ATMEGA649V-8AU - 64KB Flash 8MHz LCD AVR MCU | Microchip
MPN: ATMEGA649V-8AU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $10.12 | $10.12 |
| 10 | $9.36 | $93.60 |
| 100 | $8.52 | $852.00 |
| 500 | $7.9 | $3,950.00 |
| 1,000 | $7.28 | $7,280.00 |
ATMEGA649V-8AU Overview
A microcontroller unit (MCU) is a single integrated circuit that combines a processor core, memory, and programmable peripherals on one die. Within the embedded hierarchy, the ATmega649 sits in Microchip's AVR ATmega family of 8-bit microcontrollers, a product class that evolved from simple 4-bit MCUs and today competes with ARM Cortex-M0 parts in cost-sensitive, low-power applications.
Key features include 54 general purpose I/O lines in the 64-pin package, an on-chip LCD controller capable of driving up to 25 segments x 4 commons, a JTAG interface for boundary-scan and on-chip debugging, and read-while-write Flash for self-programming bootloaders. The low-voltage V variant operates from 1.8V to 5.5V, enabling direct battery-powered designs.
Technically, the AVR core uses a Harvard architecture with 32 general purpose working registers directly connected to the ALU, executing most instructions in a single clock cycle - yielding up to 8 MIPS at 8MHz. The V-speed grade trades peak performance for a wide 1.8V-5.5V operating range, and the digchip listing notes the newer ATMEGA649A as the recommended successor.
Typical applications include battery-powered metering displays, appliance front panels with segmented LCDs, industrial handheld instruments, and low-power sensor nodes where the integrated LCD driver eliminates an external LCD controller IC.
A key design consideration is clock selection: at 3.3V the maximum safe CPU frequency derates below 8MHz, so verify the speed-grade graph in the manufacturer datasheet against your supply voltage.
This page synthesizes distributor pricing, drop-in family alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA649V-8AU β 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-8AU (same form factor and footprint) β differing in Package, General Purpose I/O, LCD Controller, Flash Memory, Supply Voltage Range.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA649A-AUR
β Drop-Inβ In Stock
$5.72 / Unit
View Datasheet βATMEGA649A-MU
β Drop-Inβ In Stock
$4.42 / Unit
View Datasheet βATMEGA649P-MU
β Drop-Inβ In Stock
$3.91 / Unit
View Datasheet βATMEGA645V-8AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA329V-8AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA640V-8AU
β Drop-Inβ In Stock
$3.95 / Unit
View Datasheet βATMEGA649V-8AU Maximum Ratings & Electrical Characteristics
| Core | 8-bit AVR RISC |
| Flash Memory | 64 KB (32K x 16), ISP, read-while-write |
| EEPROM | 2 KB |
| SRAM | 4 KB |
| Maximum Clock Speed | 8 MHz |
| Supply Voltage Range | 1.8 V to 5.5 V |
| General Purpose I/O | 54 I/O lines (69 available on 100-pin variant) |
| LCD Controller | Integrated segment LCD driver (up to 25 segments x 4 commons) |
| ADC | 10-bit, 8 channels |
| Debug / Boundary Scan | JTAG interface (IEEE 1149.1 boundary-scan) |
| Working Registers | 32 general purpose registers |
| Programming | In-System Programmable (ISP), ICSP via MPLAB SNAP |
| Package | 64-TQFP, 14 x 14 mm |
| Operating Temperature | -40C to +85C (industrial) |
| Data Bus Width | 8 Bit |
| Mounting Type | Surface Mount |
| RoHS / Green | GREEN package per ADatasheet listing |
| Peripherals | Timers, USART, SPI, TWI, RTC/TOSC pins |
ATMEGA649V-8AU 64-tqfp, 14 x 14 mm Pin Configuration Guide
Pin configuration for ATMEGA649V-8AU (64-tqfp, 14 x 14 mm 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-8AU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA649V-8AU is suitable for 6 applications: Utility and Energy Metering Displays, Appliance and White-Good Front Panels, Industrial Handheld Instruments, Battery-Powered Sensor Nodes, POS and Vending Human-Machine Interfaces, Automotive-adjacent Instrument Clusters and Test Rigs.
Utility and Energy Metering Displays
The ATMEGA649V-8AU fits electricity, water, and gas meter front ends because its integrated LCD driver drives the segmented display directly and its 1.8V-5.5V supply range tolerates battery back-up rails without an extra regulator. In a typical design the MCU runs from a 3.6V lithium cell at a few MHz, wakes from power-down via the TOSC RTC, updates the LCD and energy counters, and returns to sleep - extending battery life for years. The 64KB Flash holds firmware, metrology tables, and a bootloader, while the 2KB EEPROM stores calibration data through 100k+ write cycles. The 10-bit ADC can monitor battery voltage for end-of-life indication, and JTAG supports production boundary-scan test of the meter PCB.
Recommended
Appliance and White-Good Front Panels
Ovens, washing machines, and HVAC thermostats use segmented LCDs, buttons, and relays - exactly the peripheral mix of the ATMEGA649V-8AU. The integrated LCD controller drives temperature, time, and cycle-position segments without an external LCD driver IC, cutting BOM cost and PCB area in the slim front-panel boards typical of appliances. The 54 GPIO lines in the TQFP-64 package handle a key matrix, relay drive, buzzer, and sensor inputs simultaneously. Industrial -40C to +85C temperature rating covers kitchen and boiler-side environments, and 64KB Flash supports multilingual menu firmware plus OTA-style field updates via a Flash bootloader using read-while-write. The 5V-tolerant V-variant also interfaces directly with legacy 5V appliance logic.
Recommended
Industrial Handheld Instruments
Handheld multimeters, ultrasonic thickness gauges, and panel test tools benefit from the ATMEGA649V-8AU's combination of a 10-bit ADC, integrated LCD driver, and JTAG debugging in one 64-TQFP device. The wide 1.8V-5.5V operating range allows a 2xAA supply to drain down to 0.9V per cell through a boost stage while keeping code compatibility across a 3V/5V product family - one firmware image serves both. With most AVR instructions executing in a single 8MHz cycle, display refresh and ADC averaging loops run comfortably in real time. The 4KB SRAM buffers measurement sweeps for on-screen plotting, and the EEPROM retains calibration constants across battery changes. Production units benefit from JTAG boundary-scan during ICT fixture test.
Recommended
Battery-Powered Sensor Nodes
For low-power sensor nodes that periodically display status on a small segmented LCD, the ATMEGA649V-8AU eliminates the classic two-chip solution of MCU plus LCD controller. The V speed grade permits clocking at 32.768kHz-1MHz from the TOSC-capable oscillator pins in standby, cutting current into the microamp range, with periodic wakeups to sample the ADC and refresh the display. USART, SPI, and TWI interfaces connect radio modules or I2C sensors, while 64KB Flash hosts the protocol stack and bootloader. Compared with moving to an ARM Cortex-M platform, the 8-bit AVR keeps code footprint small and startup latency short, which matters for burst-operated, sleep-dominated duty cycles typical of metering-grade IoT nodes.
Recommended
POS and Vending Human-Machine Interfaces
Vending machines, ticket terminals, and simple point-of-sale keypads need rugged, cheap, LCD-based HMI boards - a strong fit for the ATMEGA649V-8AU. The LCD driver renders price, credit, and status segments; 54 GPIO lines scan a large key matrix and drive coin-mech and dispense relays; and 64KB Flash stores tariff tables plus a field-update bootloader using read-while-write so the terminal never appears dead during an upgrade. The industrial temperature rating and 5V operation simplify integration into existing 24V/5V vending backplanes. JTAG supports boundary-scan on the HMI board during automated production test, and the part's long AVR ecosystem tooling (AVR Studio line, MPLAB X) reduces firmware maintenance cost over the typical decade-long service life of vending hardware.
Recommended
Automotive-adjacent Instrument Clusters and Test Rigs
Low-end dashboards, forklift instrument clusters, and engineering test rigs in the 12V domain use the ATMEGA649V-8AU where an LCD is required but full automotive qualification is not. A simple 5V regulator from the 12V rail supplies the MCU, whose integrated LCD driver shows speed, hours, and fault codes, while the ADC reads sender potentiometers and NTC temperature probes. The JTAG interface accelerates firmware bring-up on the bench, and 32 single-cycle registers keep display-multiplexing ISR overhead minimal at modest clock rates. Note this commercial-grade part is not AEC-Q100 qualified: for harsh automotive platforms select an automotive-qualified MCU family instead, and reserve the ATmega649 for off-highway, marine, and industrial-vehicle applications with relaxed qualification requirements.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA649V-8AU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA649A-AUR | ATMEGA649A-MU | ATMEGA645V-8AU | ATMEGA329V-8AU | ATMEGA640V-8AU |
|---|---|---|---|---|---|---|
| Package | 64-TQFP (14x14 mm) | 64-TQFP - same | 64-QFN - footprint differs | 64-TQFP - same | 64-TQFP - same | 64-TQFP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 64 KB | 64 KB | 64 KB | 64 KB | 32 KB | 64 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 4 KB | 2 KB | 4 KB |
| Max Clock Speed | 8 MHz (V grade) | 20 MHz | 20 MHz | 8 MHz | 8 MHz | 8 MHz |
| Supply Voltage | 1.8 V - 5.5 V | 1.8 V - 5.5 V | 1.8 V - 5.5 V | 1.8 V - 5.5 V | 1.8 V - 5.5 V | 1.8 V - 5.5 V |
| Integrated LCD Driver | Yes | Yes | Yes | Yes | Yes | No |
| JTAG Interface | Yes | Yes | Yes | No | Yes | Yes |
| Low-Power Technology | Original Atmel generation | picoPower | picoPower | Original generation | Original generation | Original generation |
Key Differentiators
- Integrated LCD driver in a 64-pin TQFP (vs ATMEGA640V-8AU)
- JTAG boundary-scan and on-chip debug (vs ATMEGA645V-8AU)
- Double the memory of the LCD-series sibling (vs ATMEGA329V-8AU)
- Wide 1.8V-5.5V operating range at 8MHz (vs ATMEGA649A-AUR)
Design Notes
The V speed grade is rated 8MHz only across the full 1.8V-5.5V range, but verify the frequency-versus-VCC safe operating area in the Microchip datasheet before picking a crystal: at low VCC, aggressive clocking near the maximum reduces timing margin and can cause marginal startup at cold temperatures. For battery metering designs, clock the core from the internal RC at 1-2MHz and use the TOSC 32.768kHz crystal for the RTC, waking via power-down mode to cut average current into the microamp range.
Place a 100nF ceramic decoupling capacitor directly across each VCC/GND pin pair of the TQFP-64, plus a 10uF bulk capacitor near the supply entry. The LCD driver bias pins require the datasheet-recommended capacitor network on VLCD - do not omit it, or segment contrast and ghosting will result. Keep the LCD segment traces routed away from the crystal and JTAG signals; the LCD lines switch at low frequency but the high pin count of the TQFP-64 makes crosstalk routing discipline important on two-layer boards.
Reserve the JTAG pins if you plan boundary-scan production test or on-chip debugging - JTAG is fuse-disabled in some configurations and cannot be recovered once the relevant lock/settle bits are programmed without erasing the chip. Also note the ATMEGA649V-8AU is the original Atmel generation: Microchip flags ATMEGA649A as the newer device for this part number, so for long-lifetime designs qualify the 649A-AUR (same TQFP-64 footprint) as a second source on your AVL before the V-variant's end-of-life notice appears.
Compliance Information
Distributor listing (ADatasheet) describes the package as GREEN, which denotes RoHS-compliant lead-free packaging. No AEC-Q100 qualification is indicated; this is an industrial-temperature commercial part. Formal REACH and conflict-minerals declarations should be requested from Microchip.
