16 Mbps, ESD Protected, Full-Duplex RS-485 Transceivers Data Sheet ADM1490E/ADM1491E FEATURES FUNCTIONAL BLOCK DIAGRAMS V CC RS-485/RS-422 full-duplex transceiver for high speed motor control applications ADM1490E 16 Mbps data rate 8 kV ESD protection on RS-485 input/output pins A RO R Complies with ANSI/TIA/EIA-485-A-1998 B Open circuit fail-safe Suitable for 5 V power supply applications Z D DI 32 nodes on the bus (1 unit load) Y Thermal shutdown protection Operating temperature range: 40C to +85C ADM1490E packages GND Narrow body, 8-lead SOIC Figure 1. 8-lead MSOP V CC ADM1491E packages Narrow-body, 14-lead SOIC ADM1491E 10-lead MSOP A RO R APPLICATIONS B RE RS-485/RS-422 interfaces Industrial field networks DE High data rate motor control Z D Multipoint data transmission systems DI Y Single-ended-to-differential signal conversion GND Figure 2. GENERAL DESCRIPTION The ADM1490E/ADM1491E are RS-485/RS-422 transceivers maximum output current to 250 mA during fault conditions. with 8 kV ESD protection and are suitable for high speed, full- A thermal shutdown circuit senses if the die temperature rises duplex communication on multipoint transmission lines. In above 150C and forces the driver outputs into a high impedance state under this condition. particular, the ADM1490E/ADM1491E are designed for use in motor control applications requiring communications at data The receiver of the ADM1490E/ADM1491E contains a fail-safe rates up to 16 Mbps. feature that results in a logic high output state if the inputs are The ADM1490E/ADM1491E are designed for balanced trans- unconnected (floating). mission lines and comply with TIA/EIA-485-A-98. The devices The ADM1490E/ADM1491E feature extremely fast and closely each have a 12 k receiver input impedance for unit load RS-485 matched switching times. Minimal driver propagation delays operation, allowing up to 32 nodes on the bus. permit transmission at data rates up to 16 Mbps, and low skew minimizes EMI interference. The differential transmitter outputs and receiver inputs feature electrostatic discharge circuitry that provides protection to 8 kV The ADM1490E/ADM1491E are fully specified over the using the human body model (HBM). commercial and industrial temperature ranges. The ADM1490E The ADM1490E/ADM1491E operate from a single 5 V power is available in two packages: a narrow body, 8-lead SOIC and an supply. Excessive power dissipation caused by bus contention 8-lead MSOP. The ADM1491E is also available in two packages: or output shorting is prevented by short-circuit protection and a narrow body, 14-lead SOIC and a 10-lead MSOP. thermal circuitry. Short-circuit protection circuits limit the Rev. D 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 www.analog.com 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. Fax: 781.461.3113 20082012 Analog Devices, Inc. All rights reserved. 07430-002 07430-001ADM1490E/ADM1491E Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Typical Performance Characteristics ..............................................7 Applications ....................................................................................... 1 Test Circuits ........................................................................................9 Functional Block Diagrams ............................................................. 1 Theory of Operation ...................................................................... 10 General Description ......................................................................... 1 Truth Tables................................................................................. 10 Revision History ............................................................................... 2 ESD Transient Protection Scheme ........................................... 10 Specifications ..................................................................................... 3 Applications Information .............................................................. 12 Timing Specifications .................................................................. 4 Differential Data ......................................................................... 12 Absolute Maximum Ratings ............................................................ 5 Cable and Data Rate ................................................................... 12 Thermal Resistance ...................................................................... 5 Typical Applications ................................................................... 12 ESD Caution .................................................................................. 5 Outline Dimensions ....................................................................... 14 Pin Configurations and Function Descriptions ........................... 6 Ordering Guide .......................................................................... 15 REVISION HISTORY 2/12Rev. C to Rev. D Changes to Figure 8 .......................................................................... 6 Updated Outline Dimensions ....................................................... 14 12/10Rev. B to Rev. C Changes to Figure 29 ...................................................................... 12 Changes to Figure 30 ...................................................................... 13 7/09Rev. A to Rev. B Added ADM1490E, 8-Lead SOIC, and 8-Lead MSOP .... Universal Changes to Table 4 ............................................................................ 5 Added Figure 7 Renumbered Figures Sequentially ..................... 6 Changes to Table 5 ............................................................................ 6 Changes to Typical Applications Section .................................... 12 Added Figure 29 .............................................................................. 12 Changes to Figure 30 ...................................................................... 13 Updated Outline Dimensions ....................................................... 14 Changes to Ordering Guide .......................................................... 15 2/09Rev. 0 to Rev. A Change to Table 9 ........................................................................... 11 12/08Revision 0: Initial Version Rev. D Page 2 of 16