Full-Duplex, Low Power, Slew Rate Limited, EIA RS-485 Transceivers Data Sheet ADM488A/ADM489A FEATURES FUNCTIONAL BLOCK DIAGRAMS Complies with ANSI TIA/EIA-485-A-1998 and ADM488A ISO 8482: 1987(E) A 250 kbps data rate RO R B 4 kV HBM ESD protection on all pins Single 5 V 10% supply Z 7 V to +12 V bus common-mode range DI D Connect up to 32 nodes on the bus Y Reduced slew rate for low EM interference Short-circuit protection Figure 1. ADM488A 30 A supply current ADM489A APPLICATIONS A Low power RS-485 and RS-422 systems RO R B DTE-DCE interface RE Packet switching DE Local area networks Z DI D Data concentration Y Data multiplexers Integrated services digital network (ISDN) Figure 2. ADM489A GENERAL DESCRIPTION Excessive power dissipation that is caused by bus contention or output shorting is prevented by a thermal shutdown circuit. This The ADM488A and ADM489A are low power, differential line feature forces the driver output into a high impedance state if, transceivers suitable for communication on multipoint bus during fault conditions, a significant temperature increase is transmission lines. They are intended for balanced data detected in the internal driver circuitry. transmission and comply with both RS-485 and RS-422 standards of the Electronics Industries Association (EIA). Both The receiver contains a fail-safe feature that results in a logic products contain a single differential line driver and a single high output state if the inputs are unconnected (floating). differential line receiver, making them suitable for full-duplex The ADM488A/ADM489A are fabricated on BiCMOS, an data transfer. The ADM489A contains an additional receiver advanced mixed technology process combining low power and driver enable control. CMOS with fast switching bipolar technology. The input impedance is 12 k, allowing 32 transceivers to be The ADM488A/ADM489A are fully specified over the industrial connected on the bus. The ADM488A/ADM489A operate from temperature range and are available in SOIC and MSOP packages. a single 5 V 10% power supply. Rev. B Document Feedback 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 Tel: 781.329.4700 2009-2014 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. 08498-002 08498-001ADM488A/ADM489A Data Sheet TABLE OF CONTENTS Typical Performance Characteristics ..............................................8 Features .............................................................................................. 1 Test Circuits ........................................................................................9 Applications ....................................................................................... 1 Switching Characteristics .......................................................... 10 General Description ......................................................................... 1 Theory of Operation ...................................................................... 11 Functional Block Diagrams ............................................................. 1 Applications Information .............................................................. 13 Revision History ............................................................................... 2 Differential Data Transmission ................................................ 13 Specifications ..................................................................................... 3 Cable and Data Rate ................................................................... 13 Timing Specifications .................................................................. 4 Outline Dimensions ....................................................................... 14 Absolute Maximum Ratings ............................................................ 5 Ordering Guide .......................................................................... 15 ESD Caution .................................................................................. 5 Pin Configurations and Function Descriptions ........................... 6 REVISION HISTORY 6/14Rev. A to Rev. B Changes to Features Section............................................................ 1 Changes to Table 3 ............................................................................ 5 11/10Rev. 0 to Rev. A Changes to Table 2 ............................................................................ 4 Changes to Figure 20 ...................................................................... 11 Changes to Figure 21 ...................................................................... 12 Added New Figure 23, Renumbered Subsequent Figures, Moved Old Figure 23 to New Figure 25 ...................................... 14 Changes to Ordering Guide .......................................................... 15 10/09Revision 0: Initial Version Rev. B Page 2 of 16