ATMEGA325V-8MU - 8MHz AVR MCU, 32KB Flash | Microchip
MPN: ATMEGA325V-8MU ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.91 | $5.91 |
| 10 | $5.32 | $53.20 |
| 100 | $4.75 | $475.00 |
| 500 | $4.28 | $2,140.00 |
| 1,000 | $3.9 | $3,900.00 |
ATMEGA325V-8MU Overview
An 8-bit microcontroller is an integrated circuit that executes embedded control programs using an 8-bit CPU datapath; it belongs to the microcontroller hierarchy of embedded processor -> MCU -> 8-bit AVR family -> ATmega325V. Microcontrollers combine CPU, memory, and peripherals on one die, so a single chip can sense, compute, and drive outputs in embedded systems.
Key features include the advanced RISC AVR architecture with 131 powerful instructions, most executing in a single clock cycle, achieving close to 1 MIPS per MHz. Peripherals include an 8-channel 10-bit ADC, USART, SPI, two-wire interface (TWI), two 8-bit timers, one 16-bit timer with RTC capability, and a programmable watchdog timer.
Technically, the ATmega325V uses a Harvard architecture with separate program and data buses and in-system programmable (ISP) flash via SPI, supporting bootloader-based field updates. Power management features include idle, ADC noise reduction, power-save, power-down, standby, and extended standby sleep modes for battery designs.
Typical applications include battery-powered instrumentation, low-voltage industrial sensors, handheld meters, and consumer control panels where 1.8V operation extends battery life.
Design consideration: the 8 MHz speed grade limits compute headroom, so size timing loops and UART baud rates accordingly.
This page adds value beyond the manufacturer datasheet with drop-in alternatives, pricing tiers, and design notes.
Drop-in alternatives for ATMEGA325V-8MU — 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-8MU (same form factor and footprint) — differing in Package, Number of I/O, Instructions, ADC, RoHS Status.
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✓ In Stock
$1.65 / Unit
View Datasheet →ATMEGA325P-20MUR
✅ Drop-In✓ In Stock
$2.86 / Unit
View Datasheet →ATMEGA325-16MI
✅ Drop-In✓ In Stock
$3.05 / Unit
View Datasheet →ATMEGA325V-8MU Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 8 MHz |
| Program Memory Size | 32KB (16K x 16) FLASH |
| RAM Size | 2K x 8 |
| EEPROM Size | 1K x 8 |
| Supply Voltage Range | 1.8 V to 5.5 V |
| Number of I/O | 54 |
| ADC Resolution | 10-Bit |
| ADC Channels | 8 |
| Connectivity | SPI, UART/USART, TWI (I2C) |
| Timers | 2 x 8-Bit, 1 x 16-Bit (RTC capable) |
| Instructions | 131 (most single-cycle) |
| Package | 64-QFN (9x9 mm) Exposed Pad |
| Mounting Type | Surface Mount |
| Programming | In-System Programmable (ISP via SPI) |
| Sleep Modes | Idle, ADC NR, Power-Save, Power-Down, Standby, Extended Standby |
| Watchdog Timer | Yes |
| Life Cycle Stage | Active |
ATMEGA325V-8MU 64-qfn (9x9 mm) exposed pad Pin Configuration Guide
Pin configuration for ATMEGA325V-8MU (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-8MU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA325V-8MU is suitable for 6 applications: Battery-Powered Instrumentation, Low-Voltage Industrial Sensors, Handheld Meters and Test Devices, Consumer Control Panels, IoT Sensor End Nodes, Motor Control and Actuator Drivers.
Battery-Powered Instrumentation
The ATMEGA325V-8MU fits battery-powered instruments because its 1.8V to 5.5V supply range lets the MCU run directly from a single lithium cell or two alkaline cells without a boost regulator, and its 8 MHz clock delivers up to 8 MIPS for meter math and display updates. The device uses six sleep modes; power-down mode with watchdog disabled cuts supply current to microamp levels, extending battery life to years in standby. Designers typically connect the internal 8 MHz RC oscillator for cost savings and use the 10-bit ADC with the ADC noise reduction sleep mode to sample sensor inputs cleanly. Trade-off: the V variant draws more sleep current than the picoPower ATMEGA325PV-10MU, so new ultra-long-life designs should consider the P variant in the same footprint.
Recommended
Low-Voltage Industrial Sensors
Industrial sensor nodes benefit from the ATMEGA325V-8MU because its 1.8V floor tolerates sagging rails in long cable runs and its 54 I/O lines interface directly with switches, LEDs, and multi-drop peripherals. The integrated USART and TWI (I2C) support Modbus-style ASCII links and digital sensor buses without external controllers, while the 8-channel 10-bit ADC digitizes analog transducer outputs at up to 15 kSPS at full resolution. The SPI interface connects external flash or ADCs where higher accuracy is needed. The 64-QFN 9x9 mm package with exposed pad provides good thermal and ground performance on a compact node PCB. For extreme temperature industrial builds, pair with the industrial-temperature ATMEGA325-16MI variant, accepting its 4.5V-5.5V supply requirement.
Recommended
Handheld Meters and Test Devices
Handheld multimeters, environmental meters, and portable testers use the ATMEGA325V-8MU because one chip supplies the CPU, 32KB of program flash for measurement and UI firmware, 2KB SRAM for data logging buffers, and 1KB EEPROM for calibration constants that survive battery removal. The 8-channel 10-bit ADC reads selector-position and measurement front ends, and the USART streams readings to a PC over a USB-serial bridge. Running from 1.8V extends operation as cells discharge, and the internal RC oscillator removes the crystal cost from a BOM-sensitive handheld design. Power-save sleep mode between user interactions keeps pushbutton wake-up responsive while conserving the battery, an approach documented in the Atmel application literature for portable designs.
Recommended
Consumer Control Panels
Control panels for appliances, HVAC, and access systems leverage the ATMEGA325V-8MU's 54 I/O lines to drive segment LCDs, LED matrices, keypads, and relay outputs from a single controller. The 32KB flash accommodates menu-driven firmware plus bootloader overhead for field updates, and the 1KB EEPROM stores user settings through power cycles. Its 8 MHz execution rate (roughly 8 MIPS) multiplexes displays and scans keys without visible lag, while TWI connects RTC and sensor peripherals on a two-wire bus. Operating across 1.8V to 5.5V simplifies power tree design when panels mix 3.3V logic and 5V actuator drive. The 64-QFN exposed-pad package aids heat dissipation when driving multiple LED segments simultaneously on the same die.
Recommended
IoT Sensor End Nodes
IoT end nodes pair the ATMEGA325V-8MU with a radio module over UART or SPI: the MCU handles sensor acquisition through its 10-bit ADC, packet framing, and low-power scheduling, while the radio handles connectivity. The 2KB SRAM supports protocol buffers for lightweight stacks, and six sleep modes let the node duty-cycle aggressively between transmissions, critical for battery-operated deployments. The 1.8V minimum supply matches modern coin-cell and Li-SOCl2 cell chemistries without regulators, reducing board area and quiescent loss. The calibrated internal oscillator suffices for UART baud generation in most temperature ranges, saving a crystal. For nodes with the tightest sleep budgets, the pin-compatible ATMEGA325PV-10MU picoPower version reduces power-down current below one microamp.
Recommended
Motor Control and Actuator Drivers
Simple motor and actuator controllers use the ATMEGA325V-8MU's 16-bit timer with output-compare PWM channels to drive H-bridge inputs for DC motor speed control, while the 8-channel ADC reads current-sense and position feedback for closed-loop correction. At 8 MHz, single-cycle AVR instruction execution provides deterministic interrupt latency suitable for moderate-speed servo loops in the kHz range. The watchdog timer recovers firmware from stalls in unattended equipment, and 54 I/O lines handle limit switches, encoders, and indicator outputs without glue logic. The 5.5V maximum supply directly drives 5V H-bridge logic inputs. Designs requiring faster PWM resolution should step to the 16 MHz ATMEGA325-16MI, trading away the 1.8V low-voltage capability.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA325V-8MU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA325PV-10MU | ATMEGA325PA-MUR | ATMEGA325P-20MUR | ATMEGA325-16MI |
|---|---|---|---|---|---|
| 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 | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max Clock Speed | 8 MHz | 10 MHz | 20 MHz (5V) | 20 MHz (5V) | 16 MHz |
| 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 | 4.5 V to 5.5 V |
| Flash | 32KB | 32KB | 32KB | 32KB | 32KB |
| SRAM | 2KB | 2KB | 2KB | 2KB | 2KB |
| picoPower Sleep Modes | No (standard power management) | Yes | Yes | Yes | No |
| Key Peripherals | 10-bit ADC 8-ch, USART, SPI, TWI | 10-bit ADC 8-ch, USART, SPI, TWI | 10-bit ADC 8-ch, USART, SPI, TWI | 10-bit ADC 8-ch, USART, SPI, TWI | 10-bit ADC 8-ch, USART, SPI, TWI |
| Drop-in Compatible | - | Yes - same footprint | Yes - same footprint | Yes - same footprint | Yes - same footprint |
Key Differentiators
- Widest supply range in the ATmega325 family (vs ATMEGA325-16MI)
- Standard power management at lower cost (vs ATMEGA325PV-10MU)
- Speed ceiling limits compute-heavy firmware (vs ATMEGA325P-20MUR)
Design Notes
Operating ATMEGA325V-8MU below 2.7V limits full-speed operation; verify the speed-versus-voltage curve in the ATmega325V datasheet before fixing the clock. At 8 MHz, keep VCC within the datasheet's green region - typically 2.7V or higher is required for the full 8 MHz grade. Decouple VCC and AVCC independently with 100 nF ceramic caps plus 10 uF bulk; connect AVCC to VCC through a low-pass LC filter when using the ADC with analog sensors to keep digital switching noise out of the 10-bit conversions.
The 64-QFN (9x9) exposed pad must be soldered to a grounded thermal pad array on the PCB - typically a 3x3 or 4x4 via pattern to the ground plane per IPC QFN land-pattern guidelines. The exposed pad is the primary ground return; relying on perimeter pins alone increases ground impedance and degrades ADC accuracy and EMC performance. Use solder paste segmentation on large exposed pads to prevent voiding and tombstoning during reflow.
Do not assume the RESET pin is a general-purpose I/O: on the ATmega325V, RESET has no alternate I/O function, and disabling the external reset fuse removes in-circuit reprogramming access. Program fuse bits carefully - setting SPIEN incorrectly can brick ISP access requiring high-voltage parallel programming. Also confirm the internal RC oscillator calibration byte is used if UART timing matters; the uncalibrated 8 MHz oscillator tolerance is roughly plus/minus 10 percent, marginal for high baud rates.
For UART links above 38.4 kbaud, use a crystal or ceramic resonator rather than the internal RC oscillator, or enable the datasheet's oscillator calibration routine against a reference. Keep XTAL traces short (under 10 mm) with guard ground, and place the ICSP header with series 100R resistors on MOSI/SCK to avoid loading the SPI bus during runtime operation.
Compliance Information
Compliance data not present in the provided Verified Web Data; confirm on the Microchip ATmega325 product page before procurement.
