JAJSKN2B November   2020  – September 2021 TPS25864-Q1 , TPS25865-Q1

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  4. 4 Revision History
  5. 5 概要 (続き)
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Timing Requirements
    7. 8.7 Switching Characteristics
    8. 8.8 Typical Characteristics
  9. 9 Parameter Measurement Information
  10. 10Detailed Description
    1. 10.1 Overview
    2. 10.2 Functional Block Diagram
    3. 10.3 Feature Description
      1. 10.3.1  Power-Down or Undervoltage Lockout
      2. 10.3.2  Input Overvoltage Protection (OVP) - Continuously Monitored
      3. 10.3.3  Buck Converter
      4. 10.3.4  FREQ/SYNC
      5. 10.3.5  Bootstrap Voltage (BOOT)
      6. 10.3.6  Minimum ON-Time, Minimum OFF-Time
      7. 10.3.7  Internal Compensation
      8. 10.3.8  Selectable Output Voltage (VSET)
      9. 10.3.9  Current Limit and Short Circuit Protection
        1. 10.3.9.1 USB Switch Current Limit
        2. 10.3.9.2 Interlocking for Two-Level USB Switch Current Limit
        3. 10.3.9.3 Cycle-by-Cycle Buck Current Limit
        4. 10.3.9.4 OUT Current Limit
      10. 10.3.10 Cable Compensation
      11. 10.3.11 Thermal Management With Temperature Sensing (TS) and OTSD
      12. 10.3.12 Thermal Shutdown
      13. 10.3.13 USB Specification Overview
      14. 10.3.14 USB Port Operating Modes
        1. 10.3.14.1 Dedicated Charging Port (DCP) Mode
          1. 10.3.14.1.1 DCP BC1.2 and YD/T 1591-2009
          2. 10.3.14.1.2 DCP Divider-Charging Scheme
          3. 10.3.14.1.3 DCP 1.2-V Charging Scheme
        2. 10.3.14.2 DCP Auto Mode
    4. 10.4 Device Functional Modes
      1. 10.4.1 Shutdown Mode
      2. 10.4.2 Active Mode
  11. 11Application and Implementation
    1. 11.1 Application Information
    2. 11.2 Typical Applications
      1. 11.2.1 Design Requirements
      2. 11.2.2 Detailed Design Procedure
        1. 11.2.2.1 Output Voltage Setting
        2. 11.2.2.2 Switching Frequency
        3. 11.2.2.3 Inductor Selection
        4. 11.2.2.4 Output Capacitor Selection
        5. 11.2.2.5 Input Capacitor Selection
        6. 11.2.2.6 Bootstrap Capacitor Selection
        7. 11.2.2.7 Undervoltage Lockout Set-Point
        8. 11.2.2.8 Cable Compensation Set-Point
      3. 11.2.3 Application Curves
  12. 12Power Supply Recommendations
  13. 13Layout
    1. 13.1 Layout Guidelines
    2. 13.2 Layout Example
    3. 13.3 Ground Plane and Thermal Considerations
  14. 14Device and Documentation Support
    1. 14.1 Receiving Notification of Documentation Updates
    2. 14.2 サポート・リソース
    3. 14.3 Trademarks
    4. 14.4 Electrostatic Discharge Caution
    5. 14.5 Glossary
  15. 15Mechanical, Packaging, and Orderable Information

10.3.10 Cable Compensation

When a load draws current through a long or thin wire, there is an IR drop that reduces the voltage delivered to the load. In the vehicle from the voltage regulator output VOUT to VBUS (input voltage of portable device), the total resistance of PCB trace, connector, and cable resistances causes an IR drop at the portable device input, so the charging current of most portable devices is less than their expected maximum charging current. The voltage drop is shown in Figure 10-8.

GUID-9CBBC950-1C8E-4F1D-BF34-299F49D33CB9-low.gifFigure 10-8 Voltage Drop

To handle this case, the TPS2586x-Q1 has a built-in cable compensation function where the droop compensation linearly increases the voltage at the SENSE pin of the TPS2586x-Q1 as load current increases, to maintain a fairly constant output voltage at the load-side voltage.

For the TPS2586x-Q1, the internal comparator compares the current-sense output voltage of the two current-limit switches and uses the larger current-sense output voltage to compensate for the line drop voltage. The cable compensation amplitude increases linearly as the load current increases. The cable compensation also has an upper limitation. The cable compensation at output currents greater than 2.4 A is 90 mV and is shown in Figure 10-9. Note the cable compensation only works when you short the VSET to GND. For the other VSET configuration, the cable compensation is not available.

GUID-E0521098-EED9-455C-8F79-779872C40BBB-low.gifFigure 10-9 Dual Ports Cable Compensation