The EFM32 32-bit Happy Gecko MCUs are designed to deliver the lowest USB power drain, enabling longer battery life and energy harvesting applications. Based on the ARM Cortex-M0+ core and low-energy peripherals, the Happy Gecko family offers USB connectivity for a range of IoT applications including smart metering, home and building automation, alarm and security systems, smart accessories and wearable devices.
According to the company, USB is the fastest growing interface for consumer applications and is also gaining significant traction in industrial automation, “In today’s IoT world, developers have discovered that adding USB interfaces to portable, battery-powered connected devices can double the application current consumption. Silicon Labs’ Happy Gecko MCUs provide an ideal energy-friendly USB connectivity solution for these power-sensitive IoT applications.”
Happy Gecko USB MCUs have an energy management system with five energy modes enabling applications to remain in an energy-optimal state by spending as little time as possible in active mode. In deep-sleep mode, Happy Gecko MCUs use 0.9 μA standby current consumption (with a 32.768 kHz RTC, RAM/CPU state retention, brown-out detector and power-on-reset circuitry active). Active-mode power consumption drops down to 130 µA/MHz at 24 MHz with real-world code (prime number algorithm). The USB MCUs further reduce power consumption with a 2-microsecond wakeup time from standby mode.
Happy Gecko family includes the Peripheral Reflex System (PRS) feature, which greatly enhances overall energy efficiency. The six-channel PRS monitors complex system-level events and allows different MCU peripherals to communicate autonomously with each other without CPU intervention. The PRS watches for specific events to occur before waking the CPU, thereby keeping the Cortex-M0+ core in an energy-saving standby mode as long as possible.
Happy Gecko MCUs feature many of the same low-energy precision analogue peripherals included in other family devices. These low-energy peripherals include an analogue comparator, supply voltage comparator, on-chip temperature sensor, programmable current digital-to-analogue converter (IDAC), and a 12-bit analogue-to-digital converter (ADC) with 350 μA current consumption at a 1 MHz sample rate. On-chip AES encryption enables the secure deployment of wireless connectivity for IoT applications such as smart meters and wireless sensor networks.
Integration enables developers to reduce component count and bill-of-materials (BOM) cost. While typical USB connectivity alternatives require external components such as crystals and regulators, the highly integrated Happy Gecko MCUs eliminate nearly all of these discretes with a crystal-less architecture featuring a full-speed USB PHY, an on-chip regulator and resistors. Happy Gecko MCUs are available in a choice of QFN, QFP and chip-scale package (CSP) options small enough for use in USB connectors and thin-form-factor wearable designs.
Simplifying USB Design
The Happy Gecko family is supported by Silicon Labs’ Simplicity Studio development platform, which helps developers simplify low-energy design. The Simplicity Energy Profiler enables real-time energy profiling and debugging of code. The Simplicity Battery Estimator calculates expected battery life based on an application profile, energy modes and peripherals in use.
The Simplicity Configurator provides a visual interface for MCU pin configuration, automatically generating initialisation code. Code developed for other EFM32 MCUs can be reused with Happy Gecko applications. Developers can download Simplicity Studio and access Silicon Labs’ USB source code and software examples at no charge at www.silabs.com/simplicity-studio
The device family is supported by the ARM mbed ecosystem, which includes new power management APIs developed by Silicon Labs and ARM. These low-power mbed APIs are designed with low-energy application scenarios in mind, enabling rapid prototyping for energy-constrained IoT designs. ARM mbed APIs running on EFM32 MCUs automatically enable the optimal sleep mode based on the MCU peripherals in use, reducing system-level energy consumption; www.silabs.com/mbed
In 24-pin and 32-pin QFN, 48-pin QFP and 3 x 2.9 mm CSP packages, Happy Gecko MCU pricing begins at $0.83 (10,000). The Happy Gecko SLSTK3400A starter kit is available now and priced at $29.
Silicon Labs; www.silabs.com