The industry’s most energy-friendly USB-enabled MCUs

Silicon Labs developed the Happy Gecko family to address the rising demand for cost-effective, low-power USB connectivity solutions. With more than 3bn USB-enabled devices shipping each year, 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.

The USB MCUs feature an advanced 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, the devices have an industry-leading 0.9μA standby current consumption. Active-mode power consumption drops down to 130µA/MHz at 24MHz with real-world code. The Happy Gecko MCUs feature a 2μs wakeup time from standby mode, further reducing power consumption.

Like all EFM32 MCUs, the 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, reducing system power consumption and extending battery life.

The Happy Gecko MCUs feature many of the same low-energy precision analogue peripherals included in other popular EFM32 devices. These low-energy peripherals include an analogue comparator, a supply voltage comparator, an on-chip temperature sensor, a programmable current DAC, and a 12-bit ADC with 350μA current consumption at a 1MHz sample rate. On-chip AES encryption enables the secure deployment of wireless connectivity for IoT applications such as smart meters and wireless sensor networks.

The family’s exceptional single-die integration enables developers to reduce component count and 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. The devices are available in a choice of space-saving QFN, QFP and CSP options small enough for use in USB connectors and thin-form-factor wearable designs.

“The Happy Gecko MCUs bring the benefits of Silicon Labs’ energy-friendly EFM32 architecture to developers seeking an economical, plug-and-play solution for adding USB connectivity to their battery-powered IoT applications,” said Daniel Cooley, Vice President and General Manager, MCU and Wireless Products, Silicon Labs. “The combination of Happy Gecko USB MCUs and our Simplicity Studio development environment enables system designers to connect their 32-bit applications to virtually anything with the lowest energy consumption and BOM cost.”

The Happy Gecko MCUs are available now, priced at $0.83 and sold in 10,000-unit quantities. A Happy Gecko SLSTK3400A starter kit is also available and priced at $29.