SLLSFX4A February   2025  – February 2025 TCAN857-Q1

PRODUCTION DATA  

  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 Specification
    4. 5.4  Recommended Operating Conditions
    5. 5.5  Thermal Characteristics
    6. 5.6  Power Supply Characteristics
    7. 5.7  Dissipation Ratings
    8. 5.8  Electrical Characteristics
    9. 5.9  Switching Characteristics
    10. 5.10 Typical 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 Pin Description
        1. 7.3.1.1 TXD
        2. 7.3.1.2 GND
        3. 7.3.1.3 VCC
        4. 7.3.1.4 RXD
        5. 7.3.1.5 VIO
        6. 7.3.1.6 CANH and CANL
        7. 7.3.1.7 S (Silent)
      2. 7.3.2 CAN Bus States
      3. 7.3.3 TXD Dominant Timeout (DTO)
      4. 7.3.4 CAN Bus Short-circuit Current Limiting
      5. 7.3.5 Thermal Shutdown (TSD)
      6. 7.3.6 Undervoltage Lockout
      7. 7.3.7 Unpowered Device
      8. 7.3.8 Floating pins
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operating Modes
      2. 7.4.2 Normal Mode
      3. 7.4.3 Silent Mode
      4. 7.4.4 Driver and Receiver Function
  9. 8 Application Information Disclaimer
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
        1. 8.2.1.1 CAN Termination
      2. 8.2.2 Detailed Design Procedures
        1. 8.2.2.1 Bus Loading, Length and Number of Nodes
      3. 8.2.3 System Examples
      4. 8.2.4 Application Curve
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 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

7.3.6 Undervoltage Lockout

The supply pins, VCC and VIO, have undervoltage detection that places the device into a protected state. This protects the bus during an undervoltage event on either supply pin.

Table 7-1 Undervoltage Lockout - TCAN857(V)-Q1
VCCDEVICE STATEBUSRXD PIN
> UVVCCNormalPer TXDMirrors bus
< UVVCCProtectedHigh impedance
Weak pull-down to ground(1)		High impedance
(1) VCC = GND, see ILKG(OFF)
Table 7-2 VIO Undervoltage Lockout - TCAN857(V)-Q1
VCCVIODEVICE STATEBUSRXD PIN
> UVVCC> UVVIONormalPer TXDMirrors bus
< UVVCC> UVVIOS = VIO: Silent modeHigh impedance
Weak pull-down to ground(1)		Recessive
S = GND: Protected mode
> UVVCC< UVVIOProtectedHigh impedance
< UVVCC< UVVIOProtectedHigh impedance
(1) VCC = GND, see ILKG(OFF)

Once the undervoltage condition is cleared and tMODE has expired, the device transitions to normal mode. The host controller can again send and receive CAN traffic.