ATMEGA325V-8AI - 8-bit AVR MCU, 32KB Flash, 8MHz, 1.8V | Microchip
MPN: ATMEGA325V-8AI ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.2 | $5.20 |
| 10 | $4.68 | $46.80 |
| 100 | $4.16 | $416.00 |
| 500 | $3.64 | $1,820.00 |
| 1,000 | $3.2 | $3,200.00 |
ATMEGA325V-8AI Overview
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that executes most instructions in a single clock cycle, positioning it within the broader hierarchy of microcontrollers (MCU) and embedded processors. AVR MCUs are widely used for general-purpose embedded control where deterministic execution, low power, and simple tooling matter more than raw compute throughput.
Key features of the ATMEGA325V-8AI include 54 general-purpose I/O lines, 32 general-purpose working registers, a JTAG interface for boundary-scan, on-chip debugging, and in-system programming, three flexible Timer/Counters with compare modes, and an on-chip ADC. The V speed grade sustains full 8MHz operation down to low supply voltages, unlike the 16MHz/20MHz grades that require 4.5V or higher.
The AVR core combines a rich instruction set with single-cycle ALU operation, delivering up to 8 MIPS at 8MHz. ISP Flash with read-while-write permits firmware updates in the field without halting code execution, and the 1KB EEPROM retains calibration and configuration data through power cycles. The JTAG port supports IEEE boundary-scan test, OCD, and programming through a single connector.
Typical applications include battery-powered instruments that exploit the 1.8V operation, industrial automation controllers, and building/HVAC control nodes. The 54 GPIO lines suit panel control, relay driving, and multi-peripheral designs.
When designing, remember that the V grade is limited to 8MHz: to run faster you must switch to the P or non-V grades, which requires only a board swap to a same-footprint variant.
This page synthesizes distributor availability, same-footprint drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA325V-8AI — 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-8AI (same form factor and footprint) — differing in Package, EEPROM, Operating Temperature, SRAM, Packaging.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA325V-8AU
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA325PA-AUR
✅ Drop-In✓ In Stock
$3.9 / Unit
View Datasheet →ATMEGA3250V-8AUR
✅ Drop-In✓ In Stock
$3.38 / Unit
View Datasheet →ATMEGA3250PA-AUR
✅ Drop-In✓ In Stock
$2.98 / Unit
View Datasheet →ATMEGA325PV-10AU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA325-16AU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.4 / Unit
View Datasheet →ATMEGA645V-8AU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA325V-8AI Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Program Memory (Flash) | 32KB (16K x 16), ISP with read-while-write |
| EEPROM | 1KB |
| SRAM | 2KB |
| Maximum Clock Frequency | 8MHz |
| Supply Voltage Range | 1.8V to 5.5V |
| General Purpose I/O Lines | 54 |
| Working Registers | 32 general purpose |
| Timer/Counters | 3 flexible Timer/Counters with compare modes |
| Debug/Programming Interface | JTAG (boundary-scan, on-chip debug, programming) |
| ADC | On-chip ADC (per ATmega325 family datasheet) |
| Package | 64-TQFP (14x14 mm, 0.8 mm pitch) |
| Mounting Type | Surface Mount |
| Temperature Grade | Industrial (I suffix), -40C to +85C |
| Terminal Form | Gull Wing |
| Series | AVR ATmega ATmega325 |
ATMEGA325V-8AI 64-tqfp (14x14 mm, 0.8 mm pitch) Pin Configuration Guide
Pin configuration for ATMEGA325V-8AI (64-tqfp (14x14 mm, 0.8 mm pitch) 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-8AI.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA325V-8AI is suitable for 6 applications: Battery-Powered Portable Instruments, Industrial Automation and Control Nodes, Building and HVAC Control, Sensor Data Acquisition Systems, JTAG-Based Development and Test Systems, Consumer Appliance Control Boards.
Battery-Powered Portable Instruments
The ATMEGA325V-8AI is well suited to two-cell and three-cell battery instruments because it regulates and computes correctly down to 1.8V, eliminating boost-converter cost and quiescent drain. Its 8MHz V-grade core provides adequate MIPS for measurement sequencing, LCD driving, and button handling, while sleep modes cut average draw to microamp levels between readings. Typical circuits place the MCU between the battery rail and an on-chip ADC front end sampling sensor bridges, with the 1KB EEPROM storing calibration constants that survive battery replacement. Compared with 5V-only 16MHz grades, the V part trades clock speed for wide-range direct battery operation, which is usually the correct trade in portable test and metering products.
Recommended
Industrial Automation and Control Nodes
In factory control panels and machine I/O nodes, the ATMEGA325V-8AI contributes 54 general-purpose I/O lines, three Timer/Counters with compare modes, and an industrial -40C to +85C temperature grade in a single 64-TQFP device. The JTAG boundary-scan capability lets production test the assembled board's interconnects per the family datasheet, while JTAG on-chip debug shortens field-firmware bring-up. A typical node uses timer compare outputs for PWM-driven actuators or relay timing, the ADC for analog setpoints, and EEPROM for node configuration. Designers should budget the 8MHz core carefully against communication stacking, but for discrete I/O and PWM control the performance headroom is generally ample.
Recommended
Building and HVAC Control
Thermostats, damper controllers, and rooftop-unit boards fit the ATMEGA325V-8AI because they combine many discrete I/O points (relays, triac drives, keypad lines) with modest analog sensing, exactly matching the 54-GPIO plus ADC resource profile. The wide 1.8V to 5.5V supply range tolerates unregulated transformer-derived supplies after rectification, and the industrial temperature grade covers equipment-room extremes. Firmware typically runs a timer-interrupt state machine at low duty cycle, so the 8MHz limit is not a constraint, and EEPROM retains setpoint and schedule data through power outages. JTAG programming allows on-board firmware updates during manufacturing without removing the MCU from the panel.
Recommended
Sensor Data Acquisition Systems
The on-chip ADC of the ATMEGA325V-8AI, combined with 2KB SRAM for sample buffering, makes the device a compact acquisition controller for multi-channel sensor boards. The family datasheet specifies an ADC with selectable reference and prescaling, adequate for temperature, humidity, and pressure front ends in the 8-12 bit effective range typical of these sensors. The 1KB EEPROM stores per-channel calibration coefficients, and the UART/USART resources stream results to a host. Designs requiring lower average power can migrate to the picoPower ATMEGA325PA-AUR on the same PCB footprint, since the TQFP-64 pinout is unchanged across the ATmega325 family.
Recommended
JTAG-Based Development and Test Systems
Boards that must support boundary-scan production test and in-circuit firmware updates benefit directly from the ATMEGA325V-8AI's JTAG port, which the Microchip datasheet defines for boundary-scan, on-chip debugging, and JTAG programming. This suits engineering prototype systems and serviceable industrial products where field firmware upgrades through a test connector are a requirement, not an option. A typical implementation routes the JTAG port to a standard 10-pin header shared between a boundary-scan tester in production and a JTAG ICE-class debugger in development. The 32KB ISP Flash with read-while-write permits bootloader-driven self-reprogramming, complementing the JTAG path during deployment.
Recommended
Consumer Appliance Control Boards
Dishwasher, cooker, and small-appliance controllers use the ATMEGA325V-8AI where a single MCU must drive display multiplexing, key scanning, relay outputs, and temperature sensing simultaneously. Three Timer/Counters with compare modes handle display refresh and buzzer tones without CPU polling, and 32 working registers keep interrupt service routines short at the 8MHz clock. The V-grade's tolerance of 1.8V-5.5V supplies eases power-supply design from transformer secondaries, while the 32KB Flash accommodates localized multi-language UI firmware. Designers should verify surge immunity of the I/O structure and add external transient protection on mains-adjacent lines, as with any appliance control MCU.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA325V-8AI — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA325V-8AU | ATMEGA325PA-AUR | ATMEGA3250V-8AUR | ATMEGA645V-8AU |
|---|---|---|---|---|---|
| Package | 64-TQFP (14x14 mm) | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash | 32KB | 32KB | 32KB | 32KB | 64KB |
| SRAM / EEPROM | 2KB / 1KB | 2KB / 1KB | 2KB / 1KB | 2KB / 1KB | 4KB / 2KB |
| Max Clock | 8MHz | 8MHz | 20MHz (at 5V) | 8MHz | 8MHz |
| Supply Voltage Range | 1.8V to 5.5V | 1.8V to 5.5V | 1.8V to 5.5V | 1.8V to 5.5V | 1.8V to 5.5V |
| GPIO Lines | 54 | 54 | 54 | 69 | 54 |
| Power Technology | Standard AVR | Standard AVR | picoPower | Standard AVR | Standard AVR |
| Temperature Suffix | I (industrial) | U (green flow) | Industrial (AUR) | Industrial (AUR) | U (green flow) |
Key Differentiators
- Full functionality down to 1.8V at 8MHz (vs ATMEGA325-16AU)
- Lower power in new designs (vs ATMEGA325PA-AUR)
- More I/O when needed (vs ATMEGA3250V-8AUR)
Design Notes
The V speed grade guarantees operation at up to 8MHz from 1.8V to 5.5V, but do not assume this transfers to other grades: the 16MHz ATMEGA325 requires 4.5V minimum. If your board may later be populated with a faster suffix, design the regulator and brown-out detector for the 4.5V-5.5V window. Always enable the internal brown-out reset when running from unregulated or battery supplies, and decouple each VCC pin with 100nF ceramics placed within 5mm of the pins.
The 64-TQFP uses a 0.8mm pitch and 14x14mm body; plan a 3x3 thermal via array under the center of the footprint even though dissipation is low, as it simplifies rework and improves ground return. Keep the JTAG (Port C), XTAL1/XTAL2, and RESET traces short and away from switching loads such as relay coils. Gull-wing leads tolerate hand rework well, but use a drag-solder tip and flux, and inspect with magnification for bridges between the fine-pitch pins.
Frequent migration mistake: swapping ATMEGA325V-8AI for the picoPower ATMEGA325PA-AUR without rechecking clock configuration fuses. The PA die supports higher clock speeds, but startup time and sleep-mode register behavior differ from the non-P die; re-verify your bootloader timing and watchdog settings. Also confirm suffix temperature requirements - the -8AU variant follows the green commercial flow, while this -8AI part is industrial grade. Consult Microchip's migration app notes before qualifying a second source on production boards.
Compliance Information
Compliance status not stated in provided web data; the AU/UR sibling suffixes use green mold compound, but verify RoHS/REACH declarations for the exact AI suffix with Microchip before procurement.
