SLLS983L June   2009  – October 2023 ISO1050

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information
    5. 6.5  Power Ratings
    6. 6.6  Insulation Specifications
    7. 6.7  Safety-Related Certifications
    8. 6.8  Safety Limiting Values
    9. 6.9  Electrical Characteristics - DC Specification
    10. 6.10 Switching Characteristics
    11. 6.11 Insulation Characteristics Curves
    12. 6.12 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 CAN Bus States
      2. 8.3.2 Digital Inputs and Outputs
      3. 8.3.3 Protection Features
        1. 8.3.3.1 TXD Dominant Time-Out (DTO)
        2. 8.3.3.2 Thermal Shutdown
        3. 8.3.3.3 Undervoltage Lockout and Fail-Safe
        4. 8.3.3.4 Floating Pins
        5. 8.3.3.5 CAN Bus Short-Circuit Current Limiting
    4. 8.4 Device Functional Modes
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Bus Loading, Length and Number of Nodes
        2. 9.2.2.2 CAN Termination
      3. 9.2.3 Application Curve
  11. 10Power Supply Recommendations
    1. 10.1 General Recommendations
    2. 10.2 Power Supply Discharging
  12. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 PCB Material
    2. 11.2 Layout Example
  13. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  14. 13Mechanical, Packaging, and Orderable Information

9.2.2.2 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 may be removed from the bus, the termination must be carefully placed so that it is not removed from the bus.

GUID-25C84B75-490E-4FD6-8922-568D44C1C2FF-low.gifFigure 9-2 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 may be used. (See Figure 9-3). 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-7AC640F5-0B23-4F42-96F8-49933842B400-low.gifFigure 9-3 CAN Bus Termination Concepts