IoT wireless MCU comes with dual-core, dual radio support

February 22, 2018 // By Peter Clarke
STMicroelectronics NV has introduced a wireless microcontroller, the STM32WB, suitable for Internet of Things applications that use 2.4GHz short-range radio such as Bluetooth and IEEE802.15.4 standards such as OpenThread, ZigBee and proprietary protocols.

Unlike competitor products it, includes two ARM cores – a Cortex-M0 to handle the radio and a Cortex-M4 to handle applications. The combination means that the wireless MCU can perform functions more quickly and return to sleep modes for greater power efficiency and longer battery life. There are also a number of security features, such as AES 256bit acceleration and on-chip ID to help securing IoT nodes and to support secure over-the-air (OTA) updating of firmware and radio protocols.

The MCU can operate at a clock frequency of up to 64MHz for the Cortex-M4 and 32MHz for the Cortex-M0 and comes with up to 1Mbyte of flash memory and 256kbytes of RAM and draws just 3.8mA in receive and 5.5mA in transmit. The device operates at 3.6V down to 1.7V and offers energy saving and supersaving modes of operation for when it is sleeping.

The SoC includes integrated radio balun, power amplifier and low-noise amplifier and so needs almost no external components. The ST32WB offers anRF link budget of -102dBm and is capable of +6dBm output power.

Typical applications intended for the wireless MCU include home security, audio, smart lighting, wearables, industrial and medical applications, beaconing, asset tracking and fleet maintenance.

The new devices leverage rich STM32 digital and analog peripherals that are engineered for extended battery life and complex functionalities, including timers, ultra-low-power comparators, 12/16-bit SAR ADC, a capacitive touch controller, LCD controller, and industry-standard connectivity including crystal-less USB 2.0 FS, I2C, SPI, SAI audio interface, and a Quad-SPI supporting execution in place.

The STM32WB is compatible with the STM32 development ecosystem and an additional STM32CubeMonitor-RF to ease radio testing. Evaluation kits come in Nucleo board form and as a USB dongle.

STM32WB devices will be available in a choice of 48-pin UQFN, 68-pin VQFN, or 100-pin WLCSP with up to 72 general-purpose I/O pins. Each package can be specified with any of three memory configurations, giving a choice