ATMEGA645V-8AUR - 8-bit AVR MCU 64KB Flash 8MHz | Microchip
MPN: ATMEGA645V-8AUR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.42 | $6.42 |
| 10 | $5.78 | $57.80 |
| 100 | $5.14 | $514.00 |
| 500 | $4.66 | $2,330.00 |
| 1,000 | $4.2 | $4,200.00 |
ATMEGA645V-8AUR Overview
An 8-bit microcontroller is an integrated circuit that combines a processor core, program memory, data memory, and peripherals on a single chip. Within the power-management hierarchy of embedded systems, an MCU sits at the lowest processing layer, executing control logic for sensors, displays, actuators, and communication interfaces. The AVR family, originally developed by Atmel and now manufactured by Microchip Technology, is built on an advanced RISC architecture executing most of its 130 instructions in a single clock cycle.
Key features of the ATMEGA645V-8AUR include its 64KB self-programmable Flash for firmware storage, 64-pin TQFP footprint with gull-wing terminals suited to automated assembly, an AVR RISC core with 32 general-purpose working registers, and low-power operation across a wide supply range, with the V-grade suffix indicating extended low-voltage operation from 1.8 V. This makes the device suitable for battery-powered designs where 5 V rails are unavailable.
Technically, the core achieves roughly 1 MIPS per MHz throughput, meaning an 8 MHz clock yields approximately 8 MIPS of integer performance. The ATmega645 family integrates an LCD controller along with standard AVR peripherals including timers, USART, SPI, and a 10-bit ADC, consolidating display-driving capability directly into the MCU and reducing external component count in segmented-LCD products.
Typical applications include battery-operated metering devices, appliance control panels with segmented LCDs, industrial sensor nodes, and low-voltage portable instrumentation. The combination of Flash self-programming, EEPROM for calibration data, and an integrated LCD driver fits single-chip meter and panel-controller architectures particularly well.
Design consideration: because the V-suffix device is specified at 8 MHz maximum, designs needing higher throughput should select the 16 MHz ATMEGA645-16AI variant, which trades low-voltage range for speed.
This page synthesizes distributor pricing, verified drop-in alternatives within the ATmega645/3290 families, and practical design guidance not found in the manufacturer datasheet alone.
Drop-in alternatives for ATMEGA645V-8AUR — 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 ATMEGA645V-8AUR (same form factor and footprint) — differing in RoHS Status, Core Architecture, Operating Temperature, Package, EEPROM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA645V-8AI
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →ATMEGA645V-8AU
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA6450V-8AU
✅ Drop-In✓ In Stock
$2.31 / Unit
View Datasheet →ATMEGA3290V-8AUR
✅ Drop-In✓ In Stock
$2.3 / Unit
View Datasheet →ATMEGA645-16AI
✅ Drop-In✓ In Stock
$6.45 / Unit
View Datasheet →ATMEGA645V-8AUR Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC, 130 instructions |
| Flash Memory | 64 KB In-System Programmable |
| EEPROM | 2 KB |
| SRAM | 4 KB |
| Maximum Clock Frequency | 8 MHz |
| Operating Voltage | 1.8 V to 5.5 V (V-grade) |
| Package | TQFP-64 |
| Mounting Type | Surface Mount |
| Terminal Form | Gull Wing |
| Package Shape | Square |
| Number of Terminals | 64 |
| Temperature Grade | Industrial |
| Throughput | Up to 8 MIPS at 8 MHz (approx. 1 MIPS/MHz) |
| Packing | Tape & Reel (R suffix) |
| RoHS Status | Compliant (green package per FindIC listing) |
| Programming Method | In-System Programmable (ISP) |
ATMEGA645V-8AUR square Pin Configuration Guide
Pin configuration for ATMEGA645V-8AUR (square 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 ATMEGA645V-8AUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA645V-8AUR is suitable for 6 applications: Battery-Powered Utility Metering, Appliance Control Panels with Segmented LCD, Industrial Sensor Nodes, Portable Low-Voltage Instrumentation, Building Automation and HVAC Controllers, Legacy System Maintenance and Repair.
Battery-Powered Utility Metering
The ATMEGA645V-8AUR fits battery-powered metering architectures because its V-grade silicon operates from a 1.8 V supply, extending battery life versus 5 V-class MCUs, while 2KB EEPROM preserves meter constants and calibration data across power loss. The ATmega645 family integrates an LCD controller, so energy, water, and gas meters can drive segmented displays directly without an external LCD driver IC, cutting BOM cost and board area. In a typical design the MCU sleeps between measurement cycles, waking on a timer or sensor interrupt, with the 8 MHz RISC core executing the accumulation math in microseconds before returning to low-power idle. Firmware images fit comfortably in the 64KB Flash, and In-System Programming supports field firmware updates through the meter's communication port, reducing total cost of ownership over a multi-year deployment life.
Recommended
Appliance Control Panels with Segmented LCD
Home appliances such as ovens, washing machines, and refrigerators require segmented LCD user interfaces driven by long-life controllers. The ATMEGA645V-8AUR consolidates the LCD driver, timers for buzzer and relay sequencing, and a 10-bit ADC for NTC temperature sensing inside a single 64-pin TQFP, replacing what would otherwise require an MCU plus a discrete LCD driver chip. Its 4KB SRAM holds menu state machines and localization strings, while 64KB Flash accommodates multi-language firmware images. The industrial temperature grade withstands kitchen and laundry chamber environments near the control board, and the gull-wing TQFP terminals suit standard reflow assembly used in high-volume appliance manufacturing. The 1.8 V V-grade also supports designs powered from single-cell lithium or low-voltage standby rails, simplifying standby power compliance.
Recommended
Industrial Sensor Nodes
Distributed industrial sensing benefits from the ATMEGA645V-8AUR's combination of a 10-bit ADC, USART, and SPI interfaces for connecting ADCs, RTD front ends, or RS-485 transceivers. The 8 MHz AVR core delivers roughly 8 MIPS, adequate for local filtering, linearization, and threshold decisions before reporting over the bus. With 4KB SRAM, nodes can buffer burst samples during communication outages, and the 2KB EEPROM stores node address, calibration coefficients, and event counters that must survive power cycling. The industrial temperature rating and TQFP-64 surface-mount package suit DIN-rail and IP-rated enclosure electronics assembled on standard SMT lines. Because the V-grade accepts 1.8 V operation, designers can run single-supply analog front ends at low voltage, reducing sensor-interface offset and simplifying the power tree in battery or energy-harvesting installations.
Recommended
Portable Low-Voltage Instrumentation
Handheld and portable instruments powered by two alkaline cells or a single lithium cell benefit directly from the ATMEGA645V-8AUR's 1.8 V V-grade operation, which keeps the MCU alive deep into the battery discharge curve where 4.5 V-class parts would have already browned out. The 64KB Flash hosts measurement routines, compensation tables, and UI code, while the integrated LCD controller drives the segmented readout without extra drivers - critical where every square millimeter and every microamp count. The 130-instruction AVR RISC core completes single-cycle arithmetic for FFT pre-processing and digital filtering at 8 MHz. In-System Programming allows calibration rigs to flash gain and offset constants in production, and the 2KB EEPROM retains the last calibration through battery replacement, a hard requirement for traceable portable measurement products.
Recommended
Building Automation and HVAC Controllers
Zone controllers, thermostats, and damper actuators in building automation use the ATMEGA645V-8AUR's ADC for thermistor and humidity-sensor acquisition, timers for PWM control of valves and fans, and USART for RS-485 Modbus links. The 64KB Flash accommodates full control-state machines plus PID loops with headroom for protocol stacks, and 4KB SRAM buffers network transactions and trend logs between polls. The industrial temperature grade covers ceiling plenum and rooftop installations where ambient extremes exceed consumer ratings. Using the V-grade part at reduced clock speed reduces average current draw in thermostat products that run on power-stealing loops from HVAC wiring. The TQFP-64 gull-wing package assembles reliably on standard contract-manufacturer SMT lines, supporting the volume production typical of building-products OEMs.
Recommended
Legacy System Maintenance and Repair
Many installed Atmel-era products - medical bench accessories, test fixtures, kiosks, and legacy industrial equipment - were designed around the ATmega645 family, and repair shops must source exact-footprint replacement parts. The ATMEGA645V-8AUR in Tape & Reel suits both prototype rework and production-service spares: because it is the original silicon in the original 64-pin TQFP, existing firmware images program directly via ISP with no porting effort. Where the exact suffix is unavailable, ATMEGA645V-8AI and ATMEGA645V-8AU are electrically identical (packing differs only), giving repair organizations three purchasable order codes for the same socket. This matters for obsolescence-risk management: standardizing repair stock on one die family with multiple package/suffix options extends service life for installed equipment fleets without redesign.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA645V-8AUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA645V-8AI | ATMEGA645V-8AU | ATMEGA6450V-8AU | ATMEGA3290V-8AUR | ATMEGA645-16AI |
|---|---|---|---|---|---|---|
| Package | TQFP-64 | TQFP-64 - same | TQFP-64 - same | TQFP-64 - same | TQFP-64 - same | TQFP-64 - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max Clock Frequency | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 16 MHz |
| Supply Voltage Grade | 1.8 V low-voltage (V-grade) | 1.8 V (V-grade) | 1.8 V (V-grade) | 1.8 V (V-grade) | 1.8 V (V-grade) | 4.5-5.5 V standard grade |
| Packing | Tape & Reel | Tray | Tray | Tray | Tape & Reel | Tray |
Key Differentiators
- Identical-die reel packing for high-volume assembly (vs ATMEGA645V-8AI)
- Double the program memory of the LCD sibling (vs ATMEGA3290V-8AUR)
- True low-voltage operation (vs ATMEGA645-16AI)
- V-grade speed headroom matches battery designs (vs ATMEGA6450V-8AU)
Design Notes
The V-suffix ATmega645 is a low-voltage grade; run it from a regulated 1.8 V to 3.3 V rail to exploit its extended battery-life advantage. Never power it above the V-grade supply ceiling - if your board has a fixed 5 V rail, choose ATMEGA645-16AI instead, which is pin-compatible in the same 64-pin TQFP but rated for 5 V at 16 MHz. Decouple VCC pins with 0.1 uF ceramics placed within a few millimeters of each supply terminal, and tie AREF through its recommended network per the family datasheet.
For the 64-pin TQFP footprint, use 0.5 mm-pitch land patterns per the manufacturer package drawing and fan out fine-pitch traces with 0.2 mm width where routing allows. Place the ISP header (MOSI, MISO, SCK, RESET, VCC, GND) at the board edge so field reprogramming is possible without disassembly. Because the ATmega645 family drives an LCD, route LCD segment traces away from the crystal and analog ADC inputs to prevent visible display crosstalk and ADC noise coupling.
The most common substitution error is mixing V-grade and non-V parts: ATMEGA645-16AI will not function reliably below 4.5 V, so it is NOT a drop-in on a 1.8-3.3 V board even though the footprint is identical. Also confirm clock expectations: this 8 MHz part cannot run firmware timing loops calibrated for 16 MHz variants without rework. Finally, the R suffix denotes Tape & Reel; when ordering low-volume prototypes, tray-packed ATMEGA645V-8AI or ATMEGA645V-8AU avoids minimum-reel-quantity commitments.
Compliance Information
FindIC product records list the part as GREEN, indicating RoHS-compliant lead-free/halogen-free construction. REACH and conflict-minerals status not stated in provided data.
