SPRADB7 September   2023 AM2431 , AM2432 , AM2434 , AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-Q1 , AM263P4 , AM263P4-Q1 , AM2732 , AM2732-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 How to Use This Application Note
    2. 1.2 Glossary
  5. 2Thermal Resistance Overview
    1. 2.1 Junction Vs. Ambient Temperature
    2. 2.2 Package Defined Thermal Resistance Characteristics
    3. 2.3 Board Defined Thermal Resistances
  6. 3Board Design Choices that Affect Thermal Performance
    1. 3.1 Thermal Vias
    2. 3.2 Board Size
    3. 3.3 Air Flow, Heat Sinking, and Enclosures
    4. 3.4 Copper Thickness
    5. 3.5 Relative Position of Heat Emitters
    6. 3.6 Layer Count
    7. 3.7 Breaks in Thermal Pathing
  7. 4Thermal Design Best Practices Review
  8. 5AM263x EVM Thermal Comparison with Data
    1. 5.1 Test Setup and Materials
    2. 5.2 Measurement Logging Software
    3. 5.3 AM263x EVM Comparison
    4. 5.4 Measurement Results
      1. 5.4.1 Lid Temperature Readings
      2. 5.4.2 Power Readings over Temperature
      3. 5.4.3 Calculated Thermal Resistance Values
      4. 5.4.4 Recorded Junction and Ambient Temperatures
      5. 5.4.5 Calculated Junction Temperature at Ambient Temperature Extremes
  9. 6Using the Thermal Model
  10. 7References

5.4.1 Lid Temperature Readings

The lid temperature readings remained relatively consistent with little variance across ambient temperature regardless of R5 core utilization. It would be expected that the LP and CC SoC lid readings would be practically the same due to the package-defined RΘJC value. Differences between the graphs can be attributed to the different amounts of tape on the package as well as the position of the thermocouple probe, both of which affect the thermal resistance between the case and ambient air temperature or RΘCA.

Note: The ThermalAir system was programmed to soak at each temperature for 10 minutes before incrementing up by 5℃. The thermalAir airstream output began at -50℃ and increments up to 165℃. This results in an ambient temperature range of approximately -30℃ to 118℃.
GUID-E6C9BF2E-3241-4363-A3A9-06665BF52AD3-low.png Figure 5-3 AM263x Control Card Lid Temperature Reading
GUID-8EAEE1F3-7DB0-4CB1-A6CC-1BD5EDBE08B3-low.png Figure 5-4 AM263x LaunchPad Lid Temperature Reading