Silicon Labs EFM8BB21F16G-B-QFN20, 8bit CIP-51 Microcontroller, EFM8BB, 50MHz, 16 kB Flash, 20-Pin QFN

The EFM8 Busy Bee 8-bit Microcontroller (MCU) devices are designed for use in a wide variety of general purpose applications. They operate at up 50MHz with a pipelined 8-bit C8051 core.

Up to 22 multifunction, +5V tolerant I/O pins
Priority crossbar for flexible pin mapping
12-bit Analogue to Digital converter (ADC) with up to 20 channels
Up to five 16-bit timers
Integrated temperature sensor
UART, SPI and SMBus/I²C serial communication

The EFM8 8-bit microcontroller family has an unparalleled combination of features and capabilities including a high-speed pipelined 8051 core, ultra-low power, precision analogue and enhanced communication peripherals, integrated oscillators, small-footprint packages, and a crossbar architecture that enables flexible digital and analogue multiplexing to simplify PCB design and I/O signal routing. These next-generation 8-bit devices are aimed at the engineer developing products for the Internet-of-Things (IoT) which will be very small, perform complex processing and run off tiny batteries.