ATMEGA2561V-8MU - 8-bit AVR MCU 256KB Flash 8MHz | Microchip
MPN: ATMEGA2561V-8MU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $11.2 | $11.20 |
| 10 | $10.15 | $101.50 |
| 100 | $9.1 | $910.00 |
| 500 | $8.35 | $4,175.00 |
| 1,000 | $7.6 | $7,600.00 |
ATMEGA2561V-8MU Overview
A microcontroller (MCU) is a single-chip computer that integrates a processor core, program memory, data memory, and peripherals such as timers, serial interfaces, and analog-to-digital converters. Within the embedded systems hierarchy, the ATmega2561 sits in Microchip's high-density AVR ATmega family: an 8-bit MCU -> AVR RISC microcontroller -> embedded processor. These devices typically serve as the main control element in industrial controllers, sensor hubs, and communication nodes.
Key features include the Advanced RISC architecture with 131 powerful instructions, most executing in a single clock cycle, delivering up to 16 MIPS throughput. The device integrates 86 general-purpose I/O lines, 32 general-purpose working registers, a real-time counter, six flexible timer/counters with compare and PWM modes, and four programmable serial USARTs. The V suffix denotes a 1.8V to 5.5V operating voltage range, enabling battery-powered and low-voltage designs.
Technical depth: the AVR core is a fully static Harvard-architecture design with on-chip 2-cycle multiply, in-system programmable Flash via SPI, byte-oriented 2-wire (I2C-compatible) serial interface, master/slave SPI serial interface, programmable watchdog timer with separate on-chip oscillator, on-chip analog comparator, and interrupt and wake-up on pin change. Boundary-scan per JTAG (where applicable in the family) and debug support simplify development. Boot code sections allow self-programming for field firmware updates.
Typical applications include industrial automation controllers requiring multiple USART links, battery-powered data loggers benefiting from the wide 1.8V to 5.5V supply range and low-power idle/power-down modes, and motor control or building-management nodes using the six timer/counters and PWM outputs.
Design consideration: the 64-QFN (MU) land pattern differs from the TQFP-64 (AU) footprint of ATmega2560 siblings, so package choice must be locked early; the exposed pad should be soldered to a grounded copper pour for thermal and electrical performance.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA2561V-8MU 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-8MU (same form factor and footprint) β differing in ADC, Package, Core Architecture, Supply Voltage Range, Instructions.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA2561V-8MI
β Drop-Inβ In Stock
$7.65 / Unit
View Datasheet βATMEGA2561-16MU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA2561V-8MU Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Core Size | 8-bit |
| Maximum Clock Frequency | 8 MHz |
| Program Memory Size | 256KB (128K x 16) Flash |
| Program Memory Type | ISP In-System Programmable Flash |
| SRAM Size | 8 KB |
| EEPROM Size | 4 KB |
| Number of I/O Lines | 86 general purpose I/O |
| Supply Voltage Range | 1.8 V to 5.5 V (V-grade) |
| Data Bus Width | 8 bit |
| Timers | Six flexible timer/counters |
| Serial Interfaces | Four programmable serial USART, SPI, 2-wire (I2C-compatible) |
| ADC | 8/16-channel, 10-bit ADC |
| Package | 64-QFN (9x9 mm) MLF with exposed pad |
| Mounting Style | Surface Mount |
| Performance | Up to 16 MIPS throughput at 16 MHz (fully static) |
| Instructions | 131 powerful instructions, most single-cycle |
| RoHS Status | Compliant |
ATMEGA2561V-8MU 64-qfn (9x9 mm) mlf with exposed pad Pin Configuration Guide
Pin configuration for ATMEGA2561V-8MU (64-qfn (9x9 mm) mlf 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 ATMEGA2561V-8MU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA2561V-8MU is suitable for 6 applications: Industrial Automation Controllers, Battery-Powered Data Loggers, Embedded Networking and Gateway Nodes, Motor Control and PWM Systems, Building Management and HVAC, Sensor Hubs and Instrumentation.
Industrial Automation Controllers
The ATMEGA2561V-8MU fits industrial automation controller boards because its 256KB Flash and 8KB SRAM host full protocol stacks, while four programmable serial USARTs drive Modbus RTU, RS-485 fieldbus, and HMI links simultaneously. Its 86 general-purpose I/O lines and six flexible timer/counters with PWM outputs directly drive relays, actuators, and stepper or DC motor channels without external expansion. Operating at up to 8 MHz, the AVR RISC core provides deterministic single-cycle instruction execution for real-time loop control, and the programmable watchdog timer with separate on-chip oscillator recovers hung firmware in unattended installations. The 5V-tolerant 64-QFN design integrates cleanly into DIN-rail and panel controller PCBs.
Recommended
Battery-Powered Data Loggers
The ATMEGA2561V-8MU suits battery-powered data loggers because the V suffix grants a 1.8V to 5.5V supply range, allowing direct operation from two-cell alkaline or single-cell lithium sources without a regulator. The AVR power management system offers idle, ADC noise reduction, power-save, power-down, standby, and extended standby modes; wake-up on pin change or watchdog interrupt lets the MCU sleep for extended intervals between measurements. The 4KB EEPROM retains calibration constants through battery replacement, and 256KB Flash stores months of logged records locally. The 10-bit ADC samples multi-channel analog sensors, while the 2-wire and SPI interfaces connect external memory or RF modules for occasional data offload.
Recommended
Embedded Networking and Gateway Nodes
The ATMEGA2561V-8MU serves embedded gateway and networking nodes because its four hardware USARTs connect concurrently to field devices, a modem, and a debug console, while the master/slave SPI and byte-oriented 2-wire serial interfaces link to Ethernet or wireless co-processors. The 256KB Flash accommodates dual firmware images for over-the-air-style updates via the boot loader self-programming feature, and 8KB SRAM provides buffer space for packet assembly. Running at 8 MHz with up to 16 MIPS-class throughput, the core handles framing, checksums, and protocol state machines with headroom. The 9x9 mm 64-QFN package keeps gateway PCB area compact for DIN-rail and wall-mount enclosures.
Recommended
Motor Control and PWM Systems
The ATMEGA2561V-8MU addresses motor control applications by pairing six flexible timer/counters with compare channels and PWM modes against the AVR core's fast interrupt response, enabling closed-loop speed and position control of DC, stepper, and brushless motors. The output compare modulator and 10-bit ADC feed back current and position measurements for PID loops executed deterministically in firmware. At 8 MHz, the single-cycle 8x8 multiply accelerates control arithmetic. Operating from 1.8V to 5.5V, the MCU interfaces cleanly with gate-driver logic levels across common motor bus voltages. The 64-QFN exposed pad provides a low-impedance ground reference that reduces PWM switching noise coupling into analog sensing circuits.
Recommended
Building Management and HVAC
The ATMEGA2561V-8MU is a strong fit for building management and HVAC controllers because the four USARTs support simultaneous daisy-chained sensor buses, RS-485 trunk communication, and service interfaces, while 86 general-purpose I/O lines operate dampers, valves, fans, and relays directly. The real-time counter with a 32 kHz crystal maintains wall-clock scheduling through power interruptions, and the programmable watchdog guarantees safe restart of critical climate loops. With 256KB Flash, full BACnet-style or proprietary protocol stacks plus a web-style service layer fit on-chip, and the 4KB EEPROM stores setpoints and schedules without external memory. The wide 1.8V to 5.5V range simplifies power architecture in mixed-voltage panels.
Recommended
Sensor Hubs and Instrumentation
The ATMEGA2561V-8MU works as the hub in multi-sensor instrumentation because the 10-bit ADC with 8 or 16 channel multiplexing samples numerous analog inputs, while the SPI and 2-wire interfaces aggregate digital sensors. The 256KB Flash supports per-sensor linearization tables, compensation routines, and logging, and the 4KB EEPROM preserves calibration data across power cycles. The ADC noise reduction sleep mode lowers conversion noise for precision measurements, and the on-chip analog comparator adds a fast threshold-detection channel. At 8 MHz the RISC core performs single-cycle arithmetic for real-time filtering. The 9x9 mm QFN fits compact instrument PCBs while the exposed pad anchors a clean analog ground plane.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA2561V-8MU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA2561V-8MI | ATMEGA2561-16MU |
|---|---|---|---|
| Package | 64-QFN (9x9 mm) MU | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology |
| Max Clock Frequency | 8 MHz | 8 MHz | 16 MHz |
| Supply Voltage Range | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 4.5 V to 5.5 V |
| Flash Memory | 256KB (128K x 16) | 256KB (128K x 16) | 256KB (128K x 16) |
| SRAM | 8 KB | 8 KB | 8 KB |
| Temperature Grade | Standard (MU) | Industrial (MI) | Standard (MU) |
| Pin-to-Pin Compatibility | Reference | Pin-to-pin identical | Pin-to-pin identical |
Key Differentiators
- Widest supply range in the family (vs ATMEGA2561-16MU)
- Industrial temperature option pin-identical (vs ATMEGA2561V-8MI)
- Compact QFN footprint vs TQFP siblings (vs ATMEGA2560V-8AU)
Design Notes
The 64-QFN (9x9 mm) MLF package has an exposed die pad that must be soldered to a grounded copper pour with an array of thermal vias. This pad is the primary ground return for the AVR core and peripherals; omitting it causes unreliable grounding, elevated noise on the ADC, and degraded thermal performance. Follow the Microchip MLF/QFN application guidelines: 4x4 via array under the pad, solder paste segmented into 60-70% coverage to avoid voiding, and clearance per stencil design for the 0.5 mm pitch perimeter balls.
Decouple each VCC/AVCC pin pair with 100 nF ceramic capacitors placed within 2 mm of the pins, plus one bulk 10 uF capacitor per supply domain. AVCC must be connected to VCC even if the ADC is unused, per the datasheet, through a low-pass filter (10 uH inductor or ferrite plus 100 nF) when ADC noise performance matters. Keep the 1.8V to 5.5V operating range in mind: brown-out detection should be enabled and its threshold set below the minimum expected rail to prevent Flash corruption during slow supply decay.
With four USARTs plus SPI and 2-wire interfaces active, route high-speed clock and serial lines away from the ADC input traces and the crystal pads. Use series termination (22-33 ohm) on long USART RS-485 driver lines to control ringing. For the crystal, keep load capacitors and the crystal tightly looped to XTAL1/XTAL2 with a ground guard ring; the on-chip oscillator is sensitive to layout at 8 MHz. Avoid routing PWM outputs parallel to analog sensing traces to minimize coupled switching noise.
Compliance Information
RoHS compliance per Microchip standard product page; detailed REACH/halogen declarations not present in retrieved data.
