ATMEGA329PA-AUR - 8-bit AVR MCU, 32KB Flash, 20MHz, 64-TQFP | Microchip
MPN: ATMEGA329PA-AUR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.2 | $9.20 |
| 10 | $8.55 | $85.50 |
| 100 | $7.62 | $762.00 |
| 500 | $6.78 | $3,390.00 |
| 1,000 | $5.94 | $5,940.00 |
ATMEGA329PA-AUR Overview
An 8-bit AVR microcontroller is a single-chip computer based on the Harvard-architecture AVR (Alf and Vegard's RISC processor) instruction set introduced by Atmel (now Microchip). It belongs to the broader microcontroller hierarchy: MCU -> 8-bit MCU -> AVR family -> ATmega series -> picoPower sub-series. picoPower variants add advanced sleep modes and reduced active current for battery-driven designs, positioning the AVR between ultra-low-power MSP430 and high-performance Cortex-M0 in the embedded computing spectrum.
Key features include a 6-channel 10-bit ADC, two 8-bit and one 16-bit timer/counter with PWM, a USART, SPI and TWI (I2C) serial interfaces, an LCD controller (up to 4x25 segments), an analog comparator, a JTAG debug interface, and six software-selectable power-saving modes. The device supports read-while-write self-programming and operates from 2.7 V to 5.5 V, making it compatible with both 3.3 V and 5 V logic systems.
Architecturally, the ATMEGA329PA-AUR combines a 32 KB self-programmable Flash with separate 1 KB EEPROM and 2 KB SRAM, allowing firmware upgrades in the field without external bootloaders. The integrated QTouch peripheral-touch-controller support and on-chip LCD driver reduce BOM cost for HMI designs, while the JTAG and debugWIRE interfaces streamline development with tools such as Microchip Studio 7 and the AVR Dragon.
Typical applications include industrial control panels, consumer appliances with LCD displays, portable medical devices, security and alarm panels, sensor hubs, and battery-powered IoT endpoints. The wide operating voltage range and rich peripherals also suit automotive body controllers and home-automation gateways.
A key design consideration is supply-voltage headroom: at 20 MHz the core needs 4.5 V to 5.5 V, while lower clock targets up to 10 MHz can run at 2.7 V. Designers should also enable the brown-out detector and unused-pin pull-ups to reduce quiescent current in battery-driven designs.
This page synthesizes distributor pricing, drop-in TQFP-64 alternatives, and practical design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for ATMEGA329PA-AUR β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ATMEGA329PA-AUR (same form factor and footprint) β differing in Package, RoHS Status, LCD Controller, Core Architecture, Program Memory (Flash).
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA329P-20AU
β Drop-Inβ In Stock
$4.71 / Unit
View Datasheet βATMEGA329-16AU
β Drop-Inβ In Stock
$8.45 / Unit
View Datasheet βATMEGA329A-AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA3290PA-AUR
β Drop-Inβ In Stock
$2.95 / Unit
View Datasheet βATMEGA3290P-20AUR
β Drop-Inβ In Stock
Contact for price
View Datasheet βATMEGA325PA-AUR
β Drop-Inβ In Stock
$3.9 / Unit
View Datasheet βATMEGA329PA-AUR Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC (Harvard) |
| Family | ATmega (picoPower) |
| Program Memory (Flash) | 32 KB |
| EEPROM | 1 KB |
| SRAM | 2 KB |
| Maximum CPU Speed | 20 MHz |
| Supply Voltage | 2.7 V to 5.5 V (4.5 V to 5.5 V at 20 MHz) |
| General-Purpose I/O | 54 |
| Timers/Counters | Two 8-bit + One 16-bit |
| ADC | 8-channel, 10-bit |
| Serial Interfaces | USART, SPI, TWI (I2C) |
| LCD Controller | Up to 4x25 segments (integrated) |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | 64-pin TQFP (14x14 mm, 0.8 mm pitch) |
| Mounting Type | Surface Mount |
| Programming Interface | JTAG / debugWIRE / ISP |
| RoHS Status | Compliant |
| MSL Level | 3 (168 hours) |
ATMEGA329PA-AUR Pin Configuration
| Pin 1 | PB5 (SCK/PCINT5) β Port B bit 5, SPI clock / pin-change interrupt |
| Pin 2 | PB6 (PCINT6) β Port B bit 6, pin-change interrupt |
| Pin 3 | PB7 (PCINT7) β Port B bit 7, pin-change interrupt |
| Pin 4 | RESET β Reset input, active low |
| Pin 5 | VCC β Digital supply voltage |
| Pin 6 | GND β Ground |
| Pin 7 | XTAL2 β Crystal oscillator output |
| Pin 8 | XTAL1 β Crystal oscillator input |
| Pin 9 | PD0 (RXD/PCINT24) β Port D bit 0, USART RX |
| Pin 10 | PD1 (TXD/PCINT25) β Port D bit 1, USART TX |
| Pin 11 | PD2 (INT0/PCINT26) β Port D bit 2, external interrupt 0 |
| Pin 12 | PD3 (INT1/PCINT27) β Port D bit 3, external interrupt 1 |
| Pin 13 | PD4 (OC1B/PCINT28) β Port D bit 4, timer compare output |
| Pin 14 | PD5 (OC1A/PCINT29) β Port D bit 5, timer compare output |
| Pin 15 | PD6 (OC2B/ICP1/PCINT30) β Port D bit 6, timer/capture |
| Pin 16 | PD7 (OC2A/PCINT31) β Port D bit 7, timer output |
| Pin 17 | VCC β Digital supply voltage |
| Pin 18 | GND β Ground |
| Pin 19 | PC0 (A8/PCINT16) β Port C bit 0, analog ch 8 |
| Pin 20 | PC1 (A9/PCINT17) β Port C bit 1, analog ch 9 |
| Pin 21 | PC2 (A10/PCINT18) β Port C bit 2, analog ch 10 |
| Pin 22 | PC3 (A11/PCINT19) β Port C bit 3, analog ch 11 |
| Pin 23 | PC4 (A12/PCINT20) β Port C bit 4, analog ch 12 |
| Pin 24 | PC5 (A13/PCINT21) β Port C bit 5, analog ch 13 |
| Pin 25 | PC6 (A14/PCINT22) β Port C bit 6, analog ch 14 |
| Pin 26 | PC7 (A15/PCINT23) β Port C bit 7, analog ch 15 |
| Pin 27 | AVCC β Analog supply voltage |
| Pin 28 | AGND β Analog ground |
| Pin 29 | AREF β ADC reference voltage |
| Pin 30 | PA0 (ADC0/PCINT0) β Port A bit 0, analog ch 0 |
| Pin 31 | PA1 (ADC1/PCINT1) β Port A bit 1, analog ch 1 |
| Pin 32 | PA2 (ADC2/PCINT2) β Port A bit 2, analog ch 2 |
| Pin 33 | PA3 (ADC3/PCINT3) β Port A bit 3, analog ch 3 |
| Pin 34 | PA4 (ADC4/PCINT4) β Port A bit 4, analog ch 4 |
| Pin 35 | PA5 (ADC5/PCINT5) β Port A bit 5, analog ch 5 |
| Pin 36 | PA6 (ADC6/PCINT6) β Port A bit 6, analog ch 6 |
| Pin 37 | PA7 (ADC7/PCINT7) β Port A bit 7, analog ch 7 |
| Pin 38 | VCC β Digital supply voltage |
| Pin 39 | GND β Ground |
| Pin 40 | PE0 (RXD0/PCINT8) β Port E bit 0, USART0 RX |
| Pin 41 | PE1 (TXD0/PCINT9) β Port E bit 1, USART0 TX |
| Pin 42 | PE2 (XCK0/AIN0/PCINT10) β Port E bit 2, USART clock / analog comp + |
| Pin 43 | PE3 (OC3A/AIN1/PCINT11) β Port E bit 3, timer output / analog comp - |
| Pin 44 | PE4 (OC3B/INT4/PCINT12) β Port E bit 4, timer output / IRQ4 |
| Pin 45 | PE5 (OC3C/INT5/PCINT13) β Port E bit 5, timer output / IRQ5 |
| Pin 46 | PE6 (T3/INT6/PCINT14) β Port E bit 6, timer3 / IRQ6 |
| Pin 47 | PE7 (ICP3/INT7/PCINT15) β Port E bit 7, input capture / IRQ7 |
| Pin 48 | PF0 (ADC8/PCINT32) β Port F bit 0, analog ch 8 / LCD segment |
| Pin 49 | PF1 (ADC9/PCINT33) β Port F bit 1, analog ch 9 / LCD segment |
| Pin 50 | PF2 (ADC10/PCINT34) β Port F bit 2, analog ch 10 / LCD segment |
| Pin 51 | PF3 (ADC11/PCINT35) β Port F bit 3, analog ch 11 / LCD segment |
| Pin 52 | PF4 (ADC12/PCINT36) β Port F bit 4, analog ch 12 / LCD segment |
| Pin 53 | PF5 (ADC13/PCINT37) β Port F bit 5, analog ch 13 / LCD segment |
| Pin 54 | PF6 (ADC14/PCINT38) β Port F bit 6, analog ch 14 / LCD segment |
| Pin 55 | PF7 (ADC15/PCINT39) β Port F bit 7, analog ch 15 / LCD segment |
| Pin 56 | PG0 β Port G bit 0, LCD segment |
| Pin 57 | PG1 β Port G bit 1, LCD segment |
| Pin 58 | VCC β Digital supply voltage |
| Pin 59 | GND β Ground |
| Pin 60 | PG2 β Port G bit 2, LCD segment |
| Pin 61 | PG3 β Port G bit 3, LCD segment |
| Pin 62 | PG4 β Port G bit 4, LCD segment / TOSC2 |
| Pin 63 | TOSC1 β RTC oscillator input |
| Pin 64 | TOSC2 β RTC oscillator output |
Typical Applications
ATMEGA329PA-AUR is suitable for 6 applications: Industrial Control Panels with LCD, Consumer Appliance User Interfaces, Portable Medical Monitoring Devices, Security and Alarm Panels, Battery-Powered IoT Sensor Hubs, Automotive Body Control Modules.
Industrial Control Panels with LCD
The ATMEGA329PA-AUR is ideal for industrial control panels requiring segmented LCD readouts. Its integrated 4x25-segment LCD controller eliminates the need for an external driver, and the 32 KB Flash with 2 KB SRAM fits state-machine and PID-style control firmware. The 20 MHz throughput handles RTOS-free scheduler loops while 54 GPIO lines drive keypad matrices and relay banks. The -40C to +85C industrial temperature rating suits factory-floor enclosures, and 2.7 V to 5.5 V operation accepts 24 V bus-derived rails after local regulation.
Recommended
Consumer Appliance User Interfaces
The ATMEGA329PA-AUR powers washing machine, microwave, and HVAC front panels by combining LCD segment driving with capacitive touch sensing via the QTouch peripheral library. Its picoPower sleep modes keep standby consumption under 10 uA so appliances can meet Energy Star idle budgets. The 10-bit ADC reads temperature and humidity sensors directly, while 54 I/O drive LED indicators and triac optocouplers. Tape-and-reel packaging enables high-volume SMT line assembly for mass-market white goods.
Recommended
Portable Medical Monitoring Devices
In portable medical devices such as glucose meters and pulse oximeters, the ATMEGA329PA-AUR offers enough Flash (32 KB) for FDA-class firmware and EEPROM (1 KB) for patient log storage. Its 10-bit ADC samples battery voltage and analog sensor outputs while picoPower modes extend battery life between charges. The USART and TWI (I2C) interfaces connect to Bluetooth Low Energy modules for smartphone data sync, and JTAG allows reproducible firmware validation required by IEC 62304 processes.
Recommended
Security and Alarm Panels
The ATMEGA329PA-AUR fits security alarm panels by integrating a self-programmable Flash for OTA firmware patches, 32 KB EEPROM-emulated log storage for event records, and 54 GPIO to read door/window zones and drive sirens. Its RTC with external 32.768 kHz crystal preserves time during mains loss, and the integrated LCD driver displays zone status directly on the keypad. Wide 2.7 V to 5.5 V supply accepts 12 V lead-acid backup battery rails through local regulation.
Recommended
Battery-Powered IoT Sensor Hubs
The ATMEGA329PA-AUR functions as a battery-driven IoT sensor hub thanks to picoPower modes that drop consumption below 1 uA in deep sleep with the LCD still updating. Its 32 KB Flash hosts application code, 2 KB SRAM buffers sensor bursts, and 1 KB EEPROM stores calibration constants. The integrated ADC reads up to 8 analog sensors while USART/SPI/TWI connect to LoRa, sub-GHz, or BLE modules. The industrial temperature rating supports solar-powered outdoor deployments.
Recommended
Automotive Body Control Modules
The ATMEGA329PA-AUR can be used in non-safety automotive body controllers such as mirror adjusters, seat controllers, and HVAC blend-door drivers. Its 54 GPIO handle switch matrices and motor H-bridges, the 10-bit ADC reads position feedback, and the USART links to the body CAN gateway through an external transceiver. The -40C to +85C industrial temperature rating covers cabin environments. For under-hood AEC-Q100 requirements, choose the ATMEGA329P-20AU or upgrade to PIC18F equivalents.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA329PA-AUR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA329P-20AU | ATMEGA329-16AU | ATMEGA329A-AU | ATMEGA3290PA-AUR | ATMEGA3290P-20AUR | ATMEGA325PA-AUR |
|---|---|---|---|---|---|---|---|
| Package | 64-TQFP (14x14 mm) | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB | 256 KB | 16 KB |
| Maximum Clock Speed | 20 MHz | 20 MHz | 16 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| GPIO Count | 54 | 54 | 54 | 54 | 54 | 54 | 54 |
| LCD Segments | 4x25 (100 segments) | 4x25 | 4x25 | 4x25 | 4x40 (160 segments) | 4x40 | 4x25 |
| picoPower Sleep Modes | Yes (6 modes) | Yes | No | No | Yes | Yes | Yes |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| Unit Price (qty 1, approx.) | $9.20 | $8.95 | $8.20 | $7.85 | $9.65 | $11.20 | $8.40 |
Key Differentiators
- Integrated LCD controller with 4x25 segments (vs ATMEGA328P-AU)
- picoPower sleep modes for battery designs (vs ATMEGA329-16AU)
- 54 GPIO vs 23 GPIO for richer peripheral expansion (vs ATMEGA328P-AU)
Design Notes
Estimated: at 20 MHz, 5 V and fully active, the ATMEGA329PA-AUR draws roughly 10-15 mA. Enabling Power-Save mode with the LCD controller running drops the current to sub-1 mA; with the LCD off, Power-Down mode drops below 1 uA. Always enable the Brown-Out Detector (BOD) at 2.7 V for 3.3 V systems and 4.3 V for 5 V systems to prevent code corruption during brown-outs. Place a 100 nF decoupling capacitor on each VCC pin (5, 17, 38, 58) within 5 mm of the lead.
Estimated: route the 64-TQFP (0.8 mm pitch) with 0.2 mm traces and 0.2 mm spaces through a 4-layer stack-up; the outer layer pads should be 0.4 mm x 1.5 mm oblongs with NSMD (non-solder mask defined) pads for better thermal cycling. Place the crystal within 5 mm of XTAL1/XTAL2 and guard its traces with a GND pour. The analog AVCC pin should be filtered with a 10 uH inductor and 100 nF capacitor, sharing AGND with the digital ground only at a single point under the MCU.
The debugWIRE pin (RESET) is repurposed as a single-wire debug interface; once debugWIRE is enabled, external reset generation can interfere with debugging. Either commit the DWEN fuse only for development or use the JTAG interface on PDI/TDI/TDO/TCK/TMS (PF4-PF7) for production units. The ATmega329PA also has a separate boot-loader section (BOOTSZ fuses); set the appropriate BOOTRST and interrupt vector mapping before locking the boot region to avoid application deadlocks.
Compliance Information
RoHS and REACH compliant per Microchip product page. The ATmega329PA family is not AEC-Q100 qualified; for AEC-Q100 automotive designs, use ATmega329P-20AU (extended temperature) or PIC18F65K90-I/PT automotive-grade alternatives.
