ATMEGA164P-20AUR from Microchip Tech, in a TQFP-44(10x10). 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	PB5	bidirectional	Port B bit 5, 8-bit bi-directional I/O with internal pull-up; alternate functions MOSI (SPI master data out/slave data in) and PCINT13.
2	PB6	bidirectional	Port B bit 6, bi-directional I/O with internal pull-up; alternate functions MISO (SPI master data in/slave data out) and PCINT14.
3	PB7	bidirectional	Port B bit 7, bi-directional I/O with internal pull-up; alternate functions SCK (SPI clock) and PCINT15.
4	RESET	input	Reset input; a low level longer than the minimum pulse length generates a reset even if the clock is not running.
5	VCC	power_in	Digital supply voltage.
6	GND	power_in	Ground.
7	XTAL2	output	Output from the inverting oscillator amplifier.
8	XTAL1	input	Input to the inverting oscillator amplifier and input to the internal clock operating circuit.
9	PD0	bidirectional	Port D bit 0, bi-directional I/O with internal pull-up; alternate functions RXD0 (USART0 receive) and PCINT24.
10	PD1	bidirectional	Port D bit 1, bi-directional I/O with internal pull-up; alternate functions TXD0 (USART0 transmit) and PCINT25.
11	PD2	bidirectional	Port D bit 2, bi-directional I/O with internal pull-up; alternate functions INT0, RXD1 (USART1 receive) and PCINT26.
12	PD3	bidirectional	Port D bit 3, bi-directional I/O with internal pull-up; alternate functions INT1, TXD1 (USART1 transmit) and PCINT27.
13	PD4	bidirectional	Port D bit 4, bi-directional I/O with internal pull-up; alternate functions OC1B, XCK1 (USART1 external clock) and PCINT28.
14	PD5	bidirectional	Port D bit 5, bi-directional I/O with internal pull-up; alternate functions OC1A and PCINT29.
15	PD6	bidirectional	Port D bit 6, bi-directional I/O with internal pull-up; alternate functions ICP1 (Timer/Counter1 input capture), OC2B and PCINT30.
16	PD7	bidirectional	Port D bit 7, bi-directional I/O with internal pull-up; alternate functions OC2A and PCINT31.
17	VCC	power_in	Digital supply voltage.
18	GND	power_in	Ground.
19	PC0	bidirectional	Port C bit 0, bi-directional I/O with internal pull-up; alternate functions SCL (2-wire serial clock) and PCINT16.
20	PC1	bidirectional	Port C bit 1, bi-directional I/O with internal pull-up; alternate functions SDA (2-wire serial data) and PCINT17.
21	PC2	bidirectional	Port C bit 2, bi-directional I/O with internal pull-up; alternate functions TCK (JTAG) and PCINT18.
22	PC3	bidirectional	Port C bit 3, bi-directional I/O with internal pull-up; alternate functions TMS (JTAG) and PCINT19.
23	PC4	bidirectional	Port C bit 4, bi-directional I/O with internal pull-up; alternate functions TDO (JTAG) and PCINT20.
24	PC5	bidirectional	Port C bit 5, bi-directional I/O with internal pull-up; alternate functions TDI (JTAG) and PCINT21.
25	PC6	bidirectional	Port C bit 6, bi-directional I/O with internal pull-up; alternate functions TOSC1 and PCINT22.
26	PC7	bidirectional	Port C bit 7, bi-directional I/O with internal pull-up; alternate functions TOSC2 and PCINT23.
27	AVCC	power_in	Supply voltage pin for Port A and the ADC; it must be connected to VCC even if the ADC is not used, through a low-pass filter if the ADC is used.
28	GND	power_in	Ground.
29	AREF	input	Analog reference pin for the Analog-to-digital Converter.
30	PA7	bidirectional	Port A bit 7, bi-directional I/O with internal pull-up and ADC7 analog input; also PCINT7.
31	PA6	bidirectional	Port A bit 6, bi-directional I/O with internal pull-up and ADC6 analog input; also PCINT6.
32	PA5	bidirectional	Port A bit 5, bi-directional I/O with internal pull-up and ADC5 analog input; also PCINT5.
33	PA4	bidirectional	Port A bit 4, bi-directional I/O with internal pull-up and ADC4 analog input; also PCINT4.
34	PA3	bidirectional	Port A bit 3, bi-directional I/O with internal pull-up and ADC3 analog input; also PCINT3.
35	PA2	bidirectional	Port A bit 2, bi-directional I/O with internal pull-up and ADC2 analog input; also PCINT2.
36	PA1	bidirectional	Port A bit 1, bi-directional I/O with internal pull-up and ADC1 analog input; also PCINT1.
37	PA0	bidirectional	Port A bit 0, bi-directional I/O with internal pull-up and ADC0 analog input; also PCINT0.
38	VCC	power_in	Digital supply voltage.
39	GND	power_in	Ground.
40	PB0	bidirectional	Port B bit 0, bi-directional I/O with internal pull-up; alternate functions T0 (Timer/Counter0 external input), XCK0 (USART0 external clock) and PCINT8.
41	PB1	bidirectional	Port B bit 1, bi-directional I/O with internal pull-up; alternate functions T1 (Timer/Counter1 external input), CLKO (divided system clock output) and PCINT9.
42	PB2	bidirectional	Port B bit 2, bi-directional I/O with internal pull-up; alternate functions AIN0 (analog comparator positive input), INT2 and PCINT10.
43	PB3	bidirectional	Port B bit 3, bi-directional I/O with internal pull-up; alternate functions AIN1 (analog comparator negative input), OC0A and PCINT11.
44	PB4	bidirectional	Port B bit 4, bi-directional I/O with internal pull-up; alternate functions SS (SPI slave select input), OC0B and PCINT12.

Key specifications

Parameter	Value
Manufacturer	Microchip Tech
Package	TQFP-44(10x10)
Category	Embedded Processors & Controllers
Pins	44

Electrical characteristics

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

Parameter	Symbol	Min	Typ	Max	Unit	Conditions	Page
Output Low Voltage	VOL			0.9	V	IOL = 20 mA, VCC = 5V	322
Output Low Voltage	VOL			0.6	V	IOL = 10 mA, VCC = 3V	322
Output High Voltage	VOH	4.2			V	IOH = -20 mA, VCC = 5V	322
Output High Voltage	VOH	2.3			V	IOH = -10 mA, VCC = 3V	322
Input Leakage Current I/O Pin (pin low)	IIL			1	µA	VCC = 5.5V, pin low (absolute value)	322
Input Leakage Current I/O Pin (pin high)	IIH			1	µA	VCC = 5.5V, pin high (absolute value)	322
Reset Pull-up Resistor	RRST	30		60	kΩ		322
I/O Pin Pull-up Resistor	RPU	20		50	kΩ		322
Analog Comparator Input Offset Voltage	VACIO			40	mV	VCC = 5V, Vin = VCC/2	323
Analog Comparator Input Leakage Current	IACLK	-50		50	nA	VCC = 5V, Vin = VCC/2	323
Analog Comparator Propagation Delay	tACID			750	ns	VCC = 2.7V	323
Analog Comparator Propagation Delay	tACID			500	ns	VCC = 4.0V	323
Power Supply Current, Active	ICC		0.4	0.5	mA	Active 1 MHz, VCC = 2V	324
Power Supply Current, Active	ICC		2.1	2.7	mA	Active 4 MHz, VCC = 3V	324
Power Supply Current, Active	ICC		7.4	9	mA	Active 8 MHz, VCC = 5V	324
Power Supply Current, Idle	ICC		0.1	0.15	mA	Idle 1 MHz, VCC = 2V	324
Power Supply Current, Idle	ICC		0.5	0.7	mA	Idle 4 MHz, VCC = 3V	324
Power Supply Current, Idle	ICC		1.9	5	mA	Idle 8 MHz, VCC = 5V	324
Power Supply Current, Power-down mode	ICC		4.3	8	µA	WDT enabled, VCC = 3V	324
Power Supply Current, Power-down mode	ICC		0.2	2	µA	WDT disabled, VCC = 3V	324
Voltage on RESET with respect to Ground		-0.5		13	V	with respect to Ground	322
Operating Temperature		-55		125	°C		322
Storage Temperature		-65		150	°C		322
DC Current per I/O Pin				40	mA		322

CAD (KiCad official)

Symbol: ATMEGA164P-20AUR
Footprint: Package_QFP:TQFP-44_10x10mm_P0.8mm
3D model: TQFP-44(10x10) (KiCad packages3D, STEP)
3D model files: atmega164p-20aur-etched.step / atmega164p-20aur-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); atmega164p-20aur.step / atmega164p-20aur.glb are the bare package body.

Provenance

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

Datasheet: Microchip Tech datasheet (496 pp, sha256 5edda0efd505127f, retrieved 2026-11-05, tier: lcsc)
Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-sonnet-5-5 (text+vision), consensus claude-opus-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

ATMEGA164P-20AUR

Verified ATMEGA164P-20AUR

Verification log 1 record

3D Model

Symbol & Footprint

Schematic Symbol

PCB Footprint

Datasheet

README