WOW! This was SUPER FUN - Micro Madness! A showdown between demo boards using Cortex-M microcontrollers. Criteria was randomly generated and both technical and fun - so any board had a fair shot. What a great moment to share with an entire group!

The board I chose was STM32L496AG Discovery, the ARM® Cortex®-M4 core-based STM32L496xx microcontroller.

The final question posed was the lowest power per MHz, running fast. From the datasheet, the answer was surprising as it had two results — both of which are impressively low power: 91 uA/MHz run mode (LDO mode) and 37 uA/MHz run mode (at 3.3V SMPS mode).

This left me curious about what the differences were, and seeing if the result represents real-world operation.

The top 3 learnings were:

1. There’s a 3 uA/MHz difference when using the same settings, but with only 0.05 V difference to VDD12. Wow!
2. There is a multi speed internal RC oscillator (MSI RC) that can generate 12 frequencies ranging from 100 kHz - 48 MHz. This would be really interesting to learn how it is configured, and see the results on a spectrum analyzer.
3. There are a variety of run modes, each with their own configuration, that can be chosen from. It will be fun to experiment with these!

Here’s the learning journey: