SLLSFC5C November   2021  – January 2023 ISOUSB211

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
    10. 6.10 Switching Characteristics
    11. 6.11 Insulation Characteristics Curves
    12. 6.12 Typical Characteristics
  8. 7 Parameter Measurement Information
    1. 7.1 Test Circuits
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Power Supply Options
      2. 8.3.2  Power Up
      3. 8.3.3  Symmetric Operation, Dual-Role Port and Role-Reversal
      4. 8.3.4  Connect and Speed Detection
      5. 8.3.5  Disconnect Detection
      6. 8.3.6  Reset
      7. 8.3.7  LS/FS Message Traffic
      8. 8.3.8  HS Message Traffic
      9. 8.3.9  Equalization and Pre-emphasis
      10. 8.3.10 L2 Power Management State (Suspend) and Resume
      11. 8.3.11 L1 Power Management State (Sleep) and Resume
      12. 8.3.12 HS Test Mode Support
      13. 8.3.13 CDP Advertising
    4. 8.4 Device Functional Modes
  10. 9 Power Supply Recommendations
  11. 10Application and Implementation
    1. 10.1 Typical Application
      1. 10.1.1 Isolated Host or Hub
      2. 10.1.2 Isolated Peripheral - Self-Powered
      3. 10.1.3 Isolated Peripheral - Bus-Powered
      4. 10.1.4 Application Curve
        1. 10.1.4.1 Insulation Lifetime
    2. 10.2 Meeting USB2.0 HS Eye-Diagram Specifications
    3. 10.3 Thermal Considerations
      1. 10.3.1 VBUS / V3P3V Power
      2. 10.3.2 VCCx / V1P8Vx Power
      3. 10.3.3 Example Configuration 1
      4. 10.3.4 Example Configuration 2
      5. 10.3.5 Example Configuration 3
  12. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Layout Example
      2. 11.1.2 PCB Material
  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
    1. 13.1 Tape and Reel Information

8.3.9 Equalization and Pre-emphasis

The ISOUSB211 has inbuilt programmable receive equalization and transmit pre-emphasis to cancel signal loss caused by board traces, which helps in meeting USB2.0 high-speed TX and RX eye-diagram templates. These settings are controlled by EQ11 and EQ10 on side 1 and EQ21 and EQ20 on side 2. The EQxx pins can be connected to ground, connected to 3.3-V supply or left floating, together creating 9 different equalization levels. EQ11 and EQ10 can be chosen based on the length of D+/D- board trace and corresponding channel loss estimated on side 1, and similarly EQ21 and EQ20 for side 2. Typical 45-Ohm trace in FR4 has about 0.15 dB/inch for 480 Mbps signaling. Further adjustments to the EQ settings can be made by observing the transmit eye-diagram at the connector. If the trace lengths are very small, no equalization may be needed, and the EQxx pins can be connected to ground.

ISOUSB211 samples EQxx pins only at power up, so it is not recommended to change the EQxx settings on the fly after power up.