ATMEGA88PA-AU from Microchip, in a TQFP-32(7x7). Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	PD3/PCINT19/OC2B/INT1	bidirectional	Port D bit 3. Alt: external interrupt INT1, Timer/Counter2 compare match B output OC2B, pin-change interrupt PCINT19.
2	PD4/PCINT20/XCK/T0	bidirectional	Port D bit 4. Alt: USART external clock XCK, Timer/Counter0 external counter input T0, pin-change interrupt PCINT20.
3	GND	power_in	Digital ground.
4	VCC	power_in	Digital supply voltage, 1.8-5.5 V.
5	GND	power_in	Digital ground.
6	VCC	power_in	Digital supply voltage, 1.8-5.5 V.
7	PB6/PCINT6/XTAL1/TOSC1	bidirectional	Port B bit 6. Alt: crystal oscillator input XTAL1 or 32 kHz Timer2 oscillator input TOSC1, pin-change interrupt PCINT6. Function selected by CKSEL/AS2 fuses.
8	PB7/PCINT7/XTAL2/TOSC2	bidirectional	Port B bit 7. Alt: crystal oscillator output XTAL2 or 32 kHz Timer2 oscillator output TOSC2, pin-change interrupt PCINT7.
9	PD5/PCINT21/OC0B/T1	bidirectional	Port D bit 5. Alt: Timer/Counter0 compare match B output OC0B, Timer/Counter1 external counter input T1, pin-change interrupt PCINT21.
10	PD6/PCINT22/OC0A/AIN0	bidirectional	Port D bit 6. Alt: Timer/Counter0 compare match A output OC0A, analog comparator positive input AIN0, pin-change interrupt PCINT22.
11	PD7/PCINT23/AIN1	bidirectional	Port D bit 7. Alt: analog comparator negative input AIN1, pin-change interrupt PCINT23.
12	PB0/PCINT0/CLKO/ICP1	bidirectional	Port B bit 0. Alt: divided system clock output CLKO, Timer/Counter1 input capture ICP1, pin-change interrupt PCINT0.
13	PB1/PCINT1/OC1A	bidirectional	Port B bit 1. Alt: Timer/Counter1 compare match A output OC1A, pin-change interrupt PCINT1.
14	PB2/PCINT2/SS/OC1B	bidirectional	Port B bit 2. Alt: SPI slave-select SS, Timer/Counter1 compare match B output OC1B, pin-change interrupt PCINT2.
15	PB3/PCINT3/OC2A/MOSI	bidirectional	Port B bit 3. Alt: SPI master-out/slave-in MOSI, Timer/Counter2 compare match A output OC2A, pin-change interrupt PCINT3.
16	PB4/PCINT4/MISO	bidirectional	Port B bit 4. Alt: SPI master-in/slave-out MISO, pin-change interrupt PCINT4.
17	PB5/SCK/PCINT5	bidirectional	Port B bit 5. Alt: SPI serial clock SCK, pin-change interrupt PCINT5.
18	AVCC	power_in	Analog supply pin for the A/D converter, PC3:0 and ADC7:6. Must be connected to VCC (through an LC filter when ADC is used).
19	ADC6	input	Analog input channel 6 to the 10-bit A/D converter. Available only on TQFP and QFN/MLF packages; powered from the analog supply.
20	AREF	passive	Analog reference input for the A/D converter. Decouple to AGND with 100 nF.
21	GND	power_in	Analog/digital ground (shared).
22	ADC7	input	Analog input channel 7 to the 10-bit A/D converter. Available only on TQFP and QFN/MLF packages; powered from the analog supply.
23	PC0/ADC0/PCINT8	bidirectional	Port C bit 0. Alt: A/D converter channel 0 input, pin-change interrupt PCINT8.
24	PC1/ADC1/PCINT9	bidirectional	Port C bit 1. Alt: A/D converter channel 1 input, pin-change interrupt PCINT9.
25	PC2/ADC2/PCINT10	bidirectional	Port C bit 2. Alt: A/D converter channel 2 input, pin-change interrupt PCINT10.
26	PC3/ADC3/PCINT11	bidirectional	Port C bit 3. Alt: A/D converter channel 3 input, pin-change interrupt PCINT11.
27	PC4/ADC4/SDA/PCINT12	bidirectional	Port C bit 4. Alt: TWI (I2C) serial data SDA, A/D converter channel 4 input, pin-change interrupt PCINT12. Open-drain when TWI enabled.
28	PC5/ADC5/SCL/PCINT13	bidirectional	Port C bit 5. Alt: TWI (I2C) serial clock SCL, A/D converter channel 5 input, pin-change interrupt PCINT13. Open-drain when TWI enabled.
29	PC6/RESET/PCINT14	input	Active-low reset input when RSTDISBL fuse is unprogrammed (default). A low level longer than the minimum pulse length generates a reset. If RSTDISBL is programmed, PC6 becomes a general-purpose I/O pin (with different electrical characteristics from other Port C pins).
30	PD0/RXD/PCINT16	bidirectional	Port D bit 0. Alt: USART receive data input RXD, pin-change interrupt PCINT16.
31	PD1/TXD/PCINT17	bidirectional	Port D bit 1. Alt: USART transmit data output TXD, pin-change interrupt PCINT17.
32	PD2/INT0/PCINT18	bidirectional	Port D bit 2. Alt: external interrupt INT0, pin-change interrupt PCINT18.

Key specifications

Parameter	Value
Manufacturer	Microchip
Package	TQFP-32(7x7)
Category	MCU
Pins	32

Ordering variants

ATMEGA88PA-AU
ATMEGA88PA-AUR
ATMEGA88PA-AUMU
ATMEGA88PA-AUMUR
ATMEGA88PA-AUMMH
ATMEGA88PA-AUMMHR
ATMEGA88PA-AUPU
ATMEGA88PA-AUCU
ATMEGA88PA-AUCCU

CAD (KiCad official)

Symbol: ATMEGA88PA-AU
Footprint: Package_QFP:TQFP-32_7x7mm_P0.8mm
3D model: TQFP-32(7x7) (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`atmega88pa-au.step`	443 KB	You want the bare part, or you mark your own boards.
`atmega88pa-au-etched.step`	3.6 MB	You want the part with `ATMEGA88PA-AU` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 909 faces against 515 in the bare model. It survives export, section views, and rendering in any CAD tool, and it drops straight into KiCad or Fusion with no extra setup.

Provenance

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

Datasheet: Microchip datasheet (31 pp, sha256 194fdd0f35c63d3b, retrieved 2026-08-17, tier: manufacturer)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF