STMicroelectronics has begun volume production of ultra-low-power STM32L45x MCUs, supported by a development ecosystem based on the easy-to-use and affordable STM32Cube platform. The STM32L451, STM32L452, and STM32L462 lines integrate a DFSDM, enabling advanced audio capabilities such as noise cancellation or sound localisation on an inexpensive microcontroller. Up to 512 Kbyte on-chip Flash and 160 Kbyte SRAM provide generous code and data storage.
The new MCUs also feature a True Random-Number Generator (TRNG) that streamlines development of security-conscious applications such as connected smart devices. The STM32L462 further enhances support for developing secure devices by integrating an AES-256 cryptographic hardware accelerator.
Other features include smart analog peripherals such as a 12-bit 5Msample/s ADC, internal voltage reference, and ultra-low-power comparators. There are multiple timers, a motor-control channel, temperature sensor, a capacitive-sensing interface, and the STM32L452 also has a crystal-less USB2.0 controller.
The development ecosystem includes the STM32CubeMX initialisation-code generator and STM32CubeL4 package comprising middleware components, Nucleo-64 Board-Support Package (BSP), Hardware Abstraction Layer (HAL), and Low-Layer APIs (LLAPIs). STM32CubeMX has a power-estimation wizard that assists low-power design and additional wizards for managing clock signals and pin assignments.
The Nucleo-64 board, NUCLEO-L452RE, provides an affordable and flexible way for users to try out new ideas and build prototypes. It integrates the ST-LINK/V2 probe-free debugger/programmer and can be expanded via Arduino-compatible headers.
Offering features unavailable in other ultra-low-power MCUs, the new STM32L4 devices deliver both high core performance and outstanding ultra-low-power efficiency. The EEMBC CoreMark score of 273 outperforms other ultra-low-power cores, while the ULPBench score of 245 confirms greater energy efficiency. Active-mode current of just 36µA/MHz enables longer runtime on small batteries and extends scope to create energy-neutral products powered from ambient sources.
Devices can be ordered now, in small-form-factor packages from QFN-48 to LQFP-100, including a 3.36mm x 3.66mm WLCSP. Prices start from $2.773 for the STM32L451CCU6 with 256 Kbytes Flash and 160 Kbytes SRAM in QFN-48, for orders of 10,000 pieces.
Prices for development boards start at $14 for the legacy-compatible Nucleo-64 board (NUCLEO-L452RE), which is available now. The NUCLEO-L452RE-P board with external DC/DC converter will be available to distributors in June 2017.