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

 

  1.   Trademarks
  2. Introduction
  3. The Goal of Thermal Management
  4. 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. Package Type
  6. PCB Copper Heat Sink
  7. PCB Layout Tips
  8. 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. Measuring Thermal Performance
    1. 8.1 Thermal Camera
    2. 8.2 Thermocouple
    3. 8.3 Internal Diode
  10. Thermal Design Example
  11. 10Conclusion
  12. 11References

Junction Temperature Calculation

Equation 1 shows the key to calculating junction temperature. The next sections detail what each of the terms mean and how they are determined.

Equation 1. GUID-20201105-CA0I-TKPK-FLT4-7QFRTBV4QZD0-low.gif