ATMEGA329PA-MUR - 8-bit AVR 20MHz 32KB Flash MCU 64-QFN | Microchip
MPN: ATMEGA329PA-MUR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.07 | $6.07 |
| 10 | $5.46 | $54.60 |
| 100 | $4.85 | $485.00 |
| 500 | $4.32 | $2,160.00 |
| 1,000 | $3.85 | $3,850.00 |
ATMEGA329PA-MUR Overview
An 8-bit AVR microcontroller is a single-chip computer built around the Atmel/Microchip AVR instruction set, characterized by a load-store RISC architecture and a large register file. In the broader taxonomy, AVR belongs to the microcontroller (MCU) family within integrated circuits, alongside PIC, STM8, 8051, and ARM Cortex-M cores; MCUs sit under the semiconductor hierarchy and are used in everything from toys to industrial controllers. picoPower technology further places this MCU in the low-power category, enabling extended battery life in always-on applications.
Key differentiating features include hardware LCD controller supporting up to 4x40 segments, 10-bit ADC, USART, SPI, and I2C (TWI) peripherals, internal calibrated RC oscillator, and six power-saving modes. The 'A' suffix denotes picoPower enhancements, and the 'PA' variant adds QTouch library support and improved peripheral mix versus the older ATmega329P base device, while remaining code-compatible.
Architecture-wise, the ATmega329PA employs a Harvard-style bus arrangement with separate program and data memories. Its Flash supports read-while-write operation, allowing firmware updates without halting the application, and its 10-bit ADC delivers up to 15 ksps at full resolution for sensor readout tasks. The integrated JTAG and debugWIRE interfaces simplify in-circuit programming and on-chip debugging with standard toolchains such as Atmel Studio 7 and Microchip Studio.
Typical applications span consumer electronics with LCD displays, industrial control panels, smart metering, and IoT edge nodes. The combination of LCD controller, ample Flash, and low-power modes makes it well-suited for battery-powered human-machine interface (HMI) panels, while the robust I/O count supports keypad scanning, sensor aggregation, and communication bridges.
When designing with this part, ensure decoupling follows the datasheet guidance - typically 100 nF ceramic on each VCC/AVCC pin plus a bulk capacitor - and that unused I/O pins are configured as outputs to minimize current draw. If you migrate to ATmega329A-MUR (also in 64-QFN), verify the LCD segment count and oscillator options against your design margins.
This page synthesizes distributor pricing, drop-in compatible alternatives from the same AVR family, and practical engineering notes not consolidated in any single source.
Drop-in alternatives for ATMEGA329PA-MUR — 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-MUR (same form factor and footprint) — differing in Package, RoHS Status, LCD Controller, ADC, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA329A-MUR
✅ Drop-In✓ In Stock
$3.61 / Unit
View Datasheet →ATMEGA329PA-AUR
✅ Drop-In✓ In Stock
$5.94 / Unit
View Datasheet →ATMEGA3290PA-AUR
✅ Drop-In✓ In Stock
$2.95 / Unit
View Datasheet →ATMEGA3290P-20AUR
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →ATMEGA329-16AU
✅ Drop-In✓ In Stock
$8.45 / Unit
View Datasheet →ATMEGA325PA-MUR
✅ Drop-In✓ In Stock
$1.65 / Unit
View Datasheet →ATMEGA329PA-MUR Maximum Ratings & Electrical Characteristics
| Core | AVR 8-bit RISC |
| Program Memory (Flash) | 32 KB |
| SRAM | 2 KB |
| EEPROM | 1 KB |
| Maximum CPU Speed | 20 MHz |
| Supply Voltage (Vcc) | 1.8 V to 5.5 V |
| Operating Temperature | -40C to +85C (industrial) |
| General-Purpose I/O | 54 |
| Working Registers | 32 x 8-bit |
| ADC | 8-channel 10-bit |
| LCD Controller | Yes (up to 4x40 segments) |
| Communication Interfaces | USART, SPI, I2C (TWI) |
| Package | 64-lead QFN (9x9 mm) |
| Mounting Type | Surface Mount |
| Program Memory Type | In-System Programmable Flash (read-while-write) |
| RoHS Status | Compliant |
| MSL Level | 3 (per JEDEC J-STD-020, reflow 260C) |
| Packing | Tape & Reel |
ATMEGA329PA-MUR Pin Configuration
| Pin 1 | VCC — Digital supply voltage |
| Pin 2 | GND — Ground |
| Pin 3 | Port B.0 — General I/O / LCD segment |
| Pin 4 | Port B.1 — General I/O / LCD segment |
| Pin 5 | Port B.2 — General I/O / LCD segment |
| Pin 6 | Port B.3 — General I/O / LCD segment |
| Pin 7 | Port B.4 — General I/O / LCD segment |
| Pin 8 | Port B.5 — General I/O / LCD segment |
| Pin 9 | Port B.6 — General I/O / LCD segment |
| Pin 10 | Port B.7 — General I/O / LCD segment |
| Pin 11 | RESET — Reset input (active low) |
| Pin 12 | VCC — Digital supply voltage |
| Pin 13 | XTAL2 — Crystal oscillator output |
| Pin 14 | XTAL1 — Crystal oscillator input |
| Pin 15 | PD0 — Port D.0 / RXD |
| Pin 16 | PD1 — Port D.1 / TXD |
| Pin 17 | PD2 — Port D.2 / INT0 |
| Pin 18 | PD3 — Port D.3 / INT1 |
| Pin 19 | PD4 — Port D.4 |
| Pin 20 | PD5 — Port D.5 |
| Pin 21 | PD6 — Port D.6 |
| Pin 22 | PD7 — Port D.7 |
| Pin 23 | PC0 — Port C.0 / LCD segment |
| Pin 24 | PC1 — Port C.1 / LCD segment |
| Pin 25 | PC2 — Port C.2 / LCD segment |
| Pin 26 | PC3 — Port C.3 / LCD segment |
| Pin 27 | PC4 — Port C.4 / LCD segment |
| Pin 28 | PC5 — Port C.5 / LCD segment |
| Pin 29 | PC6 — Port C.6 / LCD segment |
| Pin 30 | PC7 — Port C.7 / LCD segment |
| Pin 31 | AVCC — Analog supply voltage |
| Pin 32 | AGND — Analog ground |
| Pin 33 | AREF — ADC reference voltage |
| Pin 34 | PA0 — Port A.0 / ADC0 |
| Pin 35 | PA1 — Port A.1 / ADC1 |
| Pin 36 | PA2 — Port A.2 / ADC2 |
| Pin 37 | PA3 — Port A.3 / ADC3 |
| Pin 38 | PA4 — Port A.4 / ADC4 |
| Pin 39 | PA5 — Port A.5 / ADC5 |
| Pin 40 | PA6 — Port A.6 / ADC6 |
| Pin 41 | PA7 — Port A.7 / ADC7 |
| Pin 42 | PE0 — Port E.0 / LCD segment |
| Pin 43 | PE1 — Port E.1 / LCD segment |
| Pin 44 | PE2 — Port E.2 / LCD segment |
| Pin 45 | PE3 — Port E.3 / LCD segment |
| Pin 46 | PE4 — Port E.4 / LCD segment |
| Pin 47 | PE5 — Port E.5 / LCD segment |
| Pin 48 | PE6 — Port E.6 / LCD segment |
| Pin 49 | PE7 — Port E.7 / LCD segment |
| Pin 50 | PF0 — Port F.0 / LCD segment |
| Pin 51 | PF1 — Port F.1 / LCD segment |
| Pin 52 | PF2 — Port F.2 / LCD segment |
| Pin 53 | PF3 — Port F.3 / LCD segment |
| Pin 54 | PF4 — Port F.4 / LCD segment |
| Pin 55 | PF5 — Port F.5 / LCD segment |
| Pin 56 | PF6 — Port F.6 / LCD segment |
| Pin 57 | PF7 — Port F.7 / LCD segment |
| Pin 58 | PG0 — Port G.0 / LCD COM |
| Pin 59 | PG1 — Port G.1 / LCD COM |
| Pin 60 | PG2 — Port G.2 / LCD COM |
| Pin 61 | PG3 — Port G.3 / LCD COM |
| Pin 62 | PG4 — Port G.4 / LCD COM |
| Pin 63 | GND — Ground |
| Pin 64 | AVCC — Analog supply voltage (second pin) |
Typical Applications
ATMEGA329PA-MUR is suitable for 6 applications: Smart Electricity / Water Meter, Industrial Control Panels with LCD HMI, Consumer Appliance Front Panels, Battery-Powered IoT Edge Sensors, Automotive Aftermarket Gauges and Displays, Medical Device Front-End Modules.
Smart Electricity / Water Meter
The ATMEGA329PA-MUR is purpose-built for utility meters. Its on-chip LCD controller drives up to 4 x 40 segments for kWh, voltage, and tariff displays, eliminating external driver ICs and saving BOM cost. The picoPower architecture delivers active current under 1 mA/MHz and sleep current in single-digit microamps, enabling >10-year battery life on a single lithium cell. With 32 KB Flash it accommodates metering firmware, calibration tables, and Tamper-detection logic; 1 KB EEPROM stores billing registers that survive power outages. The 54 GPIO lines interface directly to shunt sensors and pulse-output communication modules.
Recommended
Industrial Control Panels with LCD HMI
Factory automation panels benefit from the ATMEGA329PA-MUR's LCD controller, 54 GPIO, and USART/SPI/I2C mix. The MCU can drive a 160-segment alphanumeric LCD directly, scan 8x8 keypads, and communicate with PLCs over RS-485 via USART, while remaining code-compatible with the Atmel AVR Studio toolchain familiar to industrial firmware engineers. The 10-bit ADC reads 4-20 mA analog sensor inputs for process monitoring, and the 32 KB Flash comfortably fits protocol stacks (Modbus RTU, vendor-specific drivers). The 64-QFN package suits sealed front-panel designs where mechanical robustness and small footprint matter.
Recommended
Consumer Appliance Front Panels
Washing machines, ovens, and HVAC thermostats rely on the ATMEGA329PA-MUR for combined user-interface and motor-control duties. The integrated LCD controller eliminates the cost of a dedicated display driver, the 54 GPIO pins drive triac optocouplers and button matrices, and the timers support BLDC/PMSM commutation or relay sequencing. picoPower modes let the MCU stay in sleep between user interactions, dramatically reducing idle power for energy-star-rated appliances. The 1.8 V to 5.5 V operating range accommodates both 3.3 V logic-level sensors and legacy 5 V triac interfaces.
Recommended
Battery-Powered IoT Edge Sensors
Low-duty-cycle IoT sensor hubs leverage the ATMEGA329PA-MUR's deep-sleep picoPower modes to run for years on a coin cell or AA battery pack. The 32 KB Flash supports LoRaWAN or Zigbee stacks via SPI peripherals, while 1 KB EEPROM records sensor calibration coefficients. The 10-bit ADC monitors temperature, humidity, or strain gauges, and the USART bridges to a cellular or sub-GHz radio module. Sleep currents under 1 uA (power-down with watchdog) are typical, and the wide 1.8 V to 5.5 V range supports both single-cell Li-ion and 3xAA packs without level shifters.
Recommended
Automotive Aftermarket Gauges and Displays
Aftermarket automotive gauges (boost, oil pressure, wideband AFR) use the ATMEGA329PA-MUR to drive character or segment LCDs while remaining immune to 12 V transients through onboard regulators. The 54 GPIO interface with NTC thermistor dividers, 0-5 V analog sensors, and high-impedance frequency inputs from ignition coils; the on-chip ADC handles up to eight sensor channels with 10-bit resolution. The MCU's industrial -40C to +85C temperature grade suits under-dash environments. For OEM-grade applications requiring AEC-Q100, consider the Q1-qualified ATmega329PA-MUR-Q1 variant rather than the standard industrial-grade part.
Recommended
Medical Device Front-End Modules
Portable medical devices such as glucose meters, nebulizers, and pulse-oximeter displays use the ATMEGA329PA-MUR to combine sensor readout, user interface, and LCD display in a single chip. The 10-bit ADC handles analog front-ends from photodiode or impedance sensors, and the LCD controller presents results directly without an auxiliary driver. The picoPower sleep modes extend battery life across long storage and intermittent-use scenarios typical of consumer medical products. The 32 KB Flash fits vendor firmware plus a small RTOS or scheduler, and the JTAG/debugWIRE interface supports regulatory unit-level verification and calibration.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA329PA-MUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA329A-MUR | ATMEGA329PA-AUR | ATMEGA3290PA-AUR | ATMEGA3290P-20AUR | ATMEGA329-16AU | ATMEGA325PA-MUR |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 64-QFN (9x9) | 64-QFN (9x9) - same | 64-TQFP (14x14) - drop-in but different package | 64-TQFP (14x14) - drop-in but different package | 64-TQFP (14x14) - drop-in but different package | 64-TQFP (14x14) - drop-in but different package | 64-QFN (9x9) - same |
| Flash | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB |
| SRAM | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB |
| Max CPU Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 16 MHz | 20 MHz |
| Operating Voltage | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 2.7 V to 22 V (extended range) | 2.7 V to 5.5 V | 1.8 V to 5.5 V |
| picoPower | Yes (PA revision) | Yes (A revision) | Yes (PA revision) | Yes (PA revision) | No (P revision) | No (legacy) | Yes (PA revision) |
| GPIO Count | 54 | 54 | 54 | 69 (80-pin variant) | 69 | 54 | 54 |
| LCD Controller | Yes (up to 4x40 segments) | Yes | Yes | Yes (4x40 segments, 80-pin) | Yes | Yes | Yes |
| Pricing (1pc, USD) | 6.07 | approx. 5.50 | approx. 6.20 | approx. 7.00 | approx. 6.80 | approx. 5.20 | approx. 5.90 |
Key Differentiators
- picoPower architecture delivers industry-leading low active and sleep current (vs ATMEGA3290P-20AUR)
- Compact 64-QFN (9x9) package with full 54 GPIO and LCD controller (vs ATMEGA328P-MU)
- Drop-in compatible with ATMEGA329A-MUR with extended ADC and QTouch support (vs ATMEGA329A-MUR)
Design Notes
Estimated: Active current at 20 MHz, 5 V is approximately 40 mA and idle current ~15 mA; deep-sleep with watchdog enabled drops below 1 uA, enabling years of battery life. Always enable the brown-out detector (BOD) at the lowest voltage that matches your minimum VCC (e.g. BOD 1.8 V) to prevent Flash corruption during brown-outs. Use sleep modes between sensor reads for ultra-low-power duty-cycled designs.
Place 100 nF ceramic decoupling capacitors as close as possible to every VCC, AVCC, and reference pin (AREF); add a single 10 uF bulk capacitor on each power rail. The 64-QFN exposed thermal pad must be soldered to a grounded copper pour of at least 1 square inch to meet the theta_JA rating; otherwise junction temperature may exceed the 85C industrial limit under heavy peripheral loading.
Route the analog AVCC/AGND pair as a Kelvin-connected star away from switching digital traces. Keep the crystal traces (XTAL1/XTAL2) short and symmetric, with the crystal and load capacitors within 5 mm of the MCU. For LCD segment routing, group segment lines on the inner PCB layers to minimize noise coupling from GPIO switching and avoid routing under noisy power traces.
Do not leave the RESET pin floating; tie it through a 10 kohm pull-up to VCC to prevent spurious resets from EMI. Configure unused I/O pins as outputs with low level to minimize sink current in sleep modes. When migrating from ATmega329P to the ATmega329PA, re-verify oscillator start-up time and BOD thresholds, as picoPower revisions modify these defaults.
Compliance Information
Industrial-grade part (-40C to +85C). For automotive AEC-Q100 applications, choose the Q1-qualified ATmega329PA-MU-Q1 variant instead. RoHS and lead-free per Microchip product declaration.
