TIDT254 January   2022

 

  1.   Description
  2.   Features
  3.   Applications
  4. 1Test Prerequisites
    1. 1.1 Voltage and Current Requirements
    2. 1.2 Required Equipment
    3. 1.3 Dimensions
  5. 2Testing and Results
    1. 2.1 Efficiency Graphs
    2. 2.2 Efficiency Data
    3. 2.3 Load Regulation
    4. 2.4 Voltage Regulation
    5. 2.5 Thermal Images
  6. 3Waveforms
    1. 3.1 Switching
    2. 3.2 Output Voltage Ripple
    3. 3.3 Short-Circuit Protection
    4. 3.4 Load Transients
    5. 3.5 Start-up Sequence
    6. 3.6 Undervoltage Protection

Description

This reference design is an open-loop LLC converter, which provides four 18 V and 2.5 V outputs, up to 2.4 W for onboard charger applications. The UCC25800-Q1 device is used here as the controller. The LLC topology allows the transformer to have significant leakage inductance, but a much smaller primary-secondary capacitance, which significantly reduces common-mode current injection through the bias transformer.