SNVAA82 august   2023 LMR38020

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Fly-Buck Converter
  6. 3Fly-Buck Basic Operation
    1. 3.1 Basic Intervals of Steady State Operation
    2. 3.2 Impact Of Leakage Inductor On Fly-Buck Operation
  7. 4Design A Fly-Buck Converter with LMR38020
    1. 4.1 IC Select
    2. 4.2 Switching Frequency Set
    3. 4.3 Transformer Design
      1. 4.3.1 Turns Ratio
      2. 4.3.2 Magnetic Inductance
      3. 4.3.3 Check Ipk
    4. 4.4 Output Capacitor Selection
      1. 4.4.1 Primary Output Capacitor
      2. 4.4.2 Secondary Output Capacitor
    5. 4.5 Secondary Output Diode
    6. 4.6 Preload Resistor
  8. 5Bench Test Results
    1. 5.1 Typical Switching Waveforms Under Steady State
    2. 5.2 Start Up
    3. 5.3 Efficiency
    4. 5.4 Load Regulation
    5. 5.5 Short Circuit
    6. 5.6 Thermal Performance
  9. 6Design Considerations
  10. 7Summary
  11. 8References

5.4 Load Regulation

The load regulation shown in Figure 5-11 and Figure 5-12 ,The regulation tolerance on the primary Vout can achieve 1% over the entire load range, and the secondary Vout can achieve<10%. Adding some preload at secondary output can improve the load regulation performance.
GUID-20230802-SS0I-HPSH-92JQ-74ZMRC8VSZQS-low.svgFigure 5-11 Load Regulation vs Primary Output Current
GUID-20230802-SS0I-XRQV-XZPP-6WFDMQT7RZXM-low.svgFigure 5-12 Load Regulation vs Secondary Output Current