SLLSFF7A may   2021  – december 2021 ISOW1044

PRODUCTION DATA  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Revision History
  6. Description Continued
  7. Device Comparison Table
  8. Pin Configuration and Functions
  9. Specifications
    1. 8.1  Absolute Maximum Ratings
    2. 8.2  ESD Ratings
    3. 8.3  Recommended Operating Conditions
    4. 8.4  ThermalInformation
    5. 8.5  Power Ratings
    6. 8.6  Insulation Specifications
    7. 8.7  Safety-Related Certifications
    8. 8.8  Safety Limiting Values
    9. 8.9  Electrical Characteristics
    10. 8.10 Supply Current Characteristics
    11. 8.11 Switching Characteristics
    12. 8.12 Insulation Characteristics Curves
    13. 8.13 Typical Characteristics
  10. Parameter Measurement Information
  11. 10Detailed Description
    1. 10.1 Overview
    2. 10.2 Power Isolation
    3. 10.3 Signal Isolation
    4. 10.4 CAN Transceiver
      1. 10.4.1 Remote Wake Request via Wake-Up Pattern (WUP) in Standby Mode
    5. 10.5 Functional Block Diagram
    6. 10.6 Feature Description
      1. 10.6.1 CAN Bus States
      2. 10.6.2 Digital Inputs and Outputs: TXD (Input) and RXD (Output)
      3. 10.6.3 TXD Dominant Timeout (DTO)
      4. 10.6.4 Power-Up and Power-Down Behavior
      5. 10.6.5 Protection Features
      6. 10.6.6 Floating Pins, Unpowered Device
      7. 10.6.7 Glitch-Free Power Up and Power Down
    7. 10.7 Device Functional Modes
    8. 10.8 Device I/O Schematics
  12. 11Application and Implementation
    1. 11.1 Application Information
    2. 11.2 Typical Application
      1. 11.2.1 Design Requirements
      2. 11.2.2 Detailed Design Procedure
        1. 11.2.2.1 Bus Loading, Length and Number of Nodes
        2. 11.2.2.2 CAN Termination
      3. 11.2.3 Application Curve
      4. 11.2.4 Insulation Lifetime
  13. 12Power Supply Recommendations
  14. 13Layout
    1. 13.1 Layout Guidelines
    2. 13.2 Layout Example
  15. 14Device and Documentation Support
    1. 14.1 Documentation Support
      1. 14.1.1 Related Documentation
    2. 14.2 Receiving Notification of Documentation Updates
    3. 14.3 Support Resources
    4. 14.4 Trademarks
    5. 14.5 Electrostatic Discharge Caution
    6. 14.6 Glossary
  16. 15Mechanical, Packaging, and Orderable Information

CAN Termination

The ISO11898 standard specifies the interconnect to be a single twisted pair cable (shielded or unshielded) with 120-Ω characteristic impedance (ZO). Resistors equal to the characteristic impedance of the line should be used to terminate both ends of the cable to prevent signal reflections. Unterminated drop-lines (stubs) connecting nodes to the bus should be kept as short as possible to minimize signal reflections. The termination may be in a node, but if nodes are removed from the bus, the termination must be carefully placed so that it is not removed from the bus.

GUID-57144F4B-5958-4B33-B476-F73A340D09A6-low.gif Figure 11-2 Typical CAN Bus

Termination may be a single 120-Ω resistor at the end of the bus, either on the cable or in a terminating node. If filtering and stabilization of the common-mode voltage of the bus is desired, then split termination can be used as below termination concepts. Split termination improves the electromagnetic emissions behavior of the network by eliminating fluctuations in the bus common-mode voltages at the start and end of message transmissions.

GUID-061CBCD0-D90F-4751-9BB3-9F604258C094-low.gif Figure 11-3 CAN Bus Termination Concepts