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 V Operate with 3.3 V supply CC Interoperable with 5 V logic ADM3483/ EIA RS-422 and RS-485 compliant over full ADM3485 common-mode range R RO Data rate options A RE ADM3483/ADM3488: 250 kbps DE ADM3485/ADM3490/ADM3491: 10 Mbps B Half- and full-duplex options DI D Reduced slew rates for low EMI (ADM3483 and ADM3488) 2 nA supply current in shutdown mode GND (ADM3483/ADM3485/ADM3491) Figure 1. Up to 32 transceivers on the bus V CC 7 V to +12 V bus common-mode range Specified over the 40C to +85C temperature range A R RO 8 ns skew (ADM3485/ADM3490/ADM3491) B 8-lead SOIC and 14-lead SOIC (ADM3491 only) packages ADM3488/ ADM3490 APPLICATIONS Z Low power RS-485/RS-422 applications DI D Y Telecom Industrial process control GND HVAC Figure 2. GENERAL DESCRIPTION ADM3491 The ADM3483/ADM3485/ADM3488/ADM3490/ADM3491 are A R RO low power, differential line transceivers designed to operate using a B RE single 3.3 V power supply. Low power consumption, coupled with a DE shutdown mode, makes the ADM3483/ADM3485/ADM3488/ Z ADM3490/ADM3491 ideal for power-sensitive applications. DI D Y The ADM3488/ADM3490/ADM3491 feature full-duplex com- 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 k, 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. 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Trademarks and registered trademarks are the property of their respective owners. 05524-025 05524-026 05524-027ADM3483/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 Devices Without Receiver/Driver Enables Revision History ............................................................................... 2 ADM3488/ADM3490................................................................ 14 Specifications..................................................................................... 4 Reduced EMI and Reflections (ADM3483/ADM3488) ....... 14 Timing SpecificationsADM3485/ADM3490/ADM3491.... 5 Low Power Shutdown Mode Timing SpecificationsADM3483/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 11/11Rev. D to Rev. E Changes to Digital I/O Voltage (DE, , DI) Parameter, RE 10/06Rev. A to Rev. B Table 6 ................................................................................................ 7 Updated Format..................................................................Universal Moved Typical Performance Characteristics Section .................. 9 Added ADM3491 ...............................................................Universal Moved Test Circuits Section.......................................................... 11 Changes to Specifications Section...................................................4 Moved Switching Characteristics Section ................................... 13 Changes to Typical Applications Section .................................... 14 Changes to Note 1, Table 8 ............................................................ 14 Changes to Outline Dimensions................................................... 17 7/06Rev. 0 to Rev. A Changes to Applications...................................................................1 12/10Rev. C to Rev. D Changes to General Description .....................................................1 Changes to Figure 33...................................................................... 15 Changes to Figure 19...................................................................... 10 Changes to Typical Applications Section .................................... 13 8/10Rev. B to Rev. C Changes to Figure 31 and Figure 32............................................. 14 Changes to Table 2, Driver Input Logic......................................... 4 Updated Outline Dimensions....................................................... 15 10/05Revision 0: Initial Version Rev. E Page 2 of 20