SLVUCP8 September   2024 TPS26750

 

  1.   1
  2.   Description
  3.   Get Started
  4.   Features
  5.   Applications
  6.   6
  7. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specification
    4. 1.4 Device Information
  8. 2Hardware
    1. 2.1 Additional Images
    2. 2.2 Power Requirements
    3. 2.3 Setup
    4. 2.4 Header Information
    5. 2.5 Jumper Information
    6. 2.6 Push Buttons
    7. 2.7 Interfaces
    8. 2.8 Debug Information
    9. 2.9 Test Points and LEDS
  9. 3Software
    1. 3.1 Software Description
    2. 3.2 Software Installation
      1. 3.2.1 Web Browser
      2. 3.2.2 Native Application
    3. 3.3 Software Development
    4. 3.4 Using the Application Customization Tool
      1. 3.4.1 Default View
      2. 3.4.2 Selecting a Configuration
      3. 3.4.3 Filling Out the Questionnaire
      4. 3.4.4 Advanced Configuration Mode
      5. 3.4.5 Flashing Configuration to TPS26750
      6. 3.4.6 Additional Settings
        1. 3.4.6.1 Generating a New Configuration
        2. 3.4.6.2 Exporting and Importing Settings
        3. 3.4.6.3 Generating the Binary
        4. 3.4.6.4 Generating the VIF File
  10. 4Application Specific Use Cases
    1. 4.1 Liquid Detection and Corrosion Mitigation Overview
      1. 4.1.1 Liquid Detection and Corrosion Mitigation Hardware Setup
      2. 4.1.2 Liquid Detection and Corrosion Mitigation Software Setup
      3. 4.1.3 Liquid Detection Detailed Implementation
        1. 4.1.3.1 Liquid Detection Config Register (0x98)
    2. 4.2 Use With the BQ25756EVM
      1. 4.2.1 Hardware Setup with BQ25756EVM
      2. 4.2.2 Software Setup with the BQ25756EVM
  11. 5Hardware Design Files
    1. 5.1 Schematics
    2. 5.2 PCB Layouts
    3. 5.3 Bill of Materials (BOM)
  12. 6Additional Information
    1. 6.1 Trademarks
    2. 6.2 Electrostatic Discharge Caution
    3. 6.3 Terminology
    4. 6.4 Device Support
      1. 6.4.1 Third-Party Products Disclaimer
      2. 6.4.2 Supplemental Content
    5. 6.5 Documentation Support
    6. 6.6 Receiving Notification of Documentation Updates
    7. 6.7 Support Resources

4.1 Liquid Detection and Corrosion Mitigation Overview

The TPS26750 supports Liquid Detection and Corrosion Mitigation as described in section A.3.1 of the USB Type-C® Cable and Connector Specification Revision 2.3 to protect the system from unexpected shorts (liquid, moisture, debris) on the USB Type-C port. The TPS26750 uses the SBU1 and SBU2 pins on the connector as measurement pins and toggles the known bias level between Ground (0V) and 3.3V when taking measurement samples. When the SBU lines are biased to 3.3V (pulled-high) the TPS26750 is checking for any unknown shorts to Ground (0V) pins. When the SBU lines are biased to Ground (pulled-low to 0V), the TPS26750 is checking for unknown shorts to positive voltage pins (that is, VBUS, CC, Vconn). At any point if the expected voltage reading does not meet the known bias level (thresholds are configurable through the GUI), the TPS26750 determines a short is detected.

The TPS26750EVM supports Liquid Detection and Corrosion Mitigation out-of-the box. To enable both Liquid Detection and Corrosion Mitigation, select Yes under Question 8 in the Questionnaire when setting up the device configuration. Once the configuration has been flashed to the TPS26750EVM, no further steps are needed to enable this feature.

If Corrosion Mitigation is enabled, then the TPS26750 automatically disables the USB Type-C connector by removing voltage from VBUS and the CC lines (corrosion mitigation can be turned off, while leaving liquid detection on; see Section 4.1.3.1). During this time, the TPS26750 continues to sample the voltage reading from SBU line. When the voltage reading passes the Dry threshold, the TPS26750 resumes normal operation and applies voltage back to VBUS and the CC lines (if necessary, based on the USB-C and USB-PD state machines).

Refer to the block diagram below for the hardware implementation. Note that for the TPS26750EVM, GPIO6 is configured to GPIOx, and GPIO7 is configured to GPIOy. For individual designs with the TPS26750, GPIOx and GPIOy can be moved to other available GPIOs, hence the use of a variable naming convention.

TPS26750EVM Liquid Detection/Corrosion Mitigation Setup Figure 4-1 Liquid Detection/Corrosion Mitigation Setup
Note: Liquid Detection, Corrosion Mitigation and BC1.2 cannot be configured in the same system. Both applications utilizes GPIO4 and GPIO5 of TPS26750 for different functions.