Wireless MCUs deliver ultra-low-power performance

It is suited to remote sensors, wearable trackers, building-automation controllers, computer peripherals, drones, and other IoT devices.

Security features strengthen the STM32WBx5’s IoT credentials and include Customer Key Storage (CKS), Public Key Authorisation (PKA), and encryption engines for the radio MAC and upper layers. Security managed by the Cortex-M0+, including OTA secure firmware update for application and radio stack, protects device integrity and intellectual property, and ensures easy, robust product management.

Feature integration lets product developers minimise bill-of-material costs and footprint. STM32WBx5 MCUs have up to one megabyte of on-chip Flash and a Quad-SPI port for efficient connection to external memory, if needed. Additional features include crystal-less Full-Speed USB, 32MHz RF oscillator with trimming capacitors, a touch-sense controller, LCD controller, analog peripherals, and multiple timers and watchdogs. The balun for antenna connection is also integrated.

Leveraging ultra-low-power technologies of the STM32L4 line, STM32WBx5 MCUs feature multiple power-saving modes including 13nA Shutdown mode, adaptive voltage scaling, and the adaptive real-time ART Accelerator to maximise energy efficiency and ensure long-lasting performance in self-powered applications.

The integrated radio transmitter is optimised for high RF performance and low power consumption to maximise battery runtime. The RF output power is programmable up to +6dBm in 1dB increments, and the MCU draws only 5.2mA when transmitting at 0dB. Receive sensitivity is -96dBm for BLE communication at one megabit per second. Designed for a link budget of 102dB, the radio ensures robust communication over long connection distances and includes support for an external Power Amplifier (PA).

Developing with the STM32WBx5 line is well served through the STM32Cube ecosystem. Developers not only get free access to an extensive set of tools but can also take advantage of the STM32CubeWB MCU Package featuring peripheral drivers, middleware, and connectivity libraries, and the STM32WB55 Nucleo pack (P-NUCLEO-WB55). The dedicated STM32CubeMon-RF connectivity tool for RF testing and custom use-case scripting comes as a new addition to STM32Cube to further accelerate time-to-market.

Devices are available in a selection of packages from UFQFPN48 up to UFBGA129, offering flexibility to meet cost, size, and complexity demands with plentiful user I/Os in each option.

The STM32WBx5 line is in production now, priced from $3.26 for orders of 10,000 pieces and $2 for high-volume orders.