STMicroelectronics has introduced new STM32U3 microcontrollers designed with power-saving innovations for smart connected technology deployment in remote locations. These MCUs are developed for IoT devices that must operate for extended periods without maintenance while using limited energy from sources such as coin cells or ambient solar or thermoelectric power.
The STM32U3 series incorporates near-threshold chip design technology that operates IC transistors at extremely low voltage, which saves energy proportionately according to a square law. This implementation uses AI-driven adaptive voltage scaling at wafer level to compensate for foundry process variations. The devices achieve a Coremark-per-milliwatt score of 117 while operating with the Arm Cortex-M33 core at speeds up to 96MHz. The dynamic power consumption has been reduced to 10µA/MHz, and the stop current reaches as low as 1.6µA.
These microcontrollers feature up to 1MB of dual-bank Flash memory and 256kB of SRAM. For security purposes, the STM32U3 MCUs confine secret keys permanently in secure memory to eliminate vulnerable CPU fetches. Attestation credentials for each device are provisioned during manufacturing, which enhances security and simplifies provisioning. The MCUs contain SESIP3 and PSA Level3 certifiable security assets, including cryptographic accelerators, TrustZone isolation, random generators, and product lifecycle features that help customers comply with upcoming RED and CRA regulations.
The STM32U3 series is available in two product lines, offering MCUs with or without hardware cryptographic accelerators. These devices integrate efficient peripherals, including the latest I3C digital connectivity standard. The microcontrollers are available in commercial temperature range (-40°C to 85°C) and extended industrial temperature range (-40°C to 105°C). The series is currently in production, with pricing starting from $1.93 for orders of 10,000 pieces.
Common applications for these microcontrollers include utility meters, healthcare devices such as glucose meters and insulin pumps, animal care monitors, environmental sensors, industrial sensors like thermostats and smoke detectors, and consumer products, including smartwatches and wearable technology.
