ATMEGA325V-8MI - 8-bit AVR MCU 32KB Flash 8MHz 64-QFN | Microchip
MPN: ATMEGA325V-8MI ✓ Active| Qty | Unit Price | Extended |
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| 1 | $0 | $0.00 |
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| 500 | $0 | $0.00 |
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ATMEGA325V-8MI Overview
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.
Drop-in alternatives for ATMEGA325V-8MI — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ATMEGA325V-8MI (same form factor and footprint) — differing in Package, RoHS Status, ADC, Instructions, Number of I/O.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA325PV-10MU
✅ Drop-In✓ In Stock
$2.19 / Unit
View Datasheet →ATMEGA325PA-MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.65 / Unit
View Datasheet →ATMEGA325PA-AUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.9 / Unit
View Datasheet →ATMEGA325-16MI
✅ Drop-In✓ In Stock
$3.05 / Unit
View Datasheet →ATMEGA3250V-8AUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.38 / Unit
View Datasheet →ATMEGA3250PA-AUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.98 / Unit
View Datasheet →ATMEGA325V-8MI Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Instruction Set | 130 powerful instructions, most single-cycle |
| Flash Memory | 32KB (16K x 16) In-System Programmable |
| Maximum Clock Frequency | 8 MHz |
| Supply Voltage Range | 1.8 V to 5.5 V |
| Package | 64-QFN (9x9 mm) Exposed Pad |
| Mounting Type | 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 Pin Configuration Guide
Pin configuration for ATMEGA325V-8MI (64-qfn (9x9 mm) exposed pad package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for ATMEGA325V-8MI.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA325V-8MI is suitable for 6 applications: 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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA325V-8MI — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | 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) |
Key Differentiators
- Widest voltage headroom in the 325 family at 8MHz (vs ATMEGA325-16MI)
- No LCD controller overhead (vs ATMEGA3250V-8AUR)
- Lower speed grade means lower dynamic power (vs ATMEGA325PA-MUR)
Design Notes
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.
Compliance Information
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.
