SLLSFL2A April   2022  – May 2024 TUSB1142

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 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 Supply Characteristics
    6. 5.6  Control I/O DC Electrical Characteristics
    7. 5.7  USB Electrical Characteristics
    8. 5.8  Timing Requirements
    9. 5.9  Switching Characteristics
    10. 5.10 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 4-Level Inputs
      2. 7.3.2 USB Receiver Linear Equalization
        1. 7.3.2.1 Linear EQ Configuration
        2. 7.3.2.2 Full Adaptive Equalization
        3. 7.3.2.3 Fast Adaptive Equalization
      3. 7.3.3 USB Transmitter
        1. 7.3.3.1 Linearity VOD
        2. 7.3.3.2 Limited VOD
        3. 7.3.3.3 Transmit Equalization (Limited Redriver Mode Only)
      4. 7.3.4 USB 3.2 2:1 MUX Description
      5. 7.3.5 USB Polarity Inversion
      6. 7.3.6 Receiver Detect Control
    4. 7.4 Device Functional Modes
      1. 7.4.1 MODE Pin
      2. 7.4.2 Rx EQ Configuration in Pin-Strap Mode
      3. 7.4.3 USB 3.2 Power States
      4. 7.4.4 Disabling U1 and U2
    5. 7.5 Programming
      1. 7.5.1 Pseudocode Examples
        1. 7.5.1.1 Fixed EQ with Linear Redriver Mode
        2. 7.5.1.2 Fixed EQ with Limited Redriver Mode
        3. 7.5.1.3 Fast AEQ with Linear Redriver Mode
        4. 7.5.1.4 Fast AEQ with Limited Redriver Mode
        5. 7.5.1.5 Full AEQ with Linear Redriver Mode
        6. 7.5.1.6 Full AEQ with Limited Redriver Mode
      2. 7.5.2 TUSB1142 I2C Address Options
      3. 7.5.3 TUSB1142 I2C Target Behavior
    6. 7.6 Register Map
      1. 7.6.1 TUSB1142 Registers
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 USB SSTX Receiver Configuration
        2. 8.2.2.2 USB CRX1/2 Receiver Configuration
          1. 8.2.2.2.1 Fixed Equalization
          2. 8.2.2.2.2 Full Adaptive Equalization
          3. 8.2.2.2.3 Fast Adaptive Equalization
        3. 8.2.2.3 ESD Protection
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.2.3 Fast Adaptive Equalization

The Fast AEQ mode is used to distinguish two channels (short channel and a long channel) and choose the appropriate receiver equalization setting for that channel. Because Fast AEQ only distinguishes between two choices, the AEQ time is a lot shorter than Full AEQ mode which minimizes impact to USB link training.

When Fast AEQ is enabled and channel is determined to be short, the TUSB1142 will use the value programmed into the CEQx_SEL, where x = 1 or 2. If the TUSB1142 determines channel is not short, the TUSB1142 will switch to EQ value programmed into LONG_EQx register, where x = 1 or 2. During initial system evaluation, it is recommended to perform both short and long channel USB 3.1 RX JTOL Gen2 testing and program CEQx_SEL and LONG_EQx to the value which produced the best results for each channel configuration.

The TUSB1142 will determine short and long based on the estimate eye height. The value programmed into FASTAEQ_LIMITS register will determine the eye height limits. Software can change the defaults of this register to lower or raise the limits.

Note:

Fast AEQ is only supported in I2C mode.

EQ_OVERRIDE field must be set for values programmed into CEQx_SEL and LONG_EQx to be used.