SLLSFX4B February   2025  – October 2026 TCAN857-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  ESD Ratings, IEC Specification
    4. 6.4  Recommended Operating Conditions
    5. 6.5  Thermal Information
    6. 6.6  Power Supply Characteristics
    7. 6.7  Dissipation Ratings
    8. 6.8  Electrical Characteristics
    9. 6.9  Switching Characteristics
    10. 6.10 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 Pin Description
        1. 8.3.1.1 TXD
        2. 8.3.1.2 GND
        3. 8.3.1.3 VCC
        4. 8.3.1.4 RXD
        5. 8.3.1.5 VIO
        6. 8.3.1.6 CANH and CANL
        7. 8.3.1.7 S (Silent)
      2. 8.3.2 CAN Bus States
      3. 8.3.3 TXD Dominant Timeout (DTO)
      4. 8.3.4 CAN Bus Short-circuit Current Limiting
      5. 8.3.5 Thermal Shutdown (TSD)
      6. 8.3.6 Undervoltage Lockout
      7. 8.3.7 Unpowered Device
      8. 8.3.8 Floating pins
    4. 8.4 Device Functional Modes
      1. 8.4.1 Operating Modes
      2. 8.4.2 Normal Mode
      3. 8.4.3 Silent Mode
      4. 8.4.4 Driver and Receiver Function
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
        1. 9.2.1.1 CAN Termination
      2. 9.2.2 Detailed Design Procedures
        1. 9.2.2.1 Bus Loading, Length and Number of Nodes
      3. 9.2.3 System Examples
      4. 9.2.4 Application Curve
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

8.3.2 CAN Bus States

The CAN bus has two logical states during operation: recessive and dominant. See Figure 8-1.

A dominant bus state occurs when the bus is driven differentially and corresponds to a logic low on the TXD and RXD pins. A recessive bus state occurs when the bus is biased to VCC/2 though the high-resistance internal input resistors RIN) of the receiver, and corresponds to a logic high on the TXD and RXD pins.

A dominant state overwrites the recessive state during arbitration. Multiple CAN nodes may be transmitting a dominant bit at the same time during arbitration, and in this case, the differential voltage of the bus is greater than the differential voltage of a single driver.

TCAN857-Q1 Bus StatesFigure 8-1 Bus States