SLLSEQ7E December   2015  – December 2019 TCAN330 , TCAN330G , TCAN332 , TCAN332G , TCAN334 , TCAN334G , TCAN337 , TCAN337G

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Block Diagram
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Device Options
  7. 7 Pin Configuration and Functions
    1.     Pin Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Switching Characteristics
    7. 8.7 Typical Characteristics
    8. 8.8 Typical Characteristics, TCAN330 Receiver
    9. 8.9 Typical Characteristics, TCAN330 Driver
  9. 9 Parameter Measurement Information
  10. 10Detailed Description
    1. 10.1 Overview
    2. 10.2 Functional Block Diagram
    3. 10.3 Feature Description
      1. 10.3.1 TXD Dominant Timeout (TXD DTO)
      2. 10.3.2 RXD Dominant Timeout (RXD DTO)
      3. 10.3.3 Thermal Shutdown
      4. 10.3.4 Undervoltage Lockout and Unpowered Device
      5. 10.3.5 Fault Pin (TCAN337)
      6. 10.3.6 Floating Pins
      7. 10.3.7 CAN Bus Short Circuit Current Limiting
      8. 10.3.8 ESD Protection
      9. 10.3.9 Digital Inputs and Outputs
    4. 10.4 Device Functional Modes
      1. 10.4.1 CAN Bus States
      2. 10.4.2 Normal Mode
      3. 10.4.3 Silent Mode
      4. 10.4.4 Standby Mode with Wake
      5. 10.4.5 Bus Wake via RXD Request (BWRR) in Standby Mode
      6. 10.4.6 Shutdown Mode
      7. 10.4.7 Driver and Receiver Function Tables
  11. 11Application and Implementation
    1. 11.1 Application Information
      1. 11.1.1 Bus Loading, Length and Number of Nodes
    2. 11.2 Typical Application
      1. 11.2.1 Design Requirements
        1. 11.2.1.1 CAN Termination
      2. 11.2.2 Detailed Design Procedure
      3. 11.2.3 Application Curves
    3. 11.3 System Examples
      1. 11.3.1 ISO11898 Compliance of TCAN33x Family of 3.3-V CAN Transceivers Introduction
      2. 11.3.2 Differential Signal
      3. 11.3.3 Common-Mode Signal and EMC Performance
  12. 12Power Supply Recommendations
  13. 13Layout
    1. 13.1 Layout Guidelines
    2. 13.2 Layout Example
  14. 14Device and Documentation Support
    1. 14.1 Related Links
    2. 14.2 Support Resources
    3. 14.3 Trademarks
    4. 14.4 Electrostatic Discharge Caution
    5. 14.5 Glossary
  15. 15Mechanical, Packaging, and Orderable Information

10.3.4 Undervoltage Lockout and Unpowered Device

The VCC supply terminal has under voltage detection which will place the device in protected mode if the supply drops below the UVLO threshold. This protects the bus during an under voltage event on VCC by placing the bus into a high impedance biased to ground state and the RXD terminal into a tri-stated (high impedance) state. During undervoltage the device does not pass any signals from the bus. If the device is in normal mode and VCC supply is lost the device will transition to a protected mode.

The device is designed to be an "ideal passive" or “no load” to the CAN bus if the device is unpowered. The bus terminals (CANH, CANL) have low leakage currents when the device is unpowered, so the device does not load the bus. This is critical if some nodes of the network are unpowered while the rest of the of network remains operational. Logic pins also have low leakage currents when the device is unpowered, so the device does not load other circuits which may remain powered.

Table 1. Undervoltage Protection 3.3-V Single Supply Devices

VCC DEVICE STATE BUS RXD
GOOD Operational Per Operating Mode Per Operating Mode
BAD Protected Common mode bias to GND High Impedance
UNPOWERED Unpowered High Impedance (no load) High Impedance