ATMEGA2561V-8AUR - 8-bit AVR MCU 256KB Flash TQFP-64 | Microchip
MPN: ATMEGA2561V-8AUR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $15.82 | $15.82 |
| 10 | $14.4 | $144.00 |
| 100 | $13.1 | $1,310.00 |
| 500 | $12.2 | $6,100.00 |
| 1,000 | $11.5 | $11,500.00 |
ATMEGA2561V-8AUR Overview
An 8-bit microcontroller (MCU) is a self-contained computing device that integrates a processor core, program memory, data memory, and peripherals on a single chip. Within the power-management hierarchy of embedded systems, the ATmega family sits in the microcontroller IC category: MCU -> embedded processor -> integrated circuit. The AVR core uses an advanced Harvard RISC architecture with 131 instructions, most executing in a single clock cycle, and 32 general purpose working registers, delivering fully static operation and roughly 8 MIPS throughput at the 8 MHz clock limit of the V-8 speed grade.
Key differentiating features include six flexible timer/counters with compare modes and PWM, four programmable serial USARTs, a master/slave SPI serial interface, a byte-oriented 2-wire serial interface (TWI/I2C), an 8-channel 10-bit ADC, a real-time counter, and a programmable watchdog timer with a separate on-chip oscillator. The device also provides an on-chip analog comparator, JTAG boundary-scan and on-chip debug, plus interrupt and wake-up on pin change for low-power designs.
Architecturally, the ATmega2561 combines 256 KB of self-programmable ISP Flash (organized as 128K x 16) with a boot-loader section, enabling field firmware updates over any of the serial interfaces. The generous 8 KB SRAM and 4 KB EEPROM make it well suited to data logging, protocol handling, and parameter storage without external memory in many designs.
Typical applications include industrial automation and control nodes, battery-powered instrumentation where the low-voltage V-grade supply range helps, building control panels, and multi-channel sensor acquisition systems leveraging the 8-channel 10-bit ADC and four USARTs.
A key design consideration: the V suffix denotes a lower-speed (8 MHz) grade, so do not clock above 8 MHz; if 5 V and 16 MHz operation are required, select the ATMEGA2561-16AU sibling instead, which shares the same TQFP-64 footprint.
This page synthesizes verified distributor pricing, drop-in alternatives, pinout guidance, and practical design notes not consolidated in the manufacturer datasheet alone.
Drop-in alternatives for ATMEGA2561V-8AUR 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 ATMEGA2561V-8AUR (same form factor and footprint) β differing in General Purpose I/O, Package, Core Architecture, EEPROM, Flash Memory.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA2561V-8AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA2561V-8AI
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA2561-16AU
β Drop-Inβ In Stock
$12.25 / Unit
View Datasheet βATMEGA2561-16AI
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA2561V-8AUR Maximum Ratings & Electrical Characteristics
| Core | AVR 8-bit RISC |
| Program Memory Size | 256 KB (128K x 16) ISP Flash |
| SRAM Size | 8 KB |
| EEPROM Size | 4 KB |
| Maximum Clock Frequency | 8 MHz |
| Throughput | up to 16 MIPS (family rating; 8 MIPS at 8 MHz) |
| Instruction Set | 131 instructions, mostly single-cycle |
| General Purpose I/O | 86 lines |
| Timer/Counters | 6 flexible timer/counters with compare modes and PWM |
| USART | 4 programmable serial USART |
| ADC | 8-channel, 10-bit |
| Serial Interfaces | SPI (Master/Slave), TWI (byte-oriented 2-wire) |
| Operating Temperature | -40C to +85C |
| Package | 64-TQFP (14x14 mm) |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (R suffix) |
| Special Peripherals | Watchdog timer with separate on-chip oscillator, analog comparator, JTAG, real-time counter |
| RoHS Status | Compliant (GREEN series per distributor data) |
ATMEGA2561V-8AUR 64-tqfp (14x14 mm) Pin Configuration Guide
Pin configuration for ATMEGA2561V-8AUR (64-tqfp (14x14 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 ATMEGA2561V-8AUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA2561V-8AUR is suitable for 6 applications: Industrial Automation and Control, Battery-Powered Instrumentation, Multi-Channel Sensor Acquisition, Building and HVAC Control Panels, Embedded Communication Gateways, Motor Control and Actuator Drives.
Industrial Automation and Control
The ATMEGA2561V-8AUR fits industrial control nodes that need substantial code space and rich connectivity without a 32-bit processor. Its 256 KB ISP Flash accommodates large ladder-logic interpreters or protocol stacks, while 8 KB SRAM buffers process data. Four USARTs allow simultaneous links to PLC backplanes, HMIs, and modems, and SPI/TWI handle local sensors. The six timers with PWM drive actuators and motor control loops directly. At 8 MHz the AVR core delivers deterministic single-cycle execution for real-time I/O, and the industrial -40C to +85C rating plus GREEN series construction suits factory-floor hardware. Bootloader-based field firmware updates over USART minimize maintenance downtime in installed equipment.
Recommended
Battery-Powered Instrumentation
In battery-operated meters and data loggers, the V-8 speed grade of the ATMEGA2561V-8AUR is an advantage: the AVR core is fully static down to low clock rates, so engineers can scale the clock to trade throughput against current draw, while 32 working registers and single-cycle execution keep per-task energy low. The 4 KB EEPROM stores calibration and logged parameters without external non-volatile memory, and the 8-channel 10-bit ADC digitizes multiple sensor inputs on-chip. Pin-change interrupt wake-up allows the MCU to sleep between events. With 256 KB Flash, a logger can hold complex compression and reporting firmware while remaining a single-chip solution in the 14x14 mm TQFP-64 package.
Recommended
Multi-Channel Sensor Acquisition
The ATMEGA2561V-8AUR consolidates sensor front-ends that would otherwise need multiple chips: its 8-channel, 10-bit ADC samples up to eight analog sources, and 86 GPIO lines handle digital sensor reads, mux control, and status signaling. The four USARTs stream acquired data simultaneously to telemetry radios, local displays, and host controllers, while SPI moves data at high rate from external converters if higher resolution is later required. The AVR's 8 MHz clock is typically sufficient for channel scanning and filtering at industrial rates, and JTAG on-chip debug simplifies bring-up of mixed analog/digital boards. The watchdog timer with separate on-chip oscillator guarantees autonomous recovery in unattended monitoring installations.
Recommended
Building and HVAC Control Panels
Building controllers benefit from the ATMEGA2561V-8AUR's blend of memory and communication. The 256 KB Flash holds scheduling, BAColm-style protocol logic, and OTA-update bootloaders; the TWI (2-wire) interface bus-connects room sensors and display boards cheaply over two wires, and the four USARTs link to gateways and power-line or RS-485 transceivers. Six timers generate PWM for damper motors, valve actuators, and blower speed control with hardware independence from software timing. The real-time counter keeps wall-clock scheduling across power cycles using a backup source. Its 64-TQFP 14x14 mm footprint suits compact panel PCBs, and industrial temperature qualification covers rooftop and mechanical-room environments reliably.
Recommended
Embedded Communication Gateways
Protocol-conversion gateways exploit the ATMEGA2561V-8AUR's four independent USARTs to bridge serial fieldbusses - for example Modbus RTU to a vendor-specific link - while SPI or TWI connects to Ethernet or radio modules. The 256 KB Flash leaves ample room for multiple protocol stacks plus a bootloader, and the 8 KB SRAM buffers frame reassembly without external RAM in typical packet sizes. Hardware compare/PWM channels handle status LED and relay timing. Fully static operation lets firmware throttle the clock when traffic is idle, conserving power in fanless enclosures. Because the AVR toolchain (AVR GCC, Microchip Studio) is mature, protocol code is easily ported across the ATmega family if I/O needs grow.
Recommended
Motor Control and Actuator Drives
The ATMEGA2561V-8AUR provides the timing resources small motor drives need: six timer/counters with output-compare channels generate complementary PWM for brushed DC, stepper, and small BLDC drives, with input-capture pins measuring feedback periods. At 8 MHz, PWM resolution and loop bandwidth are adequate for fan, pump, and conveyor applications up to the 5 V peripheral limit, and the 86 GPIO handles limit switches, encoders, and safety interlocks without port expanders. The 10-bit ADC reads current-shunt and position feedback, and the on-chip analog comparator supports zero-crossing detection for sensorless commutation. The industrial temperature rating and watchdog timer suit sealed, unattended actuator housings in harsh service.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA2561V-8AUR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA2561V-8AU | ATMEGA2561V-8AI | ATMEGA2561-16AU | ATMEGA2561-16AI |
|---|---|---|---|---|---|
| Package | 64-TQFP (14x14 mm) | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 256 KB | 256 KB | 256 KB | 256 KB | 256 KB |
| SRAM / EEPROM | 8 KB / 4 KB | 8 KB / 4 KB | 8 KB / 4 KB | 8 KB / 4 KB | 8 KB / 4 KB |
| Maximum Clock | 8 MHz | 8 MHz | 8 MHz | 16 MHz | 16 MHz |
| GPIO Count | 86 | 86 | 86 | 86 | 86 |
| Speed Grade / Voltage Class | V-8 (low-voltage class) | V-8 | V-8 | 16 (5 V class) | 16 (5 V class) |
| Packaging Format | Tape & Reel (R suffix) | Tray | Tray / Reel variant | Tray | Tray / Reel variant |
Key Differentiators
- Low-voltage 8 MHz speed grade for power-sensitive designs (vs ATMEGA2561-16AU)
- Reel packaging for automated SMT assembly (vs ATMEGA2561V-8AU)
- Memory headroom in a 64-pin footprint (vs ATMEGA2561V-8AI)
Design Notes
Respect the V-8 speed grade: the ATMEGA2561V-8AUR is qualified for a maximum of 8 MHz. Clocking above this rating violates the datasheet operating conditions even if the silicon appears to run. If a design later needs 16 MHz, migrate to ATMEGA2561-16AU - the TQFP-64 footprint is identical, so only the BOM and fuse settings (clock divider, CKOUT) change. Verify fuse bits (CLKDIV8, CKSEL) before first programming, since shipping fuse defaults affect the actual system clock.
Provide clean power distribution for the 64-TQFP: place 100 nF ceramic decoupling capacitors at each VCC/AVCC pin pair as close to the package as possible, plus a bulk 10 uF capacitor near the supply entry. Tie AGND and DGND at a single star point to keep ADC noise low, and route the 8 ADC channel traces away from PWM and USART switching lines. Keep the JTAG header accessible for on-chip debug and boundary scan; disabling JTAG via fuse frees four port pins if unused.
The EEPROM and Flash write operations draw transient current peaks; ensure the supply can source them without drooping, or use brown-out detection (BOD fuse) to prevent corrupted writes during power-down. For battery designs, leverage the AVR's sleep modes with pin-change interrupt wake-up - the watchdog's separate on-chip oscillator keeps timing alive during deep sleep. Confirm the exact operating voltage range for the V-grade from the datasheet's DC characteristics table before finalizing the regulator choice.
Compliance Information
GREEN series designation appears in distributor comparison data for the ATMEGA2561 family, indicating RoHS-aware construction. Full REACH and conflict-minerals statements should be confirmed on the Microchip product page.