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

8.3.4 Connect and Speed Detection

When there is no peripheral device connected to the downstream side of ISOUSB211, internal 15 kΩ pull-down resistors on DD+ and DD- pins pull the bus lines to zero, creating an SE0 state. When either the DD+ or DD- lines is pulled up higher than the VIH threshold, for a time period higher than TFILTCONN, the ISOUSB211 device treats this as a connect. The ISOUSB211 device configures internal pull-up on the upstream side to match the pull-up detected on the downstream side. After connect is detected, the ISOUSB211 device waits for a reset to be asserted by the host/hub on the upstream side. Depending on whether DD+ or DD- is pulled up at the start of reset, the speed of the ISOUSB211 repeater is set. Once set, the speed of the repeater can only be changed after a power down or disconnect event.

A high-speed (HS) capable device is attached to the ISOUSB211 device would proceed to perform high-speed handshake using chirp signaling as specified in the USB2.0 standard. This would be followed by chirp signals from the host. The ISOUSB211 device reflects these chirp signals across the barrier, including HS idle (SE0) states from downstream to upstream and vice versa. Upon successful completing of the HS handshake ISOUSB211 speed is set to High speed. Once set to high-speed, the speed of the repeater can only be changed after power down, HS disconnect event, or if the peripheral or host/hub do not perform HS handshake after a reset.