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

8.3.3.3 Undervoltage Lockout and Fail-Safe

The supply pins have undervoltage detection that places the device in protected or fail-safe mode. This protects the bus during an undervoltage event on VCC1 or VCC2 supply pins. If the bus-side power supply VCC2 is lower than about 4 V, the power shutdown circuits in the ISO1050 will disable the transceiver to prevent false transmissions due to an unstable supply. If VCC1 is still active when this occurs, the receiver output (RXD) will go to a fail-safe HIGH (recessive) value in about 6 microseconds.

Table 8-1 Undervoltage Lockout and Fail-Safe
VCC1VCC2DEVICE STATEBUS OUTPUTRXD
GOODGOODFunctionalPer Device State and TXDMirrors Bus
BADGOODProtectedRecessiveHigh Impedance (3-state)
GOODBADProtectedHigh ImpedanceRecessive (Fail-Safe High)

Note:

After an undervoltage condition is cleared and the supplies have returned to valid levels, the device typically resumes normal operation in 300 µs