3.3 V Slew Rate Limited, Half- and Full-Duplex, RS-485/RS-422 Transceivers ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 FUNCTIONAL BLOCK DIAGRAMS VCC ADM3483/ ADM3485 DE DI The ADM3488/ADM3490/ADM3491 feature full-duplex communication, while the ADM3483/ADM3485 are designed for half-duplex communication. The ADM3483/ADM3488 feature slew rate limited drivers that minimize EMI and reduce reflections caused by improperly terminated cables, allowing error-free data transmission at data rates up to 250 kbps. The ADM3485/ADM3490/ADM3491 transmit at up to 10 Mbps. The receiver input impedance is 12 k, allowing up to 32 transceivers to be connected on the bus. A thermal shutdown circuit prevents excessive power dissipation caused by bus contention or by output shorting. If a significant temperature increase is detected B D GND Figure 1. VCC R RO A B ADM3488/ ADM3490 Z DI D Y GND Figure 2. GENERAL DESCRIPTION The ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 are low power, differential line transceivers designed to operate using a single 3.3 V power supply. Low power consumption, coupled with a shutdown mode, makes the ADM3483/ADM3485/ADM3488/ ADM3490/ADM3491 ideal for power-sensitive applications. A RE APPLICATIONS Low power RS-485/RS-422 applications Telecom Industrial process control HVAC R RO 05524-027 Operate with 3.3 V supply Interoperable with 5 V logic EIA RS-422 and RS-485 compliant over full common-mode range Data rate options ADM3483/ADM3488: 250 kbps ADM3485/ADM3490/ADM3491: 10 Mbps Half- and full-duplex options Reduced slew rates for low EMI (ADM3483 and ADM3488) 2 nA supply current in shutdown mode (ADM3483/ADM3485/ADM3491) Up to 32 transceivers on the bus -7 V to +12 V bus common-mode range Specified over the -40C to +85C temperature range 8 ns skew (ADM3485/ADM3490/ADM3491) 8-lead SOIC and 14-lead SOIC (ADM3491 only) packages 05524-026 FEATURES ADM3491 R RO B RE DE DI A Z D Y 05524-025 Data Sheet Figure 3. in the internal driver circuitry during fault conditions, then the thermal shutdown circuit forces the driver output into a high impedance state. If the inputs are unconnected (floating), the receiver contains a fail-safe feature that results in a logic high output state. The parts are fully specified over the commercial and industrial temperature ranges. The ADM3483/ADM3485/ ADM3488/ADM3490 are available in 8-lead SOIC_N; the ADM3491 is available in a 14-lead SOIC_N. 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 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. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 (c)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 (ADM3483/ADM3485/ADM3491)......................................... 14 Functional Block Diagrams............................................................. 1 Revision History ............................................................................... 2 Specifications..................................................................................... 4 Timing Specifications--ADM3485/ADM3490/ADM3491.... 5 Devices Without Receiver/Driver Enables-- ADM3488/ADM3490................................................................ 14 Reduced EMI and Reflections (ADM3483/ADM3488) ....... 14 Timing Specifications--ADM3483/ADM3488........................ 5 Low Power Shutdown Mode (ADM3483/ADM3485/ADM3491)......................................... 14 Timing Specifications-- ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 ...... 6 Driver Output Protection.......................................................... 14 Absolute Maximum Ratings............................................................ 7 ESD Caution.................................................................................. 7 Pin Configurations and Function Descriptions ........................... 8 Typical Performance Characteristics ............................................. 9 Test Circuits..................................................................................... 11 Propagation Delay ...................................................................... 14 Typical Applications................................................................... 14 Line Length vs. Data Rate ......................................................... 15 Outline Dimensions ....................................................................... 17 Ordering Guide .......................................................................... 18 REVISION HISTORY 11/11--Rev. D to Rev. E Changes to Digital I/O Voltage (DE, RE, DI) Parameter, Table 6 ................................................................................................ 7 Moved Typical Performance Characteristics Section .................. 9 Moved Test Circuits Section.......................................................... 11 Moved Switching Characteristics Section ................................... 13 Changes to Note 1, Table 8 ............................................................ 14 Changes to Outline Dimensions................................................... 17 12/10--Rev. C to Rev. D Changes to Figure 33...................................................................... 15 8/10--Rev. B to Rev. C Changes to Table 2, Driver Input Logic......................................... 4 10/06--Rev. A to Rev. B Updated Format..................................................................Universal Added ADM3491 ...............................................................Universal Changes to Specifications Section...................................................4 Changes to Typical Applications Section .................................... 14 7/06--Rev. 0 to Rev. A Changes to Applications ...................................................................1 Changes to General Description .....................................................1 Changes to Figure 19...................................................................... 10 Changes to Typical Applications Section .................................... 13 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 Part No. ADM3483 ADM3485 ADM3488 ADM3490 ADM3491 Guaranteed Data Rate (Mbps) 0.25 10 0.25 10 10 Supply Voltage (V) 3.0 to 3.6 3.0 to 3.6 3.0 to 3.6 3.0 to 3.6 3.0 to 3.6 Half-/FullDuplex Half Half Full Full Full Slew Rate Limited Yes No Yes No No Rev. E | Page 3 of 20 Driver/Receiver Enable Yes Yes No No Yes Shutdown Current (nA) 2 2 N/A N/A 2 Pin Count 8 8 8 8 14 ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 Data Sheet SPECIFICATIONS VCC = 3.3 V 0.3 V, TA = TMIN to TMAX, unless otherwise noted. Table 2. Parameter DRIVER Differential Output Voltage (VOD) |VOD| for Complementary Output States 1 Common-Mode Output Voltage (VOC) |VOC| for Common-Mode Output Voltage1 DRIVER INPUT LOGIC CMOS Input Logic Threshold Low (VIL) CMOS Input Logic Threshold High (VIH) CMOS Logic Input Current (IIN1) Input Current--A, B (IIN2) Min Unit Test Conditions/Comments 0.2 3 0.2 V V V V V V RL = 100 (RS-422), VCC = 3.3 V 5% (see Figure 17) RL = 54 (RS-485) (see Figure 17) RL = 60 (RS-485), VCC = 3.3 V (see Figure 18) RL = 54 or 100 (see Figure 17) RL = 54 or 100 (see Figure 17) RL = 54 or 100 (see Figure 17) 0.1 V V A mA mA A -0.1 A 0.01 A -0.01 A DE, DI, RE DE, DI, RE DE, DI, RE VIN = 12 V, DE = 0 V, VCC = 0 V or 3.6 V VIN = -7 V, DE = 0 V, VCC = 0 V or 3.6 V VIN = 12 V, DE = 0 V, RE = 0 V, VCC = 0 V or 3.6 V, ADM3491 only VIN = -7 V, DE = 0 V, RE = 0 V, VCC = 0 V or 3.6 V, ADM3491 only VIN = 12 V, DE = 0 V, RE = VCC, VCC = 0 V or 3.6 V, ADM3491 only VIN = -7 V, DE = 0 V, RE = VCC, VCC = 0 V or 3.6 V, ADM3491 only 0.8 2.0 2 1.0 -0.8 Output Leakage (Y, Z) in Shutdown Mode (IO) -0.2 +0.2 50 VCC - 0.4 0.4 1 12 Supply Current in Shutdown Mode (ISHDN) Driver Short-Circuit Output Current (IOSD) Receiver Short-Circuit Output Current (IOSR) Max 2.0 1.5 1.5 Output Leakage--Y, Z (IO) RECEIVER Differential Input Threshold Voltage (VTH) Input Hysteresis ( VTH) CMOS Output Voltage High (VOH) CMOS Output Voltage Low (VOL) Three-State Output Leakage Current (IOZR) Input Resistance (RIN) POWER SUPPLY CURRENT Supply Current (ICC) Typ 8 V mV V V A k -7 V < VCM < +12 V VCM = 0 V IOUT = -1.5 mA, VID = 200 mV (see Figure 19) IOUT = 2.5 mA, VID = 200 mV (see Figure 19) VCC = 3.6 V, 0 V VOUT VCC -7 V < VCM < +12 V 1.1 2.2 mA DE = VCC, RE = 0 V or VCC, no load, DI = 0 V or VCC 0.95 0.002 1.9 1 -250 250 60 mA A mA mA mA DE = 0 V, RE = 0 V, no load, DI = 0 V or VCC DE = 0 V, RE = VCC, DI = VCC or 0 V VOUT = -7 V VOUT = 12 V 0 V < VRO < VCC VOD and VOC are the changes in VOD and VOC, respectively, when DI input changes state. 1 Rev. E | Page 4 of 20 Data Sheet ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 TIMING SPECIFICATIONS--ADM3485/ADM3490/ADM3491 VCC = 3.3 V, TA = 25C, unless otherwise noted. Table 3. Parameter DRIVER Differential Output Delay (tDD) Differential Output Transition Time (tTD) Propagation Delay, Low-to-High Level (tPLH) Propagation Delay, High-to-Low Level (tPHL) |tPLH - tPHL| Propagation Delay Skew 1 (tPDS) Min Typ Max Unit Test Conditions/Comments 1 3 7 7 22 8 22 22 35 25 35 35 8 ns ns ns ns ns RL = 60 (see Figure 20 and Figure 26) RL = 60 (see Figure 20 and Figure 26) RL = 27 (see Figure 21 and Figure 27) RL = 27 (see Figure 21 and Figure 27) RL = 27 (see Figure 21 and Figure 27) 45 45 40 40 650 650 90 90 80 80 900 900 ns ns ns ns ns ns RL = 110 (see Figure 23 and Figure 29) RL = 110 (see Figure 22 and Figure 28) RL = 110 (see Figure 22 and Figure 28) RL = 110 (see Figure 23 and Figure 29) RL = 110 (see Figure 23 and Figure 29) RL = 110 (see Figure 22 and Figure 28) DRIVER OUTPUT ENABLE/DISABLE TIMES (ADM3485/ ADM3491 ONLY) Output Enable Time to Low Level (tPZL) Output Enable Time to High Level (tPZH) Output Disable Time from High Level (tPHZ) Output Disable Time from Low Level (tPLZ) Output Enable Time from Shutdown to Low Level (tPSL) Output Enable Time from Shutdown to High Level (tPSH) 1 Measured on |tPLH (Y) - tPHL (Y)| and |tPLH (Z) - tPHL (Z)|. TIMING SPECIFICATIONS--ADM3483/ADM3488 VCC = 3.3 V, TA = 25C, unless otherwise noted. Table 4. Parameter DRIVER Differential Output Delay (tDD) Differential Output Transition Time (tTD) Propagation Delay, Low-to-High Level (tPLH) Propagation Delay, High-to-Low Level (tPHL) |tPLH - tPHL| Propagation Delay Skew 1 (tPDS) DRIVER OUTPUT ENABLE/DISABLE TIMES (ADM3483 ONLY) Output Enable Time to Low Level (tPZL) Output Enable Time to High Level (tPZH) Output Disable Time from High Level (tPHZ) Output Disable Time from Low Level (tPLZ) Output Enable Time from Shutdown to Low Level (tPSL) Output Enable Time from Shutdown to High Level (tPSH) 1 Min Typ Max Unit Test Conditions/Comments 600 400 700 700 900 700 1000 1000 100 1400 1200 1500 1500 ns ns ns ns ns RL = 60 (see Figure 20 and Figure 26) RL = 60 (see Figure 20 and Figure 26) RL = 27 (see Figure 21 and Figure 27) RL = 27 (see Figure 21 and Figure 27) RL = 27 (see Figure 21 and Figure 27) 900 600 50 50 1.9 2.2 1300 800 80 80 2.7 3.0 ns ns ns ns s s RL = 110 (see Figure 23 and Figure 29) RL = 110 (see Figure 22 and Figure 28) RL = 110 (see Figure 22 and Figure 28) RL = 110 (see Figure 23 and Figure 29) RL = 110 (see Figure 23 and Figure 29) RL = 110 (see Figure 22 and Figure 28) 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 VCC = 3.3 V, TA = 25C, unless otherwise noted. Table 5. Parameter RECEIVER Time to Shutdown (tSHDN) ADM3483/ADM3485/ADM3491 1 Propagation Delay, Low-to-High Level (tRPLH) ADM3485/ADM3490/ADM3491 ADM3483/ADM3488 Propagation Delay, High-to-Low Level (tRPHL) ADM3485/ADM3490/ADM3491 ADM3483/ADM3488 |tPLH - tPHL| Propagation Delay Skew (tRPDS) ADM3485/ADM3490/ADM3491 ADM3483/ADM3488 RECEIVER OUTPUT ENABLE/DISABLE TIMES (ADM3483/ADM3485/ADM3491 ONLY) Output Enable Time to Low Level (tPRZL) Output Enable Time to High Level (tPRZH) Output Disable Time from High Level (tPRHZ) Output Disable Time from Low Level (tPRLZ) Output Enable Time from Shutdown to Low Level (tPRSL) Output Enable Time from Shutdown to High Level (tPRSH) 1 Min Typ Max Unit Test Conditions/Comments 80 190 300 ns 25 25 65 75 90 120 ns ns VID = 0 V to 3.0 V, CL = 15 pF (see Figure 24 and Figure 30) 25 25 65 75 90 120 ns ns VID = 0 V to 3.0 V, CL = 15 pF (see Figure 24 and Figure 30) 10 20 ns ns VID = 0 V to 3.0 V, CL = 15 pF (see Figure 24 and Figure 30) 25 25 25 25 720 50 50 45 45 1400 ns ns ns ns ns CL = 15 pF (see Figure 25 and Figure 31) CL = 15 pF (see Figure 25 and Figure 31) CL = 15 pF (see Figure 25 and Figure 31) CL = 15 pF (see Figure 25 and Figure 31) CL = 15 pF (see Figure 25 and Figure 31) 720 1400 ns CL = 15 pF (see Figure 25 and Figure 31) 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 TA = 25C, unless otherwise noted. Table 6. Parameter VCC to GND Digital I/O Voltage (DE, RE, DI) Digital I/O Voltage (RO) Driver Output/Receiver Input Voltage Operating Temperature Range Storage Temperature Range JA Thermal Impedance 8-Lead SOIC 14-Lead SOIC Lead Temperature Soldering (10 sec) Vapor Phase (60 sec) Infrared (15 sec) Rating 7V -0.3 V to +6 V VCC - 0.5 V to VCC + 0.5 V -7.5 V to +12.5 V -40C to +85C -65C to +125C Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ESD CAUTION 121C/W 86C/W 300C 215C 220C Rev. E | Page 7 of 20 ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 Data Sheet RO 1 ADM3483/ ADM3485 RE 2 DE 3 TOP VIEW (Not to Scale) DI 4 8 VCC 7 B 6 A 5 GND 05524-028 PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS VCC 1 RO 2 DI 3 GND 4 ADM3488/ ADM3490 8 A 7 B TOP VIEW (Not to Scale) 6 Z 5 Y 05524-029 Figure 4. ADM3483/ADM3485 Pin Configuration Figure 5. ADM3488/ADM3490 Pin Configuration NC 1 14 VCC RO 2 RE 3 13 VCC ADM3491 12 A TOP VIEW 11 B (Not to Scale) 10 Z DI 5 GND 6 9 Y GND 7 8 NC NC = NO CONNECT 05524-030 DE 4 Figure 6. ADM3491 Pin Configuration Table 7. Pin Function Descriptions ADM3483/ ADM3485 Pin No. 1 ADM3488/ ADM3490 Pin No. 2 ADM3491 Pin No. 2 Mnemonic RO 2 Not applicable 3 RE 3 Not applicable 4 DE 4 3 5 DI 5 Not applicable Not applicable 6 Not applicable 7 Not applicable 8 Not applicable 4 5 6 Not applicable 8 Not applicable 7 1 Not applicable 6, 7 9 10 Not applicable 12 Not applicable 11 13, 14 1, 8 GND Y Z A A B B VCC NC Description Receiver Output. When enabled, if A > B by 200 mV, then RO = high. If A < B by 200 mV, then RO = low. 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. 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. 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. Ground. Noninverting Driver Output. Inverting Driver Output. Noninverting Receiver Input A and Noninverting Driver Output A. Noninverting Receiver Input A. Inverting Receiver Input B and Inverted Driver Output B. Inverting Receiver Input B. Power Supply (3.3 V 0.3 V). No Connect. Rev. E | Page 8 of 20 Data Sheet ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 TYPICAL PERFORMANCE CHARACTERISTICS 30 0.8 0.7 0.6 OUTPUT VOLTAGE (V) 20 15 10 0.5 0.4 0.3 0.2 5 05524-012 0 0.1 0 0.5 1.0 1.5 2.0 2.5 0 -40 -30 -20 -10 3.5 3.0 05524-015 OUTPUT CURRENT (mA) 25 0 OUTPUT VOLTAGE (V) 10 20 30 40 50 60 70 80 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 OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) 80 -12 -10 -8 -6 -4 70 60 50 40 30 05524-013 0 0 0.5 1.0 1.5 2.0 2.5 10 0 3.5 3.0 05524-016 20 -2 0 0.5 1.0 OUTPUT VOLTAGE (V) 1.5 2.0 2.5 3.0 3.5 OUTPUT VOLTAGE (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 2.4 OUTPUT VOLTAGE (V) 3.20 3.15 3.10 2.2 2.1 2.0 1.9 1.8 05524-014 3.05 3.00 -40 -30 -20 -10 2.3 0 10 20 30 40 50 60 70 1.7 1.6 -40 -30 -20 -10 80 TEMPERATURE (C) Figure 9. Receiver Output High Voltage vs. Temperature, IRO = 1.5 mA 05524-017 OUTPUT VOLTAGE (V) 3.25 0 10 20 30 40 50 60 70 80 TEMPERATURE (C) Figure 12. Driver Differential Output Voltage vs. Temperature, RL = 54 Rev. E | Page 9 of 20 ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 140 Data Sheet 1.2 1.1 120 80 60 40 0.9 0.8 DE = RE = X* 0.7 0.6 DE = RE = GND 0.5 0 0.4 05524-018 20 0 2 4 6 8 *X = DON'T CARE 0.3 -40 -30 -20 -10 12 10 0 OUTPUT VOLTAGE (V) 10 20 30 40 50 60 70 80 70 80 05524-020 SUPPLY CURRENT (mA) OUTPUT CURRENT (mA) 1.0 100 TEMPERATURE (C) Figure 13. Output Current vs. Driver Output Low Voltage Figure 15. Supply Current vs. Temperature -125 90 -115 80 SHUTDOWN CURRENT (nA) -85 -75 -65 -55 -45 -35 -25 -15 -5 -7 -6 -5 -4 -3 -2 -1 0 1 2 70 60 50 40 30 20 10 0 -40 -30 -20 -10 3 OUTPUT VOLTAGE (V) 05524-021 -95 05524-019 OUTPUT CURRENT (mA) -105 0 10 20 30 40 50 60 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 RL = OUT 60 D GENERATOR1 VOD 50 VOC B/Z 05524-003 VCC RL/2 CL = 15pF2 05524-036 RL/2 1PPR = 250kHz, 50% DUTY CYCLE, t 6.0ns, Z = 50. R O 2C INCLUDES PROBE AND STRAY CAPACITANCE. L Figure 17. Differential Output Voltage and Common-Mode Voltage Drivers Figure 20. Driver Differential Output Delay and Transition Times VOM RL = 27 375 S1 OUT D VCC VCM = -7V TO +12V RL 50 VCC 375 VOM = VOH + VOL 2 1.5V 1PPR = 250kHz, 50% DUTY CYCLE, t 6.0ns, Z = 50. R O 2C INCLUDES PROBE AND STRAY CAPACITANCE. L Figure 18. Differential Output Voltage Drivers with Varying Common-Mode Voltage 05524-037 VOD CL = 15pF2 05524-004 D GENERATOR1 Figure 21. Driver Propagation Delays S1 0V OR 3V OUT D CL = 50pF2 R GENERATOR1 50 0 IOL (+) VOH IOH (-) VOM = 05524-005 VOL VOH + VOL 2 1.5V 1PPR = 250kHz, 50% DUTY CYCLE, t 6.0ns, Z = 50. R O 2C INCLUDES PROBE AND STRAY CAPACITANCE. L Figure 19. CMOS Output Voltage High and CMOS Output Voltage Low Receivers Figure 22. Driver Enable and Disable Times (tPZH, tPSH, tPHZ) Rev. E | Page 11 of 20 05524-038 VID RL = 110 ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 VCC +1.5V RL = 110 Data Sheet S1 S3 VID -1.5V R S1 0V OR 3V CL = 50pF2 GENERATOR1 S2 CL2 OUT D VCC 1k GENERATOR1 50 1PPR = 250kHz, 50% DUTY CYCLE, t 6.0ns, Z = 50. R O 2C INCLUDES PROBE AND STRAY CAPACITANCE. L 1PPR = 250kHz, 50% DUTY CYCLE, t 6.0ns, Z = 50. R O 2C INCLUDES PROBE AND STRAY CAPACITANCE. L Figure 25. Receiver Enable and Disable Times Figure 23. Driver Enable and Disable Times (tPZL, tPSL, tPLZ) 50 R OUT CL = 15pF2 1.5V 0 VOM = VCC 2 1PPR = 250kHz, 50% DUTY CYCLE, t 6.0ns, Z = 50. R O 2C INCLUDES PROBE AND STRAY CAPACITANCE. L 05524-040 VID GENERATOR1 Figure 24. Receiver Propagation Delays Rev. E | Page 12 of 20 05524-041 05524-039 50 Data Sheet ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 SWITCHING CHARACTERISTICS +3V 1.5V 3V 1.5V 0 tDD 90% 50% 10% 90% tPZH +2V 50% 10% tTD tPHZ 0.25V OUT -2V tTD 1.5V 0 tDD VOH VOM 05524-006 OUT 1.5V IN 0 Figure 26. Driver Differential Output Delay and Transition Times 05524-008 IN Figure 28. Driver Enable and Disable Times (tPZH, tPSH, tPHZ) 3V 1.5V 1.5V 3V 0V tPLH IN tPHL 1.5V 1.5V 0 VOH A/Y OUT VOM tPSL VOM VCC VOL tPHL tPLZ OUT tPLH VOM 0.25V B/Z OUT VOM VOM VOL Figure 27. Driver Propagation Delays Figure 29. Driver Enable and Disable Times (tPZL, tPSL, tPLZ) 3V 1.5V IN 1.5V 0 tRPLH tRPHL VCC VOM VOM 05524-010 OUT 0 Figure 30. Receiver Propagation Delays +3V 1.5V 0 tPRZH tPRSH OUT S1 OPEN S2 CLOSED S3 = +1.5V +3V IN 1.5V VOH VCC OUT 1.5V 1.5V 0 +3V IN 1.5V 0 VOL S1 OPEN S2 CLOSED S3 = +1.5V +3V 1.5V IN 0 tPRHZ OUT +0.25V 0 tPRZL tPRSL S1 CLOSED S2 OPEN S3 = -1.5V S1 CLOSED S2 OPEN S3 = -1.5V tPRLZ VOH VCC OUT 0 +0.25V Figure 31. Receiver Enable and Disable Times Rev. E | Page 13 of 20 VOL 05524-011 IN VOL 05524-007 VOH 05524-009 IN ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 Data Sheet CIRCUIT DESCRIPTION The ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 are low power transceivers for RS-485 and RS-422 communications. The ADM3483/ADM3488 transmit and receive at data rates up to 250 kbps; the ADM3485/ADM3490/ADM3491 transmit at up to 10 Mbps. The ADM3488/ADM3490/ADM3491 are full-duplex transceivers, while the ADM3483/ADM3485 are half-duplex transceivers. Driver enable (DE) and receiver enable (RE) pins are included on the ADM3483/ADM3485/ADM3491. When disabled, the driver and receiver outputs are high impedance. DEVICES WITH RECEIVER/DRIVER ENABLES (ADM3483/ADM3485/ADM3491) Table 8. Transmitting Truth Table Transmitting Input DE DI RE Transmitting Output B1 A1 X2 X2 0 1 0 1 High-Z3 High-Z3 1 1 0 0 1 0 X2 X2 1 0 High-Z3 High-Z3 Mode Normal Normal Normal Shutdown 1 A and B outputs are Y and Z, respectively, for full-duplex part (ADM3491). X = don't care. 3 High-Z = high impedance. 2 Table 9. Receiving Truth Table RE 0 0 0 1 1 2 3 Receiving Input DE1 A-B 0 0 0 0 +0.2 V -0.2 V Inputs Open X2 Receiving Output RO 1 0 1 High-Z3 Mode Normal Normal Normal Shutdown DE is a don't care; X for the full-duplex part (ADM3491). X = don't care. High-Z = high impedance. DEVICES WITHOUT RECEIVER/DRIVER ENABLES-- ADM3488/ADM3490 Table 10. Transmitting Truth Table Transmitting Input DI 1 0 Transmitting Output Z Y 0 1 1 0 Table 11. Receiving Truth Table Receiving Input A-B +0.2 V -0.2 V Inputs open Receiving Output RO 1 0 1 REDUCED EMI AND REFLECTIONS (ADM3483/ADM3488) The ADM3483/ADM3488 are slew rate limited transceivers, minimizing EMI and reducing reflections caused by improperly terminated cables. LOW POWER SHUTDOWN MODE (ADM3483/ADM3485/ADM3491) A low power shutdown mode is initiated by bringing RE high and DE low. The devices do not shut down unless both the driver and receiver are disabled (high impedance). In shutdown mode, the devices typically draw only 2 nA of supply current. For these devices, the tPSH and tPSL enable times assume the part is in the low power shutdown mode; the tPZH and tPZL enable times assume the receiver or driver was disabled, but the part is not shut down. DRIVER OUTPUT PROTECTION Two methods are implemented to prevent excessive output current and power dissipation caused by faults or by bus contention. Current limit protection on the output stage provides immediate protection against short circuits over the whole common-mode voltage range (see the Typical Performance Characteristics section). In addition, a thermal shutdown circuit forces the driver outputs into a high impedance state if the die temperature rises excessively. PROPAGATION DELAY Skew time is the difference between the low-to-high and highto-low propagation delays. Small driver/receiver skew times help maintain a symmetrical mark-space ratio (50% duty cycle). The receiver skew time (|tPRLH - tPRHL|) is under 10 ns (20 ns for ADM3483/ADM3488). The driver skew times are 8 ns for ADM3485/ADM3490/ADM3491 and typically under 100 ns for ADM3483/ADM3488. TYPICAL APPLICATIONS The ADM3483/ADM3485/ADM3491 transceivers are designed for half-duplex bidirectional data communications on multipoint bus transmission lines, Figure 32 and Figure 33 show typical network applications circuits. The ADM3488 and the ADM3490 full-duplex transceivers are designed to be used in a daisy-chain network topology or in a point-to-point application, see Figure 34 and Figure 35. The ADM3491 can be used as line repeat Figure 36. To minimize reflections, the line must be terminated at both ends in its characteristic impedance, and stub lengths off the main line must be kept as short as possible. The slew rate limited ADM3483/ADM3488 are more tolerant of imperfect termination. 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. MAXIMUM NUMBER OF TRANSCEIVERS ON BUS = 32 ADM3483/ ADM3485 R RO ADM3483/ ADM3485 VCC R1 A RE RT DE DE B R2 A A B ADM3483/ ADM3485 DI ADM3483/ ADM3485 R R D RO D B RE DE DI D RE RO DI DE 05524-022 D DI RO RE RT B R A NOTES 1. RT IS EQUAL TO THE CHARACTERISTIC IMPEDANCE OF THE CABLE. Figure 32. ADM3483/ADM3485 Typical Half-Duplex RS-485 Network R B SLAVE R1 A RO MAXIMUM NUMBER OF NODES = 32 VCC MASTER Y RT RT RE D Y B RT RT A DI DE R1 R2 Z DE DI D Z RE R RO VCC ADM3491 R2 A B Z Y A B Z ADM3491 Y SLAVE SLAVE RO R D RE DE DI RO D RE DE DI NOTES 1. RT IS EQUAL TO THE CHARACTERISTIC IMPEDANCE OF THE CABLE. Figure 33. ADM3491 Typical Full-Duplex RS-485 Network Rev. E | Page 15 of 20 ADM3491 05524-090 R ADM3491 ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 SLAVE ADM3488/ ADM3490 ADM3488/ ADM3490 A Y B Z Z B Y A D R D R A B Z Y A B Z ADM3488/ ADM3490 R D R D RO DI RO DI SLAVE Figure 34. ADM3488/ADM3490 Full-Duplex Daisy-Chain Network SLAVE MASTER ADM3488/ ADM3490 A Y B Z Z B Y A ADM3488/ ADM3490 R RO DI D R D DI RO Figure 35. ADM3488/ADM3490 Full-Duplex Point-to-Point Applications ADM3491 A RO R B RE RT DATA IN RT DATA OUT Z DE DI RO 05524-042 SLAVE DI Y ADM3488/ ADM3490 05524-043 DI MASTER D Y NOTES 1. RT IS EQUAL TO THE CHARACTERISTIC IMPEDANCE OF THE CABLE. Figure 36. Line Repeater for ADM3491 Rev. E | Page 16 of 20 05524-091 RO Data Sheet Data Sheet ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 OUTLINE DIMENSIONS 5.00 (0.1968) 4.80 (0.1890) 8 4.00 (0.1574) 3.80 (0.1497) 1 5 6.20 (0.2441) 5.80 (0.2284) 4 1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0040) COPLANARITY 0.10 SEATING PLANE 1.75 (0.0688) 1.35 (0.0532) 0.51 (0.0201) 0.31 (0.0122) 0.50 (0.0196) 0.25 (0.0099) 45 8 0 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.0157) 012407-A COMPLIANT TO JEDEC STANDARDS MS-012-AA CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. 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) 8 14 1 7 1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0039) COPLANARITY 0.10 0.51 (0.0201) 0.31 (0.0122) 6.20 (0.2441) 5.80 (0.2283) 0.50 (0.0197) 0.25 (0.0098) 1.75 (0.0689) 1.35 (0.0531) SEATING PLANE 45 8 0 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.0157) COMPLIANT TO JEDEC STANDARDS MS-012-AB CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. 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 060606-A 4.00 (0.1575) 3.80 (0.1496) ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 Data Sheet ORDERING GUIDE Model 1 ADM3483ARZ ADM3483ARZ-REEL7 Temperature Range -40C to +85C -40C to +85C Package Description 8-Lead Narrow Body Small Outline (SOIC_N) 8-Lead Narrow Body Small Outline (SOIC_N) Package Option R-8 R-8 ADM3485ARZ ADM3485ARZ-REEL7 -40C to +85C -40C to +85C 8-Lead Narrow Body Small Outline (SOIC_N) 8-Lead Narrow Body Small Outline (SOIC_N) R-8 R-8 1,000 ADM3488ARZ ADM3488ARZ-REEL7 -40C to +85C -40C to +85C 8-Lead Narrow Body Small Outline (SOIC_N) 8-Lead Narrow Body Small Outline (SOIC_N) R-8 R-8 1,000 ADM3490ARZ ADM3490ARZ-REEL7 ADM3491AR ADM3491AR-REEL ADM3491AR-REEL7 ADM3491ARZ ADM3491ARZ-REEL ADM3491ARZ-REEL7 -40C to +85C -40C to +85C 8-Lead Narrow Body Small Outline (SOIC_N) 8-Lead Narrow Body Small Outline (SOIC_N) 14-Lead Narrow Body Small Outline (SOIC_N) 14-Lead Narrow Body Small Outline (SOIC_N) 14-Lead Narrow Body Small Outline (SOIC_N) 14-Lead Narrow Body Small Outline (SOIC_N) 14-Lead Narrow Body Small Outline (SOIC_N) 14-Lead Narrow Body Small Outline (SOIC_N) R-8 R-8 R-14 R-14 R-14 R-14 R-14 R-14 1 -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C Z = RoHS Compliant Part. Rev. E | Page 18 of 20 Ordering Quantity 1,000 1,000 2,500 1,000 2,500 1,000 Data Sheet ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 NOTES Rev. E | Page 19 of 20 ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 NOTES (c)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 Data Sheet