Parts Automotive Automotive Microcontrollers SAM Microcontrollers Family SAMD21G ATSAMD21G18A-AF

MCHPATSAMD21G18A-AF

Name: ATSAMD21G18A-AF
Brand: Microchip Technology

Microchip Technology

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

Active1,491 in stock

Datasheet Digi-Key Compare Prices

Overview

The ATSAMD21G18A-AF is a Microchip SAM D21 family 32-bit microcontroller based on the ARM Cortex-M0+ core. It is a general-purpose MCU with 256 KB of Flash and a 48 MHz maximum CPU clock, packaged in a 48-TQFP. The FuSa designation indicates it is positioned for functional-safety-oriented designs where Microchip's documentation and device features support safety-related development.

Why Choose This Part

This MCU gives engineers a familiar ARM Cortex-M0+ platform with a broad Microchip ecosystem behind it. The 48-TQFP package is practical for cost-sensitive boards that still need a manageable pin count and easier assembly than very fine-pitch packages. With 256 KB of Flash, it has room for nontrivial firmware, bootloaders, and protocol stacks without moving to a larger MCU family.

Applications

Industrial control nodes

Used as a local control MCU for sensors, actuators, and deterministic task scheduling in compact industrial equipment.

Safety-related subsystems

A fit for functional-safety-oriented embedded designs that need a documented MCU platform for safety analysis and diagnostics.

Connected IoT endpoints

Useful for small connected devices that need a low-power 32-bit controller with enough Flash for application and protocol stacks.

Smart home controllers

Well suited for wall controllers, lighting interfaces, and other compact control panels that need moderate GPIO and firmware space.

Embedded protocol bridges

Can handle bridging between UART, SPI, I2C, USB, or other board-level interfaces in small embedded products.

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 ~ 125degC (TA)

Supplier Device Package 48-TQFP (7x7)

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

Getting Started

Start with a SAM D21 Xplained Pro or a compatible SAM D21 development board if you want a low-friction hardware path. Microchip's MPLAB X IDE and the XC32 toolchain are the standard starting point, and the part is also commonly used with Arduino-style workflows on SAMD21 boards. For bring-up, verify the clock tree, power pins, and any required programming/debug interface early, then test GPIO and serial output before adding peripherals.

Dev Boards

Development boards and breakout modules featuring the ATSAMD21G18A-AF 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
ATSAMD21G18A-AF (this part)	TQFP-48	-40degC ~ 125degC ..	1,491
ATSAMD21G18A-AU	TQFP-48	-40degC ~ 85degC (..	3,277
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

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

Also Consider

ATSAMD21G18A-AU MCHPMicrochip Technology - Same SAM D21G18A device in a different package option, useful if you want the same core and memory with a different footprint.

STM32G031K8T6

STMicroelectronics - A compact Cortex-M0+ MCU alternative for cost-sensitive control designs that do not need the exact SAM D21 ecosystem.

ATSAMD21E18A-AU MCHPMicrochip Technology - Another SAM D21 option from the same family if you can use a smaller feature set or different package arrangement.