Silicon Labs unveiled a series of energy-friendly microcontrollers based on technology from recent acquisition Energy Micro. The 32-bit EFM32 Zero Gecko MCU family, based on the ARM Cortex-M0+ core, is designed to achieve the lowest system energy consumption for battery-powered and energy-harvesting applications. The 16 members of the new family are pin- and code-compatible with the existing Gecko portfolio.
An integrated programmable-current digital-to-analog converter (IDAC) generates a biasing current from 0.05 to 64 µA with only 10-nA overhead. It provides an accurate bias and/or control capability for companion ICs and other external circuits, including amplifiers, sensors, Wheatstone bridges, and resistor ladders, eliminating the need for external power-amplifier components. In addition, a 128-bit Advanced Encryption Standard (AES) hardware block suits the Zero Gecko MCUs for RF transmitters and transceivers.
Thanks to a sophisticated energy management system with five energy modes, applications can remain in an energy-optimal state, spending as little time as possible in the energy-hungry active mode. In deep-sleep mode, Zero Gecko MCUs consume 0.9-μA standby current with an active 32.768-kHz RTC, RAM/CPU state retention, brown-out detector, and power-on-reset circuitry.
Active-mode power consumption scales down to 110 µA/MHz at 24 MHz. Real-world code (prime-number search algorithm) is executed from flash. Current consumption runs less than 20 nA in shut-off mode. The EFM32 MCUs further reduce power consumption with a 2-µs wakeup time from standby mode.