SNVA790A October   2020  – July 2022 LMR36520

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2 Fly-Buck Converter Device Operation
    1. 2.1 Output Current Equations and Considerations
  5. 3LMR36520 Fly-Buck Converter Design
    1. 3.1 Coupled Inductor
    2. 3.2 Primary Output Capacitor
    3. 3.3 Rectifying Diode
    4. 3.4 Secondary Output Capacitor
    5. 3.5 Preload Resistor
    6. 3.6 Zener Diode
    7. 3.7 Snubber Circuit
  6. 4Experimental Results
    1. 4.1 Steady State
    2. 4.2 Secondary Output Voltage
    3. 4.3 Load Transient
    4. 4.4 Start-up
    5. 4.5 Output Current
  7. 5Conclusion
  8. 6References
  9. 7Revision History

Abstract

The purpose of this application note is to lead the reader through the design of an isolated buck also known as a Fly-Buck™ converter using the LMR36520 from Texas Instruments. This application note will describe the typical operation of a Fly-Buck™ converter from a theoretical perspective, and then walk through the process of Fly-Buck™ converter design from a set of given operating conditions using design equations derived in referenced reports. Physical measurements will be compared to expected results, and design limitations will also be discussed.