ATMEGA644-20MUR - 8-bit AVR MCU 64KB Flash 20MHz | Microchip
料号： ATMEGA644-20MUR ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $6.86 | $6.86 |
| 10 | $6.35 | $63.50 |
| 100 | $5.85 | $585.00 |
| 500 | $5.4 | $2,700.00 |
| 1,000 | $5.05 | $5,050.00 |
ATMEGA644-20MUR 概述
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that executes most instructions in a single clock cycle, sitting within the microcontroller hierarchy between simple 8-bit MCUs and 32-bit ARM parts. ATmega devices integrate program flash, data SRAM, EEPROM, timers, USART, SPI, TWI (I2C), and a 10-bit ADC on a single die, making them complete embedded control solutions for cost-sensitive designs.
Key features include 64KB self-programmable flash with read-while-write support, 32 general-purpose I/O lines, three flexible timers/counters with compare modes and PWM, a 10-bit 8-channel ADC, and in-circuit serial programming (ICSP) compatible with the MPLAB SNAP and AVR ISP tools. The AVR core achieves close to 1 MIPS per MHz, so at 20 MHz the device delivers roughly 20 MIPS throughput while drawing low active current.
Architecturally, the ATmega644 uses 32 general-purpose working registers directly connected to the ALU, eliminating intermediate register access overhead. Boot-code sections enable field firmware updates through the flash read-while-write mechanism, and hardware debug support is available via debugWIRE.
Typical applications include industrial automation controllers, embedded sensor and instrumentation systems, motor and lighting control, and hobby/education platforms such as Arduino-compatible boards via the MightyCore hardware package.
Design consideration: this 5V part requires a 4.5V-5.5V rail; the picoPower ATMEGA644PA variant is required for 1.8V-5.5V low-power designs.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
直接替换替代料： ATMEGA644-20MUR ——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： ATMEGA644-20MUR （相同外形与封装尺寸） ——差异在于 EEPROM, Package, SRAM, Flash Memory, ADC.
快速对比工具——选择替代料号进行并排对比：
ATMEGA644PA-MU
✅ 直接替换✓ 有现货
$3.78 / 个
查看数据手册 →ATMEGA644P-20MUR
✅ 直接替换📋 参考替代料（不在目录中）
ATMEGA644PV-10MU
✅ 直接替换✓ 有现货
$4.88 / 个
查看数据手册 →ATMEGA1284-MUR
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$1.72 / 个
查看数据手册 →ATMEGA32A-MUR
✅ 直接替换📋 参考替代料（不在目录中）
ATMEGA644-20MUR 最大额定值与电气特性
| Core Architecture | 8-bit AVR RISC |
| Max Clock Frequency | 20 MHz |
| Program Memory (Flash) | 64KB (32K x 16) |
| SRAM | 4KB |
| EEPROM | 2KB |
| Supply Voltage Range | 4.5 V to 5.5 V |
| 数据总线宽度 | 8 Bit |
| General Purpose I/O | 32 I/O lines |
| Timers/Counters | 3 (with compare modes and PWM) |
| Communication Interfaces | USART, SPI, TWI (I2C) |
| ADC | 10-bit |
| Programming Interface | ICSP (In-Circuit Serial Programming), debugWIRE |
| 工作温度 | Industrial (-40C to +85C) |
| 封装 | 44-VQFN (7x7 mm) Exposed Pad |
| 安装类型 | Surface Mount |
| Lifecycle Stage | ACTIVE |
ATMEGA644-20MUR 44-vqfn (7x7 mm) exposed pad 引脚配置指南
ATMEGA644-20MUR（44-vqfn (7x7 mm) exposed pad 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： ATMEGA644-20MUR.
请参阅 数据手册 以查看完整引脚配置。
典型应用
ATMEGA644-20MUR 适用于 6 应用s: Industrial Automation Controllers, Embedded Sensor and Instrumentation Systems, IoT Sensor Nodes and Connected Devices, LED Lighting and Dimming Control, Hobby, Education, and Maker Platforms, Aftermarket Automotive Electronics.
Industrial Automation Controllers
The ATMEGA644-20MUR fits industrial automation nodes because its -40C to +85C industrial rating, 5V noise-tolerant I/O, and 64KB flash support robust PLC-adjacent control firmware. The three timers with compare modes and PWM directly drive motors, valves, and actuators, while the 10-bit ADC digitizes analog sensor inputs such as pressure and level transducers. In a typical deployment the MCU sits on a 5V industrial rail, communicates over RS-485 via its USART with an external transceiver, and uses SPI or TWI for local I/O expansion. Unlike 3.3V MCUs, its 5V logic gives higher noise margins near contactors and switching loads; the trade-off is higher dynamic power than picoPower variants, so choose the ATMEGA644PA for battery-backed nodes.
推荐
Embedded Sensor and Instrumentation Systems
In measurement and instrumentation front-ends, the ATMEGA644-20MUR's 10-bit ADC with eight multiplexed channels converts up to eight analog sensors, and its 4KB SRAM buffers data logging workloads that smaller ATmega328-class parts cannot hold. The 20 MHz AVR core executes roughly one MIPS per MHz, giving approximately 20 MIPS for filtering, scaling, and calibration math. Firmware is field-updatable through flash read-while-write boot sections, important for deployed instruments. A typical circuit uses the ADC with an external precision reference on AREF, TWI to a real-time clock and EEPROM, and USART to a host. Its 5V operation directly powers 5V analog signal chains, simplifying level shifting but increasing power dissipation versus low-voltage alternatives.
推荐
IoT Sensor Nodes and Connected Devices
For mains-powered IoT sensor nodes, the ATMEGA644-20MUR provides enough 64KB flash for protocol stacks and 2KB EEPROM for nonvolatile configuration, calibration tables, and device identity. Its USART and TWI interfaces connect to Wi-Fi, LoRa, or RS-485 communication modules, while the 10-bit ADC samples environmental sensors. The 44-VQFN 7x7 mm exposed-pad package supports compact two-layer node PCBs with solid ground return. Designers should note this 5V part is not optimized for battery duty cycles; where sleep current dominates, the ATMEGA644PA picoPower variant in the same footprint offers dramatically lower idle consumption. Typical nodes pair the MCU with a switching regulator from mains, a sensor array, and a wireless module, achieving reliable long-term unattended operation.
推荐
LED Lighting and Dimming Control
The ATMEGA644-20MUR suits intelligent lighting controllers because its three timers produce hardware PWM channels for flicker-free LED dimming, and the 20 MHz core handles DMX-512 or DALI protocol parsing in firmware via the USART. The 64KB flash stores multiple lighting scenes and communication stacks, while the 2KB EEPROM retains user-configured scenes across power cycles. Its 5V I/O drives MOSFET gate drivers directly with healthy noise margin in electrically noisy luminaire environments. A typical design uses timer PWM outputs through gate drivers to constant-current LED drivers, the ADC for thermal foldback monitoring of LED temperature, and TWI for user interfaces. The industrial temperature rating supports enclosed fixtures where ambient temperatures exceed consumer limits.
推荐
Hobby, Education, and Maker Platforms
The ATMEGA644-20MUR is a popular choice in the maker community because the MCUdude MightyCore Arduino hardware package provides full Arduino IDE support for ATmega644, enabling rapid prototyping with familiar tooling while doubling the flash of an ATmega328. Its 64KB flash accommodates large sketches, TFT display libraries, and multiple communication stacks simultaneously, and the 4KB SRAM prevents the heap fragmentation issues seen on 2KB parts. The 44-pin QFN is commonly adapted to DIP-40-style prototyping boards with published adapter designs. Educational courses use it to teach AVR architecture, timers, interrupts, and ADC operation with the MPLAB SNAP programmer providing low-cost in-circuit debugging through debugWIRE on the reset line.
推荐
Aftermarket Automotive Electronics
In aftermarket automotive modules such as gauges, telematics dongles, and body-control retrofits, the ATMEGA644-20MUR's industrial -40C to +85C range covers under-dash environments, and its 5V logic interfaces cleanly with legacy automotive 5V sensor signals. The 64KB flash supports CAN-through-USART gateways and OBD-II parsing firmware, while EEPROM stores vehicle calibration data and trip logs. Its three timers generate stepper-motor gauge drive sequences and backlight PWM. A typical module powers the MCU from a 5V linear regulator off the 12V battery rail with transient suppression, senses battery voltage through the ADC divider, and communicates over USART or TWI. Note that for genuinely high-temperature engine-bay locations, AEC-Q100-qualified parts should be evaluated instead.
推荐
推荐产品汇总
工程参考数据： ATMEGA644-20MUR ——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 | ATMEGA644PA-MU | ATMEGA644P-20MUR | ATMEGA644PV-10MU | ATMEGA1284-MU | ATMEGA32A-MUR |
|---|---|---|---|---|---|---|
| Package | 44-VQFN (7x7 mm) Exposed Pad | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same | 44-QFN - same footprint |
| Brand | Microchip Technology | Microchip Technology (Atmel) | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 64KB | 64KB | 64KB | 64KB | 128KB | 32KB |
| SRAM | 4KB | 4KB | 4KB | 4KB | 16KB | 2KB |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 10 MHz | 20 MHz | 16 MHz |
| Supply Voltage Range | 4.5 V to 5.5 V | 1.8 V to 5.5 V | 4.5 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 4.5 V to 5.5 V |
| USART Count | 1 | 1 | 2 | 1 | 2 | 1 |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| Key Special Feature | Standard ATmega644, 5V industrial | picoPower low consumption | Dual USART | Low-voltage 1.8V operation | 2x flash and 4x SRAM | Legacy cost-reduced part |
关键差异点
- Highest memory density among classic 5V ATmega644 variants （对比 ATMEGA32A-MUR)
- Lower cost than the picoPower successor in 5V-only systems （对比 ATMEGA644PA-MU)
- Upgrade headroom without redesign （对比 ATMEGA1284-MU)
设计说明
The ATMEGA644-20MUR requires a regulated 4.5V-5.5V rail; it cannot run at 20 MHz below 4.5V per the voltage-versus-frequency safe operating region of the ATmega644 family. Decouple VCC and AVCC independently with 100 nF ceramic capacitors placed within a few millimeters of each pin, plus 4.7-10 uF bulk at the board level. Power AVCC from VCC through a low-pass LC filter (e.g., 10 uH + 100 nF) when ADC accuracy matters, keeping switching-regulator ripple off the analog domain. Estimated: active current at 5V/20 MHz is in the ~10-15 mA class per family datasheet trends - verify against the current datasheet for your exact conditions.
The 44-VQFN 7x7 mm exposed pad must be soldered to a grounded thermal pad array on the PCB - it is the primary ground return for the die. Use a 3x3 via fence (approximately 0.3 mm vias) connecting the pad to the ground plane to improve heat spreading and manufacturability. For in-system programming, route the ICSP header (MOSI PB5, MISO PB6, SCK PB7, RESET) as short as possible and add a series 10k on RESET only if debugWIRE is not needed, since debugWIRE uses the RESET line for one-wire debugging with the MPLAB SNAP.
Three common pitfalls: (1) Assuming the ATmega644 has two USARTs - only the 644P/1284P variants do; firmware written for two UARTs will fail on this part. (2) Selecting this 5V-only part for a 3.3V design - use the ATMEGA644PA instead, which is footprint-compatible. (3) Leaving PB6/PB7 (MISO/SCK) loaded heavily during normal operation - these are also the SPI/ICSP pins, and excessive capacitive loading can break in-circuit programming. Keep series resistors (typically 1-10k) between the ISP pins and heavy peripheral loads.
When driving external crystal circuits, place the crystal within 10 mm of XTAL1/XTAL2 with ground-guard traces and load capacitors matched to the crystal specification (typically 12-22 pF). Avoid routing fast-switching PWM or USART lines directly adjacent to the XTAL traces. For ADC measurements, keep analog traces away from PWM and crystal lines and sample with the noise-canceling feature described in the family datasheet to improve effective resolution.
合规信息
Compliance statuses were not stated in the provided verified web data; verify RoHS/REACH status on the official Microchip product page. Not an automotive AEC-Q100 part.