用户手册 — Texas Instruments TPS23751 Evaluation Module TPS23751EVM-104

目录

• FEATURES

  1
• APPLICATIONS

  1
• DESCRIPTION

  1
• ABSOLUTE MAXIMUM RATINGS

  2
• THERMAL INFORMATION

  3
• RECOMMENDED OPERATING CONDITIONS

  3
• ELECTRICAL CHARACTERISTICS

  4
• CONTROLLER SECTION

  4
• SLEEP MODE (TPS23752 ONLY)

  5
• PoE INTERFACE SECTION

  6
• DEVICE INFORMATION

  7
  • DEVICE FUNCTIONAL BLOCK DIAGRAMS

    9
  • PIN DESCRIPTION

    11
• TYPICAL CHARACTERISTICS

  15
• DETAILED DESCRIPTION

  17
  • PoE OVERVIEW

    17
    • Threshold Voltages

      19
    • PoE Startup Sequence

      20
    • Detection

      20
    • Hardware Classification

      21
    • Inrush and Startup

      22
    • Maintain Power Signature

      22
    • Startup and Converter Operation

      22
    • PD Hotswap Operation

      23
  • Sleep Mode Operation (TPS23752 only)

    24
    • Converter Controller Features

      25
    • PWM and VFO Operation; CTL, SRT, and SRD Pin Relationships to Output Load Current

      25
    • Bootstrap Topology

      27
    • Current Slope Compensation and Current Limit

      28
    • RT

      28
    • T2P, Startup and Power Management

      28
    • Thermal Shutdown

      28
    • Adapter ORing

      28
    • Using DEN to Disable PoE

      29
    • ORing Challenges

      29
• APPLICATION INFORMATION

  30
  • • Input Bridges and Schottky Diodes

      30
    • Protection, D1

      31
    • Capacitor, C1

      31
    • Detection Resistor, RDEN

      31
    • Classification Resistor, RCLS

      31
    • APD Pin Divider Network, RAPD1, RAPD2

      31
    • Setting the PWM-VFO Threshold using the SRT pin

      31
    • Setting Frequency (RT)

      31
    • Current Slope Compensation

      32
    • Voltage Feed-Forward Compensation

      32
    • Estimating Bias Supply Requirements and Cvc

      32
    • Switching Transformer Considerations and RVC

      33
    • T2P Pin Interface

      34
    • Softstart

      34
    • Special Switching MOSFET Considerations

      35
    • Thermal Considerations and OTSD

      35
    • ESD

      35
    • Layout

      35
• REVISION HISTORY

  36