STMicroelectronics Introduces STM32U5: Next‑Generation Ultra‑Low‑Power, High‑Security MCUs for IoT

STMicroelectronics has unveiled the STM32U5 series, a new generation of power‑saving microcontrollers engineered to meet the demanding power‑performance criteria of modern IoT solutions—from wearables and medical devices to home automation and industrial sensors.

Built on a 40 nm process, the STM32U5 reduces dynamic power consumption to less than 19 µA / MHz while delivering the Arm Cortex‑M33 core’s robust performance. Coupled with the Arm Keil MDK development environment, developers can fine‑tune power usage to unprecedented levels.

IoT for the Future

In today’s expanding IoT landscape, devices must be intelligent to connect reliably. This intelligence is provided by a microcontroller that manages real‑world interfaces—sensors and actuators—while also handling network connectivity through Wi‑Fi, Bluetooth, or other protocols.

Power efficiency is critical in two extremes: active mode, where the MCU runs at full performance, and shutdown, where the device consumes almost nothing. The STM32U5 offers a spectrum of intermediate low‑power states, allowing the system to stay dormant for extended periods without compromising responsiveness.

Low Power and Security

ST’s latest series builds on the success of the STM32L5 line, delivering superior performance and security. An advanced DC/DC converter and LDO regulator keep dynamic power usage below 19 µA / MHz, while the integrated Arm TrustZone architecture safeguards against software attacks.

Key security features include:

• Hardware‑level AES encryption and public‑key authorization resistant to side‑channel attacks (DPA).
• Secure data storage powered by a unique hardware key (HUK).
• Active tamper detection and internal monitoring that can erase secrets if an attack is detected, meeting PCI SSC requirements for POS systems.

To showcase the STM32U5’s capabilities, ST introduced the STM32U5 IoT Discovery Kit (B‑U585I‑IOT02A). This reference board bundles the MCU with Wi‑Fi and Bluetooth modules, multiple sensors, and an advanced 14‑bit high‑speed ADC—making it a turnkey solution for rapid prototyping. Microsoft selected this kit as the reference board for its Azure Certified Device program, underscoring its industry‑grade reliability.

The MCU also features a multi‑function digital filter (MDF) and a digital audio filter (ADF) that enhance the sigma‑delta modulator’s DFSDM, enabling high‑fidelity audio and low‑cost AI applications. Integrated error‑correction code (ECC) memory supports safety‑critical use cases.

Currently in the sampling phase, volume production of the STM32U5 will commence in September 2021. Pricing starts at $3.60 USD, with a range of packages—including 4.2 mm × 3.95 mm WLCSP, 7 mm × 7 mm UQFN48, and UFBGA169—catering to diverse application needs.