Contents

Scope Reference Documents 3. Introduction 4. Basic Thermal Concepts 4.1. Junction Temperature 4.2. Thermal Equations 4.3. Junction-to-Air Thermal Resistance 4.4. Total Power Dissipation 4.4.1. VDDCORE and VDDCPU Dynamic Power 4.4.2. VDDCORE and VDDCPU Leakage Power 4.4.3. Analog and I/O Power 4.4.4. Part-to-Part Variability of Total Power 5. SAMA7G54 Evaluation Kit Measurements 5.1. Use Case 1: Linux Idle 5.1.1. Experiment Description 5.1.2. Measurement Results 5.2. Use Case 2: iPerf Test 5.2.1. Experiment Description 5.2.2. Measurement Results 6. Application-Specific Use Cases 6.1. Board-Specific Junction-to-Air Thermal Resistance 6.1.1. RJ-A Impact on TA_MAX 6.1.2. In-Application RJ-A Measurement 6.2. Junction Temperature as a Function of the Use Case 6.3. Junction Temperature Response Time 6.3.1. CPU Load Step Experiment Description 6.3.2. Linux Thermal Control Disabled 6.3.3. Linux Thermal Control Enabled 7. Hardware and Software Recommendations for High Temperature Applications 7.1. Software Recommendations 7.2. Hardware Recommendations 8. Appendix A: Linux-Specific Information 8.1. CPU Frequency Scaling Framework 8.2. Thermal Management Framework 9. Revision History 9.1. Rev. A - 10/2022 10. Microchip Information The Microchip Website Product Change Notification Service Customer Support Microchip Devices Code Protection Feature Legal Notice Trademarks Quality Management System Worldwide Sales and Service