STM32 ultra-low-power microcontrollers for energy-sensitive designs

May 02, 2014 // By Graham Prophet
The latest STM32L0 microcontrollers from STMicroelectronics enable applications to achieve record low power consumption. The MCUs use a combination of the energy-efficient ARM Cortex-M0+ core, optimised architecture, power-management modes, ultra-low-power peripherals, support for energy-saving USB features, and proprietary ultra-low-power process technology.

With run consumption down to 87 µA/MHz, 440 nA stop mode with full RAM data retention, a low-power time counter, and fast wakeup time of 3.5 µsec the STM32L0 allows applications to maximise use of energy-saving modes. The STM32L0 series enables designers of products such as computer peripherals, healthcare monitors and trackers, industrial sensors, and smart-home devices to deliver market-leading battery life and create slim and lightweight new styles. Where other devices suffer rapidly increasing current consumption at higher temperatures, ST’s process technology maintains stability over a wide temperature range, ensuring these devices offer the lowest power consumption at 125°C. The STM32L0 series also has the world’s lowest analogue-to-digital converter power consumption. The 12-bit on-chip ADC draws only 48 µA when operating at 100 ksample/sec. Built-in hardware oversampling increases the ADC resolution to 16 bits.

Over 30 part numbers offer basic entry-level configurations as well as variants featuring USB connectivity with the option of an LCD controller up to 8x28. USB full-speed enabled devices support crystal-less operation, USB Battery Charger Detection (BCD), and energy-saving Link Power Management (LPM).

Enhanced STM32CubeMX design tools, including the Power Consumption Calculator wizard, support the STM32L0, helping designers use the new devices to reach ultra-low power-consumption targets. STM32CubeMX helps accelerate generation of initialisation code and simplifies porting of designs between different STM32 devices. A new STM32L0 Nucleo board featuring Morpho and Arduino-compatible connectors and fully supported by will be also available in mid 2014.

ST will further expand the STM32L0 ecosystem with a Discovery kit that will host an ePaper display as well as a linear capacitive touch and self-test measurement system enabling users to measure MCU power consumption in real-time. The STM32L0 Discovery-kit will also be available in mid 2014. Both STM32L0 Nucleo board and Discovery-kit feature an ST-Link/V2 hardware debugger.

Optimised sample-code snippets dedicated to STM32L0 MCUs will also be available for both the Nucleo board and Discovery kit, providing further help