3.3 V Slew Rate Limited, Half- and Full-Duplex, RS-485/RS-422 Transceivers Data Sheet ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 FEATURES FUNCTIONAL BLOCK DIAGRAMS Operate with 3.3 V supply VCC Interoperable with 5 V logic ADM3483/ EIA RS-422 and RS-485 compliant over full ADM3485 common-mode range RO R Data rate options ADM3483/ADM3488: 250 kbps RE A ADM3485/ADM3490/ADM3491: 10 Mbps DE B Half- and full-duplex options R2 endAu scuepdp sllye wcu rrarteenst f ionr s lhouwt dEMowI (nA mDMod3e4 83 and ADM3488) DI D 05524-027 GND (ADM3483/ADM3485/ADM3491) Figure 1. Up to 32 transceivers on the bus −7 V to +12 V bus common-mode range VCC Specified over the –40°C to +85°C temperature range A 8 ns skew (ADM3485/ADM3490/ADM3491) RO R 8-lead SOIC and 14-lead SOIC (ADM3491 only) packages B ADM3488/ APPLICATIONS ADM3490 Z Low power RS-485/RS-422 applications TInedleucsotmria l process control DI D Y 05524-026 GND HVAC Figure 2. GENERAL DESCRIPTION ADM3491 The ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 are A RO R low power, differential line transceivers designed to operate using a single 3.3 V power supply. Low power consumption, coupled with a RE B shutdown mode, makes the ADM3483/ADM3485/ADM3488/ DE Z ADM3490/ADM3491 ideal for power-sensitive applications. The ADM3488/ADM3490/ADM3491 feature full-duplex com- DI D Y 05524-025 munication, while the ADM3483/ADM3485 are designed for Figure 3. half-duplex communication. The ADM3483/ADM3488 feature slew rate limited drivers that in the internal driver circuitry during fault conditions, then the minimize EMI and reduce reflections caused by improperly ter- thermal shutdown circuit forces the driver output into a high minated cables, allowing error-free data transmission at data rates impedance state. If the inputs are unconnected (floating), the up to 250 kbps. receiver contains a fail-safe feature that results in a logic high output state. The parts are fully specified over the commercial The ADM3485/ADM3490/ADM3491 transmit at up to 10 Mbps. and industrial temperature ranges. The ADM3483/ADM3485/ The receiver input impedance is 12 kΩ, allowing up to 32 trans- ADM3488/ADM3490 are available in 8-lead SOIC_N; the ceivers to be connected on the bus. A thermal shutdown circuit ADM3491 is available in a 14-lead SOIC_N. prevents excessive power dissipation caused by bus contention or by output shorting. If a significant temperature increase is detected Rev. E Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 781.329.4700 www.analog.com Trademarks and registered trademarks are the property of their respective owners. Fax: 781.461.3113 ©2005-2011 Analog Devices, Inc. All rights reserved.

ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 Data Sheet TABLE OF CONTENTS Features..............................................................................................1  Switching Characteristics..............................................................13  Applications.......................................................................................1  Circuit Description.........................................................................14  General Description.........................................................................1  Devices with Receiver/Driver Enables Functional Block Diagrams.............................................................1  (ADM3483/ADM3485/ADM3491).........................................14  Revision History...............................................................................2  Devices Without Receiver/Driver Enables— ADM3488/ADM3490................................................................14  Specifications.....................................................................................4  Reduced EMI and Reflections (ADM3483/ADM3488).......14  Timing Specifications—ADM3485/ADM3490/ADM3491....5  Low Power Shutdown Mode Timing Specifications—ADM3483/ADM3488........................5  (ADM3483/ADM3485/ADM3491).........................................14  Timing Specifications— Driver Output Protection..........................................................14  ADM3483/ADM3485/ADM3488/ADM3490/ADM3491......6  Propagation Delay......................................................................14  Absolute Maximum Ratings............................................................7  Typical Applications...................................................................14  ESD Caution..................................................................................7  Line Length vs. Data Rate.........................................................15  Pin Configurations and Function Descriptions...........................8  Outline Dimensions.......................................................................17  Typical Performance Characteristics.............................................9  Ordering Guide..........................................................................18  Test Circuits.....................................................................................11  REVISION HISTORY 11/11—Rev. D to Rev. E Changes to Digital I/O Voltage (DE, RE, DI) Parameter, Table 6................................................................................................7 10/06—Rev. A to Rev. B Moved Typical Performance Characteristics Section..................9 Updated Format..................................................................Universal Moved Test Circuits Section..........................................................11 Added ADM3491...............................................................Universal Moved Switching Characteristics Section...................................13 Changes to Specifications Section...................................................4 Changes to Note 1, Table 8............................................................14 Changes to Typical Applications Section....................................14 Changes to Outline Dimensions...................................................17 7/06—Rev. 0 to Rev. A 12/10—Rev. C to Rev. D Changes to Applications...................................................................1 Changes to Figure 33......................................................................15 Changes to General Description.....................................................1 Changes to Figure 19......................................................................10 8/10—Rev. B to Rev. C Changes to Typical Applications Section....................................13 Changes to Table 2, Driver Input Logic.........................................4 Changes to Figure 31 and Figure 32.............................................14 Updated Outline Dimensions.......................................................15 10/05—Revision 0: Initial Version Rev. E | Page 2 of 20

Data Sheet ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 Table 1. ADM34xx Part Comparison Guaranteed Supply Half-/Full- Slew Rate Driver/Receiver Shutdown Pin Part No. Data Rate (Mbps) Voltage (V) Duplex Limited Enable Current (nA) Count ADM3483 0.25 3.0 to 3.6 Half Yes Yes 2 8 ADM3485 10 3.0 to 3.6 Half No Yes 2 8 ADM3488 0.25 3.0 to 3.6 Full Yes No N/A 8 ADM3490 10 3.0 to 3.6 Full No No N/A 8 ADM3491 10 3.0 to 3.6 Full No Yes 2 14 Rev. E | Page 3 of 20

ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 Data Sheet SPECIFICATIONS V = 3.3 V ± 0.3 V, T = T to T , unless otherwise noted. CC A MIN MAX Table 2. Parameter Min Typ Max Unit Test Conditions/Comments DRIVER Differential Output Voltage (V ) 2.0 V R = 100 Ω (RS-422), V = 3.3 V ± 5% (see Figure 17) OD L CC 1.5 V R = 54 Ω (RS-485) (see Figure 17) L 1.5 V R = 60 Ω (RS-485), V = 3.3 V (see Figure 18) L CC Δ |V | for Complementary Output States1 0.2 V R = 54 Ω or 100 Ω (see Figure 17) OD L Common-Mode Output Voltage (V ) 3 V R = 54 Ω or 100 Ω (see Figure 17) OC L Δ |V | for Common-Mode Output Voltage1 0.2 V R = 54 Ω or 100 Ω (see Figure 17) OC L DRIVER INPUT LOGIC CMOS Input Logic Threshold Low (V ) 0.8 V DE, DI, RE IL CMOS Input Logic Threshold High (V ) 2.0 V DE, DI, RE IH CMOS Logic Input Current (I ) ±2 μA DE, DI, RE IN1 Input Current—A, B (I ) 1.0 mA V = 12 V, DE = 0 V, V = 0 V or 3.6 V IN2 IN CC −0.8 mA V = −7 V, DE = 0 V, V = 0 V or 3.6 V IN CC Output Leakage—Y, Z (I ) 0.1 μA V = 12 V, DE = 0 V, RE = 0 V, V = 0 V or 3.6 V, O IN CC ADM3491 only −0.1 μA V = −7 V, DE = 0 V, RE = 0 V, V = 0 V or 3.6 V, IN CC ADM3491 only Output Leakage (Y, Z) in Shutdown Mode (I ) 0.01 μA V = 12 V, DE = 0 V, RE = V , V = 0 V or 3.6 V, O IN CC CC ADM3491 only −0.01 μA V = −7 V, DE = 0 V, RE = V , V = 0 V or 3.6 V, IN CC CC ADM3491 only RECEIVER Differential Input Threshold Voltage (V ) −0.2 +0.2 V −7 V < V < +12 V TH CM Input Hysteresis (Δ V ) 50 mV V = 0 V TH CM CMOS Output Voltage High (V ) V – 0.4 V I = −1.5 mA, V = 200 mV (see Figure 19) OH CC OUT ID CMOS Output Voltage Low (V ) 0.4 V I = 2.5 mA, V = 200 mV (see Figure 19) OL OUT ID Three-State Output Leakage Current (I ) ±1 μA V = 3.6 V, 0 V ≤ V ≤ V OZR CC OUT CC Input Resistance (R ) 12 kΩ −7 V < V < +12 V IN CM POWER SUPPLY CURRENT Supply Current (I ) 1.1 2.2 mA DE = V , RE = 0 V or V ,no load, DI = 0 V or V CC CC CC CC 0.95 1.9 mA DE = 0 V, RE = 0 V, no load, DI = 0 V or V CC Supply Current in Shutdown Mode (I ) 0.002 1 μA DE = 0 V, RE = V , DI = V or 0 V SHDN CC CC Driver Short-Circuit Output Current (I ) −250 mA V = −7 V OSD OUT 250 mA V = 12 V OUT Receiver Short-Circuit Output Current (I ) ±8 ±60 mA 0 V < V < V OSR RO CC 1∆VOD and ∆VOC are the changes in VOD and VOC, respectively, when DI input changes state. Rev. E | Page 4 of 20

Data Sheet ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 TIMING SPECIFICATIONS—ADM3485/ADM3490/ADM3491 V = 3.3 V, T = 25°C, unless otherwise noted. CC A Table 3. Parameter Min Typ Max Unit Test Conditions/Comments DRIVER Differential Output Delay (tDD) 1 22 35 ns RL = 60 Ω (see Figure 20 and Figure 26) Differential Output Transition Time (tTD) 3 8 25 ns RL = 60 Ω (see Figure 20 and Figure 26) Propagation Delay, Low-to-High Level (tPLH) 7 22 35 ns RL = 27 Ω (see Figure 21 and Figure 27) Propagation Delay, High-to-Low Level (tPHL) 7 22 35 ns RL = 27 Ω (see Figure 21 and Figure 27) |tPLH – tPHL| Propagation Delay Skew1 (tPDS) 8 ns RL = 27 Ω (see Figure 21 and Figure 27) DRIVER OUTPUT ENABLE/DISABLE TIMES (ADM3485/ ADM3491 ONLY) Output Enable Time to Low Level (tPZL) 45 90 ns RL = 110 Ω (see Figure 23 and Figure 29) Output Enable Time to High Level (tPZH) 45 90 ns RL = 110 Ω (see Figure 22 and Figure 28) Output Disable Time from High Level (tPHZ) 40 80 ns RL = 110 Ω (see Figure 22 and Figure 28) Output Disable Time from Low Level (tPLZ) 40 80 ns RL = 110 Ω (see Figure 23 and Figure 29) Output Enable Time from Shutdown to Low Level (tPSL) 650 900 ns RL = 110 Ω (see Figure 23 and Figure 29) Output Enable Time from Shutdown to High Level (tPSH) 650 900 ns RL = 110 Ω (see Figure 22 and Figure 28) 1 Measured on |tPLH (Y) − tPHL (Y)| and |tPLH (Z) − tPHL (Z)|. TIMING SPECIFICATIONS—ADM3483/ADM3488 V = 3.3 V, T = 25°C, unless otherwise noted. CC A Table 4. Parameter Min Typ Max Unit Test Conditions/Comments DRIVER Differential Output Delay (tDD) 600 900 1400 ns RL = 60 Ω (see Figure 20 and Figure 26) Differential Output Transition Time (tTD) 400 700 1200 ns RL = 60 Ω (see Figure 20 and Figure 26) Propagation Delay, Low-to-High Level (tPLH) 700 1000 1500 ns RL = 27 Ω (see Figure 21 and Figure 27) Propagation Delay, High-to-Low Level (tPHL) 700 1000 1500 ns RL = 27 Ω (see Figure 21 and Figure 27) |tPLH – tPHL| Propagation Delay Skew1 (tPDS) 100 ns RL = 27 Ω (see Figure 21 and Figure 27) DRIVER OUTPUT ENABLE/DISABLE TIMES (ADM3483 ONLY) Output Enable Time to Low Level (tPZL) 900 1300 ns RL = 110 Ω (see Figure 23 and Figure 29) Output Enable Time to High Level (tPZH) 600 800 ns RL = 110 Ω (see Figure 22 and Figure 28) Output Disable Time from High Level (tPHZ) 50 80 ns RL = 110 Ω (see Figure 22 and Figure 28) Output Disable Time from Low Level (tPLZ) 50 80 ns RL = 110 Ω (see Figure 23 and Figure 29) Output Enable Time from Shutdown to Low Level (tPSL) 1.9 2.7 μs RL = 110 Ω (see Figure 23 and Figure 29) Output Enable Time from Shutdown to High Level (tPSH) 2.2 3.0 μs RL = 110 Ω (see Figure 22 and Figure 28) 1 Measured on |tPLH (Y) − tPHL (Y)| and |tPLH (Z) − tPHL (Z)|. Rev. E | Page 5 of 20

ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 Data Sheet TIMING SPECIFICATIONS—ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 V = 3.3 V, T = 25°C, unless otherwise noted. CC A Table 5. Parameter Min Typ Max Unit Test Conditions/Comments RECEIVER Time to Shutdown (t ) SHDN ADM3483/ADM3485/ADM34911 80 190 300 ns Propagation Delay, Low-to-High Level (t ) RPLH ADM3485/ADM3490/ADM3491 25 65 90 ns V = 0 V to 3.0 V, C = 15 pF (see Figure 24 and Figure 30) ID L ADM3483/ADM3488 25 75 120 ns Propagation Delay, High-to-Low Level (t ) RPHL ADM3485/ADM3490/ADM3491 25 65 90 ns V = 0 V to 3.0 V, C = 15 pF (see Figure 24 and Figure 30) ID L ADM3483/ADM3488 25 75 120 ns |t – t | Propagation Delay Skew (t ) PLH PHL RPDS ADM3485/ADM3490/ADM3491 10 ns V = 0 V to 3.0 V, C = 15 pF (see Figure 24 and Figure 30) ID L ADM3483/ADM3488 20 ns RECEIVER OUTPUT ENABLE/DISABLE TIMES (ADM3483/ADM3485/ADM3491 ONLY) Output Enable Time to Low Level (t ) 25 50 ns C = 15 pF (see Figure 25 and Figure 31) PRZL L Output Enable Time to High Level (t ) 25 50 ns C = 15 pF (see Figure 25 and Figure 31) PRZH L Output Disable Time from High Level (t ) 25 45 ns C = 15 pF (see Figure 25 and Figure 31) PRHZ L Output Disable Time from Low Level (t ) 25 45 ns C = 15 pF (see Figure 25 and Figure 31) PRLZ L Output Enable Time from Shutdown to 720 1400 ns C = 15 pF (see Figure 25 and Figure 31) L Low Level (t ) PRSL Output Enable Time from Shutdown to 720 1400 ns C = 15 pF (see Figure 25 and Figure 31) L High Level (t ) PRSH 1 The transceivers are put into shutdown by bringing the RE high and DE low. If the inputs are in this state for less than 80 ns, the parts are guaranteed not to enter shutdown. If the parts are in this state for 300 ns or more, the parts are guaranteed to enter shutdown. Rev. E | Page 6 of 20

Data Sheet ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 ABSOLUTE MAXIMUM RATINGS T = 25°C, unless otherwise noted. A Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress Table 6. rating only; functional operation of the device at these or any Parameter Rating other conditions above those indicated in the operational V to GND 7 V CC section of this specification is not implied. Exposure to absolute Digital I/O Voltage (DE, RE, DI) −0.3 V to +6 V maximum rating conditions for extended periods may affect Digital I/O Voltage (RO) V − 0.5 V to V + 0.5 V CC CC device reliability. Driver Output/Receiver Input Voltage −7.5 V to +12.5 V Operating Temperature Range −40°C to +85°C Storage Temperature Range −65°C to +125°C ESD CAUTION θ Thermal Impedance JA 8-Lead SOIC 121°C/W 14-Lead SOIC 86°C/W Lead Temperature Soldering (10 sec) 300°C Vapor Phase (60 sec) 215°C Infrared (15 sec) 220°C Rev. E | Page 7 of 20

ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 Data Sheet PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS RO 1 ADM3483/ 8 VCC RE 2 ADM3485 7 B DDEI 34 (NToOtPtoVSIEcWale) 65 AGND 05524-028 Figure 4. ADM3483/ADM3485 Pin Configuration VCC 1 ADM3488/ 8 A RO 2 ADM3490 7 B GNDDI 34 (NToOtPtoVSIEcWale) 65 ZY 05524-029 Figure 5. ADM3488/ADM3490 Pin Configuration NC 1 14 VCC RO 2 13 VCC RE 3 ADM3491 12 A DE 4 TOPVIEW 11 B (NottoScale) DI 5 10 Z GND 6 9 Y GND N7C=NOCONNECT8 NC 05524-030 Figure 6. ADM3491 Pin Configuration Table 7. Pin Function Descriptions ADM3483/ ADM3488/ ADM3491 ADM3485 Pin No. ADM3490 Pin No. Pin No. Mnemonic Description 1 2 2 RO Receiver Output. When enabled, if A > B by 200 mV, then RO = high. If A < B by 200 mV, then RO = low. 2 Not applicable 3 RE Receiver Output Enable. A low level enables the receiver output, RO. A high level places it in a high impedance state. If RE is high and DE is low, the device enters a low power shutdown mode. 3 Not applicable 4 DE Driver Output Enable. A high level enables the driver differential Output A and Output B. A low level places it in a high impedance state. If RE is high and DE is low, the device enters a low power shutdown mode. 4 3 5 DI Driver Input. With a half-duplex part when the driver is enabled, a logic low on DI forces A low and B high while a logic high on DI forces A high and B low. With a full-duplex part when the driver is enabled, a logic low on DI forces Y low and Z high while a logic high on DI forces Y high and Z low. 5 4 6, 7 GND Ground. Not applicable 5 9 Y Noninverting Driver Output. Not applicable 6 10 Z Inverting Driver Output. 6 Not applicable Not applicable A Noninverting Receiver Input A and Noninverting Driver Output A. Not applicable 8 12 A Noninverting Receiver Input A. 7 Not applicable Not applicable B Inverting Receiver Input B and Inverted Driver Output B. Not applicable 7 11 B Inverting Receiver Input B. 8 1 13, 14 VCC Power Supply (3.3 V ± 0.3 V). Not applicable Not applicable 1, 8 NC No Connect. Rev. E | Page 8 of 20

Data Sheet ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 TYPICAL PERFORMANCE CHARACTERISTICS 30 0.8 0.7 25 0.6 URRENT (mA) 2105 VOLTAGE (V) 00..54 T C UT U P 0.3 TP 10 UT U O O 0.2 5 0 05524-012 0.01 05524-015 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 OUTPUTVOLTAGE(V) TEMPERATURE(°C) Figure 7. Output Current vs. Receiver Output Low Voltage Figure 10. Receiver Output Low Voltage vs. Temperature, IRO = 2.5 mA –16 100 90 –14 80 –12 mA) mA) 70 NT ( –10 NT ( 60 E E R R UR –8 UR 50 C C UT –6 UT 40 P P T T U U 30 O –4 O 20 –20 05524-013 100 05524-016 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 OUTPUTVOLTAGE(V) OUTPUTVOLTAGE(V) Figure 8. Output Current vs. Receiver Output High Voltage Figure 11. Driver Output Current vs. Differential Output Voltage 3.30 2.6 2.5 3.25 2.4 V) V) 2.3 E ( 3.20 E ( G G 2.2 A A T T L L O 3.15 O 2.1 V V T T U U 2.0 P P UT 3.10 UT O O 1.9 1.8 3.05 3.00 05524-014 11..67 05524-017 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 TEMPERATURE(°C) TEMPERATURE(°C) Figure 9. Receiver Output High Voltage vs. Temperature, IRO = 1.5 mA Figure 12. Driver Differential Output Voltage vs. Temperature, RL = 54 Ω Rev. E | Page 9 of 20

ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 Data Sheet 140 1.2 1.1 120 1.0 A) 100 A) RENT (m 80 RENT (m 00..98 UR UR DE=RE=X* T C 60 Y C 0.7 U L TP PP 0.6 OU 40 SU 0.5 DE=RE= GND 20 0 05524-018 00..34 *X=DON’TCARE 05524-020 0 2 4 6 8 10 12 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 OUTPUTVOLTAGE(V) TEMPERATURE(°C) Figure 13. Output Current vs. Driver Output Low Voltage Figure 15. Supply Current vs. Temperature –125 90 –115 80 –105 A) –95 nA) 70 CURRENT (m ––––87655555 N CURRENT ( 654000 T W OUTPU ––4355 HUTDO 30 S 20 –25 –1–55 05524-019 100 05524-021 –7 –6 –5 –4 –3 –2 –1 0 1 2 3 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 OUTPUTVOLTAGE(V) TEMPERATURE(°C) Figure 14. Output Current vs. Driver Output High Voltage Figure 16. Shutdown Current vs. Temperature Rev. E | Page 10 of 20

Data Sheet ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 TEST CIRCUITS CL A/Y D R60LΩ= OUT RL/2 GENERATOR1 50Ω VOD VCC B/Z RL/2 VOC 05524-003 12PCPL RIN=C2L5U0DkEHSz,P5R0%OBDEUATNYDCYSCTRLEA,YtRCA≤P6A.0CnICsT,LAZ=NOC1=5Ep.5F02Ω. 05524-036 Figure 17. Differential Output Voltage Figure 20. Driver Differential Output Delay and Transition Times and Common-Mode Voltage Drivers VOM 375Ω RL=27Ω S1 D OUT VCM= GENERATOR1 50Ω CL=15pF2 D VOD RL –7VTO+12V VCC VCC 375Ω 05524-004 12PCPL RIN=C2L5U0DkEHSz,P5R0%OBDEUATNYDCVYSOCTMRLEA=,YVtORCHA≤P2+6A.V0COnILsT,A≈ZN1OC.5=EV.50Ω. 05524-037 Figure 18. Differential Output Voltage Drivers Figure 21. Driver Propagation Delays with Varying Common-Mode Voltage S1 0V OR3V D OUT CL=50pF2 RL=110Ω VID R GENERATOR1 50Ω 0 VOH+VOL VOL I(O+)L VOH I(O–)H 05524-005 12PCPL RIN=C2L5U0DkEHSz,P5R0%OBDEUATNYDCYSCTRLEA,YtVRCOA≤MP6=A.0CnIsT,AZ2NOC=E.50≈Ω1..5V 05524-038 Figure 19. CMOS Output Voltage High and Figure 22. Driver Enable and Disable Times (tPZH, tPSH, tPHZ) CMOS Output Voltage Low Receivers Rev. E | Page 11 of 20

ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 Data Sheet VCC +1.5V S3 1kΩ S1 VCC RL=110Ω –1.5V VID R S2 0V OR3V D S1 OUT CL2 CL=50pF2 GENERATOR1 50Ω GENERATOR1 50Ω 12PCPL RIN=C2L5U0DkEHSz,P5R0%OBDEUATNYDCYSCTRLEA,YtRCA≤P6A.0CnIsT,AZNOC=E.50Ω. 05524-039 12PCPL RIN=C2L5U0DkEHSz,P5R0F%OiBgDEuUrATeNY 2DC5YS. RCTReLcEAe,YitvRCeA≤rP 6EA.n0CnaIsTb,AlZeNO aC=nE.d50 DΩi.sable Times 05524-041 Figure 23. Driver Enable and Disable Times (tPZL, tPSL, tPLZ) VID R OUT GENERATOR1 50Ω CL=15pF2 1.5V VCC 0 VOM= 2 12PCPL RIN=C2L5U0DkEHSz,P5R0%OBDEUATNYDCYSCTRLEA,YtRCA≤P6A.0CnIsT,AZNOC=E.50Ω. 05524-040 Figure 24. Receiver Propagation Delays Rev. E | Page 12 of 20

Data Sheet ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 SWITCHING CHARACTERISTICS +3V 3V IN 1.5V 1.5V IN 1.5V 1.5V 0 0 t t DD DD t t PZH PHZ 90% 90% ≈+2V 0.25V VOH OUT 1500%% tTD 5100%%tTD ≈–2V 05524-006 OUT VOM 0 05524-008 Figure 26. Driver Differential Output Delay and Transition Times Figure 28. Driver Enable and Disable Times (tPZH, tPSH, tPHZ) 3V IN 1.5V 1.5V 0V 3V t t IN 1.5V 1.5V PLH PHL VOH 0 OAU/YT VOM VOM tPSL tPLZ VOL VCC t t OUT VOM B/Z PHL PLH VOH 0.25V VOL 05524-009 OUT VOM VOM VOL 05524-007 Figure 27. Driver Propagation Delays Figure 29. Driver Enable and Disable Times (tPZL, tPSL, tPLZ) 3V IN 1.5V 1.5V 0 t t RPLH RPHL VCC OUT VOM VOM 0 05524-010 Figure 30. Receiver Propagation Delays +3V +3V S1 OPEN S1CLOSED IN 1.5V S2CLOSED IN 1.5V S2 OPEN S3=+1.5V S3=–1.5V 0 0 tPRZH tPRZL tPRSH tPRSL VOH VCC OUT 1.5V OUT 1.5V 0 VOL +3V +3V S1 OPEN S1CLOSED IN 1.5V S2CLOSED IN 1.5V S2 OPEN S3=+1.5V S3=–1.5V 0 0 tPRHZ tPRLZ OUT+0.25V VOH VCC OUT 0 +0.25V VOL 05524-011 Figure 31. Receiver Enable and Disable Times Rev. E | Page 13 of 20

ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 Data Sheet CIRCUIT DESCRIPTION The ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 are REDUCED EMI AND REFLECTIONS low power transceivers for RS-485 and RS-422 communications. (ADM3483/ADM3488) The ADM3483/ADM3488 transmit and receive at data rates up The ADM3483/ADM3488 are slew rate limited transceivers, to 250 kbps; the ADM3485/ADM3490/ADM3491 transmit at up to minimizing EMI and reducing reflections caused by improperly 10 Mbps. The ADM3488/ADM3490/ADM3491 are full-duplex terminated cables. transceivers, while the ADM3483/ADM3485 are half-duplex transceivers. Driver enable (DE) and receiver enable (RE) pins LOW POWER SHUTDOWN MODE are included on the ADM3483/ADM3485/ADM3491. When (ADM3483/ADM3485/ADM3491) disabled, the driver and receiver outputs are high impedance. A low power shutdown mode is initiated by bringing RE high DEVICES WITH RECEIVER/DRIVER ENABLES and DE low. The devices do not shut down unless both the driver (ADM3483/ADM3485/ADM3491) and receiver are disabled (high impedance). In shutdown mode, the devices typically draw only 2 nA of supply current. For these Table 8. Transmitting Truth Table devices, the t and t enable times assume the part is in the PSH PSL low power shutdown mode; the t and t enable times assume Transmitting Input Transmitting Output PZH PZL the receiver or driver was disabled, but the part is not shut down. RE DE DI B1 A 1 Mode X2 1 1 0 1 Normal DRIVER OUTPUT PROTECTION X2 1 0 1 0 Normal Two methods are implemented to prevent excessive output current 0 0 X2 High-Z3 High-Z3 Normal and power dissipation caused by faults or by bus contention. 1 0 X2 High-Z3 High-Z3 Shutdown Current limit protection on the output stage provides immediate protection against short circuits over the whole common-mode 1 A and B outputs are Y and Z, respectively, for full-duplex part (ADM3491). 2 X = don’t care. voltage range (see the Typical Performance Characteristics section). 3 High-Z = high impedance. In addition, a thermal shutdown circuit forces the driver outputs into a high impedance state if the die temperature rises Table 9. Receiving Truth Table excessively. Receiving Input Receiving Output PROPAGATION DELAY RE DE1 A – B RO Mode 0 0 ≥ +0.2 V 1 Normal Skew time is the difference between the low-to-high and high- 0 0 ≤ −0.2 V 0 Normal to-low propagation delays. Small driver/receiver skew times help 0 0 Inputs Open 1 Normal maintain a symmetrical mark-space ratio (50% duty cycle). 1 0 X2 High-Z3 Shutdown The receiver skew time (|tPRLH − tPRHL|) is under 10 ns (20 ns for ADM3483/ADM3488). The driver skew times are 8 ns for 1 DE is a don’t care; X for the full-duplex part (ADM3491). ADM3485/ADM3490/ADM3491 and typically under 100 ns for 2 X = don’t care. 3 High-Z = high impedance. ADM3483/ADM3488. TYPICAL APPLICATIONS DEVICES WITHOUT RECEIVER/DRIVER ENABLES— ADM3488/ADM3490 The ADM3483/ADM3485/ADM3491 transceivers are designed for half-duplex bidirectional data communications on multipoint Table 10. Transmitting Truth Table bus transmission lines, Figure 32 and Figure 33 show typical Transmitting Input Transmitting Output network applications circuits. The ADM3488 and the ADM3490 DI Z Y full-duplex transceivers are designed to be used in a daisy-chain 1 0 1 network topology or in a point-to-point application, see Figure 34 0 1 0 and Figure 35. The ADM3491 can be used as line repeat Figure 36. To minimize reflections, the line must be terminated at both Table 11. Receiving Truth Table ends in its characteristic impedance, and stub lengths off the main line must be kept as short as possible. The slew rate limited Receiving Input Receiving Output ADM3483/ADM3488 are more tolerant of imperfect termination. A – B RO ≥ +0.2 V 1 ≤ −0.2 V 0 Inputs open 1 Rev. E | Page 14 of 20

Data Sheet ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 LINE LENGTH vs. DATA RATE The RS-485 and RS-422 standards cover line lengths up to 4000 feet. For line lengths greater than 4000 feet, see Figure 36. MAXIMUMNUMBEROFTRANSCEIVERSONBUS=32 ADM3483/ ADM3483/ ADM3485 VCC ADM3485 RO R R1 R RO A A RE RE RT RT DE DE B B DI D R2 D DI A B A B ADM3483/ ADM3483/ ADM3485 ADM3485 R R D D N1.ORTTE ISSEQUALTOTHECHARACTERISTICR OIMPREDEANDCEE ODFITHECABLE. RO RE DE DI 05524-022 Figure 32. ADM3483/ADM3485 Typical Half-Duplex RS-485 Network MAXIMUM NUMBER OF NODES = 32 MASTER VCC SLAVE R1 A Y RO R B RT RT Z D DI RE DE R1 DE Z R2 B RE DI D Y RT RT A R RO VCC ADM3491 R2 ADM3491 A B Z Y A B Z Y SLAVE SLAVE R R D D ADM3491 ADM3491 RO RE DE DI RO RE DE DI N1.O RTTE ISS EQUAL TO THE CHARACTERISTIC IMPEDANCE OF THE CABLE. 05524-090 Figure 33. ADM3491 Typical Full-Duplex RS-485 Network Rev. E | Page 15 of 20

ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 Data Sheet MASTER SLAVE ADM3488/ ADM3488/ ADM3490 ADM3490 A Y RO R D DI B Z Z B DI D R RO Y A A B Z Y A B Z Y ADM3488/ ADM3488/ ADM3490 ADM3490 SLAVE R D R D SLAVE RO DI RO DI 05524-042 Figure 34. ADM3488/ADM3490 Full-Duplex Daisy-Chain Network MASTER SLAVE ADM3488/ ADM3488/ ADM3490 ADM3490 A Y RO R D DI B Z Z B DI D R RO Y A 05524-043 Figure 35. ADM3488/ADM3490 Full-Duplex Point-to-Point Applications ADM3491 A RO R RE B RT DATA IN Z DE D Y RT DATA OUT DI N1.ORTTE ISSEQUALTOTHECHARACTERISTIC IMPEDANCE OFTHECABLE. 05524-091 Figure 36. Line Repeater for ADM3491 Rev. E | Page 16 of 20

Data Sheet ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 OUTLINE DIMENSIONS 5.00(0.1968) 4.80(0.1890) 8 5 4.00(0.1574) 6.20(0.2441) 3.80(0.1497) 1 4 5.80(0.2284) 1.27(0.0500) 0.50(0.0196) BSC 1.75(0.0688) 0.25(0.0099) 45° 0.25(0.0098) 1.35(0.0532) 8° 0.10(0.0040) 0° COPLANARITY 0.51(0.0201) 0.10 SEATING 0.31(0.0122) 0.25(0.0098) 10..2470((00..00510507)) PLANE 0.17(0.0067) COMPLIANTTOJEDECSTANDARDSMS-012-AA C(RINEOFNPEATRRREOENNLCLTEIHNEOGSNDELISYM)AEANNRDSEIAORRNOESUNANORDETEDAIN-POMPFRIFLOLMPIMIRLELIATIMTEEERTFSEO;RIRNECUQHSUEDIVIINMAELDENENSSTIIOGSNNFS.OR 012407-A Figure 37. 8-Lead Standard Small Outline Package [SOIC_N] Narrow Body (R-8) Dimensions shown in millimeters and (inches) 8.75 (0.3445) 8.55 (0.3366) 4.00 (0.1575) 14 8 6.20 (0.2441) 3.80 (0.1496) 1 7 5.80 (0.2283) 1.27 B(0S.C0500) 1.75 (0.0689) 00..5205 ((00..00109978)) 45° 0.25 (0.0098) 1.35 (0.0531) 8° 0.10 (0.0039) 0° COPL0A.1N0ARITY 0.51 (0.0201) SPELAATNIENG 0.25 (0.0098) 1.27 (0.0500) 0.31 (0.0122) 0.17 (0.0067) 0.40 (0.0157) COMPLIANTTO JEDEC STANDARDS MS-012-AB C(RINOEFNPEATRRREOENNLCLTEIHN EOGSN EDLSIYM)AEANNRDSEI AORRNOESU NANORDEET DAIN-PO MPFRIFLO LMPIIMRLELIATIMTEEER TFSEO; RIRN ECUQHSU EDI VIINMA LEDENENSSTIIOGSN NFS.OR 060606-A Figure 38. 14-Lead Narrow Body Small Outline [SOIC_N] Narrow Body (R-14) Dimensions shown in millimeters and (inches) Rev. E | Page 17 of 20

ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 Data Sheet ORDERING GUIDE Model1 Temperature Range Package Description Package Option Ordering Quantity ADM3483ARZ −40°C to +85°C 8-Lead Narrow Body Small Outline (SOIC_N) R-8 ADM3483ARZ–REEL7 −40°C to +85°C 8-Lead Narrow Body Small Outline (SOIC_N) R-8 1,000 ADM3485ARZ −40°C to +85°C 8-Lead Narrow Body Small Outline (SOIC_N) R-8 ADM3485ARZ–REEL7 −40°C to +85°C 8-Lead Narrow Body Small Outline (SOIC_N) R-8 1,000 ADM3488ARZ −40°C to +85°C 8-Lead Narrow Body Small Outline (SOIC_N) R-8 ADM3488ARZ–REEL7 −40°C to +85°C 8-Lead Narrow Body Small Outline (SOIC_N) R-8 1,000 ADM3490ARZ −40°C to +85°C 8-Lead Narrow Body Small Outline (SOIC_N) R-8 ADM3490ARZ–REEL7 −40°C to +85°C 8-Lead Narrow Body Small Outline (SOIC_N) R-8 1,000 ADM3491AR −40°C to +85°C 14-Lead Narrow Body Small Outline (SOIC_N) R-14 ADM3491AR-REEL −40°C to +85°C 14-Lead Narrow Body Small Outline (SOIC_N) R-14 2,500 ADM3491AR-REEL7 −40°C to +85°C 14-Lead Narrow Body Small Outline (SOIC_N) R-14 1,000 ADM3491ARZ −40°C to +85°C 14-Lead Narrow Body Small Outline (SOIC_N) R-14 ADM3491ARZ-REEL −40°C to +85°C 14-Lead Narrow Body Small Outline (SOIC_N) R-14 2,500 ADM3491ARZ-REEL7 −40°C to +85°C 14-Lead Narrow Body Small Outline (SOIC_N) R-14 1,000 1 Z = RoHS Compliant Part. Rev. E | Page 18 of 20

Data Sheet ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 NOTES Rev. E | Page 19 of 20

ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 Data Sheet NOTES ©2005-2011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D05524-0-11/11(E) Rev. E | Page 20 of 20

Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: A nalog Devices Inc.: ADM3483ARZ ADM3483ARZ-REEL7 ADM3485ARZ ADM3485ARZ-REEL7 ADM3488ARZ ADM3488ARZN ADM3488ARZN-RL7 ADM3488ARZ-REEL7 ADM3490ARZ ADM3490ARZ-REEL7 ADM3491AR ADM3491AR- REEL7 ADM3491ARZ ADM3491ARZ-REEL ADM3491ARZ-REEL7