Atmel adds ARM Cortex-M based MCU at 35µA/MHz power usage

March 31, 2015 // By Graham Prophet
Staking a claim for the lowest power microcontroller based on the ARM Cortex-M core series, the Atmel | SMART SAM L Family uses one-third the power of alternative offerings and achieves an EEMBC ULPBench Score of 185 .

With power consumption down to 35 µA/MHz in active mode and 200 nA in sleep mode, the ultra-low power SAM L family broadens the Atmel | SMART 32-bit ARM-based MCU portfolio and extends battery life, “from years to decades” for devices such as fire alarms, healthcare, medical, wearable, and devices placed in rural, agriculture, offshore and other remote areas. The SAM L21 combines ultra-low power with Flash and SRAM that are large enough to run both the application and wireless stacks—three features that are cornerstones of most IoT applications. Sampling now, the SAM L21 comes with a development platform including an Xplained PRO kit, code libraries and Atmel Studio support.

The family integrates the company’s proprietary ultra-low power picoPower technology. While running the EEMBC ULPBench benchmark , the SAM L21 achieves a score of 185, the highest publicly-recorded score for any Cortex-M based processor or MCU. Atmel’s SAM L21 family consumes less than 940 nA with full 40 kB SRAM retention, real-time clock and calendar and 200 nA in the deepest sleep mode.

The ultra-low power is based on, among other factors;

- Best-available active mode current consumption.

- SRAM back-biasing to reduce leakage in sleep modes.

- Sleep modes that do not only gate away the clock signal to stop switching consumption, but also remove power from sub domains to fully eliminate leakage.

- SAM L21 peripherals that support Sleepwalking—a technology that enables peripherals to request a clock when needed, to wake-up from sleep modes and perform tasks without having to power up the CPU Flash and other support systems.

- Atmel’s proprietary Event System that allows peripherals to work together to solve complex tasks using minimal gates and also the lowest possible power.

- Ultra-low power capacitive touch sensing peripheral that can run in all operating modes and supports wake-up on touch.

“With over two decades of MCU experience, ultra-low power picoPower technology is part of Atmel’s heritage,