ATMEGA644PA-ANR - 8-bit AVR MCU 64KB Flash 44-TQFP | Microchip
MPN： ATMEGA644PA-ANR ✓ 啟用中ATMEGA644PA-ANR 概覽
A microcontroller (MCU) is a single integrated circuit that combines a processor core, memory, and programmable peripherals into one chip, forming the heart of embedded systems. The ATmega family sits within the broader hierarchy of 8-bit microcontrollers, part of Microchip's AVR line, which is widely used in industrial control, consumer devices, and hobbyist electronics. picoPower technology makes this part a member of the low-power MCU class suited for battery-operated designs.
Key features include an advanced RISC architecture with 131 powerful instructions, most executing in a single clock cycle, and throughput up to 20 MIPS at 20 MHz. Peripherals include two USARTs, an 8-channel 10-bit ADC, a byte-oriented Two-Wire Interface (TWI/I2C), SPI, three flexible timer/counters with compare modes and PWM, a real-time counter, an on-chip 2-cycle multiplier, and an on-chip debug interface. The picoPower technology supports multiple sleep modes for aggressive power reduction.
The ATMEGA644PA-ANR is manufactured in Microchip's high-density nonvolatile memory process, and the ISP Flash can be reprogrammed in-system through the SPI serial interface, by a conventional programmer, or by an on-chip boot program, enabling firmware updates in the field. Verified data lists a 16 MHz speed grade with operation to 105 C and a Tape & Reel (TR) supply format.
Typical applications include industrial automation nodes, sensor acquisition systems using the 10-bit ADC, motor control with PWM timers, and embedded communication products using the dual USARTs or TWI bus.
A key design consideration: the AVR core is fully static, so clock speed can be scaled down to reduce power, and the internal RC oscillator eliminates an external crystal in non-timing-critical designs.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
直接替換替代品，適用於 ATMEGA644PA-ANR — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： ATMEGA644PA-ANR （相同外形與佔位） — 差異在於 RoHS Status, Package, SRAM, Core Architecture, EEPROM.
ATMEGA644PA-AUR
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA644PA-AU
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA644P-20PQ
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA644-20AU
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA324PA-AU
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA164PA-AU
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA644PA-ANR 最大額定值與電氣特性
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 16 MHz |
| Program Memory Size | 64 KB (32K x 16) |
| Program Memory Type | FLASH |
| EEPROM Size | 2 KB |
| RAM Size | 4 KB |
| Number of I/O | 32 |
| Oscillator Type | Internal |
| Peripherals | Brown-out Detect/Reset, POR, PWM, WDT |
| Connectivity | I2C, SPI, USART |
| ADC Resolution | 10-bit, 8 channels |
| Architecture Features | 131 instructions, most single-cycle, 2-cycle on-chip multiplier |
| 封裝 / 外殼 | 44-TQFP (10x10 mm) |
| 工作溫度 | -40C to +105C |
| 安裝類型 | Surface Mount |
| Packaging | Tape & Reel (TR) |
| Technology | picoPower |
| RoHS 狀態 | Green (RoHS compliant per FindIC listing) |
ATMEGA644PA-ANR 44-tqfp (10x10 mm) 腳位配置指南
ATMEGA644PA-ANR（44-tqfp (10x10 mm) 封裝）的腳位配置。 此數位 IC 包含 GPIO、通訊介面（UART、SPI、I2C）與電源腳位。替代腳位功能與配置選項請參閱製造商資料表。對嵌入式系統設計與 PCB 佈局至關重要。
無詳細腳位定義資料： ATMEGA644PA-ANR.
請參閱 資料表 以查看完整腳位配置。
典型應用
ATMEGA644PA-ANR 適用於 6 應用s: Industrial Automation Nodes, Sensor Acquisition Systems, Motor Control with PWM, Embedded Communication Products, Battery-Powered Portable Devices, Hobby and Rapid Prototyping Platforms.
Industrial Automation Nodes
The ATMEGA644PA-ANR fits industrial automation nodes because it combines 64 KB Flash for protocol stacks and state machines, 32 GPIO lines for driving relays and reading limit switches, and an operating range of -40C to +105C per Mouser data, which covers control-cabinet temperatures. Its two USARTs, TWI (I2C), and SPI buses let one MCU bridge field sensors to a supervisory controller, while the brown-out detector and watchdog timer (WDT peripherals listed in verified data) provide fault recovery in unattended installations. Used as a Modbus-over-UART or TWI slave, the 10 MIPS single-cycle RISC core handles communication framing without external co-processors. The trade-off is that heavy communication workloads are software-polled unless interrupt-driven ISRs are carefully sized within the 4 KB SRAM.
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Sensor Acquisition Systems
The ATMEGA644PA-ANR is well matched to sensor acquisition systems because its integrated 8-channel 10-bit ADC digitizes up to eight analog sensor inputs without an external converter, and picoPower sleep modes keep average current low in battery-powered dataloggers. The 4 KB SRAM provides buffering for multi-channel sample streams, and the 2-cycle on-chip multiplier accelerates calibration math such as offset and gain correction in firmware. Designers typically sample via the ADC in interrupt mode, store results in RAM, and stream data out over one USART to a radio or logging module, while the second USART services a debug console. A performance consideration: ADC accuracy depends on AVCC filtering and AREF stability, so decoupling quality directly determines effective resolution in noisy industrial environments.
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Motor Control with PWM
The ATMEGA644PA-ANR supports motor control applications through its three flexible timer/counters with compare modes and PWM, listed among the product's peripherals, which generate the gate-drive waveforms for DC motor H-bridges or stepper drivers. The 16 MHz RISC core closes speed and current loops in software, and the 10-bit ADC reads back shunt-resistor current or tachometer feedback. Because the device is fully static, PWM frequency and loop rate can be traded against power consumption. The 32 I/O lines leave headroom for limit switches, encoders, and fault inputs on the same chip. The key trade-off: unlike dedicated motor MCUs, this AVR has no hardware quadrature decoder or FOC accelerator, so commutation complexity is bounded by firmware bandwidth and must be budgeted within the 64 KB Flash.
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Embedded Communication Products
With two USARTs, SPI, and a byte-oriented TWI (I2C) interface, the ATMEGA644PA-ANR serves embedded communication products such as protocol converters, gateways, and remote I/O modules. A common topology uses USART1 for the field link (RS-485 via external transceiver), USART0 for a cellular or radio module, and TWI for local configuration EEPROMs or RTCs. The 64 KB ISP Flash with read-while-write support allows an on-chip boot program to download new application firmware through any of these interfaces, enabling field upgrades - a capability explicitly described in the Microchip datasheet. Performance is limited by the 16 MHz clock, so sustained line rates above roughly a few hundred kbps with heavy framing should be benchmarked; the 4 KB SRAM must be partitioned between buffers and stack.
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Battery-Powered Portable Devices
The picoPower technology of the ATMEGA644PA-ANR makes it a strong choice for battery-powered portable devices such as hand-held meters, remote controls, and portable instrumentation. The internal oscillator option eliminates crystal drive current in non-timing-critical modes, the core is fully static and can be clocked down to DC, and multiple sleep modes allow the MCU to spend most of its duty cycle in low-current standby while a watchdog or external event wakes it. The 32 GPIOs and 10-bit ADC support front-panel keys and battery-voltage monitoring on one chip. Design consideration: battery life is dominated by sleep-mode and brown-out-detector currents, so these figures from the datasheet electrical characteristics should anchor the power budget estimate rather than active-mode numbers.
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Hobby and Rapid Prototyping Platforms
The ATMEGA644PA-ANR is popular in hobby and rapid-prototyping platforms because it is the same AVR architecture as the ubiquitous ATmega328P but offers 4x the Flash (64 KB vs 16 KB) and 4x the SRAM (4 KB vs 1 KB), with the same TQFP-44 pin-compatible family layout. Existing AVR toolchains, ISP programmers, and bootloaders work unchanged, and the internal oscillator plus brown-out reset allow minimal-component breadboard designs. For prototyping, engineers typically wire an ISP header to pins dedicated to SPI (MOSI/MISO/SCK/RESET) so firmware can be iterated without desoldering. The consideration is that the 44-TQFP package requires adapter boards for breadboarding, unlike DIP-packaged ATmega328P parts, so plan a breakout PCB or use a DIP sibling such as ATMEGA644P-20PU for early-stage work.
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推薦產品摘要
工程參考資料，適用於 ATMEGA644PA-ANR — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | ATMEGA644PA-AUR | ATMEGA644P-20PQ | ATMEGA324PA-AU | ATMEGA164PA-AU |
|---|---|---|---|---|---|
| Package | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) - same | 44-TQFP - same | 44-TQFP - same | 44-TQFP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory (Flash) | 64 KB (32K x 16) | 64 KB | 64 KB | 32 KB | 16 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 2 KB | 1 KB |
| Speed | 16 MHz (listed) | 16 MHz | 20 MHz | 20 MHz | 20 MHz |
| Technology | picoPower | picoPower | picopower (P variant) | picoPower | picoPower |
主要差異化特點
- 4x program memory of mainstream AVR (對比ATMEGA164PA-AU)
- picoPower low-power technology (對比ATMEGA644-20AU)
- Extended temperature operation (對比ATMEGA644PA-AU)
設計說明
For the 44-TQFP package, decouple both VCC and AVCC pins with 100 nF ceramic capacitors placed within 5 mm of each pin, plus a bulk 10 uF capacitor near the supply entry. Connect AVCC to VCC through an LC filter (ferrite bead plus capacitor) when ADC accuracy matters, because switching noise from digital I/O couples into the ADC reference. Tie AREF to ground through a 100 nF capacitor when using the internal reference, and never drive AREF externally while the internal reference is enabled, per the Microchip datasheet usage guidance.
Route the RESET pin (pin 4 of the TQFP-44) with a 10 kOhm pull-up to VCC and bring it to an ISP header - this enables in-system programming of the 64 KB Flash without desoldering the device, which is essential for field firmware updates via the on-chip boot loader. Keep the XTAL1/XTAL2 crystal traces short (under 10 mm) with guard ground if an external crystal is used; when the internal RC oscillator is sufficient, omit the crystal entirely to save board space and reduce startup time.
Do not exceed the 16 MHz speed grade listed for the -ANR suffix when selecting system clock settings - verified distributor data lists this part at 16 MHz, while 20 MHz-capable siblings exist, so configure fuses for a clock within the rated limit at your supply voltage. When substituting from ATMEGA644P (non-A) parts, re-verify picoPower sleep-mode currents and errata fixes, since the 'PA' variant incorporates power-consumption improvements that firmware power budgets may depend on.
合規資訊
FindIC lists the part as 'Green' (RoHS-compliant, lead-free). REACH, halogen-free, and conflict-minerals status not stated in verified data.