ATMEGA168P-20AU from Microchip Tech, in a TQFP-32(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	PD3	bidirectional	Port D bit 3 is a bidirectional I/O pin with internal pull-ups, also serving as external interrupt INT1, OC2B output compare output, and PCINT19 pin-change interrupt source.
2	PD4	bidirectional	Port D bit 4 is a bidirectional I/O pin with internal pull-ups, also serving as USART external clock XCK, Timer/Counter0 external counter input T0, and PCINT20.
3	GND	power_in	Ground.
4	VCC	power_in	Digital supply voltage.
5	GND	power_in	Ground.
6	VCC	power_in	Digital supply voltage.
7	PB6	input	Depending on clock fuse settings, PB6 is the input to the inverting oscillator amplifier (XTAL1) or Timer Oscillator pin 1, and when used as a clock pin it cannot be used as an I/O pin.
8	PB7	output	Depending on clock fuse settings, PB7 is the output of the inverting oscillator amplifier (XTAL2) or Timer Oscillator pin 2, and when used as a clock pin it cannot be used as an I/O pin.
9	PD5	bidirectional	Port D bit 5 is a bidirectional I/O pin with internal pull-ups, also serving as Timer/Counter1 external counter input T1, OC0B output compare output, and PCINT21.
10	PD6	bidirectional	Port D bit 6 is a bidirectional I/O pin with internal pull-ups, also serving as Analog Comparator positive input AIN0, OC0A output compare output, and PCINT22; configure as input with pull-up off when used as AIN0.
11	PD7	bidirectional	Port D bit 7 is a bidirectional I/O pin with internal pull-ups, also serving as Analog Comparator negative input AIN1 and PCINT23; configure as input with pull-up off when used as AIN1.
12	PB0	bidirectional	Port B bit 0 is a bidirectional I/O pin with internal pull-ups, also serving as Timer/Counter1 input capture ICP1, divided system clock output CLKO, and PCINT0.
13	PB1 (OC1A/PCINT1)	bidirectional	Port B bit 1 is a bidirectional I/O pin with internal pull-ups, also serving as Timer/Counter1 output compare output OC1A and PCINT1.
14	PB2 (SS/OC1B/PCINT2)	bidirectional	Port B bit 2 is a bidirectional I/O pin with internal pull-ups, also serving as SPI slave select SS, Timer/Counter1 output compare output OC1B, and PCINT2.
15	PB3 (MOSI/OC2A/PCINT3)	bidirectional	Port B bit 3 is a bidirectional I/O pin with internal pull-ups, also serving as SPI master output/slave input MOSI, Timer/Counter2 output compare output OC2A, and PCINT3.
16	PB4 (MISO/PCINT4)	bidirectional	Port B bit 4 is a bidirectional I/O pin with internal pull-ups, also serving as SPI master input/slave output MISO and PCINT4.
17	PB5 (SCK/PCINT5)	bidirectional	Port B bit 5 is a bidirectional I/O pin with internal pull-ups, also serving as SPI clock SCK and PCINT5.
18	AVCC	power_in	Supply voltage pin for the A/D Converter, PC3:0 and ADC7:6; it should be externally connected to VCC even if the ADC is not used, and through a low-pass filter if the ADC is used.
19	ADC6	input	Analog input channel 6 of the 10-bit A/D converter (TQFP and QFN/MLF packages only), powered from the analog supply.
20	AREF	input	Analog reference pin for the A/D Converter.
21	GND	power_in	Ground.
22	ADC7	input	Analog input channel 7 of the 10-bit A/D converter (TQFP and QFN/MLF packages only), powered from the analog supply.
23	PC0 (ADC0/PCINT8)	bidirectional	Port C bit 0 is a bidirectional I/O pin with internal pull-ups (Port C is 7-bit), also serving as ADC input channel 0 using analog power and PCINT8.
24	PC1 (ADC1/PCINT9)	bidirectional	Port C bit 1 is a bidirectional I/O pin with internal pull-ups, also serving as ADC input channel 1 using analog power and PCINT9.
25	PC2 (ADC2/PCINT10)	bidirectional	Port C bit 2 is a bidirectional I/O pin with internal pull-ups, also serving as ADC input channel 2 using analog power and PCINT10.
26	PC3 (ADC3/PCINT11)	bidirectional	Port C bit 3 is a bidirectional I/O pin with internal pull-ups, also serving as ADC input channel 3 using analog power and PCINT11.
27	PC4 (ADC4/SDA/PCINT12)	bidirectional	Port C bit 4 is a bidirectional I/O pin with internal pull-ups, also serving as 2-wire serial interface data SDA, ADC input channel 4 using digital power, and PCINT12.
28	PC5 (ADC5/SCL/PCINT13)	bidirectional	Port C bit 5 is a bidirectional I/O pin with internal pull-ups, also serving as 2-wire serial interface clock SCL, ADC input channel 5 using digital power, and PCINT13.
29	PC6 (RESET/PCINT14)	input	When the RSTDISBL fuse is unprogrammed this pin is a Reset input, and a low level longer than the minimum pulse length (Table 29-3) generates a Reset while shorter pulses are not ensured to reset; when RSTDISBL is programmed it is an I/O pin with electrical characteristics differing from other Port C pins.
30	PD0 (RXD/PCINT16)	bidirectional	Port D bit 0 is a bidirectional I/O pin with internal pull-ups, serving as USART receive data input RXD when the USART receiver is enabled, and PCINT16.
31	PD1 (TXD/PCINT17)	bidirectional	Port D bit 1 is a bidirectional I/O pin with internal pull-ups, serving as USART transmit data output TXD when the USART transmitter is enabled, and PCINT17.
32	PD2 (INT0/PCINT18)	bidirectional	Port D bit 2 is a bidirectional I/O pin with internal pull-ups, also serving as external interrupt source INT0 and PCINT18.

Key specifications

Parameter	Value
Manufacturer	Microchip Tech
Package	TQFP-32(7x7)
Category	Embedded Processors & Controllers
Pins	32

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 Temperature		-55		125	°C		324
Storage Temperature		-65		150	°C		324
Voltage on any pin except RESET with respect to Ground (printed max VCC+0.5 V)		-0.5			V		324
Voltage on RESET with respect to Ground		-0.5		13	V		324
Maximum Operating Voltage				6	V		324
DC Current per I/O Pin				40	mA		324
DC Current VCC and GND Pins				200	mA		324
Supply voltage (20 MHz speed grade)	VCC	2.7		5.5	V	ATmega168P-20AU speed grade 20 MHz	420
Operating temperature (industrial range)		-40		85	°C	Industrial operational range	420
Oscillator Frequency (external clock drive)	1/tCLCL	0		20	MHz	VCC = 4.5-5.5V	329
Oscillator Frequency (external clock drive)	1/tCLCL	0		10	MHz	VCC = 2.7-5.5V	329
Factory-calibrated internal RC oscillator accuracy (8.0 MHz)		-10		10	%	8.0 MHz, VCC 3V, 25C	329
User-calibrated internal RC oscillator accuracy		-1		1	%	7.3-8.1 MHz, VCC 2.7-5.5V, -40C to 85C	329
Power-on Reset Threshold Voltage (rising)	VPOT	1.1	1.4	1.6	V		330
Power-on Reset Threshold Voltage (falling)	VPOT	0.6	1.3	1.6	V		330
RESET Pin Threshold Voltage (printed as multiple of VCC)	VRST	0.2		0.9	xVCC		330
Minimum pulse width on RESET Pin	tRST	2.5			µs		330
Min Pulse Width on Brown-out Reset	tBOD	2			µs		330
Bandgap reference voltage	VBG	1	1.1	1.2	V	VCC=2.7, TA=25°C	330
Brown-out trigger level VBOT (BODLEVEL 110)	VBOT	1.7	1.8	2	V	BODLEVEL 2:0 = 110	330
Brown-out trigger level VBOT (BODLEVEL 101)	VBOT	2.5	2.7	2.9	V	BODLEVEL 2:0 = 101	330
Brown-out trigger level VBOT (BODLEVEL 100)	VBOT	4.1	4.3	4.5	V	BODLEVEL 2:0 = 100	330
Input Low Voltage, except XTAL1 and RESET pin (printed as multiple of VCC)	VIL			0.3	xVCC	VCC = 2.4V - 5.5V	324
Input High Voltage, except XTAL1 and RESET pins (printed as multiple of VCC)	VIH	0.6			xVCC	VCC = 2.4V - 5.5V	324
Input Low Voltage, XTAL1 pin (printed as multiple of VCC)	VIL1			0.1	xVCC	VCC = 1.8V - 5.5V	324
Input High Voltage, XTAL1 pin (printed as multiple of VCC)	VIH1	0.7			xVCC	VCC = 2.4V - 5.5V	324
Input Low Voltage, RESET pin (printed as multiple of VCC)	VIL2			0.1	xVCC	VCC = 1.8V - 5.5V	324
Input High Voltage, RESET pin (printed as multiple of VCC)	VIH2	0.9			xVCC	VCC = 1.8V - 5.5V	324
Input Low Voltage, RESET pin as I/O (printed as multiple of VCC)	VIL3			0.3	xVCC	VCC = 2.4V - 5.5V	324
Input High Voltage, RESET pin as I/O (printed as multiple of VCC)	VIH3	0.6			xVCC	VCC = 2.4V - 5.5V	324
Output Low Voltage except RESET pin	VOL			0.9	V	IOL = 20 mA, VCC = 5V	324
Output Low Voltage except RESET pin	VOL			0.6	V	IOL = 10 mA, VCC = 3V	324
Output High Voltage except Reset pin	VOH	4.2			V	IOH = -20 mA, VCC = 5V	324
Output High Voltage except Reset pin	VOH	2.3			V	IOH = -10 mA, VCC = 3V	324
Input Leakage Current I/O Pin (absolute value)	IIL			1	µA	VCC = 5.5V, pin low	324
Power Supply Current, Active	ICC		0.3	0.5	mA	Active 1 MHz, VCC = 2V	327
Power Supply Current, Active	ICC		1.8	2.5	mA	Active 4 MHz, VCC = 3V	327
Power Supply Current, Active	ICC		6.7	9	mA	Active 8 MHz, VCC = 5V	327
Power Supply Current, Idle	ICC		0.06	0.15	mA	Idle 1 MHz, VCC = 2V	327
Power Supply Current, Idle	ICC		0.4	0.7	mA	Idle 4 MHz, VCC = 3V	327
Power Supply Current, Idle	ICC		1.7	2.7	mA	Idle 8 MHz, VCC = 5V	327
Power Supply Current, Power-save	ICC		0.8	1.6	µA	32 kHz TOSC enabled, VCC = 1.8V	327
Power Supply Current, Power-save	ICC		0.9	2.6	µA	32 kHz TOSC enabled, VCC = 3V	327
Power Supply Current, Power-down	ICC		4.6	8	µA	WDT enabled, VCC = 3V	327
Power Supply Current, Power-down	ICC		0.1	2	µA	WDT disabled, VCC = 3V	327
2-wire Input Low-voltage (printed as multiple of VCC)	VIL			0.3	xVCC		333
2-wire Input High-voltage (printed as multiple of VCC)	VIH	0.7			xVCC		333
2-wire Output Low-voltage	VOL			0.4	V	3 mA sink current	333
Rise time for both SDA and SCL	tr			300	ns		333
Output fall time from VIHmin to VILmax	tof			250	ns	10 pF < Cb < 400 pF	333
Input current each I/O pin	Ii	-10		10	µA	0.1VCC < Vi < 0.9VCC	333
Capacitance for each I/O pin	Ci			10	pF		333
SCL Clock Frequency	fSCL	0		400	kHz	fCK > max(16fSCL, 250kHz)	333
Data hold time	tHD;DAT	0		3.45	µs	fSCL ≤ 100 kHz	333
Data setup time	tSU;DAT	250			ns	fSCL ≤ 100 kHz	333

CAD (KiCad official)

Symbol: ATMEGA168P-20AU
Footprint: Package_QFP:TQFP-32_7x7mm_P0.8mm
3D model: TQFP-32(7x7) (KiCad packages3D, STEP)
3D model files: atmega168p-20au-etched.step / atmega168p-20au-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); atmega168p-20au.step / atmega168p-20au.glb are the bare package body.

Provenance

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

Datasheet: Microchip Tech datasheet (436 pp, sha256 aab081a362918ab9, retrieved 2026-10-30, tier: manufacturer)
Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-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

ATMEGA168P-20AU

Changed since verified ATMEGA168P-20AU

Verification log 1 record

3D Model

Symbol & Footprint

Schematic Symbol

PCB Footprint

Datasheet

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