ATMEGA325PA-AUR - 8-bit AVR MCU 32KB Flash 20MHz | Microchip
MPN： ATMEGA325PA-AUR ✓ 啟用中ATMEGA325PA-AUR 概覽
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that executes most instructions in a single clock cycle, positioning itself within the broader hierarchy of microcontroller units (MCUs) under embedded processors and power management systems. The AVR ATmega family is widely used for general-purpose embedded control where in-system programmability, EEPROM data retention, and low-power sleep modes are required.
Key features include advanced RISC architecture with 131 powerful instructions, up to 20 MIPS throughput at 20 MHz, JTAG interface for on-chip debugging and boundary-scan, and picoPower technology for ultra-low power consumption in sleep and idle modes. The device operates from 1.8 V to 5.5 V, making it suitable for both battery-powered (3.3 V) and industrial 5 V systems.
The picoPower process technology reduces quiescent current in all sleep modes, while the self-programming flash enables field firmware updates over UART, SPI, or the two-wire interface without external programmer hardware in the field. The 8-channel 10-bit ADC supports sensor front-ends, and the rich peripheral set includes USART, SPI, TWI (I2C), and timers with PWM outputs.
Typical applications include industrial automation controllers, LCD-equipped metering and user-interface panels, battery-powered instrumentation, and building control nodes where 1.8-5.5 V operation and picoPower sleep currents extend battery life.
A key design consideration: maximum clock frequency derates with supply voltage and temperature, so verify the speed-versus-voltage curve before running 20 MHz at reduced VCC in industrial temperature ranges.
This page synthesizes distributor pricing, drop-in family alternatives, and practical design notes not found in the manufacturer datasheet, with pricing referenced as of 2026-09-17.
直接替換替代品，適用於 ATMEGA325PA-AUR — 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： ATMEGA325PA-AUR （相同外形與佔位） — 差異在於 Package, RoHS Status, Supply Voltage Range, Maximum Clock Frequency, Flash Memory.
ATMEGA325PA-AU
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ATMEGA325P-20AUR
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ATMEGA325A-AU
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ATMEGA3250PA-AUR
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA329PA-AUR
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA325PA-AUR 最大額定值與電氣特性
| Core Architecture | 8-bit AVR RISC |
| Flash Program Memory | 32 KB (16K x 16) |
| SRAM | 2 KB |
| EEPROM | 1 KB |
| 最大時脈頻率 | 20 MHz |
| Maximum Throughput | 20 MIPS at 20 MHz |
| Supply Voltage Range | 1.8 V to 5.5 V |
| ADC Resolution | 10-bit |
| ADC Channels | 8-channel |
| Debug / Boundary Scan | JTAG interface for on-chip debug |
| Low Power Technology | picoPower |
| I/O Ports | 32 I/O |
| 封裝 | 64-TQFP (14x14 mm) |
| 安裝類型 | Surface Mount |
| Packaging | Tape & Reel (R suffix) |
| Temperature Grade | Industrial (IND) |
| Life Cycle Stage | Active |
| RoHS 狀態 | Green / RoHS compliant |
ATMEGA325PA-AUR 64-tqfp (14x14 mm) 腳位配置指南
ATMEGA325PA-AUR（64-tqfp (14x14 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： ATMEGA325PA-AUR.
請參閱 資料表 以查看完整腳位配置。
典型應用
ATMEGA325PA-AUR 適用於 6 應用s: Industrial Automation Controllers, LCD Metering and User Interface Panels, Battery-Powered Portable Instrumentation, Building Control and HVAC Nodes, Sensor Acquisition and Data Logging, Embedded Educational and Prototyping Platforms.
Industrial Automation Controllers
The ATMEGA325PA-AUR fits industrial control nodes because its 32 KB ISP Flash holds application plus bootloader code, its 1.8-5.5 V supply tolerates noisy 5 V industrial rails, and the industrial temperature grade (IND) supports cabinet-mounted electronics. The 131-instruction single-cycle RISC core delivers up to 20 MIPS at 20 MHz, sufficient for PID loops, sensor scanning via the 8-channel 10-bit ADC, and communication over USART, SPI, or TWI. The JTAG interface enables on-chip debugging of fielded control logic without removing the PCB from the panel, shortening commissioning cycles on production lines.
推薦
LCD Metering and User Interface Panels
Metering displays, thermostats, and control panels benefit from the ATmega325 family's integrated segment LCD driving capability combined with picoPower sleep currents, allowing a panel to hold display content and wake on button press while drawing microamp-level average current. The 64-TQFP provides enough GPIO (32 I/O) for keypads, backlight control, and buzzer drive alongside the ADC channels used for battery voltage and sensor inputs. Operating at 3 V from a coin cell or lithium battery, the 1.8 V minimum supply and low-power sleep modes extend product battery life substantially compared to non-picoPower revisions.
推薦
Battery-Powered Portable Instrumentation
Handheld meters, data loggers, and portable diagnostic tools use the ATMEGA325PA-AUR for its combination of 1 KB EEPROM (calibration and log storage surviving power removal), 2 KB SRAM working memory, and picoPower technology that minimizes standby drain. The 8-channel 10-bit ADC digitizes multiple sensor inputs without an external converter, and duty-cycling the ADC with sleep intervals keeps average current low. Its 32 KB self-programming Flash supports field firmware updates through a bootloader over UART, letting service technicians update instruments in the field without disassembly or external programmers.
推薦
Building Control and HVAC Nodes
Thermostats, damper controllers, and zone-control boards leverage the ATMEGA325PA-AUR's rich timer resources for PWM actuator drive, the TWI (I2C) bus to talk to humidity and temperature sensors, and the ADC for NTC thermistor reading. The 1.8-5.5 V supply range accepts either 3.3 V logic rails from mains-referenced supplies or battery backup operation. PicoPower sleep modes keep the node's average consumption within energy-harvesting or battery-backup budgets, while the JTAG port supports boundary-scan manufacturing test of assembled control boards before installation.
推薦
Sensor Acquisition and Data Logging
The 8-channel 10-bit ADC of the ATMEGA325PA-AUR forms the core of compact multi-sensor acquisition boards: analog inputs are multiplexed internally, eliminating an external ADC, while 2 KB SRAM buffers sample blocks and 1 KB EEPROM retains calibration coefficients through power cycles. SPI and USART interfaces stream data to SD cards, radios, or hosts, and the self-programming Flash allows logging firmware with user-updatable configuration tables. With picoPower sleep between sampling bursts, a battery logger can achieve multi-year service intervals depending on sample rate.
推薦
Embedded Educational and Prototyping Platforms
The ATMEGA325PA-AUR is attractive for lab training boards and prototyping carriers because the AVR architecture is documented exhaustively, ISP programming needs only a simple SPI header, and Microchip Studio provides a free toolchain. The JTAG on-chip debug lets students and engineers single-step code with basic hardware, and the 32 KB Flash accommodates substantial demo applications. The 64-TQFP hand-solderable 0.8 mm pitch suits prototype boards, and the 1.8-5.5 V operation allows bench experimentation at both 3.3 V and 5 V without level shifting.
推薦
推薦產品摘要
工程參考資料，適用於 ATMEGA325PA-AUR — 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 | ATMEGA325PA-AU | ATMEGA325P-20AUR | ATMEGA325A-AU | ATMEGA3250PA-AUR | ATMEGA329PA-AUR |
|---|---|---|---|---|---|---|
| Package | 64-TQFP (14x14 mm) | 64-TQFP (14x14) - same | 64-TQFP (14x14) - same | 64-TQFP (14x14) - same | 64-TQFP (14x14) - same | 64-TQFP (14x14) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 32 KB ISP Flash | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB |
| SRAM | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB |
| EEPROM | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB |
| Max Clock / MIPS | 20 MHz / 20 MIPS | 20 MHz / 20 MIPS | 20 MHz / 20 MIPS | 20 MHz / 20 MIPS | 20 MHz / 20 MIPS | 20 MHz / 20 MIPS |
| Supply Voltage | 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 | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| picoPower Low Sleep Current | Yes | Yes | No (earlier revision) | No (standard) | Yes | Yes |
| LCD / Pin Allocation | ATmega325 LCD configuration | Identical | Identical | Identical | Different - verify pin mux | Different - verify pin mux |
| Packaging Variant | Tape & Reel | Tray / cut tape | Tape & Reel | Tray | Tape & Reel | Tape & Reel |
主要差異化特點
- picoPower sleep-mode current (對比ATMEGA325P-20AUR)
- Integrated segment LCD driving (對比ATMEGA324PA-AUR)
- JTAG on-chip debug and boundary scan (對比ATMEGA325A-AU)
- 1.8 V minimum supply (對比ATMEGA32-16AUR)
設計說明
The ATMEGA325PA-AUR operates from 1.8 V to 5.5 V, but the maximum safe clock frequency derates with supply voltage and temperature - running 20 MHz below the full-speed voltage threshold risks unstable execution. Estimate worst-case power by summing active-mode current at your clock rate plus sleep-mode picoPower current weighted by duty cycle; for battery designs, drive the clock from the internal RC oscillator at reduced frequency to cut active current quadratically with frequency. Decouple VCC with 100 nF ceramic capacitors at each supply pin pair, placed within 5 mm of the pins, plus bulk 10 uF.
The 64-TQFP (14x14 mm, 0.8 mm pitch) requires careful escape routing: use 0.25-0.3 mm traces with via-in-pad or dogbone escapes on the inner rows. Keep the JTAG (TCK/TMS/TDO/TDI) traces short and add a 10 kohm pull-up on TMS to prevent floating state entry into debug mode during normal operation. Place the 100 nF decoupling capacitor for the ADC reference path close to AVCC and connect AGND to a quiet ground region to preserve 10-bit ADC accuracy; avoid routing fast digital traces under the ADC input pins.
Three frequent mistakes with this part: (1) leaving the JTAG interface enabled in the fuses when the JTAG pins are needed as GPIO - the pins default to JTAG function and will not drive external circuits; (2) forgetting that the R suffix denotes tape-and-reel orientation, so reflow feeder direction must match the reel packing per datasheet carrier-tape drawing; (3) substituting an ATmega329/3250 variant on an ATmega325 PCB without checking the LCD/peripheral pin multiplexing table - the packages fit but pin functions differ. Always verify fuse settings and pin mapping against the Microchip datasheet before first power-up.
合規資訊
Listed as GREEN, RoHS-compliant per Microchip/distributor data (FindIC: 'GREEN, T&R'). REACH and conflict minerals status not stated in verified data - confirm via Microchip product compliance documentation.