SLVUCV7 April   2024 TPS23881B

 

  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 EVM Input/Output Connectors and Switches
    2. 2.2 EVM LEDs
    3. 2.3 EVM Test Points
    4. 2.4 EVM Test Jumpers
    5. 2.5 Quick Start
      1. 2.5.1 Input Power
        1. 2.5.1.1 Input Power (Labeled VPWR)
        2. 2.5.1.2 Local 3.3V (Labeled 3.3V)
        3. 2.5.1.3 External 3.3V (Labeled 3.3 V_USB)
      2. 2.5.2 PoE Port Interfaces
        1. 2.5.2.1 IEEE802.3bt 2-Pair Ports
        2. 2.5.2.2 IEEE802.3bt 4-Pair Ports
      3. 2.5.3 I2C Interfaces
        1. 2.5.3.1 USB2ANY
        2. 2.5.3.2 MSP-EXP430FR5969
      4. 2.5.4 Basic Test Setup Using Autonomous Mode
      5. 2.5.5 Basic Test Setup Using USB2ANY for I2C Interface (Auto Mode or Semi-Auto Mode Operation with I2C Monitoring)
      6. 2.5.6 Advanced Test Setup Using MSP-EX430FR5969 LaunchPad
    6. 2.6 TPS23881B1 Autonomous Operations
  9. 3Software
    1. 3.1 TPS23881B1EVM GUI Setup
      1. 3.1.1 TPS23881B1EVM GUI Installation
      2. 3.1.2 TPS23881B1EVM GUI Operation
      3. 3.1.3 MSP-EXP430FR5969 Details
        1. 3.1.3.1 Basic CCS and Terminal Setup
      4. 3.1.4 MSP430 Reference Code
        1. 3.1.4.1 Overview
        2. 3.1.4.2 Auto Mode
        3. 3.1.4.3 Semi Auto Mode
  10. 4Hardware Design Files
    1. 4.1 Schematic
    2. 4.2 PCB Drawings
      1. 4.2.1 Layout Guidelines
        1. 4.2.1.1 Supply Voltage Decoupling
        2. 4.2.1.2 Port Current Kelvin Sensing
        3. 4.2.1.3 Ground Plane Spacing and Isolation (GND, GND1, and EARTH Nets)
    3. 4.3 Bill of Materials
  11. 5Additional Information
    1. 5.1 Trademarks

1.4 Device Information

The TPS23881B is an 8-channel power sourcing equipment (PSE) controller engineered to insert power onto Ethernet cables in accordance with the IEEE 802.3bt standard. The eight individual power channels can be configured in any combination of 2-Pair (1-channel) or 4-Pair (2-channels) PoE Ports. The PSE controller can detect powered devices (PDs) that have a valid signature, complete mutual identification, and apply power.

The TPS23881B improves on the TPS2388 with reduced current sense resistors, selectable autonomous operation, SRAM programmability, programmable power limiting, capacitance measurement, and compatibility with TI's FirmPSE system firmware. Programmable SRAM enables in-field firmware upgradability over I2C to verify IEEE compliance and interoperability with the latest PoE enabled devices. Dedicated per port ADCs provide continuous port current monitoring and the ability to perform parallel classification measurements for faster port turn on times. A ±2.5% accurate programmable port power limit provides the ability to expand the maximum power sourced from 90W to upwards of 125W.

The 200mΩ current sense resistor and external FET architecture allow designs to balance size, efficiency, thermal and design cost requirements.