SNVAA87 august   2023 LMR38020

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Micro Inverter System
    2. 1.2 Typical Power Tree and Design Requirements
  5. 2Conventional Flyback Design Challenges
    1. 2.1 SSR Design Challenges
    2. 2.2 PSR Design Challenges
  6. 3New Fly-Buck Design
    1. 3.1 LMR38020 Overview
    2. 3.2 Comparison with Conventional Flyback
    3. 3.3 Design Considerations
    4. 3.4 LMR38020 Fly-Buck Design Example
  7. 4Bench Test and Result
    1. 4.1 Start Up
    2. 4.2 Typical Switching Waveforms Under Steady State
    3. 4.3 Efficiency
    4. 4.4 Load Regulation
    5. 4.5 Short Circuit
    6. 4.6 Thermal Performance
  8. 5Summary
  9. 6References

5 Summary

The Fly-Buck™ converter is a versatile, isolated-power design. The converter offers a simple and cost-effective way to generate multiple isolated outputs. For low-power applications, it is an excellent candidate to replace the classic Flyback. This application note proposes a new auxiliary power supply solution based on LMR38020 Fly-Buck™, which is intended for the classic Flyback design for micro inverter application requiring high power conversion efficiency, good thermal performance, small size and long lifetime. The test results show the design has advantages of easy design to use few components, low cost, small transformer size and well performance on efficiency, thermal, and regulation.