Silicon Laboratories has introduced what it says is the industry’s lowest power ARM Cortex-M3 processor-based microcontroller (MCU) family along with the first-of-a-kind “power-aware” development tool. The Precision32 SiM3L1xx MCUs and the new development tools have been developed to leverage mixed-signal innovations and to help developers reduce power consumption to 175 µA/MHz in active mode and less than 250 nA in sleep mode with the real-time clock (RTC) enabled at 3.6 V.
The ultra-low-power mixed-signal MCUs are suitable for smart metering, utility monitoring, home automation, wireless security, asset tracking, personal medical devices and other power-sensitive applications to enable the Internet of Things (IoT).
Ultra-low-power MCUs are seen as being key building blocks of IP-enabled devices connected to the IoT. Experts believe the IoT will comprise an estimated 50 billion intelligent devices by 2020, autonomously sensing, monitoring, processing, controlling and communicating over wireless networks. Because many of these intelligent end nodes will be powered by batteries or harvested energy sources, they require exception energy-efficient MCUs to enable developers to optimise system-level power consumption.
The SiM3L1xx family is among the most power-efficient line of 32-bit MCUs currently on the market, and have been designed to achieve ultra-low-power operation based on an ARM Cortex-M3 processor operating at up to 50 MHz. The new Precision32 mixed-signal MCUs include power-saving peripheral and architectural innovations that can reduce current consumption below that of many 8-bit MCUs, enabling developers to use higher performance 32-bit cores in their low-power embedded designs without the tradeoff of reduced battery life.
Active mode power reduction is achieved through a number of key innovations. For example, dynamic voltage scaling adjusts the internal device voltage in response to changing conditions. An integrated, high-efficiency dc-dc buck converter reduces active mode power by 40 percent compared to competing 32-bit MCUs. Dedicated peripherals such as a data transfer manager, AES encryption block and run-time encoder accelerate the processing of RF protocol for wireless applications without CPU intervention, greatly reducing system power.
Enhanced direct memory access (DMA) can reduce protocol-related power by 90 percent, and RAM and register state retention enables a fast 4 microsecond wake-up time. The MCU family also features a patented LCD controller with a charge redistribution architecture that reduces the display’s power consumption by nearly 40 percent without compromising performance.
The SiM3L1xx MCUs also achieve significant reduction in sleep-mode power by optimising on-chip peripherals (charge pump, RTC, sensor interface, sleep mode UART, comparator and LCD controller) for the lowest power consumption. The charge pump generates a power-efficient input voltage for the device circuits in sleep mode, which reduces analogue sleep currents by 35 percent and digital sleep currents by 50 percent.
The SiM3L1xx and supporting development tools were designed with the overall system power budget in mind. To minimise system-level power, the SiM3L1xx MCUs feature patented voltage conversion technology, as well as advanced peripherals that reduce the power consumed by other ICs in the system.
Silicon Labs’ complimentary Eclipse-based IDE and AppBuilder software includes a host of new capabilities for estimating power consumption and providing configuration guidance to achieve the lowest system power.
“Low-power design is especially challenging because developers must consider many different application-specific optimizations to meet their desired low-power targets,” said Mike Salas, vice president and general manager of Silicon Labs’ microcontroller products. “The new Precision32 mixed-signal MCU family provides an unprecedented combination of advanced peripherals, innovative architecture and power-aware design tools to give developers the flexibility to optimize their designs for the lowest system-level power.”
“Momentum has been building around the implementation of a wide variety of power-sensitive, connected devices that comprise the Internet of Things,” said Richard York, director of embedded processors, ARM. “Silicon Labs is addressing this major industry trend by delivering an exceptionally energy-efficient range of microcontrollers based on the ARM Cortex-M3 processor. We are encouraged by the continued innovation in this market as advanced MCUs, such as the Precision32 SiM3L1xx family from Silicon Labs, will help develop the Internet of Things market.”