ATMEGA8-16MU from Microchip Tech, in a VQFN-32-EP(5x5). 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	PD3	bidirectional	Port D bit 3, an I/O pin with internal pull-up whose alternate function is INT1 external interrupt input.
2	PD4	bidirectional	Port D bit 4, an I/O pin with internal pull-up whose alternate functions are XCK (USART clock) and T0 (timer clock input).
3	GND	power_in	Ground.
4	VCC	power_in	Digital supply voltage, 4.5V-5.5V for ATmega8 (16MHz grade).
5	GND	power_in	Ground.
6	VCC	power_in	Digital supply voltage, 4.5V-5.5V for ATmega8 (16MHz grade).
7	PB6	bidirectional	Port B bit 6, an I/O pin that, depending on clock fuse settings, is the input to the inverting oscillator amplifier (XTAL1) or TOSC1 for Timer/Counter2.
8	PB7	bidirectional	Port B bit 7, an I/O pin that, depending on clock fuse settings, is the output of the inverting oscillator amplifier (XTAL2) or TOSC2 for Timer/Counter2.
9	PD5	bidirectional	Port D bit 5, an I/O pin with internal pull-up whose alternate function is T1 (timer clock input).
10	PD6	bidirectional	Port D bit 6, an I/O pin with internal pull-up whose alternate function is AIN0 (analog comparator positive input).
11	PD7	bidirectional	Port D bit 7, an I/O pin with internal pull-up whose alternate function is AIN1 (analog comparator negative input).
12	PB0	bidirectional	Port B bit 0, an I/O pin with internal pull-up whose alternate function is ICP1 (Timer/Counter1 input capture).
13	PB1	bidirectional	Port B bit 1, an I/O pin with internal pull-up whose alternate function is OC1A (Timer/Counter1 output compare A).
14	PB2	bidirectional	Port B bit 2, an I/O pin with internal pull-up whose alternate functions are SS (SPI slave select) and OC1B.
15	PB3	bidirectional	Port B bit 3, an I/O pin with internal pull-up whose alternate functions are MOSI (SPI) and OC2.
16	PB4	bidirectional	Port B bit 4, an I/O pin with internal pull-up whose alternate function is MISO (SPI).
17	PB5	bidirectional	Port B bit 5, an I/O pin with internal pull-up whose alternate function is SCK (SPI clock).
18	AVCC	power_in	Analog supply voltage pin for the ADC section.
19	ADC6	input	ADC input channel 6, available in the TQFP and QFN/MLF packages.
20	AREF	input	Analog reference pin for the A/D converter.
21	GND	power_in	Ground.
22	ADC7	input	ADC input channel 7, available in the TQFP and QFN/MLF packages.
23	PC0	bidirectional	Port C bit 0, an I/O pin with internal pull-up whose alternate function is ADC0 input.
24	PC1	bidirectional	Port C bit 1, an I/O pin with internal pull-up whose alternate function is ADC1 input.
25	PC2	bidirectional	Port C bit 2, an I/O pin with internal pull-up whose alternate function is ADC2 input.
26	PC3	bidirectional	Port C bit 3, an I/O pin with internal pull-up whose alternate function is ADC3 input.
27	PC4	bidirectional	Port C bit 4, an I/O pin with internal pull-up whose alternate functions are ADC4 input and SDA (two-wire interface data).
28	PC5	bidirectional	Port C bit 5, an I/O pin with internal pull-up whose alternate functions are ADC5 input and SCL (two-wire interface clock).
29	PC6	bidirectional	Active-low RESET input (a low level longer than the minimum pulse length generates a reset) or, if the RSTDISBL fuse is programmed, an I/O pin with electrical characteristics differing from other Port C pins.
30	PD0	bidirectional	Port D bit 0, an I/O pin with internal pull-up whose alternate function is RXD (USART receive).
31	PD1	bidirectional	Port D bit 1, an I/O pin with internal pull-up whose alternate function is TXD (USART transmit).
32	PD2	bidirectional	Port D bit 2, an I/O pin with internal pull-up whose alternate function is INT0 external interrupt input.
33	EP	passive	Exposed pad (from the footprint; not named in the datasheet pin table).

Key specifications

Parameter	Value
Manufacturer	Microchip Tech
Package	VQFN-32-EP(5x5)
Category	Embedded Processors & Controllers
Pins	33

Electrical characteristics

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

Parameter	Symbol	Min	Max	Unit	Conditions	Page
Operating supply voltage	VCC	4.5	5.5	V	ATmega8, 16MHz speed grade	6
Clock frequency (speed grade)		0	16	MHz	ATmega8, 4.5 - 5.5V	1
Operating temperature range		-40	85	C	Industrial, ATmega8-16MU, 32M1-A	6

CAD (KiCad official)

Symbol: ATMEGA8-16MU
Footprint: Package_DFN_QFN:QFN-32-1EP_5x5mm_P0.5mm_EP3.3x3.3mm
3D model: VQFN-32-EP(5x5) (KiCad packages3D, STEP)
3D model files: atmega8-16mu-etched.step / atmega8-16mu-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); atmega8-16mu.step / atmega8-16mu.glb are the bare package body.

Provenance

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

Datasheet: Microchip Tech datasheet (12 pp, sha256 77fb79962ad7d629, retrieved 2026-10-31, 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

ATMEGA8-16MU

Verified ATMEGA8-16MU

Verification log 1 record

3D Model

Symbol & Footprint

Schematic Symbol

PCB Footprint

Datasheet

README