TIDT308 October   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 Considerations
    4. 1.4 Dimensions
    5. 1.5 Test Setup
  5. 2Testing and Results
    1. 2.1 Efficiency Graphs
    2. 2.2 Efficiency Data
    3. 2.3 Thermal Images
      1. 2.3.1 Top Side
      2. 2.3.2 Bottom Side
    4. 2.4 Bode Plots
  6. 3Waveforms
    1. 3.1 Switching
      1. 3.1.1 Secondary Side
      2. 3.1.2 Primary Side
        1. 3.1.2.1 Transistor Q8 Drain-Source
        2. 3.1.2.2 HS2-Pin of U1
          1. 3.1.2.2.1 Undershoot
          2. 3.1.2.2.2 Overshoot
    2. 3.2 Output Voltage Ripple
    3. 3.3 Load Transients
    4. 3.4 Start-Up Sequence
      1. 3.4.1 Full Load
      2. 3.4.2 Zero Load
      3. 3.4.3 Overload
    5. 3.5 Shutdown Sequence

Description

This power supply is a 140-W, full-bridge reference design for applications requiring high density and low component heights due to the planar transformer. The design is based on a hard-switched full bridge topology, using Schottky diodes on the secondary side, driven by the LM5045. A planar transformer is used to minimize the footprint and height. The printed circuit board (PCB) has six layers and the components are assembled top and bottom. The unit is designed for continuous operation at a rated load at TA < 40°C. A minimum airflow of 200 linear feet per minute (LFM) is recommended for higher ambient temperature.