SLLA486B May   2020  – October 2024 ISO1042 , ISO1042-Q1 , ISO1044 , ISO1050 , ISOW1044

 

  1.   1
  2.   Top Design Questions About Isolated CAN Bus Design
  3.   Trademarks
  4. 1 When Do I Need to Isolate CAN?
  5. 2 What are the Options Available to Isolate CAN Bus?
  6. 3 Now That I Have Isolated CAN Signal Path, How Do I Generate Isolated Power?
  7. 4 What’s the Reason Behind Terminating the Bus, Do I Need it, and How to Achieve it?
  8. 5 What’s the Difference Between Common Mode Range and Bus Standoff Mentioned in Data Sheet?
  9. 6 Now That I Have Taken Care of the Termination Resistor, What Other Components do I Need on the Bus Side?
  10. 7 When Connecting Isolated CAN Nodes in a Network, What Should be Done with the Floating Bus-Side Ground Connection?
  11. 8 Is There a Limitation on Minimum Data Rate That I Can Operate? What About the Maximum Data Rate Achievable in a Network?
  12. 9 Is There a Limit on Maximum Number of Nodes That I Can Connect in CAN Network?
  13. 10What Factors Decide the Maximum Communication Distance in a CAN Network?
  14. 11What is the Maximum Value of Bus Capacitance That Can be Introduced Between CANH to GND and CANL to GND? Can Higher Capacitance Damage the Device?
  15. 12Is There a Way to Extend the Maximum Communication Distance?
  16. 13What is Stub Length? What are the Design Considerations Around it?
  17. 14I am Seeing Larger Differential CAN Voltage for Some Bits of CAN Packet Compared to Rest of the Packet When I am Communicating in a Network with Multiple Nodes Connected. Why?
  18. 15References
  19. 16Revision History

Abstract

The controller area network (CAN) bus is a multi-master, message broadcast networking interface. It is usually preferred over other differential wired interfaces in safety-critical applications because of the features defined in its protocol such as priority based messaging, bitwise arbitration to handle bus contention and error detection and recovery. Isolating a CAN port is a common design challenge encountered in many industrial and automotive applications. TI’s integrated isolated CAN transceivers ISO1042, ISO1044, and ISOW1044 are referenced throughout this article. The following is a compilation of the most frequently asked questions about isolating CAN nodes.