SLLA272D February   2008  – May 2021

 

  1.   Trademarks
  2. 1 Introduction
  3. 2 Standard and Features
  4. 3 Network Topology
  5. 4 Signal Levels
  6. 5 Cable Type
  7. 6 Bus Termination and Stub Length
  8. 7 Failsafe
  9. 8 Bus Loading
  10. 9 Data Rate Versus Bus Length
  11. 10Minimum Node Spacing
  12. 11Grounding and Isolation
  13. 12Conclusion
    1. 12.1 References
  14. 13Revision History

12 Conclusion

The objective of this application report is to cover the main aspects of an RS-485 system design. Despite the enormous amount of technical literature on the subject, this document’s intent is to provide system designers new to RS-485 with design guidelines in a very comprehensive way.

Following the discussions presented in this document and consulting the detailed application reports in the reference section can help accomplishing a robust, RS-485-compliant system design in the shortest time possible.

Supporting the design effort, Texas Instruments provides an extensive product range of RS-485 transceivers. Device features include low EMI, low-power (1/8 UL), high ESD protection (from 16 kV up to 30 kV), and integrated failsafe functions for open-, short- and idle-bus conditions. For long-distance applications requiring isolation, the product range extends to unidirectional and bidirectional, digital isolators in dual, triple and quad versions (from DC to 150 Mbps), and isolated DC/DC converters
(with 3-V and 5-V regulated outputs), to provide the power supply across the isolation barrier.