JAJSJQ9C September   2021  – April 2022 ISOW7740 , ISOW7741 , ISOW7742 , ISOW7743 , ISOW7744

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  4. 4 Revision History
  5. 5 概要 (続き)
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information
    5. 7.5  Power Ratings
    6. 7.6  Insulation Specifications
    7. 7.7  Safety-Related Certifications
    8. 7.8  Safety Limiting Values
    9. 7.9  Electrical Characteristics - Power Converter
    10. 7.10 Supply Current Characteristics - Power Converter
    11. 7.11 Electrical Characteristics Channel Isolator - VIO, VISOIN = 5-V
    12. 7.12 Supply Current Characteristics Channel Isolator - VIO, VISOIN = 5-V
    13. 7.13 Electrical Characteristics Channel Isolator - VIO, VISOIN = 3.3-V
    14. 7.14 Supply Current Characteristics Channel Isolator - VIO, VISOIN = 3.3-V
    15. 7.15 Electrical Characteristics Channel Isolator - VIO, VISOIN = 2.5-V
    16. 7.16 Supply Current Characteristics Channel Isolator - VIO, VISOIN = 2.5-V
    17. 7.17 Electrical Characteristics Channel Isolator - VIO, VISOIN = 1.8-V
    18. 7.18 Supply Current Characteristics Channel Isolator - VIO, VISOIN = 1.8-V
    19. 7.19 Switching Characteristics - 5-V Supply
    20. 7.20 Switching Characteristics - 3.3-V Supply
    21. 7.21 Switching Characteristics - 2.5-V Supply
    22. 7.22 Switching Characteristics - 1.8-V Supply
    23. 7.23 Insulation Characteristics Curves
    24. 7.24 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
      1. 9.1.1 Power Isolation
      2. 9.1.2 Signal Isolation
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Electromagnetic Compatibility (EMC) Considerations
      2. 9.3.2 Power-Up and Power-Down Behavior
      3. 9.3.3 Protection Features
    4. 9.4 Device Functional Modes
      1. 9.4.1 Device I/O Schematics
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curve
      4. 10.2.4 Insulation Lifetime
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
      1. 12.1.1 PCB Material
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Development Support
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 サポート・リソース
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

9.3.3 Protection Features

The ISOW774x devices have multiple protection features to create a robust system level solution.

  • The Enable DC-DC / FAULT protection feature (EN/FLT) can be used as either an input pin, to enable or disable the integrated DC-DC power converter, or as an output pin, which works as an alert signal if the power converter is not operating properly. In the /FAULT use case, an alert is reported if VDD > 7 V, VDD < 2.5 V, or if the junction temperature >170°C. When a fault is detected, this pin will go low, disabling the DC-DC converter to prevent any damage.
    Figure 9-4 EN/FLT Fault Pin Diagram

  • An over-voltage clamp feature is present on VISOOUT which will clamp the voltage at 6 V, when VSEL = VISOOUT, or 4 V, when VSEL = GND2, if there is an increase in voltage seen on VISOOUT. It is recommended that the VISOOUT stays lower than the over-clamp voltage for device reliability.

  • Over-voltage lock out on VDD will occur when a voltage higher than 7 V is seen. The device will go into a low power state and the EN/FLT pin will go low.

  • The device is protected against output overload and short circuit. Output voltage starts dropping when the power converter is not able to deliver the current demanded during overload conditions. For a VISOOUT short-circuit to ground, the duty cycle of the converter is limited to help protect against any damage.
  • The device is protected against output overload and short circuit. Output voltage starts dropping when the power converter is not able to deliver the current demanded during overload conditions. For a VISOOUT short-circuit to ground, the duty cycle of the converter is limited to help protect against any damage.
  • The device is protected against output overload and short circuit. Output voltage starts dropping when the power converter is not able to deliver the current demanded during overload conditions. For a VISOOUT short-circuit to ground, the duty cycle of the converter is limited to help protect against any damage.
  • Thermal protection is also integrated to help prevent the device from getting damaged during overload and short-circuit conditions on the isolated output. Under these conditions, the device temperature starts to increase. When the temperature goes above 165°C, thermal shutdown activates and the primary controller turns off which removes the energy supplied to the VISOOUT load, which causes the device to cool off. When the junction temperature goes below 150°C, the device starts to function normally. If an overload or output short-circuit condition prevails, this protection cycle is repeated. Care should be taken in the design to prevent the device junction temperatures from reaching such high values.