SLUSBX9J March   2014  – October 2026 TPS23861

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 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Switching Characteristics
    8. 5.8 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
      1. 6.1.1 Detailed Pin Description
      2. 6.1.2 I2C Detailed Pin Description
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Detection Resistance Measurement
      2. 6.3.2  Physical Layer Classification
      3. 6.3.3  Class and Detect Fields
      4. 6.3.4  Register State Following a Fault
      5. 6.3.5  Disconnect
      6. 6.3.6  Disconnect Threshold
      7. 6.3.7  Fast Shutdown Mode
      8. 6.3.8  Legacy Device Detection
      9. 6.3.9  VPWR Undervoltage and UVLO Events
      10. 6.3.10 Timer-Deferrable Interrupt Support
      11. 6.3.11 A/D Converter and I2C Interface
      12. 6.3.12 Independent Operation when the AUTO Bit is Set
      13. 6.3.13 I2C Slave Address and AUTO Bit Programming
    4. 6.4 Device Functional Modes
      1. 6.4.1 Off
      2. 6.4.2 Manual
      3. 6.4.3 Semi-Auto
      4. 6.4.4 Auto
      5. 6.4.5 Push-Button Power On Response
      6. 6.4.6 TSTART Indicators of Detect and Class Failures
      7. 6.4.7 Device Power On Initialization
    5. 6.5 Register Map – I2C-Addressable
      1. 6.5.1  Interrupt Register
      2. 6.5.2  Interrupt Enable Register
      3. 6.5.3  Power Event Register
      4. 6.5.4  Detection Event Register
      5. 6.5.5  Fault Event Register
      6. 6.5.6  Start/ILIM Event Register
      7. 6.5.7  Supply Event Register
      8. 6.5.8  Port n Status Register
        1. 6.5.8.1 Port 1 Status Register
        2. 6.5.8.2 Port 2 Status Register
        3. 6.5.8.3 Port 3 Status Register
        4. 6.5.8.4 Port 4 Status Register
      9. 6.5.9  Power Status Register
      10. 6.5.10 I2C Slave Address Register
      11. 6.5.11 Operating Mode Register
      12. 6.5.12 Disconnect Enable Register
      13. 6.5.13 Detect/Class Enable Register
      14. 6.5.14 Port Power Priority Register
      15. 6.5.15 Timing Configuration Register
      16. 6.5.16 General Mask 1 Register
      17. 6.5.17 Detect/Class Restart Register
      18. 6.5.18 Power Enable Register
      19. 6.5.19 Reset Register
      20. 6.5.20 Legacy Detect Mode Register
      21. 6.5.21 Two-Event Classification Register
      22. 6.5.22 Interrupt Timer Register
      23. 6.5.23 Disconnect Threshold Register
        1. 6.5.23.1 Bits Description
      24. 6.5.24 ICUTnm CONFIG Register
        1. 6.5.24.1 ICUT21 CONFIG Register
        2. 6.5.24.2 ICUT43 CONFIG Register
        3. 6.5.24.3 Bits Description
      25. 6.5.25 Temperature Register
      26. 6.5.26 Input Voltage Register
      27. 6.5.27 Port n Current Register
        1. 6.5.27.1 Port 1 Current Register
        2. 6.5.27.2 Port 2 Current Register
        3. 6.5.27.3 Port 3 Current Register
        4. 6.5.27.4 Port 4 Current Register
      28. 6.5.28 Port n Voltage Register
        1. 6.5.28.1 Port 1 Voltage Register
        2. 6.5.28.2 Port 2 Voltage Register
        3. 6.5.28.3 Port 3 Voltage Register
        4. 6.5.28.4 Port 4 Voltage Register
      29. 6.5.29 PoE Plus Register
      30. 6.5.30 Firmware Revision Register
      31. 6.5.31 I2C Watchdog Register
      32. 6.5.32 Device ID Register
      33. 6.5.33 Cool Down/Gate Drive Register
      34. 6.5.34 Port n Detect Resistance Register
        1. 6.5.34.1 Port 1 Detect Resistance Register
          1. 6.5.34.1.1 Port 2 Detect Resistance Register
          2. 6.5.34.1.2 Port 3 Detect Resistance Register
          3. 6.5.34.1.3 Port 4 Detect Resistance Register
      35. 6.5.35 Port n Detect Voltage Difference Register
        1. 6.5.35.1 Port 1 Detect Voltage Difference Register
        2. 6.5.35.2 Port 2 Detect Voltage Difference Register
        3. 6.5.35.3 Port 3 Detect Voltage Difference Register
        4. 6.5.35.4 Port 4 Detect Voltage Difference Register
      36. 6.5.36 Reserved Registers
  8. 7 Application and Implementation
    1. 7.1 Introduction to PoE
    2. 7.2 Application Information
      1. 7.2.1 Kelvin Current Sensing Resistor
      2. 7.2.2 Connections on Unused Ports
    3. 7.3 Typical Application
      1. 7.3.1 Two Port, Auto Mode Application with External Port Reset
        1. 7.3.1.1 Design Requirements
      2. 7.3.2 Four Port, Auto Mode Application
        1. 7.3.2.1 Design Requirements
      3. 7.3.3 Eight Port, Semi-Auto Mode Application Using MSP430 Micro-Controller
        1. 7.3.3.1 Design Requirements
      4. 7.3.4 Detailed Design Procedure
        1. 7.3.4.1 Power Pin Bypass Capacitors
        2. 7.3.4.2 Per Port Components
        3. 7.3.4.3 System Level Components (not shown in the schematic diagrams)
      5. 7.3.5 Application Curves
    4. 7.4 System Examples
      1. 7.4.1 Overcurrent and Overload Protection
      2. 7.4.2 Inrush Protection
      3. 7.4.3 ICUT Current Limit
      4. 7.4.4 Foldback Protection (ILIM)
      5. 7.4.5 Kelvin Current Sensing Resistor
    5. 7.5 Power Supply Recommendations
      1. 7.5.1 VDD
      2. 7.5.2 VPWR
      3. 7.5.3 VPWR-RESET Sequencing
    6. 7.6 Layout
      1. 7.6.1 Layout Guidelines
        1. 7.6.1.1 Port Current Kelvin Sensing
      2. 7.6.2 Layout Example
        1. 7.6.2.1 Component Placement and Routing Guidelines
          1. 7.6.2.1.1 Power Pin Bypass Capacitors
          2. 7.6.2.1.2 Per-Port Components
  9. 8 Device and Documentation Support
    1. 8.1 Documentation Support
      1. 8.1.1 Related Documentation
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.3.3.1 Design Requirements

The design for the eight port Semi-Auto Mode application is the same as for the two port design scaled up by four. In addition, the eight port application does not require port reset so the RESET pin may be connected directly to VDD. Two TPS23861 devices are used in the eight port configuration and are managed by the I2C host device. The factory default I2C address for each TPS23861 is 0x20 when the A3 pin is low and 0x28 when the A3 pin is left open or tied to VDD.
Table 7-3 Design Parameters
DESIGN PARAMETERVALUE
Operating modeSemi-Auto Mode
Number/type of portsEight type 2 ports
Other requirementsMicro-controller managed
Note: The RESET pin must be held low until both VPWR and VDD are above their UVLO thresholds.