ATMEGA649V-8MI - AVR 8-Bit MCU, 64KB, 8MHz | Microchip
MPN: ATMEGA649V-8MI ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.2 | $6.20 |
| 10 | $5.58 | $55.80 |
| 100 | $4.96 | $496.00 |
| 500 | $4.47 | $2,235.00 |
| 1,000 | $4.02 | $4,020.00 |
ATMEGA649V-8MI Overview
An 8-bit AVR microcontroller is a single-chip processor built on the AVR advanced RISC architecture, which executes most of its 130 powerful instructions in a single clock cycle. Within the embedded processor hierarchy, the ATmega649 belongs to the AVR ATmega family -> 8-bit microcontroller -> microcontroller unit (MCU) -> semiconductor integrated circuit. The ATmega649 adds a segment LCD driver (up to 4x25 or 8x25 segments) that many general-purpose MCUs lack, making it a staple for battery-powered instruments with glass or custom LCD displays.
Key features include 64KB self-programming Flash, 2KB EEPROM, 4KB internal SRAM, an advanced RISC core, JTAG (IEEE 1149.1) boundary-scan and on-chip debugging, and a rich peripheral set: 8-channel 10-bit ADC, analog comparator, USART, SPI and Two-Wire Interface (TWI/I2C), timers/counters with PWM, and the LCD controller. Power management modes (Idle, ADC Noise Reduction, Power-save, Power-down, Standby) enable microamp-class sleep currents for battery designs.
Architecturally, the AVR core uses Harvard structure with separate program and data buses, single-cycle ALU operation, and 32 general-purpose working registers, delivering roughly 1 MIPS per MHz. At 1.8V operation the part runs at up to 4 MHz, with 8 MHz permitted at 2.7V and above, trading speed against voltage for low-power designs.
Typical applications include battery-powered meters with LCD displays, industrial instrumentation, building controllers, and portable medical devices where a low-voltage MCU with an integrated LCD driver reduces BOM cost and board area.
Design consideration: match your clock speed to the operating voltage per the AVR speed-grade derating curve; running 8 MHz below 2.7V violates the datasheet frequency-voltage envelope.
This page synthesizes distributor pricing, drop-in alternatives, design notes, and FAQ content not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA649V-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 ATMEGA649V-8MI (same form factor and footprint) — differing in Package, LCD Controller, EEPROM, RoHS Status, Debug Interface.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA649V-8MU
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA649P-MU
✅ Drop-In✓ In Stock
$3.91 / Unit
View Datasheet →ATMEGA649P-MUR
✅ Drop-In✓ In Stock
$5.1 / Unit
View Datasheet →ATMEGA649A-MU
✅ Drop-In✓ In Stock
$4.42 / Unit
View Datasheet →ATMEGA329V-8MI
✅ Drop-In✓ In Stock
$5.45 / Unit
View Datasheet →ATMEGA649V-8MI Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Flash Program Memory | 64KB (32K x 16) |
| EEPROM | 2KB |
| Internal SRAM | 4KB |
| Maximum Clock Frequency | 8 MHz |
| Operating Voltage Range | 1.8 V to 5.5 V |
| Operating Temperature | -40C to +85C (industrial) |
| Package | 64-QFN (9x9 mm, VFQFN with exposed pad) |
| Mounting Type | Surface Mount |
| LCD Controller | Segment LCD driver (up to 4x25 / 8x25 segments) |
| ADC Resolution | 10-bit |
| ADC Channels | 8 channels |
| Communication Interfaces | USART, SPI, TWI (I2C) |
| Timers | 2 x 8-bit, 1 x 16-bit with PWM |
| JTAG | IEEE 1149.1 boundary scan + on-chip debug |
| In-System Programming (ISP) | Yes, self-programming Flash |
| Instructions | 130 instructions, most single-cycle |
| Series | AVR ATmega ATMEGA649 |
ATMEGA649V-8MI 64-qfn (9x9 mm, vfqfn with exposed pad) Pin Configuration Guide
Pin configuration for ATMEGA649V-8MI (64-qfn (9x9 mm, vfqfn with 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 ATMEGA649V-8MI.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA649V-8MI is suitable for 6 applications: Battery-Powered LCD Meters, Industrial Instrumentation, Portable Medical Devices, Building Automation Nodes, Consumer Electronics with Displays, Embedded Development and Education.
Battery-Powered LCD Meters
The ATMEGA649V-8MI is purpose-built for battery-operated metering products such as utility meters, handheld gauges, and panel instruments that drive a segment LCD. Its integrated LCD controller eliminates a separate LCD driver IC, saving BOM cost and board area, while the 1.8V to 5.5V supply range allows direct operation from a 2xAAA or single lithium cell through a wide discharge curve. In Power-save mode the MCU keeps the LCD and asynchronous timer alive while the CPU sleeps, and the 8 MHz ceiling is more than sufficient for metering math. Designers typically clock the part from a 32.768 kHz watch crystal in sleep and switch to the fast RC or crystal oscillator on demand to balance display refresh against battery life.
Recommended
Industrial Instrumentation
In factory instrumentation - pressure transmitters, flow indicators, and HMI front panels - the ATMEGA649V-8MI combines the industrial -40C to +85C temperature grade with an 8-channel 10-bit ADC for sensor acquisition and the LCD driver for local readout. The 64KB Flash accommodates calibration tables, multi-language UI strings, and communication stacks in a single chip, while 2KB EEPROM stores field calibration and configuration data across power cycles. USART, SPI, and TWI interfaces support 4-20 mA companion DACs, external memory, and Modbus-style serial links. JTAG on-chip debugging shortens bring-up in electrically noisy industrial environments where traditional in-circuit emulators struggle.
Recommended
Portable Medical Devices
Portable diagnostic and monitoring accessories - thermometers, glucose meters, spirometer accessories, and test strip readers - benefit from the ATMEGA649V-8MI's combination of low-voltage operation, an LCD controller, and a 10-bit ADC with internal reference. The 1.8V floor allows coin-cell powered designs, and the ADC Noise Reduction sleep mode reduces supply noise on the ADC during precision conversions, which is important for sub-millivolt sensor front ends. The 4KB SRAM buffers measurement series for on-device statistics, and self-programming Flash enables field firmware updates from a bootloader over USART. The exposed-pad QFN also gives good thermal coupling for medical-grade reflow and reliability targets.
Recommended
Building Automation Nodes
Wall-mounted thermostats, room controllers, and occupancy sensing panels are classic ATmega649 applications: they need a display, a few buttons, a sensor bus, and a network link, all on limited board area. The ATMEGA649V-8MI drives the LCD directly, reads sensors via TWI (I2C), and communicates over USART to RS-485 transceivers or RF modules. The 64KB Flash holds a full control application plus OTA-capable bootloader, and EEPROM retains setpoints through power loss. Deep Power-down between UI activity events yields long battery life in wireless thermostats, while the industrial temperature grade covers unconditioned spaces such as mechanical rooms and outdoor enclosures.
Recommended
Consumer Electronics with Displays
Kitchen scales, timers, remote controls, and small appliances frequently use ATmega LCD MCUs because one chip covers user interface, control logic, and display. The ATMEGA649V-8MI's 4x25 segment LCD capability supports multi-digit numeric and icon-rich glasses, while capacitive-style touch can be implemented on spare GPIO with library support. The 130-instruction single-cycle AVR core gives responsive button handling even from a 32 kHz auxiliary clock, and the wide 1.8V to 5.5V range tolerates inexpensive unregulated supply schemes common in consumer products. Cost-sensitive builds often substitute the same-footprint ATMEGA329V-8MI when 32KB Flash suffices.
Recommended
Embedded Development and Education
The ATmega649 family is supported by Microchip's MPLAB SNAP programmer/debugger via ICSP and JTAG, and by the open-source MegaCore Arduino hardware package on GitHub, which covers ATmega649 among its supported devices. This makes the ATMEGA649V-8MI attractive for lab courses, prototyping, and hobbyist LCD projects where a single-chip MCU-plus-LCD combination shortens development. The self-programming Flash supports bootloader-based updates over a plain serial cable, and JTAG boundary scan helps students learn IEEE 1149.1 testing. Community toolchains (avrdude, GCC) are mature, reducing the tooling cost of adopting the platform for small teams.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA649V-8MI — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA649V-8MU | ATMEGA649P-MU | ATMEGA649A-MU | ATMEGA329V-8MI |
|---|---|---|---|---|---|
| Package | 64-QFN (9x9 mm) | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 64KB | 64KB | 64KB | 64KB | 32KB |
| SRAM | 4KB | 4KB | 4KB | 4KB | 2KB |
| Max Clock Frequency | 8 MHz | 8 MHz | 20 MHz | 16 MHz | 8 MHz |
| Operating Voltage | 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 |
| LCD Controller | Yes (segment LCD) | Yes | Yes | Yes | Yes |
Key Differentiators
- Identical silicon, alternative packing code availability (vs ATMEGA649V-8MU)
- Lower speed grade reduces risk at 8 MHz designs (vs ATMEGA649P-MU)
- Double the memory of the smaller LCD family member (vs ATMEGA329V-8MI)
Design Notes
Respect the AVR frequency-versus-voltage derating envelope: at 1.8V the ATmega649V is limited to 4 MHz; 8 MHz operation requires VCC of 2.7V or higher. Derating violations are a common cause of intermittent brown-out resets in battery products as the cell discharges. Enable the internal brown-out detector at an appropriate threshold (e.g., BOD level matched to your minimum rail) so the MCU resets cleanly instead of executing corrupt code during supply sag.
The 64-QFN exposed pad on the bottom of the package should be soldered to a ground array of vias for mechanical integrity and thermal dissipation; do not leave it floating. Decouple VCC and AVCC separately with 100 nF ceramics placed within 3 mm of the pins, and connect AVCC to VCC through an LC filter when ADC accuracy matters. Provide a programming header wired to MOSI/MISO/SCK/RESET for ICSP, or reserve the JTAG pads for the MPLAB SNAP debug interface.
The LCD driver pins are multiplexed with GPIO: configuring SEG/COM alternate functions after reset is required, and any GPIO inadvertently left on LCD-shared pins will distort display segments. Also note that replacing the V-variant with the 649P or 649A preserves pinout but changes maximum frequency and some errata - re-run timing-sensitive firmware validation. Older AVR datasheets were published under the Atmel brand; always use the latest Microchip revision to capture consolidated errata before release.
Keep the crystal or resonator traces to XTAL1/XTAL2 short (under 10 mm) with guard ground, and place the load capacitors close to the pins. In LCD products, the alternating LCD drive waveform couples onto adjacent traces; route SEG lines away from the analog ADC inputs or add ground guard traces. For ADC noise, use the ADC Noise Reduction sleep mode so the core clock is halted during conversions, and average 4-16 samples for sub-LSB effective resolution.
Compliance Information
Distributor listings describe the part as GREEN (RoHS-compliant, lead-free). REACH, halogen-free and conflict-minerals statements should be confirmed via Microchip's environmental documents on the official product page.
