SLYT793A may   2020  – may 2020 LM61460-Q1

 

  1.   1
  2. 1 Introduction
  3. 2 Managing Thermals with Flip-chip Packages
  4. 3 Board Construction Influence
  5. 4 Copper Area and Thermals
  6. 5 Estimating a Converter’s Junction Temperature
  7. 6 Challenges with Measuring Converter Junction Temperature
  8. 7 Further Thermal Optimization at the IC Level
  9. 8 Conclusion
  10. 9 References
  11. 10Related Web Sites
    1. 10.1 General Information:
    2. 10.2 Product Information:

1 Introduction

Automotive designs increasingly require higher-performance electronic components with reduced printed circuit board (PCB) cost. This trend has resulted in an uptick in signal-processing operating speeds (and density) on a single board. The increase in operating speeds has in turn raised demand for more compact power supplies to provide room for component routing. While high-performance, high-density power supplies save PCB space, they also generate heat and reduce the heat-dissipation capabilities of surrounding mounted devices, which drives the need for lower-loss power converters that enable a higher thermal margin of neighboring devices.

In recent years, improvements in semiconductor design and layout have enabled the development of more efficient converters that support higher-power applications. Greater converter efficiency also enabled faster switching frequencies, which in turn allowed design engineers to shrink the power-supply solution size and decrease cost by reducing component size and count.

Improved converter control schemes have further reduced passive component counts (Figure 1) without impacting noise or transient performance, and freed up room around the converter for routing devices or to allow for thermal management improvements.

USB Type-C™ is an automotive use case where 2-MHz converter operation allows for extra room in the board layers for additional charging diagnostics. Improved converter efficiency means less heat generation, making it possible to house the power solution in a plastic enclosure that has little airflow. Furthermore, an increase in the integrated circuit’s (IC) maximum operating temperature to 150°C (or above) furthers converter capabilities in applications requiring 105°C or higher ambient temperature ratings.