Combining features of ST’s STM32L4 Arm Cortex-M4 MCUs and in-house radio managed by a dedicated Cortex-M0+, the STM32WBx5 is capable of concurrent wireless-protocol and real-time application execution and low-power operation.
Security features include Customer Key Storage (CKS), Public Key Authorization (PKA), and encryption engines for the radio MAC and upper layers. Security managed by the Cortex-M0+, includes OTA secure firmware updates for application and radio stack, protecting device integrity and intellectual property, and ensuring easy, robust product management.
A high level of integration minimizes BoM costs and footprint. STM32WBx5 MCUs have up to 1Mbyte of on-chip Flash and a Quad-SPI port for efficient connection to external memory. Additional features include crystal-less Full-Speed USB, 32MHz RF oscillator with trimming capacitors, a touch-sense controller, LCD controller, analogue peripherals, and multiple timers and watchdogs. The balun for antenna connection is also integrated.
STM32WBx5 MCUs also have multiple power-saving modes including 13nA Shutdown mode, adaptive voltage scaling, and the adaptive real-time ART Accelerator.
The integrated radio transmitter is optimized 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 1mbps. 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).
The STM32WBx5 line is supported by the STM32Cube ecosystem. Developers get free access to an extensive set of tools and 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.