5 V, 0.8 mA PROFIBUS RS-485 Transceiver ADM1486 FEATURES FUNCTIONAL BLOCK DIAGRAM Meets and exceeds EIA RS-485 and EIA RS-422 standards ADM1486 30 Mbps data rate Recommended for PROFIBUS applications 1 8 RO R V CC 2.1 V minimum differential output with 54 termination Low power 0.8 mA ICC 2 7 B RE Thermal shutdown and short-circuit protection 0.5 ns skew driver and receiver DE 3 6 A Driver propagation delay: 11 ns Receiver propagation delay: 12 ns DI 4 D 5 GND High impedance outputs with drivers disabled or power off Superior upgrade for SN65ALS1176 Available in standard 8-lead SOIC package Figure 1. APPLICATIONS Industrial field equipment To ensure this, the ADM1486 driver features high output GENERAL DESCRIPTION impedance when disabled and when powered down. This The ADM1486 is a differential line transceiver suitable for high minimizes the loading effect when the transceiver is not being speed bidirectional data communication on multipoint bus used. The high impedance driver output is maintained over the transmission lines. It is designed for balanced data transmission, entire common-mode voltage range from 7 V to +12 V. complies with EIA Standards RS-485 and RS-422, and is recom- mended for PROFIBUS applications. The part contains a The receiver contains a fail-safe feature that results in a logic differential line driver and a differential line receiver. Both the high output state if the inputs are unconnected (floating). driver and the receiver may be enabled independently. When The ADM1486 is fabricated on BiCMOS, an advanced mixed disabled or powered down, the driver outputs are high impedance. technology process combining low power CMOS with fast The ADM1486 operates from a single 5 V power supply. switching bipolar technology. All inputs and outputs contain Excessive power dissipation caused by bus contention or output protection against ESD all driver outputs feature high source shorting is prevented by short-circuit protection and thermal and sink current capability. An epitaxial layer is used to guard circuitry. Short-circuit protection circuits limit the maximum against latch-up. output current to 200 mA during fault conditions. A thermal The ADM1486 features extremely fast and closely matched shutdown circuit senses if the die temperature rises above switching, enable, and disable times. Minimal driver propaga- 150C and forces the driver outputs into a high impedance state tion delays permit transmission at data rates up to 30 Mbps under this condition. while low skew minimizes EMI interference. Up to 50 transceivers may be connected simultaneously on a The part is fully specified over the commercial and industrial bus, but only one driver should be enabled at a time. Therefore, temperature range and is available in an 8-lead SOIC package. it is important that the remaining disabled drivers do not load the bus. Rev. A 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. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Specifications subject to change without notice. No license is granted by implication Tel: 781.329.4700 www.analog.com 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 2005 Analog Devices, Inc. All rights reserved. 02603-001ADM1486 TABLE OF CONTENTS Specifications..................................................................................... 3 Applications Information .............................................................. 13 Timing Specifications....................................................................... 4 Differential Data Transmission ................................................ 13 Absolute Maximum Ratings............................................................ 5 Cable and Data Rate................................................................... 13 ESD Caution.................................................................................. 5 Thermal Shutdown .................................................................... 13 Pin Configuration and Function Descriptions............................. 6 Propagation Delay...................................................................... 13 Test Circuits....................................................................................... 7 Receiver Open-Circuit Fail-Safe............................................... 13 Switching Characteristics ................................................................ 8 Outline Dimensions ....................................................................... 15 Typical Performance Characteristics ............................................. 9 Ordering Guide .......................................................................... 15 REVISION HISTORY 3/05Rev. 0 to Rev. A Updated Format..................................................................Universal Added PROFIBUS Logo .................................................................. 1 Updated Outline Dimensions ....................................................... 15 Changes to Ordering Guide .......................................................... 15 11/02Revision 0: Initial Version Rev. A Page 2 of 16