ATMEGA645A-MUR - 8-bit AVR MCU 64KB Flash 64-QFN | Microchip
MPN： ATMEGA645A-MUR ✓ 啟用中ATMEGA645A-MUR 概覽
An 8-bit AVR microcontroller is a self-contained computing IC that integrates a RISC processor core, program memory, data memory, peripherals, and general-purpose I/O on a single die. Within the power-management and embedded-systems hierarchy, MCUs like the ATmega645A sit at the application-control layer, executing user firmware that reads sensors, drives actuators, and manages communication in appliances, instruments, and industrial equipment.
Key features of the ATMEGA645A-MUR include the AVR enhanced RISC architecture executing most instructions in a single clock cycle, 54 general-purpose I/O lines (with the family supporting up to 54/69 I/O depending on package), 32 general-purpose working registers, in-system programmable Flash with read-while-write capability, and an industrial temperature range suitable for demanding environments. The A-suffix silicon revision offers improved performance over the original ATmega645.
Technically, the device combines a Harvard-architecture 8-bit core with 64 KB (32K x 16) Flash organized for ISP programming, 2 KB of nonvolatile EEPROM for parameter storage, and 4 KB of internal SRAM for runtime data. Peripherals typically include an 8-channel 10-bit ADC, analog comparator, USART serial interface, SPI, two-wire interface, timers/counters, and a JTAG interface for debugging and boundary scan, as described on the Microchip ATmega645A product page.
Typical applications include industrial control panels, HVAC and appliance controllers, battery-powered instrumentation, LED and LCD display systems, and embedded human-machine interfaces where a mid-range 8-bit MCU with generous Flash is required.
When designing with this part, note that it is a 4.5 V to 5.5 V supply device; ensure the power rail stays within this window and observe the indicated clock frequency rating for your temperature and voltage operating point.
This page synthesizes distributor pricing, drop-in family alternatives, and practical design notes not found in the manufacturer datasheet.
直接替換替代品，適用於 ATMEGA645A-MUR — 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： ATMEGA645A-MUR （相同外形與佔位） — 差異在於 Package, RoHS Status, Operating Temperature, EEPROM, EEPROM Size.
ATMEGA645-16MUR
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA325A-MUR
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ATMEGA329A-MUR
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ATMEGA165A-MUR
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA169A-MUR
✅ 直接替換📋 參考替代品（不在目錄中）
ATMEGA645A-MUR 最大額定值與電氣特性
| Core Architecture | AVR 8-bit RISC |
| Flash Memory | 64 KB (32K x 16) ISP Flash |
| EEPROM | 2 KB |
| SRAM | 4 KB |
| 資料匯流排寬度 | 8 bit |
| 最大時脈頻率 | 16 MHz (per DigiKey listing); family rated to 20 MHz |
| 供應電壓 | 4.5 V to 5.5 V |
| General Purpose I/O | 54 I/O lines (family 54/69 depending on package) |
| Working Registers | 32 general purpose |
| 封裝 | 64-QFN / MLF, 9x9 mm |
| 安裝類型 | Surface Mount |
| Temperature Range | Industrial (-40C to +85C) |
| Programming | In-System Programmable (ISP) Flash, read-while-write |
| Debug Interface | JTAG (debugWIRE/ICSP supported via MPLAB SNAP) |
| RoHS 狀態 | Green / RoHS compliant (per FindIC listing) |
| Packaging | Tape & Reel (R suffix) |
| 生命週期狀態 | Active |
ATMEGA645A-MUR 64-qfn / mlf, 9x9 mm 腳位配置指南
ATMEGA645A-MUR（64-qfn / mlf, 9x9 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： ATMEGA645A-MUR.
請參閱 資料表 以查看完整腳位配置。
典型應用
ATMEGA645A-MUR 適用於 6 應用s: Industrial Control Panels, Appliance and HVAC Controllers, LCD and Display Systems, Battery-Powered Instrumentation, Embedded Human-Machine Interfaces, Motor and Actuation Control Boards.
Industrial Control Panels
The ATMEGA645A-MUR fits industrial control panels because its 54 general-purpose I/O lines can drive relays, contactors, status lamps, and read numerous switches and sensors without port expanders. The 4.5 V to 5.5 V supply matches legacy 5 V industrial logic levels, simplifying interface to HMI boards and optocouplers. Its 64 KB ISP Flash accommodates communication stacks, state machines, and field-updatable firmware, while the 2 KB EEPROM stores calibration constants and configuration across power cycles. Industrial temperature rating (-40C to +85C) covers control-cabinet environments, and JTAG support enables in-circuit debugging during commissioning.
推薦
Appliance and HVAC Controllers
Home appliances and HVAC boards benefit from the ATMEGA645A-MUR's combination of 64 KB Flash for menu logic, sensor compensation algorithms, and fault logging, plus 4 KB SRAM for runtime state. The generous GPIO count directly interfaces keypad matrices, LED segments, triac/relay drivers, and temperature sensors. Because appliance designs frequently use 5 V rails derived from mains supplies, the MCU's 4.5-5.5 V window aligns without level shifting. The EEPROM retains user settings through power outages, and ISP Flash read-while-write capability allows firmware updates or parameter logging during operation, reducing service calls.
推薦
LCD and Display Systems
Display-driven products such as meters, thermostats, and set-top interfaces can use the ATMEGA645A-MUR to drive segment or dot-matrix displays; within the ATmega family, the pin-compatible ATmega329/649 variants add a dedicated LCD controller if segment LCD driving is needed on the same 64-QFN footprint. The 64 KB Flash holds font tables and graphics buffers, while the 4 KB SRAM manages framebuffer data. 54 GPIO lines support multiplexed LED displays and backlight control, and the 8-bit AVR core executes display refresh loops with deterministic timing, avoiding ghosting without a dedicated driver IC.
推薦
Battery-Powered Instrumentation
Portable instruments exploit the AVR ATmega645A's low-power idle and power-down sleep modes combined with its integrated 10-bit ADC for sensor acquisition, reducing external component count on battery-operated boards. The 64 KB Flash retains long code images including data-logging routines, and the 2 KB EEPROM stores calibration data that survives battery replacement. At 4.5-5.5 V operation, a single-cell boost converter or 4x AA/5 V LDO supply suffices. The industrial temperature rating supports field equipment, and ICSP programming through MPLAB SNAP allows field firmware updates via a two-wire plus reset interface without disassembly.
推薦
Embedded Human-Machine Interfaces
Embedded HMI nodes - keypads, rotary encoders, small touch controls, and indicator clusters - suit the ATMEGA645A-MUR because the AVR core's single-cycle execution gives responsive scan loops, and the large Flash supports multi-language menus and protocol translation between front panels and main controllers over USART, SPI, or two-wire serial links. The 54 GPIO lines directly support matrix scanning and LED indication. The A-suffix silicon provides an improved die revision for new designs, and the 64-QFN 9x9 mm footprint keeps board area compact while its exposed ground pad aids EMI performance in noisy electromechanical environments.
推薦
Motor and Actuation Control Boards
Small motor and actuator controllers use the ATMEGA645A-MUR's timers to generate PWM for DC motor drives and servo positioning, while its 10-bit ADC reads current shunts and position feedback for closed-loop control. The 5 V domain interfaces cleanly with gate-driver and H-bridge inputs, and the 64 KB Flash holds trajectory tables, commutation logic, and safety supervision code. Deterministic interrupt latency of the 8-bit AVR core supports tight control-loop timing, and the EEPROM retains limit positions and calibration. Industrial temperature rating and green RoHS packaging suit both consumer appliance and factory automation actuation boards.
推薦
推薦產品摘要
工程參考資料，適用於 ATMEGA645A-MUR — 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 | ATMEGA645-16MUR | ATMEGA325A-MUR | ATMEGA165A-MUR | ATMEGA169A-MUR |
|---|---|---|---|---|---|
| Package | 64-QFN / MLF 9x9 mm | 64-QFN / MLF 9x9 mm - same | 64-QFN / MLF 9x9 mm - same | 64-QFN / MLF 9x9 mm - same | 64-QFN / MLF 9x9 mm - same |
| Brand | Microchip Technology (Atmel) | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 64 KB | 64 KB | 32 KB | 16 KB | 16 KB |
| SRAM | 4 KB | 4 KB | 2 KB | 1 KB | 1 KB |
| EEPROM | 2 KB | 2 KB | 1 KB | 512 B | 512 B |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 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 |
| Max Clock Frequency | 16 MHz (listed); family rated 20 MHz | 16 MHz | 20 MHz | 20 MHz | 20 MHz |
| LCD Controller | No | No | No | No | Yes |
主要差異化特點
- Largest program memory in the pin-compatible 64-QFN family (對比ATMEGA325A-MUR)
- A-suffix silicon improvement over the original part (對比ATMEGA645-16MUR)
- 5 V native operation simplifies industrial interfaces (對比ATMEGA165A-MUR)
設計說明
The ATMEGA645A-MUR requires a 4.5 V to 5.5 V supply per the digchip specification summary. Design the 5 V rail with at least 100 nF decoupling per power pin plus a 10 uF bulk capacitor, and place them within a few millimeters of the QFN pads. If the design derives 5 V from a wide-input buck converter, verify ripple never breaches the 5.5 V ceiling under load transients, as AVCC and VCC must stay within ratings for the ADC and Flash write operations to remain valid.
The 64-QFN (9x9 mm) MLF package has a large exposed ground pad on the underside that must be soldered to a grounded via array - typically 5x5 or more vias connecting to the internal ground plane. Failure to adequately ground this pad is a common first-article bring-up problem, causing floating grounds, ADC noise, and intermittent resets. Follow the Microchip MLF/QFN application recommendations for stencil aperture design (about 50-70% pad coverage) to avoid voiding under the die paddle.
Reserve the JTAG pins and the ICSP lines (MOSI, MISO, SCK, RESET) on a header during layout, because the MPLAB SNAP programmer uses two I/O pins plus reset for in-circuit debugging and ISP programming per Microchip's product page. Also verify clock-source configuration before switching from internal RC to external crystal: an incorrect fuse setting can brick the part on a PCB without a recovery clock. Confirm the 16 MHz/20 MHz frequency rating against your actual supply voltage per the datasheet speed-versus-voltage curves.
合規資訊
Listed as 'Green' (Microchip green/RoHS packaging) and industrial temperature, Tape & Reel per FindIC. AEC-Q100 qualification not stated in provided data for this consumer/industrial-grade MCU.
