Silicon Labs, a provider of energy-friendly microcontroller (MCU) solutions for the Internet of Things (IoT), has introduced the latest member of its EFM8 8-bit MCU portfolio designed for ultra-low-power, small-footprint IoT applications with capacitive touch sensing requirements. The new EFM8SB1 Sleepy Bee MCUs, available in a 1.78 mm x 1.66 mm wafer-level chip-scale package (WLCSP), are the industry’s smallest MCUs – one-fourth the size of 8-bit MCUs in conventional QFN packages. These tiny MCUs are ideal for touch-based, battery-powered and space-constrained IoT and industrial applications requiring long battery lifetimes and energy-efficient human interfaces. Target applications include wearables, remote controls, Bluetooth accessories and eReaders, as well as industrial automation, home automation and office equipment.

The EFM8SB1 Sleepy Bee MCUs are Silicon Labs’ most energy-friendly 8-bit devices offering sleep mode power (50 nA with full memory retention and brown-out detection) and an ultra-fast 2 µs wake-up time. Core speeds scale up to 25 MHz, and flash sizes range from 2 kB to 8 kB. The MCUs also integrate a capacitive sense controller offering an ultra-low-power < 1 µA wake-on-touch capability and 12 robust capacitive touch channels, eliminating the need for on/off switches in many space-sensitive products such as wearables.

In addition to providing advanced on-chip capacitive sensing technology, Silicon Labs supports touch-sense interface design with its best-in-class Capacitive Sense Library available within the Simplicity Studio development platform, offering all of the features and algorithms required to add capacitive sensing interfaces to IoT products. Simplicity Studio provides firmware designers with production-ready firmware, from scanning buttons to filtering noise. By using the Simplicity Studio Capacitive Sense Profiler to visualise real-time data and the noise levels of cap-sense buttons, developers can easily customise touch and no-touch thresholds and noise filtering settings, greatly simplifying the addition of capacitive touch to IoT applications.

The EFM8SB1 MCUs offer a rich mix of analog and digital peripherals including a high-resolution capacitance-to-digital converter (CDC), a 12-bit analog-to-digital converter (ADC), high-performance timers, and enhanced SPI, I2C and UART serial ports. These and other analog/mixed-signal peripherals are all easily configurable and accessible to developers through Silicon Labs’ patented crossbar technology.

“By combining exceptional energy efficiency, capacitive touch capabilities, a rich peripheral set and a best-in-class development environment with the world’s smallest MCU footprint, the EFM8SB1 Sleepy Bee family embodies our ‘MCUs without compromise’ design philosophy,” said Tom Pannell, marketing director for microcontroller products at Silicon Labs. “If you need a tiny, ultra-low-power cap-touch MCU for applications with flash memory requirements below 8 kB, our EFM8SB1 MCUs are a perfect for your IoT design.”

EFM8SB1 Sleepy Bee MCU Highlights

•       Up to 25 MHz single-cycle 8051 processor core

•       Available in a 1.78 mm x 1.66 mm wafer-level chip-scale package (WLCSP)

•       Dedicated, on-chip 12-channel capacitive touch sense controller

•       50 nA sleep mode with full memory retention and brown out detector (BOD) enabled

•       300 nA sleep mode with internal low-frequency oscillator (LFO)

•       150 µA/MHz operation

•       Less than 1 µA wake on touch

•       Fast 2 µs wake-up time

•       Flexible clocking architecture to optimise for system and power requirements

•       Patented crossbar technology for analog and digital peripherals

•       Supported by Simplicity Studio tools such as the Capacitive Sense Profiler and Library