080MAX3082, and MAX3089 with SAL = Unconnected (Voc = +5V +5%, Ta = Tain to Tmax, unless otherwise noted. Typical values are at Voc = +5V and Ta = +25C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX | UNITS . tOPLH Figures 7 and 9, Roirr = 54Q, 500 2.03 260 Driver Input to Output . Put to Outp topH. | CL1 = CL2 = 100pF 500. 203 20 | Driver Output Skew Figures 7 and 9, Roirr = 54Q, ItDPLH - toPHL | HOSKEW | CL, = Cie = 100pF 3 +200] ns . . Figures 7 and 9, Roirr = 54Q, Driver Rise or Fall Time ton. tor Cut = C2 = 100pF 667 1320 2500 ns Maximum Data Rate fax 115 kbps Driver Enable to Output High toZH Figures 8 and 10, CL = 100pF, S2 closed 3500 ns Driver Enable to Output Low tOZL Figures 8 and 10, C_ = 100pF, $1 closed 3500 ns Driver Disable Time from Low toLz Figures 8 and 10, CL = 15pF, S1 closed 100 ns Driver Disable Time from High tDHz Figures 8 and 10, Cy. = 15pF, S2 closed 100 ns Receiver Input to Output tReLH. | Figures 11 and 13; | Vip | 2 2.0V; 127 200 ns 'RPHL tise and fall time of Vip s 15ns | tAPLH - tapH | Differential Figures 11 and 13; | Vip | 2 2.0V: Receiver Skew 'RSKD | tise and fall time of Vip < 15ns 3 #80 | ns Receiver Enable to Output Low tazt Figures 6 and 12, C, = 100pF, St closed 20 50 ns Receiver Enable to Output High tRZH Figures 6 and 12, CL = 100pF, S2 closed 20 50 ns Receiver Disable Time from Low tALZ Figures 6 and 12, C_ = 100pF, S1 closed 20 60 ns Noe Disable Time from taHz _| Figures 6 and 12, C = 100pF, $2 closed 20 50 | ns Time to Shutdown tSHDN (Note 5) 50 200 600 ns Driver Enable from Shutdown to _ Output High tDZH(SHON) | Figures 8 and 10, Cy = 15pF, S2 closed 6000 ns Driver Enable from Shutdown to . _ Output Low toZL(SHDN) | Figures 8 and 10, C, = 15pF, S1 closed 6000 ns Receiver Enable from Shutdown . _ to Output High tRZH(SHON) | Figures 6 and 12, CL = 100pF, S2 closed 3500 ns Receiver Enable from Shutdown . . to Output Low tAZL(SHDN) | Figures 6 and 12, C_ = 100pF, S1 closed 3500 ns 2-90 PRAXIAA(Voc = +5V +5%, Ta = Tain to TMAx, unless otherwise noted. Typical values are at Voc = +5V and Ta = +25C.) Fail-Safe, High-Speed (10Mbps), Siew-Rate-Limited RS-485/RS-422 Transceivers SWITCHING CHARACTERISTICS--MAX3083MAX3085, and MAX3089 with SRL = Vcc to Output Low SYMBOL CONDITIONS MIN TYP MAX | UNITS : tDOPLH Figures 7 and 9, Roirr = 540, 250 720 1000 Driver Input to Output - ' p 'p topo. | Cit = C2 = 100pF 250. 720 too] Driver Output Skew Figures 7 and 9, Roirr = 54, t - I tDPLH - toPHL | DSKEW | Cut = CL = 100pF 3 #100 | ns i Figures 7 and 9, Roire = 54Q, Driver Rise or Fall Time ton, tor Cit = Clo = 100pF 200 530 750 ns Maximum Data Rate fMAX 500 kbps Driver Enable to Output High toZH Figures 8 and 10, Cy. = 100pF, $2 closed 2500 ns Driver Enable to Output Low tozi Figures 8 and 10, CL = 100pF, S1 closed 2500 ns Driver Disable Time from Low toLz Figures 8 and 10, Cy. = 15pF, S1 closed 100 ns Driver Disable Time from High tpHz Figures 8 and 10, C= 15pF, S2 closed 100 ns . tRPLH, Figures 11 and 13; | Vip | 2 2.0V; Receiver Input to Output {RPHL rise and fall time of Vip < 15ns 127 200 ns E tRELH - tRPHL | Differential Figures 11 and 13; | Vip | 2 2.0V, Receiver Skew 'RSKD rise and fall time of Vip < 15ns 3 +30 ns Receiver Enable to Output Low tRZL Figures 6 and 12, Cy. = 100pF, S1 closed 20 50 ns Receiver Enable to Output High tRZH Figures 6 and 12, Cy, = 100pF, S2 closed 20 50 ns Receiver Disable Time from Low tALZ Figures 6 and 12, CL = 100pF, S1 closed 20 50 ns Noe Disable Time from taHz _| Figures 6 and 12, CL = 100pF, S2 closed 20 50 | ns Time to Shutdown ISHDN (Note 5) 50 200 600 ns Driver Enable from Shutdown to . Output High tDZH(SHDN) | Figures 8 and 10, CL = 15pF, S2 closed 4500 ns Driver Enable from Shutdown to : . Output Low toZL(SHDN) | Figures 8 and 10, CL = 15pF, S1 closed 4500 ns Receiver Enable from Shutdown . . to Output High tAZH(SHDN) | Figures 6 and 12, CL = 100pF, S2 closed 3500 ns Receiver Enable from Shutdown IRZL(SHDN) | Figures 6 and 12, C, = 100pF, $1 closed 3500 ns MA ARXLAA 2-91 i 680EXVN-O80EXVNMAX3080-MAX3089 Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers SWITCHING CHARACTERISTICSMAX3086-MAX3088, and MAX3089 with SRL = GND (Voc = +5V 5%, Ta = TMIN to TMAX, Unless otherwise noted. Typical values are at Vcc = +5V and Ta = +25C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX | UNITS . tOPLH Figures 7 and 9, Royer = 542, 34 60 Dr input , river input to Output PHL Cui = C2 = 100pF 34 60 ns Driver Output Skew Figures 7 and 9, Roirr = 540, t " 2. | tOPLH - topHi I DSKEW | CLy = CL2 = 100pF 28 #10 ns Driver Rise or Fall Time tor, tor Cen cope = 540, 14 25 ns Maximum Data Rate fMAX 19 Mbps Driver Enable to Output High tozH Figures 8 and 10, C, = 100pF, S2 closed 150 ns Driver Enable to Output Low toz. Figures 8 and 10, CL = 100pF, S1 closed 150 ns Driver Disable Time from Low toLz Figures 8 and 10, CL = 15pF, S1 closed 100 ns Driver Disable Time from High toHZ Figures 8 and 10, CL = 15pF, S2 closed 100 ns : tRPLH, Figures 11 and 13; | Vio } 2 2.0V: Receiver Input to Output ; IRPLL rise and fall time of Vio < 16ns 106 150 ns | tRPLH - trpHi | Differential Figures 11 and 13; | Vip | 2 2.0V; Receiver Skew 'RSKD rise and fail time of Vip < 15ns 9 +10 ns Receiver Enable to Output Low tazL Figures 6 and 12, Cy = 100pF, $1 closed 20 50 ns Receiver Enable to Output High tRZH Figures 6 and 12, Cy = 100pF, S2 closed 20 50 ns Receiver Disable Time from Low tALZ Figures 6 and 12, Cy. = 100pF, $1 closed 20 50 ns hon Disable Time from tAaHz Figures 6 and 12, CL = 100pF, S2 closed 20 50 ns Time to Shutdown tSHDN (Note 5) 50 200 600 ns Driver Enable from Shutdown to _ Output High tDZH(SHDN) | Figures 8 and 10, C, = 15pF, S2 closed 250 ns Driver Enabie from Shutdown to . _ Output Low tDZL{SHDN) | Figures 8 and 10, Cy = 15pF, S1 closed 250 ns Receiver Enable from Shutdown _ to Output High tRZH(SHDN) | Figures 6 and 12, C, = 100pF, S2 closed 3500 ns Receiver Enable from Shutdown _ to Output Low tRZLISHDN) | Figures 6 and 12, CL = 100pF, S1 closed 3500 ns Note 5: The device is put into shutdown by bringing RE high and DE tow. If the enable inputs are in this state for less than 50ns, the device is guaranteed not to enter shutdown. If the enable inputs are in this state for at least 60Ons, the device is guaranteed to have entered shutdown. 2-62 MAXISAFail-Safe, High-Speed (10Mbps), Siew-Rate-Limited RS-485/RS-422 Transceivers Typical Operating Characteristics (Vcc = +5V, Ta = +25C, unless otherwise noted.) NO-LOAD SUPPLY CURRENT OUTPUT CURRENT OUTPUT CURRENT vs, TEMPERATURE vs. RECEIVER OUTPUT LOW VOLTAGE vs. RECEIVER OUTPUT HIGH VOLTAGE 525 s 30 A: MIXDB6-MAXSOBS, 8 = MAX3089 WI = | sate eno | 50 25 5 475 w DE = Voc < <= rd LT = E = 450 = 4 ~ 20 3 go, [4 & z z Let |S De = GND 5 30 = 45 & 400 F L- a Ee L 2B am 5 5 Q 375 i E 2 E 10 o o o z 350 7 B: MAX3080-MAX3085- 1 5 = 95 MAX3089 WITH | 0 SRL = OPEN OR Voc 300 L L L 1 0 0 60 -40 -20 0 20 40 60 80 100 0 1 2 3 4 5 0 1 2 3 4 5 TEMPERATURE (C) QUTPUT LOW VOLTAGE (V) OUTPUT HIGH VOLTAGE (V) SHUTDOWN CURRENT RECEIVER QUTPUT LOW VOLTAGE RECEIVER OUTPUT HIGH VOLTAGE vs. TEMPERATURE vs. TEMPERATURE vs. TEMPERATURE 0.50 45 tao = BMA Ino = SMA _ 3% 44 2 = 3 0.40 = 43 ae & 0.35 = s s 5 42 = = 0.30 S ' = 54 8 i 025 = = 2 5 o20 3S 40 0.15 3.9 0.10 3.8 60-40 -20 0 20 40 60 80 100 60 -40 -20 0 20 40 60 80 100 -60 -40 -20 0 20 40 60 80 100 TEMPERATURE (C) TEMPERATURE (C) TEMPERATURE (C) RECEIVER PROPAGATION DELAY RECEIVER PROPAGATION DELAY DRIVER PROPAGATION DELAY (S00kbps MODE) vs. TEMPERATURE (10Mbps MODE) vs. TEMPERATURE (115kbps MODE) vs. TEMPERATURE 140 + 5 112 2.20 Coan = 100pF 110 = Ar = 540 _ y | - 2.15 z Y Z 108 2 > > > 3 % 106 % 2.10 8 130 LL B ios @ 3 | 3 5 2.05 = ns | z 102 & = a 100 & 2.00 e z & a 98 a 120 1.95 96 115 94 1.90 60 40 -20 0 20 40 60 80 100 60 -40 -20 0 20 40 60 80 100 60 -40 -20 0 20 40 60 80 100 TEMPERATURE (C) TEMPERATURE (C) TEMPERATURE {C) PRAMAKAMA 2-93 i 680EXVWI-OSOEXVNMAX3080-MAX3089 Fail-Safe, High-Speed (10Mbps)}, Siew-Rate-Limited RS-485/RS-422 Transceivers Typical Operating Characteristics (continued) (Vcc = +5V, Ta = +25C, unless otherwise noted.) DRIVER PROPAGATION DELAY DRIVER PROPAGATION DELAY DRIVER DIFFERENTIAL OUTPUT VOLTAGE (S00kbps MODE) vs. TEMPERATURE (10Mibps MODE) vs. TEMPERATURE vs. TEMPERATURE 920 ; 60 1.90 aso | Ar=540 55 R= 540 189 ~ 840 ol 2 2 50 > 800 > = 1.98 3 s 45 oo & 760 3 5 87 5 720 S 40 S @ 680 2 35 e\* 5 3 2 640 2 20 B 1.85 * 600 184 560 25 F 520 20 1.83 60 -40 -20 0 20 40 60 80 100 60 -40 -20 0 2% 40 60 80 10 60 40 -20 0 20 40 60 80 100 TEMPERATURE (C) TEMPERATURE (C) TEMPERATURE (*C) DRIVER OUTPUT CURRENT GUTPUT CURRENT vs. OUTPUT CURRENT vs. vs. DIFFERENTIAL OUTPUT VOLTAGE DRIVER OUTPUT LOW VOLTAGE _ BRIVER OUTPUT HIGH VOLTAGE 100 -100 20 z = z 2 & 10 = E 70 & ke & a 3 G -60 2 z = 3! 3 3 5 e = ze > Ss > 3 -20 10 0 0.01 a 1 2 3 4 5 0 2 4 6 8 10 12 8 4 2 0 2 4 6 DIFFERENTIAL OUTPUT VOLTAGE (V} OUTPUT LOW VOLTAGE (V) OUTPUT HIGH VOLTAGE (V) 2-94 MAAXLAAFail-Safe, High-Speed (10Mbps), Siew-Rate-Limited RS-485/RS-422 Transceivers Typical Operating Characteristics (continued) (Vec = +5V, Ta = +25C, unless otherwise noted.) RECEIVER PROPAGATION DELAY RECEIVER PROPAGATION DELAY MAX3086-MAX3038, AND MAX3089 MAX3080-MAN3O85, AND MAXSO89 WITH SRL = On WITH S&L = OPEN OR Vcc Va f : 2 , Va- | i wb oe bene : ante ij j tleteapecrel teas ota 3 ; i + i f Svfaiv Ro jot he Suciv S0nsiiv Sonsitiv i 680EXVW-O80EXVN W-Wy | Of YO. 2.5Vidiv | 2uyvdiv SVidiv Swdiv 4 25Vidiv asvidiv S00nsdiv : SOnsidiv MAXIM 205MAX3080-MAX3089 Fail-Safe, High-Speed (10Mbps}, Slew-Rate-Limited RS-485/RS-422 Transceivers Pin Description PIN MAX3080 | MAX3081 | MAX3082 MAX3083 | MAX3064 | MAX3085 MAX3089 MAX3086 | MAX3087 | MAX3068 NAME FUNCTION HALF- FULL- HALF- FOC VICES. | DUPLEX | DUPLEX | DUPLEX DEVICES| MODE MODE _ _ _ { 1 HE Half/Full-Duplex Selector Pin. Connect H/F to Vcc for half-duplex mode; connect to GND or leave unconnected for full-duplex mode. 2 2 1 2 2 RO Receiver Output. When RE is low and if A - B > -SOmvV, RO will be high; if A - B <-200mvV, RO will be low. Receiver Output Enable. Drive RE low to enable RO; RO is high 3 2 3 3 RE | impedance when Re is high. Drive RE high and DE low to enter low-power shutdown mode. Driver Output Enable. Drive DE high to enable driver outputs. These 4 _ 3 4 4 DE | outputs are high impedance when DE is low. Drive RE high and DE tow to enter low-power shutdown mode. Driver Input. With DE high, a low on Di forces noninverting output 5 3 4 5 5 DI | low and inverting output high. Similarly, a high on DI forces non- inverting output high and inverting output low. Slew-Rate-Limit Selector Pin. Connect SRL to GND for 10Mbps _ _ 6 6 SRL | communication rate; connect to Vcc for 500kbps communication rate. Leave unconnected for 115kbps communication rate. 6,7 4 5 7 7 GND | Ground Transmitter Phase. Connect TXP to GND, or leave floating for normal _ _ _ 8 8 TXP | transmitter phase/polarity. Connect to Vcc to invert the transmitter phase/polarity. 9 5 _ 9 _ Y | Noninverting Driver Output _ _ _ _ 9 Y | Noninverting Receiver Input and Noninverting Driver Output 10 6 _ 10 Z | inverting Driver Output _ _ _ 10 Z| Inverting Receiver Input and Inverting Driver Output" 11 7 - 11 ~ B | \nverting Receiver Input ~ ~ _ _ 11 B_ | Receiver input Resistors* _ _ 7 _ _ B_ | Inverting Receiver Input and Inverting Driver Output 2-96 FAAAXILMAFail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers Pin Description (continued) PIN MAX3080 | MAX3081 | MAX3082 MAX3083 | MAX3084 | MAX3085 MAX3089 MAX3086 | MAX3087 | MAX3088 NAME FUNCTION HALF- FULL- HALF- rOEVICES DUPLEX | DUPLEX | DUPLEX DEVICES| MODE MODE 12 8 _ 12 _ A | Noninverting Receiver Input _ _ 12 Receiver Input Resistors* _ _ 6 _ _~ A | Noninverting Receiver Input and Noninverting Driver Output Receiver Phase. Connect RXP to GND, or leave unconnected for 13 13 RXP_ | normal transmitter phase/polarity. Connect to Vcc to invert the receiver phase/polarity. 14 1 8 14 14 Vcc | Positive Supply; 4.75V < Vcc < 5.25V 1,8, 13 _ _ _ N.C. | Not Connected. Not internally connected. *(MAX3089 only.) In half-duplex mode, the driver outputs serve as receiver inputs. The full-duplex receiver inputs (A and B) will still have a 1/8-unit load, but are not connected to the receiver. Function Tables MAX3080/MAX3083/MAX3086 MAX3081/MAX3084/MAX3087 TRANSMITTING TRANSMITTING INPUTS OUTPUTS INPUT OUTPUTS RE DE Dl Z Y Dl Zz Y x 1 1 0 1 1 0 1 x 1 0 1 0 0 1 0 0 0 x High-Z High-Z 1 0 x Shutdown RECEIVING INPUTS OUTPUT RECEIVING A-B RO INPUTS OUTPUT 2 -0.05V 1 RE DE A-B RO <-0.2V 0 0 xX 2 -0.05V 1 Open/shorted 1 0 xX $-0.2V 0 0 Xx Open/shorted 1 1 1 X High-Z 1 0 x Shutdown X = Don't care Shutdown mode, driver and receiver outputs high impedance MAAXIIA 2-97 a 680EXVW-O80EXUWNFail-Safe, High-Speed (10Mbps), Siew-Rate-Limited RS-485/RS-422 Transceivers Function Tables (continued) MAX3080-MAX3089 MAX3082/MAX3085/MAX3088 MAX3089 TRANSMITTING TRANSMITTING INPUTS OUTPUTS INPUTS OUTPUTS RE DE DI B/Z AY TXP RE DE Bi Zz Y x 1 1 0 1 0 X 1 1 0 1 x 1 0 1 0 0 x 1 0 1 0 0 0 x High-Z High-Z 1 X 1 1 1 0 1 0 xX Shutdown 1 xX 1 0 0 1 xX 0 0 x High-Z | High-Z x 1 0 x Shutdown RECEIVING INPUTS OUTPUT RE DE AB RO RECEIVING 0 X 2 -0.05V 1 INPUTS OUTPUT 0 xX $-0.2V 0 H/F | RXP.| RE | DE A-B Y-Z RO 0 Xx Open/shorted 1 Q 0 0 Xx 2 -0.05V x 1 1 1 x High-Z 0 0 0 X $ -0.2V x 0 1 0 x Shutdown Q 1 0 x 2 -0.05V x 0 0 1 0 x s$-0.2V x 1 1 0 0 X x 2 -0.05V 1 1 0 0 x x <-0.2V 0 1 1 0 xX x 2 -0.05V 0 1 1 0 X x $-0.2V 1 o}o}o] x | Spent X Open, + }ofo]|x x eal 1 Nn, o] 1] o] x | pen x 0 Open 1] 1{o]x x oon 0 x | X 1 1 X x High-Z X x 1 0 xX X Shutdown X = Dont care Shutdown mode, driver and receiver outputs high impedance 2-98 PRAXLSAFail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers Voc DE ly 2 MAXIM Voc. RE O.1pF TOP VIEW 7 Hs =o MANGOES | N.C. i 4] Vcc MAX3086 ro [2 H3jNc. gy fe OCC | a ri man fo oe [a] ri} 1204 ot psf me (OO lsh ss i ; KN ono [7 | Ol 3 [6,7 |6nD DIP/SO it = GND DE ol te Figure 1. MAX3080/MAX3083/MAX3086 Pin Configuration and Typical Full-Duplex Operating Circuit | > maam Vee TOP VIEW Volt = MAX3081 MAN30B4 MAX30B7 RO Veo [1] ByA 1 ee B BI Fe i wot SEG Ut CO B r Dl | JAN DIP/SO 4{ GND = GND Figure 2. MAX3081/MAX3084/MAX3087 Pin Configuration and Typical Full-Duplex Operating Circuit TOP VIEW AAAXLAA ne hasanns oe Pad et i MAX3088 a1 ot <i ] [8] vec RO <r a} Vec 6 | F [2] [7] 8 r [2 a Ri i oe [3] +Ta] a oe [3] i pees Sean o [4] 5] eno ot [4] 5 ero] L - DIP/SO |e NOTE: PIN LABELS Y AND Z ON TIMING, TEST, AND WAVEFORM DIAGRAMS REFER TO PINS A AND B WHEN DE IS KIGH. Figure 3. MAX3082/MAX3085/MAX3088 Pin Configuration and Typical Half-Duplex Operating Circuit MAAXLIA 2-89 iy 680EXVN-OSOEXVUNMAX3080-MAX3089 Fail-Safe, High-Speed (10Mbps), Silew-Rate-Limited RS-485/RS-422 Transceivers Detailed Description The MAX3080-MAX3089 high-speed transceivers for RS-485/RS-422 communication contain one driver and one receiver, These devices feature fail-safe circuitry, which guarantees a logic-high receiver output when the receiver inputs are open or shorted, or when they are connected to a terminated transmission line with all drivers disabled (see Fail-Safe section). The MAX3080/ MAX3081/MAX3082 feature reduced slew-rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, allowing error-free data transmission up to 115kbps (see Reduced EM! and Reflections section). The MAX3083/MAX3084/MAX3085 offer higher driver output slew-rate limits, allowing transmit speeds up to 500kbps. The MAX3086/ MAX3087/MAX3088's driver slew rates are not limited, making transmit speeds up to 10Mbps possible. The MAX3089s slew rate is selectable between 115kbps, 500kbps, and 10Mbps by driving a selector pin with a three-state driver. The MAX3082/MAX3085/MAX3088 are half-duplex transceivers, while the MAX3080/MAX308 1/MAX3083/ MAX3084/MAX3086/MAX3087 are full-duplex trans- ceivers. The MAX3089 is selectable between half- and full-duplex communication by driving a selector pin high or low, respectively. All of these parts operate from a single +5V supply. Drivers are output short-circuit current limited. Thermal shutdown circuitry protects drivers against excessive power dissipation. When activated, the thermal shut- down circultry places the driver outputs into a high- impedance state. Receiver input Filtering The receivers of the MAX3080-MAX3085, and the MAX3089 when operating in 115kbps or 500kbps mode, incorporate input filtering in addition to input hysteresis. This filtering enhances noise immunity with differential signals that have very slow rise and fail times. Receiver propagation delay increases by 20% due to this filtering. RD TOP VIEW . WFO] Ha] Vcc | XP no [2 | fia] axe aE[3] maxzoag = fizja ve [4] i} 8 W o [5 | ho] z sat [6 | jy =O cno [7 la | rxP DIP/SO u NOTE: SWITCH POSITIONS INDICATED FOR H/F = GND Figure 4. MAX3080/MAX3089 Pin Configuration and Functional Diagram 2-100 PAAXLIAFail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers Von Voc 4 RECEIVER TEST POINT OUTPUT Figure 5. Driver DC Test Load Fail-Safe The MAX3080 family guarantees a logic-high receiver output when the receiver inputs are shorted or open, or when they are connected to a terminated transmission line with all drivers disabled. This is done by setting the receiver threshold between -50mV and -200mV. If the differential receiver input voltage (A-B) is greater than or equal to -SOmvV, RO is logic high. If A-B is less than or equal to -200mV, RO is logic low. In the case of a terminated bus with all transmitters disabled, the receiver's differential input voltage is pulled to OV by the termination. With the receiver thresholds of the MAX3080 family, this results in a logic high with a 50mV minimum noise margin. Unlike previous fail-safe devices, the -5OmV to -200mV threshold complies with the +200mV EIA/TIA-485 standard. MAX3089 Programming The MAX3089 has several programmable operating modes. Transmitter rise and fall times are programma- ble between 2500ns, 750ns, and 25ns, resulting in maximum data rates of 115kbps, 500kbps, and 10Mbps, respectively. To select the desired data rate, drive SRL to one of three possible states by using a three-state driver, by connecting it to Vcc or GND, or by leaving it unconnected. For 115kbps operation, set the three-state device in high-impedance mode or jeave SRL unconnected. For 500kbps operation, drive SRL high or connect it to Vcc. For 10Mbps operation, drive SRL low or connect it to GND. SRL can be changed during operation without interrupting data communications. Occasionally, twisted-pair lines are connected back- ward from normal orientation. The MAX3089 has two pins that invert the phase of the driver and the receiver fo correct for this problem. For normal operation, drive PAAKISA Figure 6. Receiver Enable/Disable Timing Test Load TXP and RXP low, connect them to ground, or leave them unconnected (internal pull-down). To invert the driver phase, drive TXP high or connect it to Voc. To invert the receiver phase, drive RXP high or connect it to Vcc. Note that the receiver threshold is positive when RXP is high. The MAX3088 can operate in fult- or half-duplex mode. Drive the H/F pin low, feave it unconnected (internal pull-down), or connect it to GND for full-duplex opera- tion, and drive it high for half-duplex operation. In full- duplex mode, the pin configuration of the driver and receiver is the same as that of a MAX3080 (Figure 4). In half-duplex mode, the receiver inputs are switched to the driver outputs, connecting outputs Y and Z to inputs A and B, respectively. In half-duplex mode, the internal full-duplex receiver input resistors are still connected to pins 11 and 12. Applications Information 256 Transceivers on the Bus The standard RS-485 receiver input impedance is 12kQ (one-unit load), and the standard driver can drive up to 32 unit loads. The MAX3080 family of transceivers have a 1/8-unit-load receiver input impedance (96kQ), allow- ing up to 256 transceivers to be connected in parallel on one communication line. Any cornbination of these devices and/or other RS-485 transceivers with a total of 32 unit loads or less can be connected to the line. Reduced EMI and Reflections The MAX3080-MAX3085, and MAX3089 with SRL = Vcc or unconnected, are slew-rate limited, minimizing EMI and reducing reflections caused by improperly termi- nated cables. Figure 14 shows the driver output wave- form and its Fourier analysis of a 20kHz signal transmitted by a MAX3086/MAX3087/MAX3088, and MAX3089 with SRL = GND. High-frequency harmonic 2-101 a 680EXVIN-O8SOEXVWMAX3080-MAX3089 Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers OUTPUT. UNDER TEST + r* Figure 7. Driver Timing Test Circuit Figure 8. Driver Enable/Disable Timing Test Load av i) 15V 15V ov 4a fp Yo Voir = V (Y}- V2) VolrF gy 10% 90% 0% Vo fa Lid tsew =! tru tp | OE w IV Ae * 1.5 | le leysHon), tan tur! ee ,z_ Vou 2.3 QUTPUT NORMALLY LOW Vot +0.5 OUTPUT NORMALLY HIGH 2a Vou -0.5V >| << {ZH(SHON), {2H ty | je Figure 9. Driver Propagation Delays Figure 10. Driver Enable and Disable Times (except MAX3081/MAX3084/MAX3087) =v = FE 15V 15V wv 7 Vou RO 15V 15 Vow OUTPUT : em} [e tzysiow), t2 bz e| a Voc wea te a AO 1.5V OUTPUT NORMALLY LOW Vo. +0.5V WB INPUT OUTPUT NORMALLY HIGH RO You -0SV ov > tw |< Figure 11. Receiver Propagation Delays 2-402 Figure 12. Receiver Enable and Disable Times (except MAX308 1/MAX3084/MAX3087) MAAXLMAFail-Safe, High-Speed (10Mbps), Siew-Rate-Limited RS-485/RS-422 Transceivers y+ Le RECEIVER ATE + > OUTPUT [A 200B/div OHz 100kHz/div 1MHz Figure 13. Receiver Propagation Delay Test Circuit Figure 14. Driver Output Waveform and FFT Plot of MAX3086/MAX3087/MAX3088, and MAX3089 with SAL = GND, Transmitting a 20kHz Signal Wardoeaqeee Fg-15, 200B/div Hz 100kH2/div IMHz MCInERYanD FG- 16 200B/div OHz TOOkHz/div MHz Figure 15. Driver Output Waveform and FFT Plot of MAX3083/MAX3084/MAX3085, and MAX3089 with SRL = Vcc, Transmitting a 20kHz Signal components with large amplitudes are evident. Figure 15 shows the same signal displayed for a MAX3083/ MAX3084/MAX3085, and MAX3089 with SRL = VCC), transmitting under the same conditions. Figure 15s high-frequency harmonic components are much lower in amplitude, compared with Figure 14s, and the poten- tial for EMI is significantly reduced. Figure 16 shows the same signal displayed for a MAX3080/ MAX3081/MAX3082, and MAX3089 with SRL = uncon- nected, transmitting under the same conditions. Figure 16s high-frequency harmonic components are even lower. MAAXUMA Figure 16. Driver Output Waveform and FFT Pilot of MAX3080/MAX308 1/MAX3082, and MAX3089 with SRL = Unconnected, Transmitting a 20kHz Signal In general, a transmitters rise time relates directly to the length of an unterminated stub, which can be driven with only minor waveform reflections. The following equation expresses this relationship conservatively: Length = trise / (10 x 1.5ns/ft) where trISE is the transmitter's rise time. For example, the MAX3080's rise time is typically 1320ns, which results in excellent waveforms with a stub length up to 90 feet. A system can work well with longer unterminated stubs, even with severe reflections, if the waveform settles out before the UART samples them. 2-103 a 680EXVN-O80EXUNMAX3080-MAX3089 2-104 Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers MNAAXIMA MAX3080/MAX308 1/MAX3083/ MAX3084/MAX3086/MAX3087/ MAX3089 (FULL DUPLEX) A OE z > yl es DATA OUT NOTE: RE AND DE ON MAX3083/MAX3086/MAX3089 ONLY. Ot Va-Va Po 5Vidiv Sps/div Figure 17. Line Repeater for MAX3080/MAX308 1/ MAX3083/MAX3084/MAX3086/MAX3087, and MAX3089 in Full-Duplex Mode Low-Power Shutdown Mode (except MAX3082/MAX3085/MAX3088) Low-power shutdown mode is initiated by bringing both RE high and DE low. In shutdown, the devices typically draw only 1nA 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 flow for less than 50ns. If the inputs are in this state for at least 600ns, the parts are guaranteed to enter shutdown. Enable times tzH and tz in the Switching Char- acteristics tables assume the part was not in a low- power shutdown state. Enable times tZH(SHDN) and tZL(SHDN) assume the parts were shut down. It takes drivers and receivers longer to become enabled from low-power shutdown mode (tZH(SHDN), tZH(SHDN)) than from driver/receiver-disable mode (tZx, 121). Driver Output Protection Two mechanisms prevent excessive output current and power dissipation caused by faults or by bus con- tention. The first, 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). The second, a ther- mal shutdown circuit, forces the driver outputs into a high-impedance state if the die temperature becomes excessive. Figure 18. MAX3080/MAX3081/MAX3082, and MAX3089 with SRL = Unconnected, System Differential Voltage at 50kHz Driving 4000 feet of Cable Line Length vs. Data Rate The RS-485/RS-422 standard covers line lengths up to 4000 feet. For line lengths greater than 4000 feet, use the repeater application shown in Figure 17. Figures 18, 19, and 20 show the system differential volt- age for the parts driving 4000 feet of 26AWG twisted- pair wire at 110kHz into 120Q loads. Typical Applications The MAX3082/MAX3085/MAX3088/MAX3089 trans- ceivers are designed for bidirectional data communica- tions on multipoint bus transmission lines. Figures 21 and 22 show typical network applications circuits. These parts can also be used as line repeaters, with cable lengths longer than 4000 feet, as shown in Figure 17. To minimize reflections, the line should be terminated at both ends in its characteristic impedance, and stub langths off the main line should be kept as short as possible. The slew-rate-limited MAX3082/MAX3085, and the two modes of the MAX3089, are more tolerant of imperfect termination. MAAXIAAFail-Safe, High-Speed (10Mbps), Siew-Rate-Limited RS-485/RS-422 Transceivers of Svitiv al Svidiv Va-B 4Widiv Va-VB | $Vidiv Svidiv RO 5V/civ Qus/div lps/div Figure 19. MAX3083/MAX3084/MAX3085, and MAX3089 with Figure 20. MAX3086/MAX3087/MAX3088, and MAX3089 with SRL = Vcc, System Differential Voltage at 50kHz Driving 4000 SAL = GND, System Differential Voltage at 200kMz Driving feet of Cable 4000 feet of Cable Figure 21. Typical Half-Duplex RS-485 Network MAXI 2-105 P 680EXVN-O8SOEXVNMAX3080-MAX3089 Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers DE RERO NOTE: RE AND DE ON MAX3080/MAX3083/MAX3086 ONLY. DE RE R RO yf lz MAXIM MAX3081 MAX3083 MAX3064 MAX3086 MAX3087 Figure 22. Typical Full-Duplex RS-485 Network Ordering Information (continued) PART TEMP. RANGE PIN-PACKAGE MAX3081CPA OC to +70C 8 Plastic DIP MAX3081CSA OC to +70C 8S0 MAX3081EPA -40C to +85C 8 Plastic DIP MAX3081ESA -40C to +85C 8so MAX3082CPA OC to +70C 8 Plastic DIP MAX3082CSA OC to +70C 8S0 MAX3082EPA -40C to +85C 8 Plastic DIP MAX3082ESA -40C to +85C 8S0 MAX3083CPD 0C to +70C 14 Plastic DIP MAX3083CSD OC to +70C 14S0 MAX3083EPD -40C to +85C 14 Plastic DIP MAX3083ESD -40C to +85C 1480 MAX3084CPA OC to +70C 8 Plastic DIP MAX3084CSA OC to +70C 8so MAX3084EPA -40C to +85C 8 Plastic DIP MAX3084ESA -40C to +85C 8SO MAX3085CPA OC to +70C 8 Plastic DIP MAX3085CSA OC to +70C 8SO MAX3085EPA -40C to +85C 8 Plastic DIP MAX3085ESA -40C to +85C 8SoO 2-106 PART TEMP. RANGE PIN-PACKAGE MAX3086CPD OC to +70C 14 Plastic DIP MAX3086CSD OC to +70C 1450 MAX3086EPD -40C to +85C 14 Plastic DIP MAX3086ESD -40C to +85C 14SO0 MAX3087CPA OC to +70C 8 Plastic DIP MAX3087CSA OC to +70C 8sO MAX3087EPA -40C to +85C 8 Plastic DIP MAX3087ESA -40C to +85C 8SO0 MAX3088CPA OC to +70C 8 Plastic DIP MAX3088CSA QC to +70C 8SO MAX3088EPA --40C to +85C 8 Plastic DIP MAX3088ESA -40C to +85C 8so MAX3089CPD OC to +70C 14 Plastic DIP MAX3089CSD OC to +70C 14S0 MAX308SEPD -40C to +85C 14 Plastic DIP MAX3089ESD -40C to +85C 1450 MARAAXALMA