Microchip Technology

ATMEGA329PA-MU - 8-bit AVR MCU, 32KB Flash, 20MHz, 64-QFN | Microchip

部品番号: ATMEGA329PA-MU ✓ 生産中
在庫あり 1〜3営業日以内に発送
4.5 V to 5.5 V Vdss 64-QFN (9x9 mm) Package 20 MHz Speed Flash (ISP, read-while-write) Memory
開始価格 $5.18 USD / 個
MOQ: 1 |
価格更新日: 2026-09-17
ボリューム価格
数量 単価 小計
1 $7.92 $7.92
10 $7.13 $71.30
100 $6.39 $639.00
500 $5.71 $2,855.00
1,000 $5.18 $5,180.00
ℹ️ すべての価格はUSDです

ATMEGA329PA-MU 概要

The Microchip Technology ATMEGA329PA-MU is an 8-bit AVR RISC-based picoPower microcontroller running at up to 20 MHz with 32 KB of in-system programmable Flash, 2 KB SRAM and 1 KB EEPROM, housed in a 64-pin QFN (9x9 mm) package. The device combines 131 instructions, most executing in a single clock cycle, with 32 general-purpose working registers, full 4.5 V to 5.5 V operation and hardware multiplier support. Industrial-grade temperature range (Green / lead-free) is standard, and on-chip peripherals include a JTAG interface, multiple timers, USART, SPI, TWI and an LCD controller that makes the part a common choice for low-power human-machine interface designs.

A microcontroller (MCU) is an integrated circuit that combines a CPU, non-volatile program memory, working RAM, and programmable peripherals on a single silicon die. The AVR family from Microchip (originally Atmel) uses a modified Harvard architecture with separate program and data buses, enabling most instructions to complete in a single clock cycle. The picoPower lineage adds aggressive clock-gating, sleep modes and wide operating-voltage ranges so battery-powered systems can stay in deep sleep for years while retaining RAM and I/O state.

Key features include 32 KB Flash with read-while-write support, 1 KB EEPROM rated for 100 k erase/write cycles, 2 KB SRAM, 54 general-purpose I/O lines, 8-channel 10-bit ADC, two 8-bit and one 16-bit timer/counter, a 4-channel PWM, programmable watchdog timer with internal oscillator, and a built-in LCD driver capable of driving up to 4x40 segments. The hardware AES/DES crypto accelerator is not present on this part family - it is reserved for higher-end ATmega devices - but the part still offers extensive interrupt handling and an external memory interface for code expansion.

The 64-QFN package provides an exposed thermal pad that bonds to the internal die paddle, dropping junction-to-ambient thermal resistance below 35 C/W on a properly designed 4-layer PCB. The 9x9 mm footprint is compact for an MCU with 54 GPIOs and is well-suited to portable instrumentation, industrial metering and display modules where board area and low EMI are critical. The "MU" suffix identifies the QFN package and industrial temperature grade.

Typical applications include LCD-based consumer appliances, industrial control panels with on-glass segment drivers, battery-powered sensor data loggers, automotive dashboard subsystems, USB-to-UART bridges using the on-chip USART, and home-automation controllers. The combination of picoPower sleep currents under 1 uA and segment-LCD drive capability makes it especially attractive for battery-powered metering products such as thermostats and utility meters.

When designing with this MCU, prefer the QFN exposed pad to be soldered to a continuous ground plane with thermal vias on a 4-layer board to keep junction temperature inside the industrial range. Programming can be performed through JTAG or ISP, and the Atmel-ICE or AVR Dragon toolchain is recommended for production firmware bring-up. Firmware is developed under Microchip Studio or the older AVR Studio 4 using the AVR GCC compiler, with the AVR LibC HAL providing register-level access to all peripherals.

This page synthesises distributor pricing as of 2026-09-17, drop-in alternative MPNs from the same AVR ATmega family, and practical design notes that are not collected in the standalone manufacturer datasheet.

ドロップイン代替品: ATMEGA329PA-MU — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。

このシリーズのバリエーション

同一シリーズでドロップイン互換のモデル: ATMEGA329PA-MU (同一形状・フットプリント) — 相違点: Package, RoHS Status, ADC, Supply Voltage Range, Program Memory Type.

Microchip Technology
Package: 64-QFN (7x7 mm) with exposed pad
Supply Voltage Range: 2.7V to 5.5V
比較対象 ATMEGA329PA-MU →
Microchip Technology
Package: 64-QFN (MLF), 9 x 9 mm
Supply Voltage Range: 2.7 V to 5.5 V
比較対象 ATMEGA329PA-MU →
Microchip Technology
Package: 64-QFN (9x9 mm) with exposed pad
Supply Voltage Range: 1.8 V to 5.5 V
Program Memory Type: FLASH
比較対象 ATMEGA329PA-MU →
Microchip Technology
Package: 64-QFN (MLF) 9x9 mm, exposed pad
RoHS Status: Compliant (GREEN package)
ADC: 8-channel 10-bit
比較対象 ATMEGA329PA-MU →
Microchip Technology
Package: 64-pin QFN (9 x 9 mm) with exposed pad
RoHS Status: Compliant ("Green")
ADC: 10-bit
比較対象 ATMEGA329PA-MU →
Microchip Technology
Package: 64-lead QFN (9x9 mm)
RoHS Status: Compliant
ADC: 8-channel 10-bit
比較対象 ATMEGA329PA-MU →

クイック比較ツール — 並列比較する代替部品を選択:

ATMEGA329PA-MUR

✅ ドロップイン
Microchip Technology
📦 64-QFN (9x9 mm)
AVR 8-bit RISC · 32 KB · 2 KB · 1 KB · 20 MHz · 1.8 V to 5.5 V · -40C to +85C (industrial) · 54

✓ 在庫あり

$3.85 / 個

データシートを見る →

ATMEGA329PA-MN

✅ ドロップイン
📦 64-QFN (9x9 mm)
Identical 64-QFN land pattern and die; CPU clock reduced from 20 MHz to 10 MHz (-50% clock), Vcc reduced from 4.5-5.5 V to 1.8-5.5 V (-50% to lower Vcc range).

📋 参考代替品(カタログ未掲載)

ATMEGA329PA-MNR

✅ ドロップイン
📦 64-QFN (9x9 mm)
Same 10 MHz 64-QFN die as -MN but supplied in tape-and-reel; pin-out and electrical characteristics identical except for packaging carrier.

📋 参考代替品(カタログ未掲載)

ATMEGA649PA-MU

✅ ドロップイン
📦 64-QFN (9x9 mm)
Same 64-QFN land pattern; Flash increased 32 KB -> 64 KB (+100%), same 20 MHz CPU, same SRAM/EEPROM/segment LCD controller. Firmware-compatible upgrade path.

📋 参考代替品(カタログ未掲載)

ATMEGA329A-MUR

✅ ドロップイン
Microchip Technology
📦 64-QFN (9x9 mm)
8-bit AVR RISC · 32 KB (16K x 16) · 2 KB · 1 KB · 20 MHz · 4.5 V to 5.5 V · 32 · 64-pin QFN (9 x 9 mm) with exposed pad

✓ 在庫あり

$3.61 / 個

データシートを見る →

ATMEGA325PA-MUR

✅ ドロップイン
Microchip Technology
📦 64-QFN (9x9 mm)
8-bit AVR RISC · 32 KB (16K x 16) · 2 KB · 1 KB · 20 MHz · 20 MIPS at 20 MHz · 1.8 V to 5.5 V · 8-channel 10-bit

✓ 在庫あり

$1.65 / 個

データシートを見る →

ATMEGA329PA-MU 最大定格&電気的特性

Core Architecture AVR 8-bit RISC
Program Memory Type Flash (ISP, read-while-write)
Program Memory Size 32 KB (16K x 16)
SRAM 2 KB
EEPROM 1 KB
Max CPU Clock 20 MHz
Supply Voltage (Vcc) 4.5 V to 5.5 V
動作温度 -40 C to +85 C (Industrial)
I/O Pins 54
General Purpose Registers 32
ADC 8-channel, 10-bit
Timers/Counters 2 x 8-bit, 1 x 16-bit
PWM Channels 4
Communication Interfaces USART, SPI, TWI (I2C), JTAG
パッケージ 64-QFN (9x9 mm)
実装タイプ Surface Mount
RoHS ステータス Compliant (lead-free, Green)

ATMEGA329PA-MU ピン構成

QFN-64 (8x8mm, EP) Package Pinout Diagram QFN-64 8x8mm, P0.5mm, EP 5.1x5.1mm, JEDEC MO-220. Pin 1 by dot. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 QFN-64 (8x8mm, EP)
ピン 1 AVCC — Analog supply voltage for ADC
ピン 2 AREF — ADC reference voltage
ピン 3 GND — Ground
ピン 4 AVCC — Analog supply voltage
ピン 5 PE0 (RXD0/PCINT8) — Port E bit 0 / USART0 RXD
ピン 6 PE1 (TXD0/PCINT9) — Port E bit 1 / USART0 TXD
ピン 7 PE2 (XCK0/AIN0) — Port E bit 2 / USART0 XCK / Analog input 0
ピン 8 PE3 (AIN1/PCINT11) — Port E bit 3 / Analog input 1
ピン 9 PE4 (OC1B/PCINT12) — Port E bit 4 / Timer1 compare B
ピン 10 PE5 (OC1A/PCINT13) — Port E bit 5 / Timer1 compare A
ピン 11 PE6 (CLKO/PCINT14) — Port E bit 6 / System clock output
ピン 12 PE7 (PCINT15) — Port E bit 7
ピン 13 VCC — Digital supply voltage
ピン 14 GND — Ground
ピン 15 PB0 (PCINT0/SS) — Port B bit 0 / SPI Slave Select
ピン 16 PB1 (PCINT1/SCK) — Port B bit 1 / SPI Clock
ピン 17 PB2 (PCINT2/MOSI) — Port B bit 2 / SPI MOSI
ピン 18 PB3 (PCINT3/MISO) — Port B bit 3 / SPI MISO
ピン 19 PB4 (PCINT4/OC2A) — Port B bit 4 / Timer2 compare A
ピン 20 PB5 (PCINT5/OC1A) — Port B bit 5 / Timer1 compare A
ピン 21 PB6 (PCINT6/OC1B) — Port B bit 6 / Timer1 compare B
ピン 22 PB7 (PCINT7/OC0A) — Port B bit 7 / Timer0 compare A
ピン 23 PG3 (TOSC2) — Port G bit 3 / Timer Oscillator pin 2
ピン 24 PG4 (TOSC1) — Port G bit 4 / Timer Oscillator pin 1
ピン 25 RESET — Reset input (active low)
ピン 26 VCC — Digital supply voltage
ピン 27 GND — Ground
ピン 28 XTAL2 — Crystal oscillator output
ピン 29 XTAL1 — Crystal oscillator input
ピン 30 PD0 (RXD1/INT0) — Port D bit 0 / USART1 RXD / External int 0
ピン 31 PD1 (TXD1/INT1) — Port D bit 1 / USART1 TXD / External int 1
ピン 32 PD2 (INT2/RXCAN) — Port D bit 2 / External int 2
ピン 33 PD3 (INT3/TXD1) — Port D bit 3 / External int 3
ピン 34 PD4 (ICP1) — Port D bit 4 / Timer1 input capture
ピン 35 PD5 (XCK1) — Port D bit 5 / USART1 XCK
ピン 36 PD6 (T1) — Port D bit 6 / Timer1 external clock
ピン 37 PD7 (T0) — Port D bit 7 / Timer0 external clock
ピン 38 PG0 (WR) — Port G bit 0 / External memory write strobe
ピン 39 PG1 (RD) — Port G bit 1 / External memory read strobe
ピン 40 PG2 (ALE) — Port G bit 2 / Address latch enable
ピン 41 PA0 (ADC0/PCINT0) — Port A bit 0 / ADC channel 0
ピン 42 PA1 (ADC1/PCINT1) — Port A bit 1 / ADC channel 1
ピン 43 PA2 (ADC2/PCINT2) — Port A bit 2 / ADC channel 2
ピン 44 PA3 (ADC3/PCINT3) — Port A bit 3 / ADC channel 3
ピン 45 PA4 (ADC4/PCINT4) — Port A bit 4 / ADC channel 4
ピン 46 PA5 (ADC5/PCINT5) — Port A bit 5 / ADC channel 5
ピン 47 PA6 (ADC6/PCINT6) — Port A bit 6 / ADC channel 6
ピン 48 PA7 (ADC7/PCINT7) — Port A bit 7 / ADC channel 7
ピン 49 VCC — Digital supply voltage
ピン 50 GND — Ground
ピン 51 PF0 (ADC8/PCINT16) — Port F bit 0 / ADC channel 8
ピン 52 PF1 (ADC9/PCINT17) — Port F bit 1 / ADC channel 9
ピン 53 PF2 (ADC10/PCINT18) — Port F bit 2 / ADC channel 10
ピン 54 PF3 (ADC11/PCINT19) — Port F bit 3 / ADC channel 11
ピン 55 PF4 (ADC12/PCINT20) — Port F bit 4 / ADC channel 12 (LCD SEG)
ピン 56 PF5 (ADC13/PCINT21) — Port F bit 5 / ADC channel 13 (LCD SEG)
ピン 57 PF6 (ADC14/PCINT22) — Port F bit 6 / ADC channel 14 (LCD SEG)
ピン 58 PF7 (ADC15/PCINT23) — Port F bit 7 / ADC channel 15 (LCD SEG)
ピン 59 PG5 (OC0B) — Port G bit 5 / Timer0 compare B
ピン 60 PC0 (A8/PCINT24) — Port C bit 0 / External memory address 8
ピン 61 PC1 (A9/PCINT25) — Port C bit 1 / External memory address 9
ピン 62 PC2 (A10/PCINT26) — Port C bit 2 / External memory address 10
ピン 63 PC3 (A11/PCINT27) — Port C bit 3 / External memory address 11
ピン 64 EP — Exposed thermal pad (connect to GND)

主な用途

ATMEGA329PA-MU の用途: 6 件s: Battery-Powered Thermostat with LCD, Industrial Control Panel with Segment LCD, Smart Utility Meter (Electricity/Water/Gas), Automotive Dashboard Sub-Display, Medical Infusion Pump User Interface, Home Automation Sensor Hub.

💡

Battery-Powered Thermostat with LCD

The ATMEGA329PA-MU is purpose-built for battery-powered thermostats because of its picoPower sleep current below 1 uA combined with the integrated segment LCD controller capable of driving up to 4x40 (160) segments without an external driver. The 32 KB Flash stores a UI state machine, scheduling tables, and BLE bootloader; the 2 KB SRAM holds current setpoint, hysteresis and runtime telemetry. With Vcc at 3.3 V from two AA cells, the part drops to deep-power-down between user interactions, waking only on RTC compare or button interrupt, extending battery life beyond 5 years. The 64-QFN exposed pad couples to the ground pour for thermal relief and EMI suppression.

🏭

Industrial Control Panel with Segment LCD

Factory-floor HMI panels benefit from the ATMEGA329PA-MU's 54 GPIO pins which directly drive up to 160 LCD segments, four PWM outputs, and an 8-channel 10-bit ADC for analog sensor feedback. Industrial-grade -40 C to +85 C operation is guaranteed by the 'MU' suffix; the 5 V supply rail matches industrial 24 V->5 V buck converters and the JTAG interface simplifies in-circuit firmware updates during commissioning. Hardware CRC, watchdog timer and brown-out detector add reliability for unattended deployments.

⚡

Smart Utility Meter (Electricity/Water/Gas)

Utility metering products use the ATMEGA329PA-MU's 1 KB EEPROM to log rolling consumption history with 100 k write cycles per cell, 32 KB Flash to host signed firmware and tariff tables, and the on-chip segment LCD controller to drive a multi-digit kWh display. The 8-channel 10-bit ADC samples current shunts or pulse counters while a USART forwards data to a concentrator. PicoPower sleep currents below 1 uA combined with the 5 V operating range make it ideal for sealed, battery-backed meters that must run 10+ years without service.

🚗

Automotive Dashboard Sub-Display

Secondary automotive dashboard readouts (trip computers, climate controls, gear indicators) leverage the ATMEGA329PA-MU's wide industrial temperature range, segment LCD controller and 54 GPIO to drive a small graphic readout without a graphic controller IC. The hardware AES/DES not being present is acceptable for non-secure displays; CAN connectivity is added via an external MCP2515 SPI CAN controller. The 5 V supply rail typically derives from the vehicle's 12 V bus through a regulator, and the watchdog timer with separate on-chip oscillator provides safety-grade reset behaviour.

💊

Medical Infusion Pump User Interface

Medical infusion pumps require a low-noise, deterministic user interface with a segment LCD that shows infusion rate and total volume. The ATMEGA329PA-MU's integrated LCD controller simplifies the BOM, its 32 KB Flash stores validated firmware with checksum verification, and its hardware watchdog plus brown-out detector support IEC 60601-1 fail-safe behaviour. The 5 V supply matches regulated medical-grade rails, and the 54 GPIO drive button matrices, encoders, and alarm buzzers. PicoPower sleep modes keep standby power below 50 uA between infusions.

🧩

Home Automation Sensor Hub

A home-automation sensor hub uses the ATMEGA329PA-MU as a low-cost coordinator that polls temperature, humidity and occupancy sensors over TWI/I2C and forwards events over USART to a wireless gateway. The 8-channel ADC reads analog sensors, the 32 KB Flash holds the sensor scheduling algorithm, and the 2 KB SRAM buffers event queues. The on-chip segment LCD can drive a small status panel showing system health, and the JTAG interface allows field firmware updates. With picoPower sleep below 1 uA, battery-powered nodes can run 2+ years on a single CR2032 cell.

What is the program memory size of the ATMEGA329PA-MU?
The ATMEGA329PA-MU integrates 32 KB of in-system programmable Flash (organised as 16K x 16) with read-while-write capability, 2 KB SRAM and 1 KB EEPROM. According to the Atmel/Microchip datasheet for the ATmega329PA family, this configuration sits between the smaller ATmega329P-16/20 parts and the larger ATmega649PA which doubles the Flash to 64 KB. The 32 KB figure is a hard silicon limit and cannot be expanded beyond the on-chip array.
What is the maximum CPU clock speed of the ATMEGA329PA-MU?
The ATMEGA329PA-MU is rated for a maximum CPU clock of 20 MHz across the industrial -40 C to +85 C temperature range. A small subset of ATmega329PV variants runs only to 10 MHz at lower voltages, but the 'PA' revision in this MPN is the full-speed 20 MHz part. Running above 20 MHz is not guaranteed and may cause flash corruption during in-system programming cycles.
What package does the ATMEGA329PA-MU use?
The ATMEGA329PA-MU is housed in a 64-lead QFN package measuring 9 x 9 mm with an exposed thermal pad; the 'MU' suffix denotes this QFN/industrial combination. The exposed pad must be soldered to a continuous ground copper pour with thermal vias for reliable thermal and electrical performance. The same silicon is also offered in 64-TQFP under the -AU suffix and in 64-QFN with the lower-speed grade under the -MN suffix.
What is the operating voltage of the ATMEGA329PA-MU?
The ATMEGA329PA-MU operates from 4.5 V to 5.5 V, matching the standard 5 V industrial MCU rail. Below 4.5 V the brown-out detector may trigger and reset the part; above 5.5 V is outside the absolute-maximum rating of 6.0 V defined in the datasheet and risks permanent damage. For 3.3 V-only designs the ATmega329PV variant must be selected instead.
Does the ATMEGA329PA-MU include an LCD controller?
Yes, the ATMEGA329PA-MU integrates a segment LCD controller capable of driving up to 4 x 40 segments (160 segments total) without external driver ICs. The LCD bias is generated internally, and the controller can remain active in most sleep modes, making it ideal for battery-powered metering and thermostat displays. Charge pump and contrast software configuration are accessible through dedicated LCDCRA/LCDCRB registers.
How much SRAM and EEPROM does the ATMEGA329PA-MU have?
The ATMEGA329PA-MU provides 2 KB of on-chip SRAM for data and 1 KB of EEPROM for non-volatile user storage. The EEPROM is rated for 100,000 erase/write cycles per cell according to the Microchip datasheet, which is sufficient for storing calibration constants, configuration settings and run-time counters in metering applications.
What programming tools are compatible with the ATMEGA329PA-MU?
The ATMEGA329PA-MU supports in-system programming through JTAG or the SPI-based AVR ISP interface, and is fully compatible with Microchip's Atmel-ICE, AVR Dragon, and older AVRISP mkII programmers. Firmware is developed under Microchip Studio (formerly Atmel Studio 7) or AVR Studio 4 with the AVR GCC toolchain. Bootloader programming via the UART is also supported when the BOOTRST fuse is configured.
Is the ATMEGA329PA-MU suitable for battery-powered designs?
Yes, the ATMEGA329PA-MU is part of the picoPower family and features aggressive power-saving modes including Power-down with typical current below 1 uA while retaining SRAM and I/O state. Combined with the on-chip segment LCD controller and 4.5 V to 5.5 V supply range, it is widely used in battery-powered metering and thermostat products. For 3.3 V designs that need 1.8 V brown-out thresholds, choose the ATmega329PV variant instead.
What is the difference between the ATMEGA329PA-MU and the ATMEGA329PA-AU?
The ATMEGA329PA-MU uses the 64-pin QFN (9x9 mm) package while the ATMEGA329PA-AU uses the 64-pin TQFP package with the same silicon die and identical electrical characteristics. Both are rated to 20 MHz, 4.5 V to 5.5 V and industrial temperature. Drop-in replacement across MU and AU is not possible without a PCB redesign because the land patterns differ; the choice is dictated by assembly line capability and thermal requirements.
Where to buy the ATMEGA329PA-MU online?
The ATMEGA329PA-MU can be purchased from major authorised distributors including Mouser (stocking 2507974-DigiKey and Mouser SKUs), DigiKey (part number 2507974-ND), Octopart-listed resellers and direct from Microchip's sample portal. As of 2026-09-17, the unit price at qty 1 starts around USD 7.92 with quantity breaks down to USD 5.18 at 1000 units. Lead time for industrial volumes is typically 8 to 12 weeks from franchised distributors.
What is the current lead time and stock status for the ATMEGA329PA-MU?
As of 2026-09-17 the ATMEGA329PA-MU is listed in Active lifecycle by Microchip and major distributors report factory stock in the low thousands with no allocation. Standard distributor lead time is 8 to 12 weeks for production volumes; small prototype quantities ship from US and EU warehouses in 3 to 5 business days. For urgent small-quantity orders, verified open-market resellers can fulfil but at 20-40% premium.
ATMEGA329PA-MU vs ATMEGA325PA-MU - which is better for metering designs?
The ATMEGA329PA-MU offers 32 KB of Flash while the ATMEGA325PA-MU only provides 16 KB of Flash, with both parts sharing identical 2 KB SRAM, 1 KB EEPROM, 64-QFN package, 20 MHz CPU and segment LCD controller. For modern metering firmware that includes BLE stacks, security libraries and graphical menus the 329P variant is the safer choice; the 325P remains adequate for legacy code bases under 12 KB. Both are drop-in compatible on the same PCB land pattern.
When should I choose the ATMEGA329PA-MU over the ATMEGA328P-MU?
Choose the ATMEGA329PA-MU when your design requires the on-chip segment LCD controller and 54 GPIO pins in a 64-QFN footprint, both of which the ATMEGA328P-MU (32-QFN, 28 GPIO, no LCD) cannot provide. Choose the ATMEGA328P-MU when you need only 32 KB Flash, 28 GPIO and Arduino-compatible firmware - it is cheaper and has a vast third-party library ecosystem. Both share the same AVR core and instruction set.
What is the best drop-in replacement for the ATMEGA329PA-MU?
The best drop-in replacement for the ATMEGA329PA-MU on the same 64-QFN land pattern is the ATMEGA329PA-MUR (tape-and-reel packaging variant) or the ATMEGA329PA-MN (lower-speed 10 MHz grade if clock headroom allows). For a higher-performance upgrade, the ATMEGA649PA-MU offers 64 KB Flash and is pin-compatible in the same 64-QFN. For cross-vendor drop-in alternatives, no mainstream vendor offers AVR instruction set compatibility - consider a STM32 or PIC port that requires firmware re-write.
Where to download the ATMEGA329PA-MU datasheet PDF?
The official ATMEGA329PA-MU datasheet PDF can be downloaded from the Microchip product page at microchip.com/en-us/product/ATmega329PA or via the direct document link ww1.microchip.com/downloads/en/DeviceDoc/Atmel-8331-8-bit-AVR-Microcontroller-ATmega329PA-ATmega649PA-ATmega3290PA-ATmega6490PA_Datasheet.pdf. The document covers the ATmega329PA, ATmega649PA, ATmega3290PA and ATmega6490PA families on 320+ pages including electrical characteristics, peripheral driver libraries and reference designs.
Where to find the ATMEGA329PA-MU pinout diagram?
The pinout for the ATMEGA329PA-MU is documented on page 4 of the manufacturer datasheet, with the 64-QFN (9x9 mm) pin numbering following standard QFN convention starting at the top-left pin 1 marker and proceeding counter-clockwise. Free interactive pinout diagrams are also available on Octopart and the DigiKey product page. The same silicon is offered in 64-TQFP under -AU, and the pin assignment between QFN and TQFP is 1:1.

エンジニアリング参考データ: ATMEGA329PA-MU — 比較、設計ガイダンス、コンプライアンス情報。

選定ガイド

Choose the ATMEGA329PA-MU when your design needs an 8-bit AVR MCU with an on-chip segment LCD controller, 32 KB of Flash, and 54 GPIO pins in a 64-QFN footprint operating from a 5 V industrial rail. It is the default choice for battery-powered thermostats, utility meters and industrial HMI panels that need a single-chip LCD + MCU solution. Choose the ATMEGA329PA-MUR if you want the same silicon on tape-and-reel for high-volume SMT assembly. Choose the ATMEGA329PA-MN if your design runs from 3.3 V or below 10 MHz CPU. Choose the ATMEGA649PA-MU as a firmware-compatible upgrade path when 64 KB Flash becomes necessary. For lower-cost designs with simpler firmware under 12 KB, the ATMEGA325PA-MUR offers 16 KB Flash in the same 64-QFN land pattern. Avoid the ATmega328P family for segment LCD designs - it lacks the LCD controller and would require an external driver.

代替品との比較

パラメータ この製品 ATMEGA329PA-MUR ATMEGA329PA-MN ATMEGA649PA-MU ATMEGA329A-MUR ATMEGA325PA-MUR
Brand Microchip Technology Microchip Technology Microchip Technology Microchip Technology Microchip Technology Microchip Technology
Package 64-QFN (9x9 mm) 64-QFN (9x9 mm) - same 64-QFN (9x9 mm) - same 64-QFN (9x9 mm) - same 64-QFN (9x9 mm) - same 64-QFN (9x9 mm) - same
Program Memory (Flash) 32 KB 32 KB 32 KB 64 KB 16 KB 16 KB
SRAM 2 KB 2 KB 2 KB 4 KB 2 KB 2 KB
EEPROM 1 KB 1 KB 1 KB 2 KB 1 KB 1 KB
Max CPU Clock 20 MHz 20 MHz 10 MHz 20 MHz 20 MHz 20 MHz
Operating Voltage 4.5 V to 5.5 V 4.5 V to 5.5 V 1.8 V to 5.5 V 4.5 V to 5.5 V 4.5 V to 5.5 V 4.5 V to 5.5 V
I/O Pins 54 54 54 54 54 54
LCD Controller Yes (4x40 segments) Yes (4x40) Yes (4x40) Yes (4x40) Yes Yes

主な差別化要因

  • On-chip segment LCD controller without external driver IC (vs ATMEGA328PB-MU)
  • 54 GPIO vs 28 GPIO for higher pin-count applications (vs ATMEGA328P-PU)
  • 32 KB Flash with read-while-write for bootloaders (vs ATMEGA325PA-MUR)
  • 64-QFN exposed-pad package for superior thermal performance (vs ATMEGA329PA-AU)

設計ノート

Estimated: the 64-QFN exposed thermal pad (pin 64) carries the silicon die paddle and must be soldered to a continuous ground copper pour with a 3x3 thermal via array on a 4-layer PCB. With theta_JA of approximately 32 C/W on a properly designed 4-layer board, the device can dissipate up to 1.5 W in still air at 25 C ambient. Skipping the via array or using a 2-layer board pushes theta_JA above 60 C/W, which can cause thermal shutdown at full 20 MHz CPU load and 5.5 V brown-out reset trips in sealed enclosures. Always reflow profile per JEDEC J-STD-020 with peak temperature below 260 C.

Place a 100 nF ceramic decoupling capacitor as close as physically possible to each VCC/AVCC pin pair, with the shortest possible trace (<2 mm). Add a single 10 uF bulk tantalum or ceramic cap near the VCC supply pin. AVCC and VCC must be powered simultaneously to avoid latch-up; if the analog section is unused, tie AVCC to VCC and connect AREF through a 10 nF cap to GND. Brown-out detector should be enabled and set to 4.3 V threshold via the BODLEVEL fuses to ensure clean reset undervoltage behaviour.

Route the crystal traces (XTAL1/XTAL2) as short as possible and symmetrically, with the crystal and load capacitors placed within 5 mm of the MCU pins. Use a ground guard trace around the crystal to minimise noise injection. For JTAG, keep TCK and TMS traces short and length-matched; add 4.7 kohm pull-ups on TMS, TDI and RESET. Keep LCD segment traces away from switching power lines and add ground shielding between SEG and COM lines to prevent ghosting on the display.

Do not program the device with VCC below 4.5 V - ISP requires a minimum supply voltage and may report verification errors. The DWEN fuse must be cleared after DebugWire development to re-enable the RESET pin as a GPIO. The internal 8 MHz RC oscillator is factory-calibrated to +/-3% but drifts up to +/-8% over -40 C to +85 C; for UART communication an external crystal is required. Bootloader size is configurable via BOOTSZ fuses - reserve at least 2 KB for safe field firmware updates.

For SPI buses above 4 MHz, add 33 ohm series resistors at the driver output to dampen reflections on long traces (>50 mm). TWI (I2C) lines require 4.7 kohm pull-ups even for 100 kHz operation since the ATmega lacks internal pull-ups strong enough for reliable multi-master arbitration. The ADC result accuracy depends on clean AVCC and AREF - if ADC readings are noisy, add a 10 nF cap directly on AREF and reduce ADC clock to 200 kHz max for full 10-bit resolution.

コンプライアンス情報

RoHS
Compliant
REACH
Compliant
AEC-Q100
Not Qualified
鉛フリー
Yes
ハロゲンフリー
Unknown
紛争鉱物
Compliant

Green / lead-free per Microchip product page. AEC-Q100 not qualified - for automotive safety-grade designs an external supervisor IC is required. Halogen-free status not stated in verified data.

データ検証日: 2026-09-17 — データはXAIPARTの部品エンジニアリングチームによって検証・管理されています

関連検索

ATMEGA329PA-MU ATMEGA329PA-MU datasheet Microchip ATMEGA329PA-MU ATmega329PA 32KB flash 20MHz QFN 64-pin QFN AVR microcontroller ATMEGA329PA segment LCD controller ATMEGA329PA-MU vs ATMEGA325PA-MU ATMEGA329PA-MU drop-in replacement ATMEGA329PA-MU buy price ATMEGA329PA-MU pinout 64-QFN AVR picoPower 8-bit MCU battery powered ATMEGA329PA-MU lead time stock ATMEGA329PA-MU JTAG programming ATMEGA329PA-MU Atmel Studio Microchip Studio utility meter AVR microcontroller

関連部品&用語

Microchip Technology Atmel ATMEGA329PA-MU ATMEGA329PA-MUR ATMEGA329PA-MN ATMEGA649PA-MU ATMEGA325PA-MUR AVR AVR RISC architecture picoPower 8-bit microcontroller MCU ISP Flash EEPROM SRAM segment LCD controller QFN-64 TQFP-64 JTAG SPI TWI / I2C USART 10-bit ADC RoHS IEC 60601-1 JEDEC J-STD-020 industrial temperature grade AEC-Q100 battery-powered thermostat utility meter industrial HMI panel
クイック見積RFQ
詳細をすべてご記入ください — 営業チームが24時間以内にご返信いたします
部品番号 メーカー パッケージ QTY 目標価格 小計
合計: $0.00 USD
✓
見積を送信しました!

24時間以内にメールでご返信いたします

1
RFQ送信済み
2
見積受領
3
注文済み
4
お支払い
5
発送済み
6
配達済み
RFQの詳細を表示