STM's low power line is squarely aimed at battery-powered devices. Here's a quick comparison between all of the different family members:
|
MCU version |
CPU |
Description |
|
STM32L |
Cortex-M0 |
Lowest performance and RAM and ROM space of the family, but offers fairly good efficiency. |
|
STM32L1 |
Cortex-M3 |
Higher ROM capacity and offers faster performance with the trade-off of increased power consumption. |
|
STM32L4 and STM32L4+ |
Cortex-M4 |
Have increased number-crunching capability (the STM32L4+ also offers faster clock speeds and larger internal flash storage). |
|
STM32L5 |
Cortex-M33 |
Blends performance and power and incorporates the latest ARM v8 architecture. Cortex-M33 offers additional security features, such as Trust.Zone, and executes instructions more efficiently than Cortex-M4, which allows for some additional performance while still keeping power consumption in check. |
Depending on the exact workload of a given IoT application, it may make sense to use a low-power 32-bit MCU, such as the ones in the preceding table. However, for very simple applications, low-power 8- and 16-bit MCUs should also be considered.