ATMEGA325V-8MI - 8-bit AVR MCU 32KB Flash 8MHz 64-QFN | Microchip
MPN： ATMEGA325V-8MI ✓ 啟用中ATMEGA325V-8MI 概覽
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a processor core, program memory, data memory, and peripherals on one die. Within the embedded systems hierarchy, the AVR ATmega family sits in the general-purpose microcontroller category alongside Microchip PIC, ST STM8, and NXP 8051 derivatives, serving as the central control element in a larger system that includes power management, sensing, and communication ICs.
Key features include the advanced AVR RISC architecture with 130 powerful instructions, most executing in a single clock cycle, which yields throughput close to 8 MIPS at 8MHz and allows efficient C-compiled code. In-System Programmable (ISP) Flash enables firmware update in the final application via the SPI interface without removing the device from the PCB. The low-voltage 1.8V operation suits battery-powered designs, while several power-saving sleep modes reduce average consumption in duty-cycled systems.
Architecturally, the AVR core uses a Harvard structure with separate program and data buses, fast register file access, and on-chip peripherals including timers, USART, SPI, and a 10-bit ADC, all clocked from internal RC or external crystal sources. The 64-QFN exposed-pad package provides a compact 9x9 mm footprint with a thermal pad for ground connection and improved heat spreading on the PCB.
Typical applications include industrial automation nodes, battery-operated metering and sensing equipment, medical device control boards, and consumer appliance interfaces, where the wide 1.8V-5.5V range and industrial temperature rating provide design margin across real-world supply and environmental conditions.
A key design consideration is clock selection versus supply voltage: when operating below 2.7V, the 8MHz limit is conservative and safe, but always verify the frequency-versus-voltage curve in the manufacturer datasheet before raising system clocks near the V-range boundaries.
This page synthesizes verified distributor inventory, drop-in family alternatives, and practical sourcing guidance not consolidated in the manufacturer datasheet.
直接替換替代品，適用於 ATMEGA325V-8MI — 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： ATMEGA325V-8MI （相同外形與佔位） — 差異在於 Package, RoHS Status, ADC, Instructions, Number of I/O.
ATMEGA325PV-10MU
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA325PA-MUR
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ATMEGA325PA-AUR
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ATMEGA325-16MI
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA3250V-8AUR
✅ 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 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ATMEGA325V-8MI 最大額定值與電氣特性
| Core Architecture | 8-bit AVR RISC |
| Instruction Set | 130 powerful instructions, most single-cycle |
| Flash Memory | 32KB (16K x 16) In-System Programmable |
| 最大時脈頻率 | 8 MHz |
| Supply Voltage Range | 1.8 V to 5.5 V |
| 封裝 | 64-QFN (9x9 mm) Exposed Pad |
| 安裝類型 | Surface Mount |
| Temperature Grade | Industrial (-40C to +85C) |
| Programming Method | In-System Programmable (ISP) via SPI |
| Approximate Throughput | ~8 MIPS at 8 MHz (1 MIPS/MHz) |
ATMEGA325V-8MI 64-qfn (9x9 mm) exposed pad 腳位配置指南
ATMEGA325V-8MI（64-qfn (9x9 mm) exposed pad 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： ATMEGA325V-8MI.
請參閱 資料表 以查看完整腳位配置。
典型應用
ATMEGA325V-8MI 適用於 6 應用s: Industrial Automation Nodes, Battery-Powered Metering and Sensing, Medical Device Control Boards, Consumer Appliance Interfaces, Data Acquisition and Sensor Hubs, Legacy System Maintenance and Repair.
Industrial Automation Nodes
The ATMEGA325V-8MI fits industrial control nodes because its industrial temperature rating (-40C to +85C) and 5.5V maximum supply tolerate factory-floor supply transients while its 32KB Flash accommodates communication stacks and control logic. Used as the main controller driving sensors, relays, and an RS-485/USART link, the single-cycle AVR RISC core delivers approximately 8 MIPS at 8MHz, sufficient for deterministic polling loops. The 64-QFN exposed-pad package bonds the die paddle to ground, improving noise immunity in electrically noisy cabinets. For new 24V-bus designs, pair it with a 5V buck regulator and a transceiver IC for a compact, serviceable node.
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Battery-Powered Metering and Sensing
The 1.8V to 5.5V operating range is the defining advantage for battery products: the device runs directly from two alkaline cells down to end-of-discharge without a boost converter. The AVR's multiple sleep modes allow the firmware to idle the core between measurement cycles, and the 8MHz ceiling keeps dynamic current proportionally low at the voltages where the V-variant is typically used. In a metering front-end, the MCU reads an external ADC over SPI, computes consumption totals in the 32KB Flash program space, and drives an LCD or UART telemetry output. Estimated average consumption is dominated by sleep-mode current, so duty-cycling strategy matters more than peak clock speed.
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Medical Device Control Boards
Microchip USA explicitly lists medical devices among the ATMEGA325V-8MI's target applications. The wide supply range simplifies power-tree design in portable diagnostic instruments, and the 64-pin QFN provides enough GPIO to drive keypads, displays, and multiple sensor interfaces from one controller. The 32KB ISP Flash supports field firmware updates through the SPI bootloader, which matters for regulated products requiring controlled software revisions. Designers should implement watchdog supervision and brown-out detection enabled via fuse settings, and validate the analog reference chain for measurement channels, since the device integrates a general-purpose ADC suitable for moderate-accuracy physiological sensing front ends.
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Consumer Appliance Interfaces
Appliance control panels benefit from the ATMEGA325V-8MI's combination of ample 32KB program memory, sufficient GPIO count on 64 pins, and direct 5V operation from appliance power supplies. Typical firmware handles capacitive or mechanical key scanning, LED or LCD display driving, and communication with a main appliance controller over UART. The single-cycle AVR core keeps debounce and display-refresh routines responsive even at modest clock rates, reducing EMI compared with faster processors. Because appliance boards are cost-optimized, the 9x9 mm QFN footprint conserves PCB area on single-sided control panels while the exposed pad provides a robust ground connection for EMC performance.
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Data Acquisition and Sensor Hubs
The ATMEGA325V-8MI works well as a compact acquisition hub: it gathers data from analog and digital sensors, timestamps and buffers measurements, and streams results over USART or SPI to a host. The 10-bit-class on-chip conversion resources and several timer peripherals handle periodic sampling, while the 32KB Flash stores both application code and modest lookup tables or calibration constants. Industrial sensing products particularly benefit from the -40C to +85C rating, which keeps specifications valid inside sealed outdoor enclosures. For higher channel counts, the MCU can coordinate external multiplexed front ends, trading scan rate against channel count within the 8MHz sequencing budget.
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Legacy System Maintenance and Repair
Because the ATmega325V family dates from the Atmel generation of the mid-2000s, a significant ongoing use case is repairing and sustaining deployed equipment that was designed around this exact part. The 64-QFN footprint is shared across the 325/3250 family variants, so a repair shop can stock one PCB-compatible set of replacements (V and PV speed/voltage grades) and service multiple product generations. The ISP Flash interface means replacement chips can be programmed in-circuit with a standard AVR programmer and the original firmware image. Sourcing through XAIPART and verified distributors avoids counterfeit risk, which is elevated for older Atmel parts sold outside authorized channels.
推薦
推薦產品摘要
工程參考資料，適用於 ATMEGA325V-8MI — 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 | ATMEGA325PV-10MU | ATMEGA325PA-MUR | ATMEGA325-16MI | ATMEGA3250V-8AUR |
|---|---|---|---|---|---|
| Package | 64-QFN (9x9) Exposed Pad | 64-QFN (9x9) - same | 64-QFN (9x9) - same | 64-QFN (9x9) - same | 64-QFN (9x9) - same |
| Brand | Microchip Technology (Atmel) | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 32KB (16K x 16) ISP | 32KB | 32KB | 32KB | 32KB |
| Max Clock Frequency | 8 MHz | 10 MHz | 20 MHz (at 4.5-5.5V) | 16 MHz | 8 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 | 4.5 V to 5.5 V | 1.8 V to 5.5 V |
| Core Technology | Standard AVR core | picoPower AVR core | picoPower AVR core | Standard AVR core | Standard AVR core + LCD controller |
| LCD Controller | No | No | No | No | Yes (segment LCD) |
主要差異化特點
- Widest voltage headroom in the 325 family at 8MHz (對比ATMEGA325-16MI)
- No LCD controller overhead (對比ATMEGA3250V-8AUR)
- Lower speed grade means lower dynamic power (對比ATMEGA325PA-MUR)
設計說明
The 64-QFN exposed pad is not optional: solder the die paddle to a grounded PCB pad with an array of thermal vias. Beyond heat spreading, the paddle is a primary ground return for the device, and unsoldered paddles are a common cause of intermittent brown-outs and degraded EMI performance on ATmega QFN designs. Use a solder-mask-defined pad pattern with approximately 80% coverage paste apertures split into multiple smaller windows to prevent floating during reflow.
Respect the frequency-versus-voltage safety margin. Although the V-variant is rated 8MHz across 1.8V-5.5V, systems that brown-out near 1.8V with a full-speed external crystal can misbehave before the BOD trips. Enable the internal brown-out detector via fuses and consider a conservative 2.0V system reset threshold for two-cell battery products, or derate the system clock in firmware as the battery voltage falls.
Program fuses before production, not after. ISP programming through SPI requires that no other circuitry contends with the MOSI/MISO/SCK/RESET lines during flashing - add series resistors on SPI lines shared with peripherals. Also note that migrating firmware from this part to the picoPower PV/PA variants can change sleep-mode current behavior and fuse defaults; re-verify sleep currents and fuse settings when substituting the pin-compatible PV or PA alternatives.
合規資訊
Compliance status for this specific suffix is not stated in the verified web data. Request a RoHS/REACH certificate from Microchip or the distributor before relying on compliance claims.
