Parts Microcontrollers ARM Cortex-M0 / M0+ SAM Microcontrollers Family SAMD21G ATSAMD21G18A-MU

MCHPATSAMD21G18A-MU

Name: ATSAMD21G18A-MU
Brand: Microchip Technology

Microchip Technology

ARM® Cortex®-M0+ SAM D21G, Functional Safety (FuSa) Microcontroller IC 32-Bit 48MHz 256KB (256K x 8) FLASH 48-QFN (7x7)

Active1,624 in stock

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Overview

The ATSAMD21G18A-MU is a 32-bit ARM Cortex-M0+ microcontroller from Microchip running up to 48 MHz, with 256 KB of flash and 32 KB of SRAM and integrated USB support. It is the same SAM D21 device used on Arduino Zero and many Adafruit M0 boards, offering a balance of performance and peripherals for USB-enabled embedded projects. The device is supplied in a QFN package (MU variant) commonly used on compact development boards.

Why Choose This Part

The SAM D21 provides a 32-bit Cortex-M0+ core with a relatively large 256 KB flash and 32 KB RAM for applications that outgrow 8-bit MCUs but do not need high-end performance. It includes a rich set of on-chip peripherals (ADC, timers, SERCOM modules for flexible UART/SPI/I2C) and native USB, and benefits from wide community and Arduino ecosystem support which speeds development and debugging.

Applications

USB peripherals and HID devices

Build USB keyboards, mice, MIDI controllers, or custom USB devices that need native USB connectivity.

Arduino-compatible prototyping

Use on Arduino Zero and many Adafruit M0 boards for rapid hardware and firmware prototyping with Arduino libraries.

Sensor hubs and data loggers

Aggregate sensor data, perform local processing, and stream or log data over USB to a host.

Embedded control and human-interface

Control small electromechanical systems, read ADCs, drive PWM outputs, and handle user input for UI devices.

Low- to mid-complexity IoT edge nodes

Run connectivity stacks or act as a preprocessing node for sensors before handing data off to a higher-level radio or gateway.

Key Specifications

Speed 48MHz

RAM Size 32K x 8

Core Size 32-Bit

Peripherals Brown-out Detect/Reset, DMA, I2S, POR, PWM, WDT

Connectivity I2C, LINbus, SPI, UART/USART, USB

Mounting Type Surface Mount

Number of I/O 38

Core Processor ARM Cortex-M0+

Package / Case 48-VFQFN Exposed Pad

Data Converters A/D 14x12b; D/A 1x10b

Oscillator Type Internal

Program Memory Size 256KB (256K x 8)

Program Memory Type FLASH

Operating Temperature -40degC ~ 85degC (TA)

Supplier Device Package 48-QFN (7x7)

Voltage - Supply (Vcc/Vdd) 1.62V ~ 3.6V

Getting Started

Begin with a supported dev board such as the Arduino Zero or Adafruit Feather/Metro/ItsyBitsy M0 series to get USB programming and often an onboard debugger. Toolchains include the Arduino IDE for quick sketches, Microchip Studio (formerly Atmel Studio) or an ARM GCC toolchain for production firmware; many boards expose CMSIS-DAP/EDBG-compatible debugging. Remember these MCUs use 3.3 V logic and to follow standard decoupling and USB layout practices when designing custom boards.

Dev Boards

Development boards and breakout modules featuring the ATSAMD21G18A-MU or compatible chips — ready to use for prototyping.

Seeed Studio XIAO SAMD21 Seeed Technology Co., Ltd

ATSAMD21G18 XIAO SAMD21 SAM D ARM® Cortex®-M0 MCU 32-Bit Embedded Evaluation Board

Digi-Key 509 in stock

Seeed Studio XIAO SAMD21 Seeed Technology Co., Ltd

ATSAMD21G18 XIAO SAMD21 SAM D ARM® Cortex®-M0+ MCU 32-Bit Embedded Evaluation Board

Digi-Key 3,829 in stock

Adafruit Feather M0 Express Adafruit Industries LLC

ATSAMD21G18 Feather M0 Express SAM D ARM® Cortex®-M0+ MCU 32-Bit Embedded Evaluation Board

Digi-Key Mouser 55 in stock

Arduino Nano 33 IoT Arduino

The Arduino Nano 33 IoT (ABX00027) is an advanced evaluation platform designed for IoT applications, featuring the 32 bi

Digi-Key Mouser 800 in stock

ATSAMD21G18A Microchip Technology

ARM Cortex-M0+ MCU with strong Arduino and low-power application support, useful for single-core embedded designs.

Digi-Key Mouser 2,131 in stock

Part of SAM Microcontrollers family » SAMD21G

SAMD21G Family

Comparing specs that differ across variants. The current part is highlighted.

Part Number	Package	Temp Range	Stock
ATSAMD21G18A-MU (this part)	VFQFN-48	-40degC ~ 85degC (..	1,624
ATSAMD21G18A-AU	TQFP-48	-40degC ~ 85degC (..	8,119
ATSAMD21G18A-AUT	TQFP-48	-40degC ~ 85degC (..	2,675
ATSAMD21G18A-AFT	TQFP-48	-40degC ~ 125degC ..	26,091
ATSAMD21G18A-MUT	VFQFN-48	-40degC ~ 85degC (..	4,133
ATSAMD21G18A-MFT	VFQFN-48	-40degC ~ 125degC ..	7,468
ATSAMD21G18A-AF	TQFP-48	-40degC ~ 125degC ..	1,678

Also available as: ATSAMD21G18A-MZVAO, ATSAMD21G16B-AZVAO, ATSAMD21G17D-AZVAO, ATSAMD21G18A-MF

Also Consider

ATSAMD21G18A-AU MCHPMicrochip - Same SAM D21 device in a TQFP package for easier prototyping and hand-soldering.

ATSAMD51J19A-MU MCHPMicrochip - Higher-performance SAMD51 family option if you need more CPU horsepower and memory while staying in Microchip's M0/M4 ecosystem.

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