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

3.3 Thermal Behavior

The thermal test is conducted on a modified LMR36506RFRPER EVM board to make sure that the components can withstand the industrial temperature range. The temperatures of three major components such as Inductor, DC/DC converter and the diode are observed for the minimum and maximum VIN, as shown in Figure 3-3 and Figure 3-12, respectively.

The temperature of an inductor and DC/DC converter are in the range of 48°C with the VIN of 16 V and a load of 175 mA applied on both output channels, while the diode remains at 32.6°C. With the VIN of 35 V and load of 250 mA on both output channels, the temperature of an inductor and DC/DC converter are in the range of 50°C while the diode remains at 33.4°C. This thermal output demonstrates the thermal metrics of the board, which are well within the industrial temperature range.

GUID-20230906-SS0I-RWGS-GF83-1SWJFDGSMRQM-low.pngFigure 3-3 Thermal Behavior at 16-V Vin, 175-mA Load on Both Rails
GUID-20230906-SS0I-BXJL-4BJ0-MVHPZQBSF5ZW-low.pngFigure 3-4 Thermal Behavior at 35-V Vin, 250-mA Load on Both Rails