ATMEGA2561-16MU - 8-bit AVR MCU 256KB Flash 16MHz 64-QFN | Microchip
N.º de pieza: ATMEGA2561-16MU ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $17.95 | $17,95 |
| 10 | $16.21 | $162,10 |
| 100 | $14.27 | $1.427,00 |
| 500 | $12.96 | $6.480,00 |
| 1.000 | $11.83 | $11.830,00 |
ATMEGA2561-16MU Descripción general
An AVR microcontroller (sometimes called an Advanced Virtual RISC microcontroller) is a single-chip computer built around the Atmel AVR 8-bit RISC core, executing most instructions in a single clock cycle to deliver deterministic throughput. ATmega2561 belongs to the megaAVR family, sitting between tinyAVR and XMEGA in Microchip's 8-bit hierarchy, and is commonly used where higher pin count and larger memory are needed without moving to 32-bit ARM Cortex-M parts.
Key features of the ATMEGA2561-16MU include 256 KB self-programmable Flash with Read-While-Write support, 8 KB on-chip SRAM, 4 KB true EEPROM with 100,000 erase/write cycles endurance, an internal calibrated RC oscillator, and six software-selectable power-saving modes that can reduce active current to microampere levels for battery-operated designs. The 8-channel 10-bit successive-approximation ADC delivers up to 15 kSPS at full resolution, and the on-chip analog comparator supports single-ended and differential inputs with selectable hysteresis.
Architecturally, the ATMEGA2561 uses a Harvard-style memory layout with separate program Flash and data SRAM buses, a hardware multiplier supporting signed/unsigned multiply and fractional multiply instructions, and a deterministic interrupt controller with up to 57 interrupt vectors. The peripheral interconnect allows timer/counter outputs to drive ADC triggers and PWM channels, enabling motor control and power-conversion topologies without software overhead.
Typical applications include industrial automation controllers, building automation gateways, smart energy metering, USB-to-UART bridges using external PHY, multi-channel data acquisition front-ends, robotic controller boards, automotive body and infotainment subsystems (when properly qualified), and hobbyist/education platforms such as Arduino-Mega-compatible designs. The wide memory and I/O count also make it a frequent fit for SCADA remote terminal units (RTUs).
When designing with this device, ensure decoupling follows Microchip's recommended 100 nF ceramic on each VCC pin plus a 10 uF bulk, and respect the 5.5 V absolute-maximum VCC rating even though the part is 5 V tolerant. JTAG and ISP programming both require the RESET pin to remain in a defined state; for noise immunity, place a 10 kohm pull-up on RESET and a low-value decoupling capacitor on AVCC to maximize ADC linearity.
This page synthesizes distributor inventory, 64-QFN drop-in alternatives, and practical AVR design notes not found in the manufacturer datasheet alone, accelerating part selection and PCB re-use.
Alternativas directas para ATMEGA2561-16MU — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con ATMEGA2561-16MU (mismo factor de forma y huella) — difiere en Package, USART, Timers/Counters, ADC, Operating Temperature.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
ATMEGA2561-16MUR
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
ATMEGA2561-16AU
✅ Sustitución directa✓ En stock
$11.95 / unidad
Ver hoja de datos →ATMEGA2561-16AI
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
ATMEGA1281-16MUR
✅ Sustitución directa✓ En stock
$8.78 / unidad
Ver hoja de datos →ATMEGA1281-16MUR
✅ Sustitución directa✓ En stock
$8.78 / unidad
Ver hoja de datos →ATMEGA1281-16AU
✅ Sustitución directa✓ En stock
$8.27 / unidad
Ver hoja de datos →ATMEGA2561-16MU Valores máximos y características eléctricas
| Core Architecture | AVR 8-bit RISC |
| Maximum CPU Frequency | 16 MHz |
| MIPS Throughput | 16 MIPS |
| Program Flash Memory | 256 KB (128K x 16) |
| SRAM | 8 KB |
| EEPROM | 4 KB |
| Operating Voltage (VCC) | 4.5 V to 5.5 V |
| Programmable I/O Lines | 54 |
| General-Purpose Working Registers | 32 |
| ADC | 8-channel, 10-bit |
| USART | 4 channels |
| SPI | 1 channel (Master/Slave) |
| TWI (I2C) | 1 channel (byte-oriented) |
| Timer/Counters | 2x 8-bit + 4x 16-bit with PWM |
| Watchdog Timer | Yes, with separate on-chip oscillator |
| Analog Comparator | On-chip, with selectable hysteresis |
| JTAG Debug Interface | Yes (boundary-scan capable) |
| External Memory Interface (EBI/EMI) | Yes |
| Encapsulado | 64-VFQFN (9x9 mm) with exposed pad |
| Temperatura de funcionamiento | -40 C to +85 C (industrial) |
| Tipo de montaje | Surface Mount |
| Lead-Free / RoHS | Yes / Compliant |
Configuración de pines de ATMEGA2561-16MU
| Pin 1 | VCC — Digital supply voltage |
| Pin 2 | PE0 (RXD0/PCINT8) — Port E bit 0, USART0 RXD, pin-change interrupt |
| Pin 3 | PE1 (TXD0) — Port E bit 1, USART0 TXD |
| Pin 4 | PE2 (AIN0/XCK0) — Port E bit 2, analog comparator input, USART0 XCK |
| Pin 5 | PE3 (AIN1/OC3A) — Port E bit 3, analog comparator input, timer output compare |
| Pin 6 | PE4 (INT4/OC3B) — Port E bit 4, external interrupt, timer output compare |
| Pin 7 | PE5 (INT5/OC3C) — Port E bit 5, external interrupt, timer output compare |
| Pin 8 | PE6 (INT6/TCLK3) — Port E bit 6, external interrupt, timer clock input |
| Pin 9 | PE7 (INT7/ICP3) — Port E bit 7, external interrupt, timer input capture |
| Pin 10 | VCC — Digital supply voltage |
| Pin 11 | GND — Ground |
| Pin 12 | PH0 (RXD2) — Port H bit 0, USART2 RXD |
| Pin 13 | PH1 (TXD2) — Port H bit 1, USART2 TXD |
| Pin 14 | PH2 (XCK2) — Port H bit 2, USART2 XCK |
| Pin 15 | PH3 (OC4A) — Port H bit 3, timer output compare |
| Pin 16 | PH4 (OC4B) — Port H bit 4, timer output compare |
| Pin 17 | PH5 (OC4C) — Port H bit 5, timer output compare |
| Pin 18 | PH6 (OC2B) — Port H bit 6, timer output compare |
| Pin 19 | PH7 (OC2A) — Port H bit 7, timer output compare |
| Pin 20 | PB0 (SS/PCINT0) — Port B bit 0, SPI slave select, pin-change interrupt |
| Pin 21 | PB1 (SCK/PCINT1) — Port B bit 1, SPI clock, pin-change interrupt |
| Pin 22 | PB2 (MOSI/PCINT2) — Port B bit 2, SPI MOSI, pin-change interrupt |
| Pin 23 | PB3 (MISO/PCINT3) — Port B bit 3, SPI MISO, pin-change interrupt |
| Pin 24 | PB4 (OC0A/PCINT4) — Port B bit 4, timer output compare, pin-change interrupt |
| Pin 25 | PB5 (OC1A/PCINT5) — Port B bit 5, timer output compare, pin-change interrupt |
| Pin 26 | PB6 (OC1B/PCINT6) — Port B bit 6, timer output compare, pin-change interrupt |
| Pin 27 | PB7 (OC0B/OC1C/PCINT7) — Port B bit 7, timer output compare, pin-change interrupt |
| Pin 28 | VCC — Digital supply voltage |
| Pin 29 | GND — Ground |
| Pin 30 | AVCC — Analog supply voltage (for ADC) |
| Pin 31 | AREF — ADC reference voltage |
| Pin 32 | GND — Ground |
| Pin 33 | PF0 (ADC0) — Port F bit 0, ADC input channel 0 |
| Pin 34 | PF1 (ADC1) — Port F bit 1, ADC input channel 1 |
| Pin 35 | PF2 (ADC2) — Port F bit 2, ADC input channel 2 |
| Pin 36 | PF3 (ADC3) — Port F bit 3, ADC input channel 3 |
| Pin 37 | PF4 (ADC4/TCK) — Port F bit 4, ADC input, JTAG TCK |
| Pin 38 | PF5 (ADC5/TMS) — Port F bit 5, ADC input, JTAG TMS |
| Pin 39 | PF6 (ADC6/TDO) — Port F bit 6, ADC input, JTAG TDO |
| Pin 40 | PF7 (ADC7/TDI) — Port F bit 7, ADC input, JTAG TDI |
| Pin 41 | PA0 (AD0) — Port A bit 0, external memory address/data |
| Pin 42 | PA1 (AD1) — Port A bit 1, external memory address/data |
| Pin 43 | PA2 (AD2) — Port A bit 2, external memory address/data |
| Pin 44 | PA3 (AD3) — Port A bit 3, external memory address/data |
| Pin 45 | PA4 (AD4) — Port A bit 4, external memory address/data |
| Pin 46 | PA5 (AD5) — Port A bit 5, external memory address/data |
| Pin 47 | PA6 (AD6) — Port A bit 6, external memory address/data |
| Pin 48 | PA7 (AD7) — Port A bit 7, external memory address/data |
| Pin 49 | PG2 (ALE) — Port G bit 2, external memory address latch enable |
| Pin 50 | VCC — Digital supply voltage |
| Pin 51 | GND — Ground |
| Pin 52 | PG1 (RD) — Port G bit 1, external memory read strobe |
| Pin 53 | PG0 (WR) — Port G bit 0, external memory write strobe |
| Pin 54 | PD7 (SDA) — Port D bit 7, TWI I2C data |
| Pin 55 | PD6 (SCL) — Port D bit 6, TWI I2C clock |
| Pin 56 | PD5 (XCK1) — Port D bit 5, USART1 XCK |
| Pin 57 | PD4 (ICP1) — Port D bit 4, timer1 input capture |
| Pin 58 | PD3 (INT3/TXD1) — Port D bit 3, external interrupt, USART1 TXD |
| Pin 59 | PD2 (INT2/RXD1) — Port D bit 2, external interrupt, USART1 RXD |
| Pin 60 | PD1 (INT1/SDA) — Port D bit 1, external interrupt, I2C data alt |
| Pin 61 | PD0 (INT0/SCL) — Port D bit 0, external interrupt, I2C clock alt |
| Pin 62 | RESET — Reset input, active low |
| Pin 63 | VCC — Digital supply voltage |
| Pin 64 | GND — Ground |
| Pin 65 | EPAD — Exposed thermal pad (connect to ground for thermal dissipation) |
Aplicaciones típicas
ATMEGA2561-16MU es adecuado para 6 aplicacións: Industrial Automation Controllers, Building Automation Gateways, Smart Energy Metering Front-Ends, Robotic Controller Boards, Multi-Channel Data Acquisition Front-Ends, SCADA Remote Terminal Units (RTUs).
Industrial Automation Controllers
The ATMEGA2561-16MU is well-matched to industrial PLC, HMI, and remote-I/O designs because its 54 programmable I/O lines can drive relays, optocouplers, and isolated digital inputs simultaneously, while four USARTs bridge RS-232, RS-485, and RS-422 field buses in parallel. The 16 MIPS core executes PID loops at sub-millisecond rates, and the 8-channel 10-bit ADC samples up to 15 kSPS for thermocouple or 4-20 mA signal conditioning front-ends. Its -40 C to +85 C industrial temperature range plus 256 KB Flash allows a single MCU to host both the application logic and a Modbus-RTU or Modbus-TCP stack, eliminating an external communications processor. Brown-out detect and watchdog timer with independent oscillator improve field reliability against brown-out and firmware lock-up events.
Recomendado
Building Automation Gateways
The ATMEGA2561-16MU suits BACnet, KNX, or Modbus gateway designs where the MCU must convert between multiple building-automation field buses concurrently. Its four hardware USARTs allow simultaneous RS-485 trunks at different baud rates, while the I2C and SPI ports connect to onboard sensors or radio modules. The 256 KB Flash stores the full protocol stack plus custom mapping logic, while the 4 KB EEPROM stores device bindings and configuration that must survive power cycles. Operating from 4.5 V to 5.5 V makes the part easy to integrate with 5 V supply rails common in HVAC control panels, and the 64-VFQFN footprint leaves room for optoisolator channels around the MCU.
Recomendado
Smart Energy Metering Front-Ends
The ATMEGA2561-16MU fits single-phase and three-phase energy metering front-ends because its 8-channel 10-bit ADC measures voltage and current CT/PT-derived signals, while its 16-bit timer/counters capture pulse-output from dedicated metrology ICs. The 256 KB Flash hosts the metrology algorithm plus DLMS/COSEM or ANSI C12.18/19 stack, and the 4 KB EEPROM stores tariff schedules and calibration constants. Its four USARTs support optical port, RS-485, and PLC-modem interfaces simultaneously. Operating from 4.5 V to 5.5 V and -40 C to +85 C meets outdoor cabinet requirements when paired with proper conformal coating and isolation barriers.
Recomendado
Robotic Controller Boards
Robotic controllers benefit from the ATMEGA2561-16MU's six timer/counter channels capable of multi-channel PWM at up to 16-bit resolution for servo and BLDC motor drive signals. The 16 MIPS throughput handles inverse kinematics and PID loop computation at hundreds of Hz without DSP acceleration, and the 8-channel ADC reads encoder feedback, current sense, and battery monitor channels. Its four USARTs expose debug, GPS, IMU, and radio links simultaneously. The 64-VFQFN package plus 5 V tolerance simplify integration with hobby-grade sensors and drivers, making this MCU a popular choice for educational and maker robotic platforms including Arduino-Mega-derived designs.
Recomendado
Multi-Channel Data Acquisition Front-Ends
The ATMEGA2561-16MU is a strong fit for low-speed multi-channel data loggers where its 8-channel 10-bit ADC (with optional internal 1.1 V reference) samples analog sensor channels while the on-chip USARTs offload data to a host. The 256 KB Flash stores local buffering and compression routines, and the 4 KB EEPROM retains calibration and time-stamp tables. The 64-VFQFN package's exposed thermal pad helps dissipate heat when the ADC and digital I/O run continuously. JTAG support enables in-field firmware updates during commissioning, and brown-out detect plus watchdog improve robustness against supply transients in field installations.
Recomendado
SCADA Remote Terminal Units (RTUs)
The ATMEGA2561-16MU fits SCADA RTU designs where the MCU aggregates digital inputs, analog measurements, and field-bus telemetry into a single reporting node. Its 54 I/O lines handle DI/DO channels, its 8-channel 10-bit ADC reads 4-20 mA loops or 0-10 V process signals, and its four USARTs support RS-232/RS-485 multidrop polling plus a radio modem link. The 256 KB Flash plus 4 KB EEPROM support DNP3, IEC 60870-5-104, or Modbus firmware with local event-log buffering, and the industrial -40 C to +85 C range plus 5 V supply tolerance allow direct deployment in outdoor cabinets with proper isolation. JTAG and ISP simplify commissioning and field firmware updates.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para ATMEGA2561-16MU — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | ATMEGA2561-16MUR | ATMEGA2561-16AU | ATMEGA2561-16AI | ATMEGA1281-16MU | ATMEGA1281-16MUR | ATMEGA1281-16AU |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 64-VFQFN (9x9) | 64-VFQFN (9x9) - same | 64-TQFP - NOT same footprint | 64-TQFP - NOT same footprint | 64-VFQFN (9x9) - same | 64-VFQFN (9x9) - same | 64-TQFP - NOT same footprint |
| Flash Memory | 256 KB | 256 KB | 256 KB | 256 KB | 128 KB (-50%) | 128 KB (-50%) | 128 KB (-50%) |
| SRAM | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB |
| EEPROM | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB |
| Maximum Frequency | 16 MHz (16 MIPS) | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz |
| I/O Lines | 54 | 54 | 54 | 54 | 54 | 54 | 54 |
| Operating Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V |
Diferenciadores clave
- Highest-density Flash in 64-VFQFN family (frente a ATMEGA1281-16MU)
- Pin-compatible 100% spec match (frente a ATMEGA2561-16MUR)
- Quad-USART bridge capability (frente a ATMEGA1281-16MU)
Notas de diseño
Estimated: at 16 MHz active and 5 V supply, the ATMEGA2561-16MU consumes approximately 15-20 mA active and 5-10 uA in power-down. Place a 100 nF ceramic decoupling capacitor within 5 mm of each VCC pin (five pins) plus a 10 uF bulk capacitor on the supply rail. For AVCC use an LC or ferrite-bead filter (10 ohm + 10 uF) to isolate the ADC supply from digital switching noise. Power-down mode retains SRAM/EEPROM contents for months on a coin-cell backup if needed.
The 64-VFQFN 9x9 mm package requires a center-thermal-pad land on the PCB with at least 8 thermal vias (0.3 mm drill, 1.0 mm pitch) connecting to a ground plane to achieve the 30 C/W theta-JA target. Keep high-current switching traces (relay drivers, motor drivers) away from ADC traces; route the ADC reference (AREF) capacitor within 10 mm of the pin and place a guard ring tied to AGND around sensitive analog signal traces. Exposed pad MUST be soldered to the PCB land for mechanical reliability and thermal performance.
Do not exceed 5.5 V on VCC - the ATmega2561 is not 3.3 V tolerant despite its AVR heritage. Do not connect JTAG pins (PF4-PF7/TDI/TMS/TCK/TDO) directly to external signals without considering that JTAG fuse programming can disable these as I/O. Brown-out detect should be enabled and tuned to 4.0 V or 2.7 V to prevent Flash corruption during supply transients. When migrating from ATmega1281 firmware, recompile with the ATmega2561 build profile in MCUdude MegaCore or AVR Studio to expose the larger Flash region - using the wrong linker script yields silently truncated firmware.
External memory interface (EBI/EMI) signals should be length-matched to within 5 mm if the bus runs above 8 MHz to avoid setup/hold violations; add 10-22 pF series damping resistors if ringing exceeds 0.5 Vpp. The JTAG TDO signal has a tri-state output and requires a pull-up of 10-47 kohm to avoid floating during scan chains. SPI signals should use a ground reference and series resistors if the cable length exceeds 50 mm, particularly when connecting to SD cards or radio modules.
Información de cumplimiento
ATMEGA2561-16MU is RoHS compliant per Microchip product page and is supplied in lead-free packaging. It is not AEC-Q100 qualified for automotive applications; AEC-Q100 grade parts in this family use a different part suffix. Halogen-free status not explicitly stated in the verified web data.
