3 SAMA7G54 Evaluation Kit Measurements
The SAMA7G54-EK evaluation kit is intended for evaluating and prototyping with the SAMA7G54 microprocessor. Supported by mainline Linux distribution as well as bare metal software frameworks and RTOS, the kit allows easy use case implementation and performance measurements.
Refer to www.microchip.com/en-us/development-tool/EV21H18A.
SAMA7G54-EK is a great tool to make first power consumption and junction temperature evaluations when running a real application software:
- The power consumption is measured using the on-board Microchip Quad DC Power Monitor PAC1934.
- The junction temperature is measured with the SAMA7G5 internal die temperature sensor. See Appendix A for details on junction temperature reading on Linux.
Two use cases are considered in the following sections:
- Use Case 1: Linux idle, the O/S prompts for commands.
- Use Case 2: iPerf3 test on the Gigabit Ethernet interface generating a high CPU load along with large memory transfers
Note:
- The results presented hereafter strongly depend on the PCB on which the SAMA7G54 device is mounted, and more specifically on the effective thermal resistance (RJ-A) of the chip soldered on the PCB. For the SAMA7G54-EK board, the junction-to-air thermal resistance was first characterized with a set of measurements (see the method presented in In-Application RJ-A Measurement) and its value is estimated to 30°C/W (±10%).
- Use Case 1: Linux Idle and Use Case 2: iPerf Test show the measurements of two parts, called respectively “Typical” and “Maximum”. Typical corresponds to a part having a power consumption identical to the average of the measured batch. Maximum is an extrapolation of the maximum production part (μ + 3 x σ).
- TJ measurement accuracy is ±5°C.
- To ease comparisons between curves, the x-axis always represents the device junction temperature, and not the ambient temperature. A vertical line at TJ = 105°C indicates the maximum specified junction temperature for the mounted (industrial grade) SAMA7G54 devices.