SLLSEJ0H October   2014  – March 2024 ISO7842

PRODUCTION DATA  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Pin Configuration and Functions
    1.     Pin Functions
  6. Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information
    5. 5.5  Power Ratings
    6. 5.6  Insulation Specifications
    7. 5.7  Safety-Related Certifications
    8. 5.8  Safety Limiting Values
    9. 5.9  Electrical Characteristics–5V Supply
    10. 5.10 Supply Current Characteristics–5V Supply
    11. 5.11 Electrical Characteristics—3.3V Supply
    12. 5.12 Supply Current Characteristics—3.3V Supply
    13. 5.13 Electrical Characteristics—2.5V Supply
    14. 5.14 Supply Current Characteristics—2.5V Supply
    15. 5.15 Switching Characteristics—5V Supply
    16. 5.16 Switching Characteristics—3.3V Supply
    17. 5.17 Switching Characteristics—2.5V Supply
    18. 5.18 Insulation Characteristics Curves
    19. 5.19 Typical Characteristics
  7.   Parameter Measurement Information
  8. Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Electromagnetic Compatibility (EMC) Considerations
    4. 6.4 Device Functional Modes
      1. 6.4.1 Device I/O Schematics
  9. Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
      3. 7.2.3 Application Curve
  10. Power Supply Recommendations
  11. Layout
    1. 9.1 Layout Guidelines
      1. 9.1.1 PCB Material
    2. 9.2 Layout Example
  12. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Related Links
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Community Resources
    5. 10.5 Trademarks
  13. 11Revision History
  14. 12Mechanical, Packaging, and Orderable Information

Layout Guidelines

A minimum of four layers is required to accomplish a low EMI PCB design (see Figure 9-1). Layer stacking should be in the following order (top-to-bottom): high-speed signal layer, ground plane, power plane and low-frequency signal layer.

  • Routing the high-speed traces on the top layer avoids the use of vias (and the introduction of their inductances) and allows for clean interconnects between the isolator and the transmitter and receiver circuits of the data link.
  • Placing a solid ground plane next to the high-speed signal layer establishes controlled impedance for transmission line interconnects and provides an excellent low-inductance path for the return current flow.
  • Placing the power plane next to the ground plane creates additional high-frequency bypass capacitance of approximately 100pF/inch2.
  • Routing the slower speed control signals on the bottom layer allows for greater flexibility as these signal links usually have margin to tolerate discontinuities such as vias.

If an additional supply voltage plane or signal layer is needed, add a second power or ground plane system to the stack to keep it symmetrical. This makes the stack mechanically stable and prevents it from warping. Also the power and ground plane of each power system can be placed closer together, thus increasing the high-frequency bypass capacitance significantly.

For detailed layout recommendations, refer to Digital Isolator Design Guide.