SLLSFK5 June   2021 TUSB217A

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison
  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 Electrical Characteristics
    6. 7.6 Switching Characteristics
    7. 7.7 Timing Requirements
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 High-Speed Boost
      2. 8.3.2 RX Sensitivity
    4. 8.4 Device Functional Modes
      1. 8.4.1 Low-Speed (LS) Mode
      2. 8.4.2 Full-Speed (FS) Mode
      3. 8.4.3 High-Speed (HS) Mode
      4. 8.4.4 High-Speed Downstream Port Electrical Compliance Test Mode
      5. 8.4.5 Shutdown Mode
      6. 8.4.6 I2C Mode
      7. 8.4.7 BC 1.2 Battery Charging Controller
    5. 8.5 TUSB217A Registers
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Test Procedure to Construct USB High-speed Eye Diagram
          1. 9.2.2.1.1 For a Host Side Application
          2. 9.2.2.1.2 For a Device Side Application
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Receiving Notification of Documentation Updates
    2. 12.2 Support Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9.2.2 Detailed Design Procedure

The ideal BOOST setting is dependent upon the signal chain loss characteristics of the target platform. The recommendation is to start with BOOST level 0, and then increment to BOOST level 1, and so on. Same applies to the RX sensitivity setting where it is recommended to plan for the required pads or connections to change boost settings, but to start with RX sensitivity level Low.

In order for the TUSB217A to recognize any change to the BOOST setting, the RSTN pin must be toggled. This is because the BOOST pin is latched on power up and the pin is ignored thereafter.

Note:

The TUSB217A compensates for extra attenuation in the signal path according to the configuration of the RX_SEN pin. This maximum recommended voltage for this pin is 5 V when selecting the highest RX sensitivity level.

Placement of the device is also dependent on the application goal. Table 9-4 summarizes our recommendations.

Table 9-4 Platform Placement Guideline
PLATFORM GOALSUGGESTED TUSB217A PLACEMENT
Pass USB Near End Mask at the receptacleClose to measurement point (connector)
Pass USB Far End Eye Mask at the plugClose to USB PHY
Cascade multiple TUSB217As to improve device enumerationMidway between each USB interconnect
Table 9-5 Table of Recommended Settings
BOOST and RX_SEN settings (1)for channel loss
Pre-channel cable length (Between USB PHY and TUSB217A) BOOST RX_SEN
0-3 meter Level 0 Medium or High
2-5 meter Level 1 Medium or High
Post-channel cable length (Between TUSB217A and inter-connect) BOOST RX_SEN
0-2 meter Level 0 Medium or High
1-4 meter Level 1 Medium or High
(1) These parameters are starting values for different cable lengths. Further tuning might be required based on specific host or device as well as cable length and loss profile.