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

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

10.2 Power Supply Discharging

To ensure normal re-initialization time after a power down, the power supply for the ISO1050 needs to discharge below 0.3 V, and as closely to 0 V as possible, to ensure that a communication delay does not occur. Figure 10-1 illustrates various scenarios of power-supply ramp-down and its effect on the communication delay.

GUID-A458305B-75DD-4154-A7D0-7E4CA76CA5EA-low.gifFigure 10-1 Power Supply Ramp-Down and Communication Delay Behavior

The brownout window, 0.3 V to 1.3 V (typical), represents the range of voltage in which a longer than normal re-initialization time may occur if VCC2 powers up from this voltage. The ISO1042, an upgraded device with higher isolation rating, CAN FD speeds of 5 Mbps, higher bus fault-protection voltage, stronger EMC performance, and smaller package options does not exhibit this behavior. For all new isolated CAN designs, it is recommended to use the ISO1042. If the ISO1050 must be used, ensure that VCC2 discharges to 0 V so that a longer than normal re-initialization time does not exist. If the power supplies cannot be configured in such a way that VCC2 discharge below 0.3 V on their own, implement a bleed resistor between VCC2 and GND2. The bleed resistor value should be selected such that it ensures VCC2 goes below the brownout window fast enough for any power interruption or power down sequence the system may permit. The lower the resistance, the faster VCC2 will discharge to 0V with the tradeoff of consuming power. For many systems, a bleed resistor value of 2 KΩ is sufficient.