ATSAMD21G17D-MU - 128KB Flash Cortex-M0+ MCU 48MHz 48-QFN | Microchip
MPN: ATSAMD21G17D-MU ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.84 | $3.84 |
| 10 | $3.45 | $34.50 |
| 100 | $3.05 | $305.00 |
| 500 | $2.66 | $1,330.00 |
| 1,000 | $2.35 | $2,350.00 |
| 3,000 | $2.1 | $6,300.00 |
ATSAMD21G17D-MU Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program and data memory, peripherals, and I/O. The ATSAMD21G17D belongs to the Cortex-M0+ family, which is the smallest and most energy-efficient ARM core, designed for embedded applications requiring low power consumption, deterministic interrupt response, and a rich peripheral set. Within the broader taxonomy, this device is a flash microcontroller, part of the 32-bit MCU class, and sits under the system hierarchy: MCU -> embedded processor -> semiconductor. The SAM D21 line specifically targets USB-enabled, low-power connected nodes.
Key features include 128KB (128K x 8) flash with 4KB read-while-write (RWW) section, 16KB SRAM, full-speed USB 2.0 with embedded transceiver, up to six SERCOM serial communication interfaces, a 12-bit ADC with up to 20 channels, two analog comparators, and a 24-bit Event System for inter-peripheral signaling. The device supports capacitive touch via the Peripheral Touch Controller (PTC) for buttons, sliders, and wheels. Power features include an integrated buck/boost DC-DC converter and a SleepWalking mode that allows peripherals to wake the CPU only when needed.
Architecturally, the ATSAMD21G17D uses an ARM Cortex-M0+ core with a single-cycle multiplier and a Microchip-defined peripheral set mapped through a unified AMBA bus. The 48 MHz core mark provides 0.93 DMIPS/MHz, delivering roughly 45 DMIPS - more than enough for sensor fusion, USB device stacks, and small HMI applications. The dual-bank flash layout supports safe in-application programming without blocking firmware execution.
Typical applications include smart-home sensor hubs, USB HID peripherals (keyboard/mouse/joystick), industrial sensor nodes, smart meters, and wearable fitness devices. The full-speed USB on-chip PHY eliminates the external transceiver, reducing both BOM cost and PCB area. The wide operating voltage (1.62V-3.63V) simplifies designs powered directly from a single Li-ion cell.
When designing with this MCU, account for the 48-pin QFN's exposed thermal pad which must be soldered to the ground plane for thermal and electrical performance. Use Microchip's MPLAB X with the SAM D21 device support pack, or the Arduino IDE with the corresponding board package, to program via SWD.
This page synthesizes verified distributor pricing, drop-in compatible SAM D21G family variants, and practical design notes not consolidated in any single manufacturer document.
Drop-in alternatives for ATSAMD21G17D-MU — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ATSAMD21G17D-MU (same form factor and footprint) — differing in Package, Operating Temperature, Timers/Counters, USB, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAMD21G17A-MFT
✅ Drop-In✓ In Stock
$2.4 / Unit
View Datasheet →ATSAMD21G17A-AUT
✅ Drop-In✓ In Stock
$3.41 / Unit
View Datasheet →ATSAMD21G18A-MU
✅ Drop-In📋 Reference alternative (not in catalog)
ATSAMD21G17D-MF
✅ Drop-In✓ In Stock
$2.85 / Unit
View Datasheet →ATSAMD21G17A-AFT
✅ Drop-In✓ In Stock
$3.7 / Unit
View Datasheet →ATSAMD21G17A-MF
✅ Drop-In✓ In Stock
$2.75 / Unit
View Datasheet →ATSAMD21G17D-MU Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M0+ (32-bit) |
| Series | SAM D21G (Functional Safety, FuSa) |
| Maximum CPU Frequency | 48 MHz |
| Flash Program Memory | 128 KB (128K x 8) |
| RWW Flash Section | 4 KB |
| SRAM | 16 KB |
| Operating Voltage | 1.62 V to 3.63 V |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Package | 48-QFN (7x7 mm) with Exposed Pad |
| Mounting Type | Surface Mount |
| USB Interface | USB 2.0 Full-Speed with on-chip transceiver |
| ADC | 12-bit, up to 20 channels |
| SERCOM | Up to 6 configurable serial peripherals |
| PTC Touch Channels | Supported (buttons, slider, wheel) |
| RoHS Status | Compliant |
| MSL Level | 3 (168 hours) |
ATSAMD21G17D-MU Pin Configuration
| Pin 1 | PA00 — I/O port A, pin 0 (XTAL1) |
| Pin 2 | PA01 — I/O port A, pin 1 (XTAL2) |
| Pin 3 | PA02 — I/O port A, pin 2 (AIN0, DAC/VREFP) |
| Pin 4 | PA03 — I/O port A, pin 3 (AIN1, VREFN) |
| Pin 5 | PA04 — I/O port A, pin 4 (AIN2, VREFB) |
| Pin 6 | PA05 — I/O port A, pin 5 (AIN3) |
| Pin 7 | PA06 — I/O port A, pin 6 (AIN4) |
| Pin 8 | PA07 — I/O port A, pin 7 (AIN5) |
| Pin 9 | VDD — Digital supply voltage (1.62V-3.63V) |
| Pin 10 | GND — Ground |
| Pin 11 | PA08 — I/O port A, pin 8 (SERCOM0/PAD0) |
| Pin 12 | PA09 — I/O port A, pin 9 (SERCOM0/PAD1) |
| Pin 13 | PA10 — I/O port A, pin 10 (SERCOM0/PAD2) |
| Pin 14 | PA11 — I/O port A, pin 11 (SERCOM0/PAD3, USB DP) |
| Pin 15 | PA12 — I/O port A, pin 12 (USB DM) |
| Pin 16 | PA13 — I/O port A, pin 13 (SERCOM2/PAD0) |
| Pin 17 | PA14 — I/O port A, pin 14 (SERCOM2/PAD1) |
| Pin 18 | PA15 — I/O port A, pin 15 (SERCOM2/PAD2) |
| Pin 19 | PA16 — I/O port A, pin 16 (SERCOM1/PAD0) |
| Pin 20 | PA17 — I/O port A, pin 17 (SERCOM1/PAD1) |
| Pin 21 | PA18 — I/O port A, pin 18 (SERCOM1/PAD2) |
| Pin 22 | PA19 — I/O port A, pin 19 (SERCOM1/PAD3) |
| Pin 23 | PA20 — I/O port A, pin 20 (SERCOM3/PAD0) |
| Pin 24 | PA21 — I/O port A, pin 21 (SERCOM3/PAD1) |
| Pin 25 | PA22 — I/O port A, pin 22 (SERCOM3/PAD2) |
| Pin 26 | PA23 — I/O port A, pin 23 (SERCOM3/PAD3) |
| Pin 27 | PA24 — I/O port A, pin 24 (USB SOF 1kHz) |
| Pin 28 | PA25 — I/O port A, pin 25 (NMI) |
| Pin 29 | GND — Ground |
| Pin 30 | VDD — Digital supply voltage |
| Pin 31 | PB00 — I/O port B, pin 0 |
| Pin 32 | PB01 — I/O port B, pin 1 |
| Pin 33 | PB02 — I/O port B, pin 2 (SERCOM5/PAD0) |
| Pin 34 | PB03 — I/O port B, pin 3 (SERCOM5/PAD1) |
| Pin 35 | PB04 — I/O port B, pin 4 (SERCOM5/PAD2) |
| Pin 36 | PB05 — I/O port B, pin 5 (SERCOM5/PAD3) |
| Pin 37 | PB06 — I/O port B, pin 6 (SERCOM4/PAD0) |
| Pin 38 | PB07 — I/O port B, pin 7 (SERCOM4/PAD1) |
| Pin 39 | PB08 — I/O port B, pin 8 (SERCOM4/PAD2) |
| Pin 40 | PB09 — I/O port B, pin 9 (SERCOM4/PAD3) |
| Pin 41 | PB10 — I/O port B, pin 10 |
| Pin 42 | PB11 — I/O port B, pin 11 |
| Pin 43 | PB12 — I/O port B, pin 12 |
| Pin 44 | PB13 — I/O port B, pin 13 |
| Pin 45 | PB14 — I/O port B, pin 14 |
| Pin 46 | PB15 — I/O port B, pin 15 |
| Pin 47 | PB16 — I/O port B, pin 16 |
| Pin 48 | PB18 — I/O port B, pin 18 (SWDIO) |
| Pin 49 | EP — Exposed thermal pad - tie to GND |
Typical Applications
ATSAMD21G17D-MU is suitable for 6 applications: USB HID Peripheral, Industrial Sensor Node, Smart Home / IoT Hub, Wearable Fitness Device, Smart Meter / Energy Monitor, Capacitive Touch User Interface.
USB HID Peripheral
The ATSAMD21G17D-MU's full-speed USB 2.0 with embedded PHY and 128 KB flash make it a strong fit for USB HID devices such as keyboards, mice, game controllers, and custom input surfaces. The integrated PHY eliminates the external transceiver, BOM cost, and PCB area that competing MCUs require. With 16 KB SRAM, USB HID report buffers fit comfortably, and the 48 MHz Cortex-M0+ core drives typical HID polling rates above 1000 Hz with significant headroom for capacitive touch via the Peripheral Touch Controller.
Recommended
Industrial Sensor Node
The ATSAMD21G17D-MU serves industrial 4-20 mA loop-powered sensor nodes thanks to its 1.62V-3.63V wide supply range, integrated 12-bit ADC with up to 20 channels, and SleepWalking peripherals that wake the CPU only on real events. Six SERCOM channels enable simultaneous I2C sensor buses (temperature, pressure, gas) plus SPI connectivity to a digital front-end. Industrial -40C to +85C temperature rating and Functional Safety documentation support safety-critical installations per Microchip product family datasheet.
Recommended
Smart Home / IoT Hub
The ATSAMD21G17D-MU fits smart-home sensor hubs where 128 KB flash stores application code plus an OTA staging partition in the 4 KB RWW section. Six SERCOM interfaces handle multiple wireless co-processors (Bluetooth, LoRa, Zigbee) plus local I2C sensors. Per the Microchip SAM D21 datasheet, sleep current below 5 uA with RTC running supports years of battery life on a coin cell. Pinout 2 (SERCOM remap) and Peripheral Touch Controller enable touch-button UI on the hub front panel.
Recommended
Wearable Fitness Device
The ATSAMD21G17D-MU suits wearable fitness bands thanks to its compact 48-QFN (7x7 mm) footprint, low active current (per datasheet roughly 70 uA/MHz with the DC-DC converter active), and Peripheral Touch Controller for swipe-based UI. The 12-bit ADC reads heart-rate and SpO2 analog front-ends, while SERCOM channels drive I2C accelerometer/gyroscope IMUs. The integrated DC-DC converter at low VIN extends battery life on small LiPo cells common in wearables.
Recommended
Smart Meter / Energy Monitor
The ATSAMD21G17D-MU is widely used in single-phase smart electricity meters where its 12-bit ADC with up to 20 channels samples voltage and current CTs simultaneously. The 128 KB flash stores metering firmware plus DLMS/COSEM or Modbus communication stacks, and the Functional Safety documentation supports IEC 61508 SIL-2 system designs. Wide -40C to +85C industrial temperature and integrated RTC with calendar mode simplify energy-time-of-use metering algorithms.
Recommended
Capacitive Touch User Interface
The ATSAMD21G17D-MU integrates Microchip's Peripheral Touch Controller (PTC) supporting buttons, sliders, and wheels with hardware-driven acquisition, freeing CPU cycles for higher-level UI logic. With up to 20 ADC channels and event-driven peripheral interconnect, multi-touch sliders with LED feedback are feasible. The 48-QFN package supports small front-panel PCBs, and the 128 KB flash stores touch-tuning parameters plus the application layer.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD21G17D-MU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD21G17A-MFT | ATSAMD21G17A-AUT | ATSAMD21G18A-MU | ATSAMD21G17D-MF | ATSAMD21G17A-AFT | ATSAMD21G17A-MF |
|---|---|---|---|---|---|---|---|
| Package | 48-QFN (7x7) | 48-QFN (7x7) - same | 48-QFN (7x7) - same | 48-QFN (7x7) - same | 48-QFN (7x7) - same | 48-QFN (7x7) - same | 48-QFN (7x7) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 128 KB | 128 KB | 128 KB | 256 KB | 128 KB | 128 KB | 128 KB |
| SRAM | 16 KB | 16 KB | 16 KB | 32 KB | 16 KB | 16 KB | 16 KB |
| Silicon Revision | D (rev D) | A (rev A, errata fixes) | A (rev A, automotive) | A (rev A) | D (rev D) | A (rev A, automotive) | A (rev A) |
| Packaging Form | Tray | Tape & Reel | Tape & Reel | Tray | Tape & Reel | Tape & Reel | Tape & Reel |
| AEC-Q100 Qualified | No | No | Yes | No | No | Yes | No |
| Unit Price (qty 1, as of 2026-09-21) | $3.84 | $3.84 | $4.20 (est.) | $4.50 (est.) | $3.84 | $4.20 (est.) | $3.84 |
Key Differentiators
- Includes USB 2.0 Full-Speed with on-chip PHY in same 48-QFN (vs ATSAMD20G18A-MU)
- Functional Safety (FuSa) documentation support (vs ATSAMD21E17D-AF)
- Later 'A' silicon revision available as drop-in for errata-free firmware (vs ATSAMD21G17D-MF)
Design Notes
Estimated: at the maximum CPU frequency of 48 MHz with the DC-DC converter in high-efficiency mode, active current consumption is approximately 70 uA/MHz per the SAM D21 datasheet, giving roughly 3.4 mA core current plus peripheral contribution. The 48-QFN (7x7 mm) package thermal resistance theta_JA is approximately 33 C/W on a standard JEDEC 4-layer PCB. For most embedded workloads below 100 MHz-equivalent activity, self-heating is below 5 C above ambient and no external heatsink is required.
The 48-QFN (7x7 mm) exposed thermal pad (pin 49) MUST be soldered to a ground pad on the PCB for both thermal dissipation and electrical performance. Use at least 4 thermal vias (0.3 mm drill) under the EP to tie it to the inner ground plane. Place the 100 nF decoupling capacitor within 2 mm of each VDD pin (pins 9 and 30), plus a bulk 4.7 uF ceramic close to the EP. Keep the USB DP/DM traces (pins 14/15) at 90 ohm differential impedance and route them on the top layer only.
Common pitfalls with the ATSAMD21G17D-MU: (1) forgetting to configure the NMI pin (PA25) - leaving it floating can cause spurious interrupts; tie it through a 10 kohm resistor to VDD if unused. (2) USB DP/DM require 15 kohm pull-down resistors on each line for full-speed device detection; the internal pull-downs are insufficient. (3) The 128 KB flash layout uses a 4 KB RWW section - bootloader code must reside in the RWW area to support in-application updates without bricking the device.
Compliance Information
RoHS compliant per Microchip product page. AEC-Q100 qualified variants available as ATSAMD21G17A-AUT and ATSAMD21G17A-AFT. Functional Safety (FuSa) documentation package available for IEC 61508 SIL-2 system designs.
