TIDT381 March   2024

 

  1.   1
  2.   Description
  3.   Features
  4.   Applications
  5. 1Test Prerequisites
    1. 1.1 Voltage and Current Requirements
    2. 1.2 Required Equipment
    3. 1.3 Considerations
  6. 2Testing and Results
    1. 2.1 Efficiency Graphs
    2. 2.2 Load Voltage Regulation
    3. 2.3 Efficiency Data
    4. 2.4 Thermal Images
    5. 2.5 Bode Plots
  7. 3Waveforms
    1. 3.1 Switching
    2. 3.2 Voltage Ripple
    3. 3.3 Load Transients
    4. 3.4 Start-Up Sequence
    5. 3.5 Power-Down Sequence
    6. 3.6 PoE-to-Adapter Transient

Description

This reference design implements a Power-over-Ethernet (PoE) power device (PD) active-clamp forward converter with 24V and 3A output. A TPS23730 PD with integrated pulse-width modulator (PWM) controller provides all the necessary functions to implement the PoE PD control and the PWM control for the active-clamp forward converter. This design uses secondary-side regulation (SSR) with an optocoupler feedback. An external hot swap is added to enable Class-7,8 PD applications. INA237 is used on the primary side to monitor the DC/DC input voltage and current, and the power information is sent to the secondary side by either I2C isolator or optocoupler-based circuits.