Parts SAM Microcontrollers Family SAMD21G SAMD21G18A-AU

MCHPSAMD21G18A-AU

Name: SAMD21G18A-AU
Brand: Microchip Technology

Microchip Technology

32-bit Cortex-M0+ microcontroller with native USB and more modern peripheral set if a 32-bit architecture is preferred.

Active6,107 in stock

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Overview

The SAMD21G18A-AU is a 32-bit microcontroller based on the ARM Cortex-M0+ core with native USB support. It provides 256 KB of flash, 32 KB of SRAM, a 48 MHz CPU clock, and a broad set of peripherals including I2C, SPI, UART/USART, DMA and I2S. The device runs from 1.62 V to 3.6 V and exposes around 38 GPIOs for embedded designs.

Why Choose This Part

The SAMD21G18A-AU combines a modern 32-bit Cortex-M0+ CPU with native USB and a rich peripheral set, making it suitable for USB-enabled embedded designs without external bridge chips. Its 256 KB flash and 32 KB RAM provide ample space for moderately complex firmware and libraries, while DMA and I2S support offload work from the CPU. The wide supply range and mature ecosystem (Arduino cores, Microchip tooling) reduce integration time and risk.

Applications

USB peripherals and HID devices

Implement USB device classes such as CDC, HID or custom USB interfaces for keyboards, custom input devices, or virtual serial links.

Sensor hub and data logging

Aggregate sensors over I2C/SPI and stream or store data using DMA to minimize CPU overhead and power consumption.

Battery-powered embedded controllers

Use in low-voltage battery systems where the wide supply range (1.62V to 3.6V) and modest power use are beneficial.

Simple audio interfaces

Drive basic audio paths or codecs using the I2S peripheral for low-cost audio input/output applications.

Rapid prototyping and Arduino-compatible projects

Ideal for boards like Arduino Zero or Adafruit M0 where easy bootloader support and Arduino core compatibility speed development.

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-TQFP

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-TQFP (7x7)

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

Getting Started

Begin with an off-the-shelf development board or breakout (Arduino Zero, Adafruit Feather M0, or SAMD21-based breakout boards) to avoid SMD mounting. Use the Arduino IDE with the SAMD cores for rapid prototyping, or use Microchip/Atmel tools and the ARM GCC toolchain for production firmware; debug with Atmel-ICE or Segger J-Link via SWD. Check vendor example projects and the community libraries for USB and peripheral drivers to accelerate development.

Dev Boards

Development boards and breakout modules featuring the SAMD21G18A-AU 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 3,141 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 364 in stock

Arduino Nano 33 IoT Arduino

The Arduino Nano 33 IoT with Headers (ABX00032) is a compact and versatile development board featuring the ARM® Cortex®-

Digi-Key Mouser 355 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 657 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
SAMD21G18A-AU (this part)	TQFP-48	-40degC ~ 85degC (..	6,107
ATSAMD21G18A-AUT	TQFP-48	-40degC ~ 85degC (..	4,963
ATSAMD21G18A-MU	VFQFN-48	-40degC ~ 85degC (..	1,624
ATSAMD21G18A-AFT	TQFP-48	-40degC ~ 125degC ..	20,008
ATSAMD21G18A-MUT	VFQFN-48	-40degC ~ 85degC (..	3,079
ATSAMD21G18A-MFT	VFQFN-48	-40degC ~ 125degC ..	7,004
ATSAMD21G18A-AF	TQFP-48	-40degC ~ 125degC ..	1,491