SLLSEY2G March   2017  – August 2021 ISOW7840 , ISOW7841 , ISOW7842 , ISOW7843 , ISOW7844

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
    1.     Pin 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—5-V Input, 5-V Output
    10. 7.10 Supply Current Characteristics—5-V Input, 5-V Output
    11. 7.11 Electrical Characteristics—3.3-V Input, 5-V Output
    12. 7.12 Supply Current Characteristics—3.3-V Input, 5-V Output
    13. 7.13 Electrical Characteristics—5-V Input, 3.3-V Output
    14. 7.14 Supply Current Characteristics—5-V Input, 3.3-V Output
    15. 7.15 Electrical Characteristics—3.3-V Input, 3.3-V Output
    16. 7.16 Supply Current Characteristics—3.3-V Input, 3.3-V Output
    17. 7.17 Switching Characteristics—5-V Input, 5-V Output
    18. 7.18 Switching Characteristics—3.3-V Input, 5-V Output
    19. 7.19 Switching Characteristics—5-V Input, 3.3-V Output
    20. 7.20 Switching Characteristics—3.3-V Input, 3.3-V Output
    21. 7.21 Insulation Characteristics Curves
    22. 7.22 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    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 Current Limit, Thermal Overload Protection
    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
        1. 10.2.3.1 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 Related Links
    4. 13.4 Receiving Notification of Documentation Updates
    5. 13.5 Support Resources
    6. 13.6 Trademarks
    7. 13.7 Electrostatic Discharge Caution
    8. 13.8 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

10.2.2 Detailed Design Procedure

The devices requires only external bypass capacitors to operate. These low-ESR ceramic bypass capacitors must be placed as close to the chip pads as possible.

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Optional 100 µF capacitor can be added between VCC and GND1; refer to Section 11.
Figure 10-2 Typical ISOW7841 Circuit Hook-Up

The VCC power-supply input provides power to isolated data channels and to the isolated DC-DC converter. Use Equation 1 to calculate the total power budget on the primary side.

Equation 1. ICC = (VISO × IISO) / (η × VCC) + Iinpx

where

  • ICC is the total current required by the primary supply.
  • VISO is the isolated supply voltage.
  • IISO is the external load on the isolated supply voltage.
  • η is the efficiency.
  • VCC is the supply voltage.
  • Iinpx is the total current drawn for the isolated data channels and power converter when data channels are toggling at a specific data rate. This data is shown in the Section 7.9 table.