ATMEGA644A-AU - 8-bit AVR MCU 20MHz 64KB Flash | Microchip
MPN: ATMEGA644A-AU ✓ Hoạt độngATMEGA644A-AU Tóm tắt
An 8-bit microcontroller is a single-chip processor that integrates a CPU, memory, and peripherals onto one die, sitting within the broader hierarchy of semiconductor devices under the microcontroller IC category (MCU -> embedded processor -> integrated circuit). AVR parts from Microchip use an enhanced RISC core that executes most instructions in a single clock cycle, delivering roughly one MIPS per MHz of CPU throughput, which lets designers trade clock speed directly against power consumption.
Key features include 64 KB of In-System Programmable Flash with Read-While-Write capability, a 2 KB EEPROM for data retention through power cycles, and 32 general purpose I/O lines. The peripheral set covers three flexible Timer/Counters with compare modes and PWM outputs, two USARTs, a byte-oriented 2-wire interface (TWI, I2C-compatible), and an SPI serial port. An 8-channel 10-bit ADC with an optional internal reference and a Real Time Counter round out the analog and timing resources.
Architecturally, the ATmega644A pairs its AVR core with 32 general purpose working registers that are directly connected to the arithmetic logic unit, allowing one-cycle register access. In-System Programming through SPI and self-programming boot code enable field firmware updates without removing the device from the PCB, while code lock bits provide three levels of intellectual property protection.
Typical applications include industrial automation nodes such as sensor acquisition and motor control, embedded instrumentation and test fixtures, and educational or hobby embedded platforms supported by Arduino-compatible toolchains like MightyCore.
For design, operate the internal RC oscillator or drive XTAL1/XTAL2 with an external crystal up to 20 MHz, and budget brown-out detection configuration carefully when running near the 1.8 V supply floor.
This page synthesizes verified distributor data, drop-in alternatives, and practical design notes not found in the manufacturer datasheet. Pricing references are as of 2026-09-18.
Bộ thay thế dễ dàng lắp đặt cho ATMEGA644A-AU — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với ATMEGA644A-AU (cùng hình factor và footprint) — khác nhau ở Package, Timer/Counters, Serial Interfaces, Core Architecture, EEPROM.
ATMEGA644-20AU
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ATMEGA644P-20AU
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ATMEGA644PA-AU
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ATMEGA644A-AU Tỷ lệ tối đa & tính chất điện
| Core Architecture | 8-bit AVR enhanced RISC |
| Program Memory Size | 64 KB Flash (32K x 16) |
| Program Memory Type | ISP FLASH with Read-While-Write |
| EEPROM | 2 KB |
| SRAM | 4 KB |
| Maximum CPU Speed | 20 MHz (20 MIPS) |
| Supply Voltage Range | 1.8 V to 5.5 V |
| General Purpose I/O | 32 lines |
| Working Registers | 32 general purpose registers |
| USART | 2 |
| Timer/Counters | 3 (with compare modes and PWM) |
| ADC | 8-channel, 10-bit |
| Serial Interfaces | TWI (2-wire, I2C-compatible), SPI |
| Real Time Counter | Yes (RTC) |
| Hộp | 44-TQFP (10x10 mm) |
| Kiểu lắp đặt | Surface Mount |
| Nhiệt độ hoạt động | -40C to +85C (Industrial) |
| Device Series | ATmega644A |
Hướng dẫn cấu hình chân ATMEGA644A-AU 44-tqfp (10x10 mm)
Cấu hình chân cho ATMEGA644A-AU (44-tqfp (10x10 mm) gói). IC số này bao gồm chân GPIO, giao diện truyền thông (UART, SPI, I2C) và chân nguồn. Tham khảo tài liệu thông số kỹ thuật của nhà sản xuất để biết các chức năng chân thay thế và tùy chọn cấu hình. Cực kỳ quan trọng cho thiết kế hệ thống tích hợp và lập trình PCB.
Không có dữ liệu chân cụ thể sẵn có cho ATMEGA644A-AU.
Tham khảo: tài liệu kỹ thuật cho cấu hình chân đầy đủ.
Ứng dụng tiêu biểu
ATMEGA644A-AU phù hợp cho 6 Áp dụngs: Industrial Automation and Sensor Nodes, Embedded Test and Measurement Instruments, Motor Control and PWM Actuation, IoT Sensor Endpoints and Smart Home Devices, Educational and Hobby Embedded Platforms, Medical and Health Monitoring Devices.
Industrial Automation and Sensor Nodes
The ATMEGA644A-AU fits factory-floor sensor acquisition nodes because its 8-channel 10-bit ADC digitizes multiple analog sensors directly, its two USARTs support RS-485/Modbus fieldbus links, and its 32 GPIO lines drive relays and status indicators. The industrial -40C to +85C temperature rating and wide 1.8 V to 5.5 V supply tolerance handle harsh cabinet environments and noisy power rails. In a typical node, the MCU polls sensors over TWI or SPI, filters readings in the 4 KB SRAM, and reports upstream through a USART at 115200 baud, while the 64 KB Flash holds protocol stacks and OTA-updatable firmware. PWM timers can simultaneously modulate actuator outputs without CPU intervention.
Được đề xuất
Embedded Test and Measurement Instruments
Bench instruments such as data loggers, signal generators, and calibration fixtures benefit from the ATMEGA644A-AU's combination of 64 KB Flash for command parsers and menus, two USARTs for PC and front-panel links, and three timers for precise waveform timing. The 10-bit ADC with optional internal reference captures analog inputs for measurement channels, while TWI and SPI manage external DACs, precision references, and EEPROM configuration storage. Because the AVR core executes one MIPS per MHz, time-critical trigger handling at 20 MHz achieves deterministic single-cycle register access, and Read-While-Write flash lets the instrument update its own firmware in the field through a boot section without a programmer visit.
Được đề xuất
Motor Control and PWM Actuation
Three flexible Timer/Counters with compare modes and PWM outputs make the ATMEGA644A-AU well suited to small motor and actuator control boards such as DC motor drivers, servo banks, and stepper indexers. At 20 MHz the AVR core closes control loops fast enough for most low-end motion applications, while hardware PWM channels produce jitter-free drive waveforms without CPU load. The 10-bit ADC reads back current shunts and position pots for closed-loop correction, and the 32 GPIO lines handle limit switches and encoder quadrature inputs. Operating from a single 5 V rail simplifies gate-driver interfacing, and the industrial temperature range supports enclosed drives near heat sources.
Được đề xuất
IoT Sensor Endpoints and Smart Home Devices
For mains- or battery-backed IoT endpoints such as environmental monitors and smart home controllers, the ATMEGA644A-AU provides ample 64 KB Flash for lightweight TCP/MQTT stacks over external radio modules connected via SPI or USART. The TWI bus reads humidity, temperature, and light sensors, while the ADC samples analog gas or current sensors. The 2 KB EEPROM retains calibration and network credentials through power cycles without external storage. Designs targeting sleep-dominated duty cycles should prefer the pin-compatible ATMEGA644PA-AU with picoPower for its lower sleep current, keeping the same PCB layout, firmware, and footprint while extending battery life substantially in always-on sensing products.
Được đề xuất
Educational and Hobby Embedded Platforms
The ATMEGA644A-AU is a popular teaching MCU because the open-source MightyCore Arduino hardware package on GitHub explicitly supports ATmega1284, ATmega644, ATmega324, and ATmega164, giving students the familiar Arduino API on a bigger canvas: 64 KB Flash, 4 KB SRAM, and 32 GPIO versus the classic Uno's 32 KB/2 KB. Two USARTs allow one channel for debugging and another for Bluetooth or GPS modules simultaneously, and the 8-channel 10-bit ADC supports multi-sensor lab exercises. The device programs through a standard 6-pin ISP header with low-cost programmers, and its 20 MHz crystal clock delivers headroom for interrupt-driven classroom projects such as robots, displays, and data loggers.
Được đề xuất
Medical and Health Monitoring Devices
Non-invasive, battery- or adapter-powered health devices such as pulse oximeter demonstrators, weight scales, and physiotherapy trainers leverage the ATMEGA644A-AU's 10-bit ADC for photodiode and bridge-transducer front ends, its TWI interface for digital temperature and pressure sensors, and its USART for Bluetooth data upload. The 4 KB SRAM accommodates signal-processing buffers for filtering heart-rate or impedance waveforms, while 64 KB Flash holds calibration tables and user interface assets for a small LCD driven over GPIO or SPI. The wide 1.8 V to 5.5 V supply range permits direct 3 V lithium-coin-cell designs, and the 2 KB EEPROM securely retains patient calibration data between sessions without external nonvolatile memory.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho ATMEGA644A-AU — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | ATMEGA644-20AU | ATMEGA644P-20AU | ATMEGA644PA-AU |
|---|---|---|---|---|
| Package | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 64 KB ISP Flash | 64 KB ISP Flash | 64 KB ISP Flash | 64 KB ISP Flash |
| SRAM / EEPROM | 4 KB / 2 KB | 4 KB / 2 KB | 4 KB / 2 KB | 4 KB / 2 KB |
| Maximum Clock Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Supply Voltage Range | 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 |
| Low-Power (picoPower) | No | No | Yes | Yes |
Bảo phân biệt quan trọng
- Baseline cost-optimized choice within the 64 KB pin-compatible family (vsATMEGA644P-20AU)
- Newer manufacturing process versus original ATmega644 (vsATMEGA644-20AU)
- Better value than the PA variant for non-battery products (vsATMEGA644PA-AU)
Ghi chú thiết kế
Estimate: budget decoupling with 100 nF ceramic capacitors at each of the VCC pins plus one bulk 10 uF per supply rail, placed within a few millimeters of the package. When running from a 5 V rail at 20 MHz, dynamic current scales linearly with clock frequency, so a switch to 3.3 V operation cuts core power by more than half but caps maximum frequency per the datasheet speed-versus-voltage curve - verify the curve before clocking 20 MHz below 4.5 V. Enable the internal brown-out detector for designs whose EEPROM writes must survive brown-outs.
The 44-TQFP (10x10 mm) is hand-solderable with a drag-soldering tip but fine-pitch layout requires 0.8 mm pitch land patterns per the Microchip package drawing. Place the 20 MHz crystal and its load capacitors directly beside XTAL1/XTAL2 with short, direct traces and a local ground guard to avoid stray coupling from PWM lines. Route the ADC analog inputs away from USART and PWM traces, and use the exposed grounding of a solid ground plane to keep the 10-bit ADC noise floor low. Provide a 6-pin ISP header on every production board for field reprogramming.
A frequent migration mistake is assuming every ATmega644 variant shares identical electrical characteristics: Microchip application note AVR536 warns that although ATmega644A is a functionally identical drop-in for ATmega644, the different manufacturing process means some electrical characteristics differ, so datasheet timing and current tables should be re-checked when swapping family members. Also remember that EEPROM writes have limited endurance, so avoid logging to EEPROM in tight loops; buffer in SRAM and write in blocks. JTAG/PDI pin functions should be disabled via fuse settings when those pins are needed as GPIO.
Thông tin tuân thủ
RoHS status per standard Microchip commercial MCU offering; REACH, lead-free, and halogen-free statuses were not explicitly stated in the provided web data and should be confirmed against the Microchip environmental page.