TIDT255 January   2022

 

  1.   Description
  2. 1Features
  3.   Applications
  4. 2Test Prerequisites
    1. 2.1 Voltage and Current Requirements
    2. 2.2 Required Equipment
    3. 2.3 Dimensions
  5. 3Testing and Results
    1. 3.1 Efficiency Graphs
    2. 3.2 Efficiency Data
    3. 3.3 Load Regulation
    4. 3.4 Thermal Images
    5. 3.5 EMI
  6. 4Waveforms
    1. 4.1 Switch-node Voltage
    2. 4.2 Output Voltage Ripple
    3. 4.3 Over Current Protection
    4. 4.4 Load Transients
    5. 4.5 Start-up Sequence

Description

This isolated open-loop LLC transformer driver converter provides 4 rails outputs, each output has dual +18-V and –5-V outputs up to 0.5 W for traction inverter 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. This reference design offers a high level of integration and high efficiency in a compact form factor, it has passed CISPR 25 class 3 conducted EMI standard.