ATSAMD21G17D-MU from Microchip Tech, in a QFN-48-EP(7x7). Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	PA00	bidirectional	General-purpose I/O on VDDANA supply with EXTINT[0], SERCOM1/PAD[0] and TCC2/WO[0]; also XIN32 for the 32 kHz crystal oscillator.
2	PA01	bidirectional	General-purpose I/O on VDDANA supply with EXTINT[1], SERCOM1/PAD[1] and TCC2/WO[1]; also XOUT32 for the 32 kHz crystal oscillator.
3	PA02	bidirectional	General-purpose I/O on VDDANA supply with EXTINT[2], ADC AIN[0], PTC Y[0] and DAC VOUT.
4	PA03	bidirectional	General-purpose I/O on VDDANA supply with EXTINT[3], ADC/DAC external reference VREFA, ADC AIN[1] and PTC Y[1].
5	GNDANA	power_in	Ground for the analog supply domain (VDDANA).
6	VDDANA	power_in	Analog supply input powering the analog I/O pins; operating voltage for SAM D21 is 1.62V to 3.63V.
7	PB08	bidirectional	General-purpose I/O on VDDANA supply with EXTINT[8], ADC AIN[2], PTC Y[14], SERCOM4/PAD[0] and TC4/WO[0].
8	PB09	bidirectional	General-purpose I/O on VDDANA supply with EXTINT[9], ADC AIN[3], PTC Y[15], SERCOM4/PAD[1] and TC4/WO[1].
9	PA04	bidirectional	General-purpose I/O on VDDANA supply with EXTINT[4], ADC external reference VREFB, ADC AIN[4], AC AIN[0], PTC Y[2], SERCOM0/PAD[0] and TCC0/WO[0].
10	PA05	bidirectional	General-purpose I/O on VDDANA supply with EXTINT[5], ADC AIN[5], AC AIN[1], PTC Y[3], SERCOM0/PAD[1] and TCC0/WO[1].
11	PA06	bidirectional	General-purpose I/O on VDDANA supply with EXTINT[6], ADC AIN[6], AC AIN[2], PTC Y[4], SERCOM0/PAD[2] and TCC1/WO[0].
12	PA07	bidirectional	General-purpose I/O on VDDANA supply with EXTINT[7], ADC AIN[7], AC AIN[3], PTC Y[5], SERCOM0/PAD[3] and TCC1/WO[1].
13	PA08	bidirectional	General-purpose I/O on VDDIO supply with NMI, ADC AIN[16], PTC X[0], SERCOM0/PAD[0] or SERCOM2/PAD[0], and I2C capability.
14	PA09	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[9], ADC AIN[17], PTC X[1], SERCOM0/PAD[1] or SERCOM2/PAD[1], and I2C capability.
15	PA10	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[10], ADC AIN[18], PTC X[2], SERCOM0/PAD[2] or SERCOM2/PAD[2], and TCC1/WO[0].
16	PA11	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[11], ADC AIN[19], PTC X[3], SERCOM0/PAD[3] or SERCOM2/PAD[3], and TCC1/WO[1].
17	VDDIO	power_in	Digital I/O supply input for the I/O pins; operating voltage for SAM D21 is 1.62V to 3.63V.
18	GND	power_in	Digital ground.
19	PB10	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[10], SERCOM4/PAD[2], TC5/WO[0] and TCC0/WO[4].
20	PB11	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[11], SERCOM4/PAD[3], TC5/WO[1] and TCC0/WO[5].
21	PA12	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[12], SERCOM2/PAD[0] or SERCOM4/PAD[0], TCC2/WO[0], AC/CMP[0], and I2C capability.
22	PA13	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[13], SERCOM2/PAD[1] or SERCOM4/PAD[1], TCC2/WO[1], AC/CMP[1], and I2C capability.
23	PA14	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[14], SERCOM2/PAD[2] or SERCOM4/PAD[2], TC3/WO[0] and GCLK_IO[0]; also XIN for the crystal oscillator.
24	PA15	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[15], SERCOM2/PAD[3] or SERCOM4/PAD[3], TC3/WO[1] and GCLK_IO[1]; also XOUT for the crystal oscillator.
25	PA16	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[0], PTC X[4], SERCOM1/PAD[0] or SERCOM3/PAD[0], TCC2/WO[0], GCLK_IO[2], and I2C capability.
26	PA17	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[1], PTC X[5], SERCOM1/PAD[1] or SERCOM3/PAD[1], TCC2/WO[1], GCLK_IO[3], and I2C capability.
27	PA18	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[2], PTC X[6], SERCOM1/PAD[2] or SERCOM3/PAD[2], TC3/WO[0], TCC0/WO[2] and AC/CMP[0].
28	PA19	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[3], PTC X[7], SERCOM1/PAD[3] or SERCOM3/PAD[3], TC3/WO[1], TCC0/WO[3] and AC/CMP[1].
29	PA20	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[4], PTC X[8], SERCOM5/PAD[2] or SERCOM3/PAD[2], TC7/WO[0] and GCLK_IO[4].
30	PA21	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[5], PTC X[9], SERCOM5/PAD[3] or SERCOM3/PAD[3], TC7/WO[1] and GCLK_IO[5].
31	PA22	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[6], PTC X[10], SERCOM3/PAD[0] or SERCOM5/PAD[0], TC4/WO[0], GCLK_IO[6], and I2C capability.
32	PA23	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[7], PTC X[11], SERCOM3/PAD[1] or SERCOM5/PAD[1], TC4/WO[1], USB SOF 1kHz, GCLK_IO[7], and I2C capability.
33	PA24	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[12], SERCOM3/PAD[2] or SERCOM5/PAD[2], TC5/WO[0] and USB DM; datasheet recommends enabling a pull-up if unconnected, and it has no drive strength option.
34	PA25	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[13], SERCOM3/PAD[3] or SERCOM5/PAD[3], TC5/WO[1] and USB DP; datasheet recommends enabling a pull-up if unconnected, and it has no drive strength option.
35	GND	power_in	Digital ground.
36	VDDIO	power_in	Digital I/O supply input for the I/O pins; operating voltage for SAM D21 is 1.62V to 3.63V.
37	PB22	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[6], SERCOM5/PAD[2], TC7/WO[0], TCC3/WO[0] and GCLK_IO[0].
38	PB23	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[7], SERCOM5/PAD[3], TC7/WO[1], TCC3/WO[1] and GCLK_IO[1].
39	PA27	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[15], TCC3/WO[6] and GCLK_IO[0].
40	RESET	input	External reset input, active low.
41	PA28	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[8], TCC3/WO[7] and GCLK_IO[0].
42	GND	power_in	Digital ground.
43	VDDCORE	power_out	Regulated output supply for the core.
44	VDDIN	power_in	Input supply to the device and internal voltage regulator; operating voltage for SAM D21 is 1.62V to 3.63V.
45	PA30	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[10], SERCOM1/PAD[2], TCC1/WO[0], TCC3/WO[4], and SWCLK for serial wire debug.
46	PA31	bidirectional	General-purpose I/O on VDDIO supply with EXTINT[11], SERCOM1/PAD[3], TCC1/WO[1], TCC3/WO[5], and SWDIO for serial wire debug (active only when a debugger is present).
47	PB02	bidirectional	General-purpose I/O on VDDANA supply with EXTINT[2], ADC AIN[10], PTC Y[8], SERCOM5/PAD[0], TC6/WO[0] and TCC3/WO[2].
48	PB03	bidirectional	General-purpose I/O on VDDANA supply with EXTINT[3], ADC AIN[11], PTC Y[9], SERCOM5/PAD[1], TC6/WO[1] and TCC3/WO[3].
49	EP	passive	Exposed pad (from the footprint; not named in the datasheet pin table).

Key specifications

Parameter	Value
Manufacturer	Microchip Tech
Package	QFN-48-EP(7x7)
Category	Embedded Processors & Controllers
Pins	49

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter	Symbol	Min	Typ	Max	Unit	Conditions	Page
Operating supply voltage (SAM D21)	VDD	1.62		3.63	V	SAM D21 operating voltage; same voltage on VDDIN, VDDIO and VDDANA	2
VDDIO supply voltage	VDDIO	1.62		3.63	V	Powers I/O lines, OSC8M and XOSC	35
VDDIN supply voltage	VDDIN	1.62		3.63	V	Powers I/O lines and the internal regulator	35
VDDANA supply voltage	VDDANA	1.62		3.63	V	Powers I/O lines and ADC, AC, DAC, PTC, OSCULP32K, OSC32K, XOSC32K	35
VDDCORE internal regulated voltage	VDDCORE		1.2		V	Internal regulated voltage output	35
Operating temperature (U grade)		-40		85	°C	Package grade U = -40 - 85°C Matte Sn plating	16
CPU clock frequency				48	MHz	Arm Cortex-M0+ CPU running at up to 48 MHz	1

Materials and finish

As the datasheet states them (page.json metadata.appearance; the 3D model's colours follow it).

Part	Material	Colour / plating	Datasheet says	Page
contacts		tin	including indium tin oxide (ITO) sensor grids. The PTC requires one pin per X-line and one pin per Y-line. In the self-capacitance mode, the PTC requires only one pin (Y-line) for each touch sensor.	859

CAD (KiCad official)

Symbol: ATSAMD21G17D-MU
Footprint: Package_DFN_QFN:QFN-48-1EP_7x7mm_P0.5mm_EP5.15x5.15mm
3D model: QFN-48-EP(7x7) (KiCad packages3D, STEP)
3D model files: atsamd21g17d-mu-etched.step / atsamd21g17d-mu-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); atsamd21g17d-mu.step / atsamd21g17d-mu.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: Microchip Tech datasheet (1148 pp, sha256 18ca1ccab5aa330f, retrieved 2026-10-30, tier: manufacturer)
Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-sonnet-5-5 (text), consensus claude-sonnet-5-5 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF

ATSAMD21G17D-MU

Verified ATSAMD21G17D-MU

Verification log 1 record

3D Model

Symbol & Footprint

Schematic Symbol

PCB Footprint

Datasheet

README