SNVA951 November   2020 LM61460-Q1 , LM63615-Q1 , LM63625-Q1 , LM63635-Q1 , LMR33620-Q1 , LMR33630-Q1

 

  1.   Trademarks
  2. 1 Introduction
  3. 2 The Goal of Thermal Management
  4. 3 Junction Temperature Calculation
    1. 3.1 Regulator Junction Temperature (TJ)
    2. 3.2 Ambient Temperature (TA)
    3. 3.3 Power Dissipation (PD)
    4. 3.4 Thermal Resistance (θJA)
      1. 3.4.1 Thermal Metrics
  5. 4 Package Type
  6. 5 PCB Copper Heat Sink
  7. 6 PCB Layout Tips
  8. 7 Estimating and Measuring θJA
    1. 7.1 Simple Guideline
    2. 7.2 Data Sheet Curves
    3. 7.3 Simplified Heat Flow Spreadsheet
    4. 7.4 Online Database
    5. 7.5 Thermal Simulators
  9. 8 Measuring Thermal Performance
    1. 8.1 Thermal Camera
    2. 8.2 Thermocouple
    3. 8.3 Internal Diode
  10. 9 Thermal Design Example
  11. 10Conclusion
  12. 11References

1 Introduction

Thermal management is one of the most important aspects of designing power supplies. This is especially true in the automotive environment where converters must operate in high ambient temperatures and enclosed spaces. This paper provides guidance to the designer that will make the task of thermal management proceed somewhat more smoothly.