ATMEGA644PA-PU - 8-bit AVR MCU 20MHz 64KB Flash DIP-40 | Microchip
料号： ATMEGA644PA-PU ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 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 概述
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.
直接替换替代料： ATMEGA644PA-PU ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： ATMEGA644PA-PU （相同外形与封装尺寸） ——差异在于 Package, SRAM, EEPROM, Flash Memory, Operating Temperature.
快速对比工具——选择替代料号进行并排对比：
ATMEGA644P-20PU
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$8.55 / 个
查看数据手册 →ATMEGA1284P-PU
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$6.05 / 个
查看数据手册 →ATMEGA32A-PU
✅ 直接替换✓ 有现货
$3.85 / 个
查看数据手册 →ATMEGA644PA-PU 最大额定值与电气特性
| Core Architecture | 8-bit AVR RISC |
| Core Series | AVR ATmega |
| 最大时钟频率 | 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 |
| 封装 | 40-PDIP (0.600 in, 15.24 mm) |
| 安装类型 | Through Hole |
ATMEGA644PA-PU 40-pdip (0.600 in, 15.24 mm) 引脚配置指南
ATMEGA644PA-PU（40-pdip (0.600 in, 15.24 mm) 封装）的引脚配置。 该数字 IC 包含 GPIO、通信接口（UART、SPI、I2C）和电源引脚。请参阅制造商数据手册以了解复用引脚功能和配置选项。对嵌入式系统设计和 PCB 布局至关重要。
暂无详细引脚数据： ATMEGA644PA-PU.
请参阅 数据手册 以查看完整引脚配置。
典型应用
ATMEGA644PA-PU 适用于 6 应用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.
推荐
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.
推荐
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.
推荐
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.
推荐
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.
推荐
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.
推荐
推荐产品汇总
工程参考数据： ATMEGA644PA-PU ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | 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 |
关键差异点
- picoPower low-power architecture （对比 ATMEGA644P-20PU)
- Double the memory of the common ATMEGA32A-PU in the same DIP-40 footprint （对比 ATMEGA32A-PU)
- Lowest-cost entry point to the 64 KB AVR class （对比 ATMEGA1284P-PU)
设计说明
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.
合规信息
Compliance status was not explicitly stated in the provided web data; verify RoHS/REACH status on the official Microchip product page before procurement.
