SNVAA84 October   2023 LMR36506

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Topology Selection
    2. 1.2 From Buck to Fly-Buck-Boost Converter
  5. 2Specific Implementation of the Fly-Buck-Boost Converter
    1. 2.1 Schematic
    2. 2.2 Bill of Materials
  6. 3Test Results
    1. 3.1 Start-up Behavior
    2. 3.2 System Loop Stability
    3. 3.3 Thermal Behavior
    4. 3.4 VOUT Ripple and SW Node Waveforms
    5. 3.5 Efficiency Data
      1. 3.5.1 Efficiency Data for Balanced Loads
      2. 3.5.2 Efficiency Data for Unbalanced Loads
    6. 3.6 Load Regulation
      1. 3.6.1 Load Regulation for Balanced Loads
      2. 3.6.2 Load Regulation for Unbalanced Loads
  7. 4Summary
  8. 5References

4 Summary

The LMR36506RFRPER can be configured as a split-rail output Fly Buck Boost to generate a positive and a negative output supply rail for balanced loads as well as for non-symmetrical loads. The Fly Buck Boost topology changes some system characteristics and limitations, such as input voltage range and maximum output current. The desired 125-mA load current can be supported by the topology with an input voltage range of 16 V to 35 V. The output is regulated on the negative channel in the design. This application note explains the Split Rail Fly Buck-Boost topology with the design considerations. Measurement data based on a modified EVM design is provided in this application note.