ATMEGA329V-8MU - 8MHz 8-bit AVR MCU 32KB Flash | Microchip
MPN: ATMEGA329V-8MU ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.92 | $6.92 |
| 10 | $6.18 | $61.80 |
| 100 | $5.42 | $542.00 |
| 500 | $4.83 | $2,415.00 |
| 1,000 | $4.27 | $4,270.00 |
ATMEGA329V-8MU Overview
An 8-bit AVR microcontroller is a single-chip CMOS device that combines a RISC CPU core, on-chip Flash program memory, SRAM, EEPROM, and a rich set of peripherals onto a single die. AVR microcontrollers sit in the broader taxonomy: microcontroller -> embedded MCU -> semiconductor IC. They execute one instruction per clock cycle, enabling deterministic timing at modest clock rates, and dominate applications that demand low power, real-time response, and integrated analog/digital peripherals in a compact footprint.
Key features include 131 powerful instructions (most single-cycle execution), 32 general-purpose working registers, 4.5V to 5.5V supply range for the 'V' variant, 1.8V to 5.5V in low-voltage operating modes, hardware multiplier, two 8-bit timer/counters plus one 16-bit timer/counter, 4 PWM channels, USART, SPI, I2C-compatible TWI, programmable watchdog timer with separate on-chip oscillator, and 6 sleep modes including power-save for LCD retention. The integrated LCD controller drives up to 4 common segments and 25 segments, making this device a strong fit for segment LCDs in thermostats, meters, and consumer appliances.
Architecturally, the ATmega329V uses an 8-bit Harvard-style AVR core with separate program and data buses. The 32KB self-programming Flash supports read-while-write operations, and the device includes a calibrated internal RC oscillator, brown-out detection, and a six-channel 10-bit ADC for sensor interface.
Typical applications include thermostat control boards, electricity/water/gas meters with segment LCDs, white-goods user-interface panels, handheld instrumentation, and battery-powered sensor terminals where the integrated LCD controller and rich I/O set eliminate the need for an external display driver.
When designing with this part, plan the PCB layout for the exposed thermal pad of the 64-QFN to maximize heat dissipation and ensure reliable QFN soldering. Use the JTAG or debugWIRE interface for in-circuit programming and debugging, and provide adequate decoupling near each VCC pin.
This page synthesizes distributor pricing for ATMEGA329V-8MU, lists Microchip drop-in alternatives (same 64-QFN footprint), and includes practical design notes beyond the manufacturer datasheet.
Drop-in alternatives for ATMEGA329V-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 ATMEGA329V-8MU (same form factor and footprint) — differing in ADC, Package, Operating Temperature, Communication Interfaces, LCD Controller.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA329V-8MUR
✅ Drop-In✓ In Stock
$5.5 / Unit
View Datasheet →ATMEGA329PV-10MUR
✅ Drop-In✓ In Stock
$3.99 / Unit
View Datasheet →ATMEGA329PA-MUR
✅ Drop-In✓ In Stock
$3.85 / Unit
View Datasheet →ATMEGA329A-MUR
✅ Drop-In✓ In Stock
$3.61 / Unit
View Datasheet →ATMEGA329-16AU
✅ Drop-In✓ In Stock
$8.45 / Unit
View Datasheet →ATMEGA329V-8MU Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Program Memory (Flash) | 32 KB (16K x 16) |
| SRAM | 2 KB |
| EEPROM | 1 KB |
| Maximum CPU Speed | 8 MHz |
| Supply Voltage (Vcc) | 4.5 V to 5.5 V |
| Operating Temperature Range | -40 C to +85 C (industrial) |
| GPIO Lines | 54 |
| General Purpose Working Registers | 32 |
| ADC | 10-bit, 8 channels |
| LCD Controller | Integrated segment LCD driver (up to 4 common / 25 segment) |
| Timer/Counters | 2 x 8-bit, 1 x 16-bit |
| PWM Channels | 4 |
| Communication Interfaces | 1 x USART, 1 x SPI, 1 x TWI (I2C-compatible) |
| Debug Interface | JTAG / debugWIRE |
| Package | 64-QFN (9x9 mm) with exposed pad |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
ATMEGA329V-8MU Pin Configuration
| Pin 1 | VCC — Digital supply voltage |
| Pin 2 | GND — Ground |
| Pin 3 | AVCC — Analog supply voltage |
| Pin 4 | AREF — ADC reference voltage |
| Pin 5 | ADC7 — Analog input channel 7 |
| Pin 6 | ADC6 — Analog input channel 6 |
| Pin 7 | PE0 — GPIO / RXD0 (USART0 Receive) |
| Pin 8 | PE1 — GPIO / TXD0 (USART0 Transmit) |
| Pin 9 | PE2 — GPIO / AIN0 (Analog Comparator) |
| Pin 10 | PE3 — GPIO / AIN1 (Analog Comparator) |
| Pin 11 | PE4 — GPIO / INT4 (External Interrupt) |
| Pin 12 | PE5 — GPIO / INT5 |
| Pin 13 | PE6 — GPIO / INT6 |
| Pin 14 | PE7 — GPIO / INT7 |
| Pin 15 | PB0 — GPIO / PCINT0 |
| Pin 16 | PB1 — GPIO / PCINT1 |
| Pin 17 | PB2 — GPIO / PCINT2 / OC1B |
| Pin 18 | PB3 — GPIO / PCINT3 / OC2A |
| Pin 19 | PB4 — GPIO / PCINT4 / SS-bar |
| Pin 20 | PB5 — GPIO / PCINT5 / MOSI |
| Pin 21 | PB6 — GPIO / PCINT6 / MISO |
| Pin 22 | PB7 — GPIO / PCINT7 / SCK |
| Pin 23 | PG3 — GPIO |
| Pin 24 | PG4 — GPIO |
| Pin 25 | RESET-bar — Reset input, active low |
| Pin 26 | VCC — Digital supply voltage |
| Pin 27 | GND — Ground |
| Pin 28 | XTAL2 — Crystal oscillator output |
| Pin 29 | XTAL1 — Crystal oscillator input |
| Pin 30 | PD0 — GPIO / SCL (TWI) |
| Pin 31 | PD1 — GPIO / SDA (TWI) |
| Pin 32 | PD2 — GPIO / RXD1 |
| Pin 33 | PD3 — GPIO / TXD1 / INT3 |
| Pin 34 | PD4 — GPIO / ICP1 |
| Pin 35 | PD5 — GPIO / XCK1 |
| Pin 36 | PD6 — GPIO / T1 |
| Pin 37 | PD7 — GPIO / T0 |
| Pin 38 | PG5 — GPIO / OC0B |
| Pin 39 | PG0 — GPIO / WR-bar |
| Pin 40 | PG1 — GPIO / RD-bar |
| Pin 41 | PC0 — GPIO / AREF |
| Pin 42 | PC1 — GPIO / ADC1 |
| Pin 43 | PC2 — GPIO / ADC2 |
| Pin 44 | PC3 — GPIO / ADC3 |
| Pin 45 | PC4 — GPIO / ADC4 / SDA |
| Pin 46 | PC5 — GPIO / ADC5 / SCL |
| Pin 47 | PC6 — GPIO / RESET-bar (alternate) |
| Pin 48 | PC7 — GPIO |
| Pin 49 | PJ0 — GPIO / LCD segment |
| Pin 50 | PJ1 — GPIO / LCD segment |
| Pin 51 | PJ2 — GPIO / LCD segment |
| Pin 52 | PJ3 — GPIO / LCD segment |
| Pin 53 | PJ4 — GPIO / LCD segment |
| Pin 54 | PJ5 — GPIO / LCD segment |
| Pin 55 | PJ6 — GPIO / LCD segment |
| Pin 56 | PJ7 — GPIO / LCD segment |
| Pin 57 | PA0 — GPIO / ADC0 |
| Pin 58 | PA1 — GPIO / ADC1 |
| Pin 59 | PA2 — GPIO / ADC2 |
| Pin 60 | PA3 — GPIO / ADC3 |
| Pin 61 | PA4 — GPIO / ADC4 |
| Pin 62 | PA5 — GPIO / ADC5 |
| Pin 63 | PA6 — GPIO / ADC6 |
| Pin 64 | PA7 — GPIO / ADC7 |
| Pin EP | Exposed Pad — Thermal pad, must be soldered to PCB ground for thermal dissipation |
Typical Applications
ATMEGA329V-8MU is suitable for 6 applications: Thermostat Control Board, Electricity / Water / Gas Meter, White-Goods User-Interface Panel, Handheld Test Instrument, Industrial Control Panel, Battery-Powered Sensor Terminal.
Thermostat Control Board
The ATMEGA329V-8MU fits thermostat control boards because its integrated segment LCD controller drives up to 4 common and 25 segment lines directly, eliminating an external display driver and saving BOM cost. With 8 MHz operation at 1.8 V to 5.5 V supply, the part supports battery-backed thermostats where ultra-low idle current matters. The 8-channel 10-bit ADC reads thermistor temperature sensors; 54 GPIO keys manage button inputs and relay drivers. Compared with PIC16 + external LCD driver solutions, the ATMEGA329V-8MU delivers the LCD, ADC, EEPROM, and 32 KB of Flash on a single die, simplifying PCB layout and firmware.
Recommended
Electricity / Water / Gas Meter
In metering applications, the ATMEGA329V-8MU's integrated segment LCD controller displays consumption values without an external driver, while the 1 KB EEPROM provides non-volatile storage for tariffs, calibration constants, and tamper-event logs. The 32 KB Flash accommodates metering firmware with security libraries, and the JTAG/debugWIRE interface supports factory calibration and field firmware updates. The 1.8 V to 5.5 V wide supply range allows battery-backed metering designs with up to 10-year battery life. Compared with discrete MCU + HT1621 LCD solutions, the ATMEGA329V-8MU integrates the display, ADC, and CPU in one QFN package, reducing PCB area and reliability points.
Recommended
White-Goods User-Interface Panel
Washing machines, dishwashers, and ovens benefit from the ATMEGA329V-8MU's integrated segment LCD, which displays cycle, time, and error codes without an external driver IC. The 54 GPIO directly drive keypad matrices, buzzer, relay controls, and triac interfaces for heater/pump switching. The 1 KB EEPROM retains user preferences across power cycles, and the 2 KB SRAM is sufficient for menu state machines and segment-LCD frame buffers. The 4.5 V to 5.5 V supply range matches the +5 V rails common in white-goods designs. Compared with bare 8051 cores, the ATMEGA329V-8MU's 8 MHz single-cycle execution and integrated peripherals simplify firmware and shrink the BOM.
Recommended
Handheld Test Instrument
For portable DMMs and field instruments, the ATMEGA329V-8MU provides the LCD controller for measurement readouts, the 10-bit ADC for sensor interface, and the 32 KB Flash for measurement firmware and lookup tables. The 1.8 V to 5.5 V wide supply range supports 2xAA / 1xLi coin-cell battery configurations. Hardware multiplier speeds RMS and true-RMS calculations, while the JTAG/debugWIRE enables rapid field-firmware revisions. The 64-QFN (9x9 mm) package keeps the PCB footprint compact for handheld enclosures. Compared with ATmega48/88 series, the ATMEGA329V-8MU offers more GPIO and integrated LCD, reducing the need for I/O expanders.
Recommended
Industrial Control Panel
Industrial control panels with segmented LCD readouts use the ATMEGA329V-8MU to display setpoints, alarms, and process variables. The 4 PWM channels drive LED indicators or proportional valves; the USART/SPI/TWI interfaces connect to industrial sensors, HMI touch controllers, or RS-485 transceivers. The industrial -40 C to +85 C operating range handles factory-floor environments. The 64-QFN with exposed pad supports reflow soldering and provides thermal margin for enclosed cabinets. Compared with ARM Cortex-M0 designs at this cost point, the ATMEGA329V-8MU offers deterministic 8-bit timing with no RTOS overhead.
Recommended
Battery-Powered Sensor Terminal
Battery-powered wireless sensor terminals benefit from the ATMEGA329V-8MU's 6 sleep modes (Idle, ADC-noise-reduction, Power-save, Power-down, Standby, Extended-Standby), which minimize idle current while maintaining RAM and LCD-segment memory for instant wake-up displays. The 1.8 V to 5.5 V wide supply range suits 2xAA alkaline, 1xLi primary, or lithium-thionyl-chloride batteries with 10+ year life targets. The integrated LCD and 8-channel ADC eliminate external display drivers and analog front ends, keeping total BOM under 30 components. Compared with low-power MCUs without integrated LCD, the ATMEGA329V-8MU achieves the same display capability at lower system cost.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA329V-8MU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA329V-8MUR | ATMEGA329PV-10MUR | ATMEGA329PA-MUR | ATMEGA329A-MUR |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 64-QFN (9x9) | 64-QFN (9x9) - same | 64-QFN (9x9) - same | 64-QFN (9x9) - same | 64-QFN (9x9) - same |
| Flash Memory | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB |
| Maximum CPU Clock | 8 MHz | 8 MHz | 10 MHz (+25%) | 20 MHz (+150%) | 20 MHz (+150%) |
| Supply Voltage Range | 1.8 V to 5.5 V (low-voltage variant) | 1.8 V to 5.5 V | 1.8 V to 5.5 V (Pico-Power) | 2.7 V to 5.5 V | 2.7 V to 5.5 V |
| LCD Controller | Yes (4 common / 25 segment) | Yes (4 common / 25 segment) | Yes (4 common / 25 segment) | Yes (4 common / 25 segment) | Yes (4 common / 25 segment) |
| SRAM | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB |
| Industrial Temp Range | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
Key Differentiators
- Low-voltage operation down to 1.8 V (vs ATMEGA329A-MUR)
- Identical pinout with reduced clock for power savings (vs ATMEGA329PA-MUR)
- Integrated segment LCD controller eliminates external driver (vs Discreet MCU + HT1621 LCD driver solutions)
Design Notes
The 64-QFN package of the ATMEGA329V-8MU has an exposed thermal pad that MUST be soldered to the PCB ground plane to ensure reliable thermal dissipation and mechanical solder-joint reliability. Failure to solder the EP typically results in intermittent operation during thermal cycling and reduced long-term reliability. Use at least 9 thermal vias in a 3x3 grid under the EP to spread heat to inner copper layers. Estimated: at 8 MHz and 5 V with all peripherals active, typical active current is ~5-8 mA, so power dissipation is roughly 25-40 mW; the EP is needed for reflow solderability rather than thermal margin in typical applications.
Place a 100 nF decoupling capacitor within 3 mm of each VCC and AVCC pin, plus a 10 uF bulk capacitor near the MCU supply input. Connect AVCC and VCC to the same supply rail through a ferrite bead or small resistor for ADC noise isolation. Keep the analog ADC inputs away from digital switching traces on the PCB to minimize crosstalk into the 10-bit ADC. The exposed pad must connect to a clean ground plane, not a noisy digital return path.
Do not exceed 5.5 V on VCC; the ATmega329V is the low-voltage variant - applying 5 V requires checking the V suffix in the part number. When migrating firmware to a higher-speed variant (ATmega329A-MUR at 20 MHz), verify all timer/counter prescaler settings, ADC clock divider, and USART baud-rate registers - default values may need scaling. The JTAG pins (PC2..PC5) are multiplexed with GPIO; configure the JTAG-disable fuse bit if you need those pins as regular GPIO after programming. The segment LCD controller requires external capacitors on each COM line (per datasheet) - omitting them reduces display contrast and increases ghosting.
Route the crystal traces (XTAL1, XTAL2) symmetrically and as short as possible, with the load capacitors within 3 mm of each XTAL pin. Keep digital switching traces away from the crystal traces and the AVCC / AREF pins to avoid injecting noise into the oscillator. The QFN package has 0.5 mm pitch leads - use 0.20 mm solder-pad width and 0.30 mm solder-mask opening per IPC-7351 guidelines for reliable QFN soldering. Use a 1 oz copper layer and avoid placing high-current traces near the QFN leads.
For LCD segment lines, route each segment trace with similar trace length to maintain balanced capacitive loading across the LCD matrix; unbalanced loading causes ghosting and reduced contrast. The integrated LCD controller supports up to 25 segments and 4 commons, but in multiplexed mode (>2 commons) the effective contrast drops; plan bias voltage accordingly. Place a 0.1 uF bypass capacitor near each LCD supply pin (LCDDATAVCC) to prevent digital switching noise from coupling into the LCD output drivers.
Compliance Information
RoHS and REACH compliant per Microchip product declaration. Halogen-free status not explicitly stated in distributor listings; set to unknown. Industrial temperature range -40 C to +85 C supports IEC 60721-3-5 Class 5M3 industrial environment.
