ATMEGA644PA-PU - 8-bit AVR MCU 20MHz 64KB Flash DIP-40 | Microchip
部品番号: ATMEGA644PA-PU ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $7.81 | $7.81 |
| 10 | $7.03 | $70.30 |
| 100 | $6.35 | $635.00 |
| 500 | $5.72 | $2,860.00 |
| 1,000 | $5.15 | $5,150.00 |
ATMEGA644PA-PU 概要
A microcontroller (MCU) is a single-chip computer that integrates a processor core, program memory, data memory, and peripherals such as timers and serial interfaces on one die. The ATmega family sits within the broader hierarchy of 8-bit microcontrollers under the AVR architecture, a category widely used in embedded systems, industrial control, and hobbyist electronics such as Arduino-compatible boards.
Key features include 64 KB of self-programmable ISP Flash with read-while-write capability, an 8-channel 10-bit ADC, two USARTs for serial communication, a byte-oriented Two-Wire (I2C-compatible) interface, and three flexible timer/counters with compare modes and PWM outputs. The picoPower technology provides multiple sleep modes for battery-powered designs.
Architecturally, the AVR core executes most instructions in a single clock cycle using 32 general purpose working registers, achieving throughput of up to 20 MIPS at 20 MHz. In-system programmability allows firmware updates without removing the chip from the PCB, and boot-code sections support self-programming for field upgrades.
Typical applications include industrial automation controllers, sensor data loggers, motor control boards, and educational or prototyping platforms. The through-hole DIP-40 package makes this version especially popular for breadboard prototyping, repair of legacy equipment, and low-volume production where hand soldering is required.
One design consideration: the DIP-40 package occupies significant board area compared to the 44-pin TQFP (ATMEGA644PA-AU) sibling, so high-density designs should evaluate surface-mount variants, while prototyping and serviceability favor the -PU.
This page synthesizes verified distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, with pricing referenced as of 2026-09-18.
ドロップイン代替品: ATMEGA644PA-PU — 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: ATMEGA644PA-PU （同一形状・フットプリント） — 相違点: Package, SRAM, EEPROM, Flash Memory, Operating Temperature.
クイック比較ツール — 並列比較する代替部品を選択:
ATMEGA644P-20PU
✅ ドロップイン ⚠️ 仕様未検証✓ 在庫あり
$8.55 / 個
データシートを見る →ATMEGA1284P-PU
✅ ドロップイン ⚠️ 仕様未検証✓ 在庫あり
$6.05 / 個
データシートを見る →ATMEGA32A-PU
✅ ドロップイン✓ 在庫あり
$3.85 / 個
データシートを見る →ATMEGA644PA-PU 最大定格＆電気的特性
| Core Architecture | 8-bit AVR RISC |
| Core Series | AVR ATmega |
| 最大クロック周波数 | 20 MHz |
| Flash Memory | 64 KB (32K x 16) |
| SRAM | 4 KB |
| EEPROM | 2 KB |
| General Purpose I/O Lines | 32 |
| Working Registers | 32 |
| ADC | 8-channel, 10-bit |
| USART Interfaces | 2 |
| Two-Wire Interface | Yes (byte-oriented, I2C-compatible) |
| Timer/Counters | 3, with compare modes and PWM |
| Low Power Technology | picoPower |
| パッケージ | 40-PDIP (0.600 in, 15.24 mm) |
| 実装タイプ | Through Hole |
ATMEGA644PA-PU 40-pdip (0.600 in, 15.24 mm) ピン配置ガイド
ATMEGA644PA-PU (40-pdip (0.600 in, 15.24 mm) パッケージ) のピン配置。 このデジタルICには、GPIO、通信インターフェース (UART、SPI、I2C)、および電源ピンが含まれています。代替ピン機能と設定オプションについては、メーカーのデータシートを参照してください。組み込みシステム設計とPCBレイアウトに不可欠です。
詳細なピン配置データはありません: ATMEGA644PA-PU.
詳細は データシート をご参照ください。
主な用途
ATMEGA644PA-PU の用途: 6 件s: Industrial Automation Controllers, Sensor Data Loggers, Education and Prototyping Platforms, Motor Control and PWM Systems, Legacy Equipment Repair and Retrofit, Serial Communication Gateways.
Industrial Automation Controllers
The ATMEGA644PA-PU fits industrial control nodes that need deterministic 8-bit processing, generous memory headroom, and rugged through-hole assembly. Its 64 KB Flash stores complex state machines and communication stacks, while 4 KB SRAM buffers sensor data and protocol frames. The two USARTs allow simultaneous RS-485 Modbus and debug console operation, and the three timer/counters with PWM drive actuators directly. The picoPower architecture keeps standby consumption low between polling cycles. In DIP-40 form it can be socketed, allowing field replacement of the controller without desoldering - a practical advantage for serviceable industrial equipment with long product lifetimes.
おすすめ
Sensor Data Loggers
Battery-powered data loggers benefit directly from the ATMEGA644PA-PU's picoPower sleep modes and its real-time counter that runs asynchronously in power-save mode, timestamping events while the CPU sleeps. The 8-channel 10-bit ADC samples multiple sensors - temperature, pressure, humidity - without external conversion ICs, and 2 KB EEPROM stores calibration constants that survive power loss and firmware updates. The 64 KB Flash accommodates logging firmware plus a boot loader for field upgrades over the serial port. Designers typically wake the device on a timer interrupt, burst-sample the ADC array, write results to external storage via SPI, and return to deep sleep, extending battery life to months or years.
おすすめ
Education and Prototyping Platforms
The DIP-40 package is the defining advantage for education: students can insert the ATMEGA644PA-PU into a breadboard or ZIF socket, program it with a low-cost ISP programmer, and swap chips between projects in seconds. With 64 KB Flash and 4 KB SRAM, it comfortably hosts larger student projects - display drivers, game firmware, multi-peripheral labs - that exceed the 32 KB limit of smaller ATmega parts. The 32 I/O lines expose every port on standard 0.1-inch pitch, ideal for teaching GPIO, ADC sampling, PWM, TWI, and UART fundamentals. Its architecture is compatible with the open-source avr-gcc toolchain and Arduino-style boot loaders, giving learners a professional-grade development path.
おすすめ
Motor Control and PWM Systems
The ATMEGA644PA-PU's three flexible timer/counters with compare modes and PWM outputs make it a strong fit for small motor control: DC motor speed control, servo positioning, and stepper sequencing. Two 8-bit timers handle fast PWM generation while the 16-bit timer provides precise period control for servo pulses or encoder timing. The 10-bit ADC reads current-sense shunts and potentiometers for closed-loop speed regulation, and interrupt-driven USARTs connect to higher-level controllers over RS-485. Running at 20 MHz, the single-cycle AVR core executes control loops fast enough for most mechatronic tasks, and 32 I/O lines interface directly with H-bridge drivers and limit switches without glue logic.
おすすめ
Legacy Equipment Repair and Retrofit
Many older industrial boards, consumer appliances, and scientific instruments used 40-pin DIP microcontrollers that are now discontinued. The ATMEGA644PA-PU, being socketed in these designs or adaptable to them, serves as a retrofit controller: its through-hole package matches legacy footprints, and its ample 64 KB Flash absorbs re-implemented firmware plus expansion. Service engineers appreciate that socketed DIP devices can be replaced in minutes with no reflow equipment, and in-system programming means the replacement chip can be flashed on the bench before installation. Where the original part carried less memory, the 644PA provides headroom to add modern features such as serial logging during the retrofit.
おすすめ
Serial Communication Gateways
With two independent USARTs plus a byte-oriented Two-Wire (I2C-compatible) interface, the ATMEGA644PA-PU naturally implements protocol converters and gateways: for example, bridging a Modbus RTU RS-485 bus to a TTL serial display or an I2C sensor network. The 4 KB SRAM supports ring buffers on both UARTs simultaneously, preventing data loss during burst traffic, while the 64 KB Flash holds multiple protocol stacks. Interrupt-driven USART handling combined with the single-cycle core sustains 115200 baud on both ports with CPU capacity to spare for framing, checksums, and address filtering. The picoPower design also suits intermittently-powered field gateways that sleep between polling windows.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: ATMEGA644PA-PU — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | ATMEGA644P-20PU | ATMEGA1284P-PU | ATMEGA32A-PU |
|---|---|---|---|---|
| Package | 40-PDIP (0.600 in, 15.24 mm) | 40-PDIP (0.600 in) - same | 40-PDIP (0.600 in) - same | 40-PDIP (0.600 in) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core | 8-bit AVR RISC | 8-bit AVR RISC | 8-bit AVR RISC | 8-bit AVR RISC |
| Max Clock Speed | 20 MHz | 20 MHz | 20 MHz | 16 MHz |
| Flash Memory | 64 KB | 64 KB | 128 KB | 32 KB |
| SRAM | 4 KB | 4 KB | 16 KB | 2 KB |
| EEPROM | 2 KB | 2 KB | 4 KB | 1 KB |
| Low Power Technology | picoPower | Standard (higher sleep current) | picoPower | Standard |
| Mounting Type | Through Hole | Through Hole | Through Hole | Through Hole |
主な差別化要因
- picoPower low-power architecture （vs ATMEGA644P-20PU)
- Double the memory of the common ATMEGA32A-PU in the same DIP-40 footprint （vs ATMEGA32A-PU)
- Lowest-cost entry point to the 64 KB AVR class （vs ATMEGA1284P-PU)
設計ノート
Decouple VCC with a 0.1 uF ceramic capacitor placed as close as possible to the supply pin, plus a bulk 10 uF capacitor per board section. AVR devices draw transient charging current on each clock edge; long supply traces without local decoupling cause reset glitches and ADC noise. If powering from a switching supply, add an RC or ferrite filter before the MCU to reduce ripple coupled into the 10-bit ADC reference, which directly degrades conversion accuracy.
For the DIP-40 package, if you socket the part, use a machined-pin or dual-wipe socket - low-cost solder-tail sockets add contact resistance that worsens over time in humid environments. Keep the ISP header (MOSI, MISO, SCK, RESET, VCC, GND) routed short and away from motor or relay wiring, since SPI programming lines are sensitive to induced transients that can corrupt in-system programming sessions.
When migrating code from ATMEGA644P-20PU or ATmega32A to the ATMEGA644PA-PU, recompile against the correct device header: register addresses differ between the ATmega32 and ATmega644 families despite the similar pinout, so binaries are not interchangeable. Also confirm fuse settings (clock source, brown-out detector, and JTAG/SPI enable) after replacement - incorrect clock fuses are the most common cause of a 'dead' new chip out of the box.
コンプライアンス情報
Compliance status was not explicitly stated in the provided web data; verify RoHS/REACH status on the official Microchip product page before procurement.
