ATMEGA2561V-8MI - 8-bit AVR MCU 256KB Flash 8MHz | Microchip
MPN: ATMEGA2561V-8MI β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $11.2 | $11.20 |
| 10 | $10.3 | $103.00 |
| 100 | $9.15 | $915.00 |
| 500 | $8.4 | $4,200.00 |
| 1,000 | $7.65 | $7,650.00 |
ATMEGA2561V-8MI Overview
An 8-bit AVR microcontroller is a single-chip computer built around the Harvard-architecture AVR RISC core, in which program memory and data memory are separate and all 32 general purpose working registers are directly connected to the arithmetic logic unit (ALU). Within the product hierarchy, the ATmega2561 sits in the high-pin-count, large-memory tier of the AVR ATmega family, above the ATmega128 class and one step below the 100-pin ATmega2560, making it a power management and embedded control IC for code-intensive systems.
Key features include a rich instruction set of 131 powerful instructions, most of which execute in a single clock cycle, delivering throughput of up to ten times faster than conventional CISC microcontrollers at the same clock rate. The device integrates six flexible timer/counters with compare modes and PWM, four USARTs, a byte-oriented 2-wire serial interface (I2C-compatible), an SPI interface, an 8-channel 10-bit ADC, a real-time counter, and JTAG boundary scan with on-chip debugging and programming.
The ATMEGA2561V-8MI belongs to the V voltage grade, operating from a 1.8V to 5.5V supply with a maximum clock frequency of 8 MHz, which allows battery-powered designs to run directly from two alkaline cells or a single lithium cell. The M suffix denotes industrial temperature range (-40C to +85C) and the I suffix indicates industrial qualification within the ordering code.
Typical applications include industrial automation controllers, building control and HVAC systems, battery-operated instrumentation, and embedded gateways where four independent USART ports are used to talk to multiple peripherals simultaneously.
A key design consideration is flash endurance and bootloader sizing: with 256 KB of ISP flash, allocate a 4 KB boot section if field firmware updates over USART are planned.
This page synthesizes verified distributor inventory, drop-in alternatives, pricing context, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for ATMEGA2561V-8MI 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-8MI (same form factor and footprint) β differing in ADC, Package, Serial Interfaces, Supply Voltage Range.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA2561V-8AI
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA2561-16MU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA2561-16AI
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA2561V-8MI Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Flash Program Memory | 256 KB (128K x 16) ISP |
| SRAM | 8 KB |
| EEPROM | 4 KB |
| Maximum Clock Frequency | 8 MHz |
| Supply Voltage Range | 1.8 V to 5.5 V |
| General Purpose I/O Lines | 86 |
| Working Registers | 32 general purpose |
| Instruction Set | 131 instructions, most single-cycle |
| Timers/Counters | 6 flexible timer/counters with compare modes and PWM |
| USART | 4 |
| Serial Interfaces | 2-wire (I2C-compatible), SPI |
| ADC | 8-channel 10-bit |
| Real-Time Counter | Yes |
| Debug/Program Interface | JTAG (boundary scan, on-chip debug, programming) |
| Operating Temperature | -40C to +85C |
| Package | 64-VFQFN Exposed Pad |
| Mounting Type | Surface Mount |
| Throughput | Up to 16 MIPS at 16 MHz (family rating) |
ATMEGA2561V-8MI 64-vfqfn exposed pad Pin Configuration Guide
Pin configuration for ATMEGA2561V-8MI (64-vfqfn 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-8MI.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA2561V-8MI is suitable for 6 applications: Industrial Automation Controllers, Battery-Powered Instrumentation, Multi-Port Communication Gateways, Building Control and HVAC Systems, Automotive-Adjacent Off-Highway Equipment, Embedded Test and Measurement Fixtures.
Industrial Automation Controllers
The ATMEGA2561V-8MI fits industrial automation controllers because its 256 KB flash holds protocol stacks, menus, and logging code, while four independent USARTs connect PLC front-ends, Modbus RTU networks, and HMI panels concurrently. The 10-bit 8-channel ADC reads analog sensor inputs such as 4-20 mA-derived voltages and thermistor bridges directly without an external converter. Operating from -40C to +85C in the 64-VFQFN exposed-pad package, it survives panel-mounted environments, and the industrial-qualified ordering code simplifies procurement for factory equipment. Because most AVR instructions execute in a single cycle at 8 MHz, deterministic scan loops are straightforward to guarantee, and JTAG boundary scan supports board-level production test of dense I/O wiring.
Recommended
Battery-Powered Instrumentation
For battery-powered data loggers and portable instruments, the ATMEGA2561V-8MI is a strong match because its V voltage grade operates from 1.8V to 5.5V, allowing direct use of two alkaline cells or one lithium cell across the full discharge curve without a boost converter. AVR power-down and power-save sleep modes, combined with the asynchronous real-time counter, let the MCU sleep at microamp-level current and wake on timer or USART events, maximizing battery life. The 8-channel 10-bit ADC samples sensors directly, the 4 KB EEPROM stores calibration constants without external memory, and 256 KB flash accommodates years of feature growth. At 8 MHz the throughput remains ample for filtering and display refresh tasks.
Recommended
Multi-Port Communication Gateways
The ATMEGA2561V-8MI excels in protocol gateways because its four USARTs can independently serve Modbus RTU slave networks, metering buses, and telemetry links simultaneously, while the byte-oriented 2-wire serial interface and SPI connect to EEPROM, RTCs, and radio modules. Its 256 KB ISP flash provides room for multiple protocol stacks, bootloaders for field firmware updates over any USART, and data tables, eliminating external flash in many designs. The AVR single-cycle instruction execution at 8 MHz keeps interrupt latency low for multi-port buffering, and 8 KB SRAM handles several concurrent RX/TX ring buffers. JTAG on-chip debugging simplifies bring-up of the multi-protocol firmware during development and production diagnostics.
Recommended
Building Control and HVAC Systems
Building controllers and HVAC units benefit from the ATMEGA2561V-8MI's combination of large flash for scheduling, logging, and BACnet-like firmware, and its industrial temperature rating of -40C to +85C for rooftop and mechanical-room environments. Six flexible timer/counters with compare modes and PWM directly drive damper motors, fan PWM inputs, and valve actuators, while the 10-bit ADC reads NTC thermistor chains and pressure sensors across eight channels. The real-time counter maintains time-of-day scheduling from a 32 kHz crystal during power-save operation, and the 2-wire interface manages RTC and display peripherals. Field firmware updates over USART via a self-programming bootloader keep installed units maintainable.
Recommended
Automotive-Adjacent Off-Highway Equipment
For off-highway and agricultural equipment electronics that do not mandate AEC-Q100 parts, the ATMEGA2561V-8MI supplies 256 KB flash for engine-adjacent control logic, four USARTs for J1939-style gateway prototyping and diagnostics, and six PWM-capable timers for actuators and gauges. The industrial -40C to +85C range covers most under-dash and engine-bay-adjacent installations, and designers needing formal automotive qualification can drop in the pin-compatible ATMEGA2561V-8AI without PCB change. The 1.8V to 5.5V V-grade supply tolerance simplifies integration with regulated 5V or 3.3V rails and load-dump-protected 5V supplies, while JTAG boundary scan supports production ICT on high-pin-count harness controller boards.
Recommended
Embedded Test and Measurement Fixtures
Production test fixtures and bench instruments use the ATMEGA2561V-8MI as a scalable fixture controller: the 10-bit ADC measures pass/fail analog thresholds, six timers generate stimulus PWM and frequency counters, and four USARTs emulate serial devices under test or talk to fixture relays over RS-485. The 256 KB flash stores multiple test scripts and result logging, and the 4 KB EEPROM retains calibration data between firmware revisions. USB or Ethernet front-ends are added through SPI or 2-wire peripherals, and the exposed-pad 64-VFQFN package keeps the controller section compact inside fixture enclosures. Single-cycle 8 MHz execution provides deterministic timing for stimulus-response test sequencing with microsecond resolution.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA2561V-8MI β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA2561V-8AI | ATMEGA2561-16MU | ATMEGA2561-16AI |
|---|---|---|---|---|
| Package | 64-VFQFN Exposed Pad | 64-VFQFN Exposed Pad - same | 64-VFQFN Exposed Pad - same | 64-VFQFN Exposed Pad - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 256 KB | 256 KB | 256 KB | 256 KB |
| SRAM | 8 KB | 8 KB | 8 KB | 8 KB |
| Max Clock Frequency | 8 MHz | 8 MHz | 16 MHz | 16 MHz |
| Supply Voltage | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V |
| Qualification Grade | Industrial (I) | Automotive (A) | Industrial (I) | Automotive (A) |
| GPIO Lines | 86 | 86 | 86 | 86 |
Key Differentiators
- Widest supply range in the ATmega2561 QFN family (vs ATMEGA2561-16MU)
- Compact 64-pin footprint versus 100-pin ATmega2560 (vs ATMEGA2560-16AU)
- Industrial-grade pricing versus automotive variant (vs ATMEGA2561V-8AI)
Design Notes
Decouple VCC and AVCC separately with 100 nF ceramic capacitors placed within 2 mm of the respective pins, plus a 4.7 uF bulk capacitor near the device. Because this is the V-grade part (1.8V to 5.5V), verify brown-out detector fuse settings against your minimum rail voltage; enable BOD at a level appropriate for your supply (for example 2.7V on a 3.3V rail) to prevent flash corruption during brown-outs. If running from a switching supply, add an RC or ferrite filter to AVCC to protect the 10-bit ADC noise floor.
The 64-VFQFN exposed pad on the package bottom must be soldered to the ground plane - it is the primary ground connection and thermal path. Define an array of thermal vias (typically 3x3 to 4x4, 0.3 mm drill) under the pad connecting to internal ground planes. QFN lead lands should follow Microchip's MLF land-pattern recommendation with slightly extended toes for inspectability. Keep the 32 kHz crystal for the real-time counter short-traced and guarded by ground for low-jitter sleep-mode timing.
Do not treat the 16 MHz siblings as transparent substitutes: ATMEGA2561-16MU/-16AI parts require 4.5V to 5.5V, so a board designed around the 1.8V to 5.5V V-grade part will not run them at 3.3V. Second, verify clock-source fuses when porting firmware between 8 MHz and 16 MHz grades - delay loops and USART baud registers scale with F_CPU. Finally, allocate a bootloader section in the 256 KB flash early if field updates are planned; changing fuse-defined boot size after production complicates programming fixtures.
Compliance Information
RoHS/lead-free status per distributor listings (Mouser, Hotenda) for the -MI ordering code. The automotive-qualified variant is ATMEGA2561V-8AI. REACH and conflict-minerals declarations should be confirmed from Microchip's official compliance portal.
