SLLSFV8A July   2024  – November 2024 TCAN1043N-Q1

ADVANCE INFORMATION  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  ESD Ratings - IEC Specifications
    4. 5.4  Recommended Operating Conditions
    5. 5.5  Thermal Information
    6. 5.6  Power Dissipation Ratings
    7. 5.7  Power Supply Characteristics
    8. 5.8  Electrical Characteristics
    9. 5.9  Timing Requirements
    10. 5.10 Switching Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Supply Pins
        1. 7.3.1.1 VSUP Pin
        2. 7.3.1.2 VCC Pin
        3. 7.3.1.3 VIO Pin
      2. 7.3.2 Digital Inputs and Outputs
        1. 7.3.2.1 TXD Pin
        2. 7.3.2.2 RXD Pin
        3. 7.3.2.3 nFAULT Pin
        4. 7.3.2.4 EN Pin
        5. 7.3.2.5 nSTB Pin
      3. 7.3.3 GND
      4. 7.3.4 INH Pin
      5. 7.3.5 WAKE Pin
      6. 7.3.6 CAN Bus Pins
      7. 7.3.7 Faults
        1. 7.3.7.1 Internal and External Fault Indicators
          1. 7.3.7.1.1 Power-Up (PWRON Flag)
          2. 7.3.7.1.2 Wake-Up Request (WAKERQ Flag)
          3. 7.3.7.1.3 Undervoltage Faults
            1. 7.3.7.1.3.1 Undervoltage on VSUP
            2. 7.3.7.1.3.2 Undervoltage on VCC
            3. 7.3.7.1.3.3 Undervoltage on VIO
          4. 7.3.7.1.4 CAN Bus Fault (CBF Flag)
          5. 7.3.7.1.5 TXD Dominant State Timeout (TXDDTO Flag)
          6. 7.3.7.1.6 TXD Shorted to RXD Fault (TXDRXD Flag)
          7. 7.3.7.1.7 CAN Bus Dominant Fault (CANDOM Flag)
      8. 7.3.8 Local Faults
        1. 7.3.8.1 TXD Dominant Timeout (TXD DTO)
        2. 7.3.8.2 Thermal Shutdown (TSD)
        3. 7.3.8.3 Undervoltage Lockout (UVLO)
        4. 7.3.8.4 Unpowered Devices
        5. 7.3.8.5 Floating Terminals
        6. 7.3.8.6 CAN Bus Short-Circuit Current Limiting
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operating Mode Description
        1. 7.4.1.1 Normal Mode
        2. 7.4.1.2 Silent Mode
        3. 7.4.1.3 Standby Mode
        4. 7.4.1.4 Go-To-Sleep Mode
        5. 7.4.1.5 Sleep Mode
          1. 7.4.1.5.1 Remote Wake Request via Wake-Up Pattern (WUP)
          2. 7.4.1.5.2 Local Wake-Up (LWU) via WAKE Input Terminal
      2. 7.4.2 CAN Transceiver
        1. 7.4.2.1 CAN Transceiver Operation
          1. 7.4.2.1.1 CAN Transceiver Modes
            1. 7.4.2.1.1.1 CAN Off Mode
            2. 7.4.2.1.1.2 CAN Autonomous: Inactive and Active
            3. 7.4.2.1.1.3 CAN Active
          2. 7.4.2.1.2 Driver and Receiver Function Tables
          3. 7.4.2.1.3 CAN Bus States
  9. 8 Application Information Disclaimer
    1. 8.1 Application Information
      1. 8.1.1 Typical Application
      2. 8.1.2 Design Requirements
        1. 8.1.2.1 Bus Loading, Length and Number of Nodes
      3. 8.1.3 Detailed Design Procedure
        1. 8.1.3.1 CAN Termination
      4. 8.1.4 Application Curves
    2. 8.2 Power Supply Recommendations
    3. 8.3 Layout
      1. 8.3.1 Layout Guidelines
      2. 8.3.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Tape and Reel Information

7.3.8.1 TXD Dominant Timeout (TXD DTO)

While the CAN driver is in active mode a TXD dominant state timeout circuit prevents the local node from blocking network communication in event of a hardware or software failure where TXD is held dominant longer than the timeout period, t > tTXDDTO. The TXD dominant state timeout circuit is triggered by a falling edge on the TXD pin. If no rising edge is seen before on TXD before t > tTXDDTO than the CAN driver is disabled releasing the bus lines to the recessive level. This keeps the bus free for communication between other nodes on the network.

The CAN driver will be activated again on the next dominant-to-recessive transition on the TXD pin. During a TXDDTO fault the high-speed receiver remains active and the RXD output pin will mirror the CAN bus.

TCAN1043N-Q1 Timing Diagram for TXD DTOFigure 7-3 Timing Diagram for TXD DTO

The minimum dominant TXD time allowed by the dominant state timeout circuit limits the minimum possible transmitted data rate of the transceiver. The CAN protocol allows a maximum of eleven successive dominant bits to be transmitted in the worst case, where five successive dominant bits are followed immediately by an error frame. The minimum transmitted data rate may be calculated using the minimum tTXDDTO time in Equation 1.

Equation 1. Minimum Data Rate = 11 bits / tTXDDTO = 11 bits / 1.2ms = 9.2kbps