STM32 L5 Ultra-Low-Power MCUs STMicroelectronics STM32 L5 Ultra-Low-Power MCUs are designed for an embedded application that requires more security and low power consumption. These MCUs are based on Arm® Cortex®-M33 processor and its TrustZone® for Armv8-M combined with ST security implementation. The STM32 L5 MCUs feature 512Kbytes of flash memory and 256Kbytes of SRAM. With the help of a new core and a new ST ART Acccelerator™, the STM32 L5 MCUs reaches an upgraded level of performance. These STM32 L5 MCUs offer a large portfolio with 7 packages and support up to 125°C ambient temperature.