ATMEGA1281V-8AUR - 8-bit AVR MCU 128KB 8MHz TQFP-64 | Microchip
MPN: ATMEGA1281V-8AUR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.9 | $6.90 |
| 10 | $6.2 | $62.00 |
| 100 | $5.45 | $545.00 |
| 500 | $4.9 | $2,450.00 |
| 1,000 | $4.4 | $4,400.00 |
ATMEGA1281V-8AUR Overview
An 8-bit AVR microcontroller is a Harvard-architecture single-chip computer that executes code directly from embedded Flash while storing variables in on-chip SRAM. Within the power-management hierarchy it serves as a complete embedded processing IC, combining CPU, memory, timers, serial interfaces, and analog-to-digital conversion in one device, eliminating external logic in cost-sensitive designs.
Key features include 133 powerful RISC instructions with mostly single-cycle execution, 32 general purpose working registers directly connected to the ALU, 54 general purpose I/O lines, four flexible timer/counters with compare and PWM modes, and multiple serial communication peripherals. The AVR core achieves throughputs of up to one MIPS per MHz, allowing the 8MHz ATMEGA1281V-8AUR to deliver roughly 8 MIPS while consuming minimal power, which is why the V-graded 1.8V supply option is attractive for battery-operated systems.
Technically, the device integrates 128KB ISP Flash organized as 64K x 16, supporting in-system programming via SPI as well as boot-loader self-programming, with an optional boot code section protected by lock bits. The 8KB internal SRAM supports an external memory interface for expansion, and 4KB EEPROM provides non-volatile parameter retention through hundreds of thousands of write cycles.
Typical applications include industrial control panels, sensor acquisition nodes, metering products, and low-voltage battery-powered instrumentation, where the wide 1.8V to 5.5V supply range removes the need for a dedicated regulator in 2-cell or 3-cell battery systems.
For design, the V-grade part is limited to 8MHz; the 16MHz-capable ATMEGA1281-16AUR should be chosen only when a 4.5V to 5.5V supply is guaranteed.
This page synthesizes distributor pricing, drop-in ATmega-family alternatives, and practical design notes not found in the manufacturer datasheet, as of 2026-09-15.
Drop-in alternatives for ATMEGA1281V-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 ATMEGA1281V-8AUR (same form factor and footprint) β differing in Package, SRAM, Supply Voltage Range, Flash Memory, Instructions.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA2561V-8AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA1281V-8AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA1281-16AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA2561-16AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA1281V-8AUR Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Flash Memory | 128KB (64K x 16), In-System Programmable |
| SRAM | 8KB |
| EEPROM | 4KB |
| Maximum Clock Speed | 8 MHz |
| Supply Voltage Range | 1.8 V to 5.5 V |
| General Purpose I/O | 54 lines |
| Data Bus Width | 8 Bit |
| Instructions | 133 instructions, most single-cycle |
| Timers/Counters | Six flexible timer/counters with compare modes and PWM |
| Operating Temperature | -40C to +85C |
| Package | 64-TQFP, 14 x 14 mm, 1 mm height |
| Mounting Type | Surface Mount |
| Series | AVR ATmega |
| Lifecycle Status | ACTIVE |
ATMEGA1281V-8AUR 64-tqfp, 14 x 14 mm, 1 mm height Pin Configuration Guide
Pin configuration for ATMEGA1281V-8AUR (64-tqfp, 14 x 14 mm, 1 mm height 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 ATMEGA1281V-8AUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA1281V-8AUR is suitable for 6 applications: Industrial Control Panels, Battery-Powered Instrumentation, Sensor Acquisition Nodes, Metering and Energy Products, Motor and Actuator Control, Legacy AVR Design Maintenance.
Industrial Control Panels
The ATMEGA1281V-8AUR fits industrial control panels because its 128KB Flash accommodates large state-machine and communication code, while 54 general purpose I/O lines directly drive relays, indicators, and keypads without port expanders. The -40C to +85C industrial temperature grade matches control-cabinet environments, and the external memory interface allows SRAM expansion for data logging. Firmware is typically deployed over the on-chip boot loader, letting field technicians update logic through the existing RS-485 link without physically reprogramming the board - a quantified maintenance advantage over fixed-logic designs.
Recommended
Battery-Powered Instrumentation
With a 1.8V to 5.5V supply range, the ATMEGA1281V-8AUR runs directly from two or three primary cells, removing a dedicated boost or LDO regulator from the power tree and its associated quiescent budget. The AVR core delivers up to one MIPS per MHz, so the 8MHz grade still provides roughly 8 MIPS of throughput for sensor scaling and display tasks. The 4KB EEPROM preserves calibration coefficients across battery replacement, and idle and power-down sleep modes cut average consumption in portable meters, loggers, and hand-held test instruments that must operate for months on a single charge.
Recommended
Sensor Acquisition Nodes
The ATMEGA1281V-8AUR serves sensor acquisition nodes where multiple analog channels are sampled and transmitted over serial links. Its integrated 10-bit ADC front-end, timer/counter peripherals for periodic sampling, and byte-oriented 2-wire serial interface for external sensor chips consolidate the entire signal-chain controller in one 64-TQFP device. Four USARTs allow simultaneous bridging of RS-232, RS-485, and telemetry radio links, so one MCU can aggregate several sensors without external UART expanders, reducing board area and BOM cost in distributed monitoring networks.
Recommended
Metering and Energy Products
Electricity, water, and heat meters benefit from the ATMEGA1281V-8AUR combination of 128KB ISP Flash for tariff and communication stacks, 4KB EEPROM for billing registers, and the external bus interface for memory expansion. The wide 1.8V to 5.5V supply range supports mains-backed low-voltage rails and battery-backed clock domains. In-system programming over the communication port enables remote firmware updates mandated by many utility standards, while the industrial temperature grade keeps the device reliable inside sealed outdoor meter enclosures exposed to seasonal extremes.
Recommended
Motor and Actuator Control
Six flexible timer/counters with compare modes and PWM outputs let the ATMEGA1281V-8AUR generate multi-channel PWM for DC motor, stepper, and actuator control directly from the MCU pins. Eight external interrupt-capable lines handle encoder and limit-switch feedback, and the AVR single-cycle ALU executes PI control loops comfortably at 8MHz for the sub-millisecond loop periods typical of small drives. Running from a 5V rail eases gate-drive interfacing with standard MOSFET driver ICs, while the 64-TQFP's thermal behavior stays modest at these low power levels.
Recommended
Legacy AVR Design Maintenance
The ATMEGA1281V-8AUR is frequently used to maintain and repair legacy AVR-based products designed around the ATmega640/1280/1281/2560/2561 family. Because the device remains an active lifecycle part and Rochester Electronics supplies an aftermarket channel, boards built years ago can still be serviced without redesign. Existing firmware assembles unchanged under avr-gcc and Microchip Studio, and the identical 64-TQFP footprint means replacement boards or daughter-card repairs keep the original PCB layout, protecting the significant investment in a qualified industrial PCB stack-up.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA1281V-8AUR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA2561V-8AUR | ATMEGA1281V-8AU | ATMEGA1281-16AUR | ATMEGA1281V-8MUR |
|---|---|---|---|---|---|
| Package | 64-TQFP (14x14 mm) | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 64-VQFN (9x9 mm) - different |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 128KB (64K x 16) | 256KB | 128KB | 128KB | 128KB |
| SRAM | 8KB | 8KB | 8KB | 8KB | 8KB |
| EEPROM | 4KB | 4KB | 4KB | 4KB | 4KB |
| Maximum Clock Speed | 8 MHz | 8 MHz | 8 MHz | 16 MHz | 8 MHz |
| Supply Voltage | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 4.5 V to 5.5 V | 1.8 V to 5.5 V |
| General Purpose I/O | 54 lines | 54 lines | 54 lines | 54 lines | 54 lines |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- Low-voltage 1.8V operation with same memory as 1281-16 (vs ATMEGA1281-16AUR)
- Smaller footprint with full 128KB/8KB/4KB memory set (vs ATMEGA1280V-8CUR)
- Right-sized Flash for cost-sensitive designs (vs ATMEGA2561V-8AUR)
Design Notes
The V-grade ATMEGA1281V-8AUR is rated 8MHz only across 1.8V to 5.5V; do not substitute a 16MHz crystal in low-voltage systems - the 16MHz grade (ATMEGA1281-16AUR) requires 4.5V to 5.5V. Estimated: overclocking beyond the 8MHz A-grade limit violates the speed-versus-VCC curve in the datasheet and risks marginal operation at low temperature. Use the internal RC oscillator or a clean 8MHz crystal with proper 12-22 pF load capacitors, and enable the brown-out detector (BOD) at a threshold below the minimum system voltage to protect EEPROM writes during supply dips.
Provide one 100 nF ceramic decoupling capacitor per VCC/GND pin pair, placed within a few millimeters of each pin, plus one bulk 10 uF capacitor per rail. Tie AVCC to VCC through a low-pass network (e.g., 10 ohm series resistor plus 100 nF) when ADC accuracy matters, and keep the AREF node clean with a recommended capacitor per the datasheet. Expose sufficient ground plane under the 64-TQFP; the 0.5 mm pin pitch demands careful solder-mask-defined pad design for reliable reflow assembly.
The ATMEGA1281V-8AUR ships with fuse settings for the internal 8MHz-ish RC oscillator - a common pitfall is fitting an external crystal without clearing the CKOUT/low-sleep fuse bits, causing the design to run at the wrong frequency or fail to start. Verify fuse bits (including JTAGEN, which keeps pins PC2-PC5 occupied by JTAG by default and loses four I/O lines if unnoticed). Also lock the boot-loader section before field deployment to prevent accidental self-erasure via the LPM/SPM instruction path.
Compliance Information
Compliance data was not explicitly stated in the provided web data. The 'UR' Tape & Reel suffix on modern Microchip parts generally corresponds to RoHS-compliant lead-free finish, but this must be confirmed on the official Microchip product page before export documentation.
