ATMEGA2561-16MU - 8-bit AVR MCU 256KB Flash 16MHz 64-QFN | Microchip
MPN: ATMEGA2561-16MU ✓ نشطATMEGA2561-16MU نظرة عامة
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.
بدائل مباشرة لـ ATMEGA2561-16MU — نفس الحزمة، متوافق دبوس بدبوس. تُستثنى القطع ذات الحزم المختلفة التي تتطلب تعديل PCB.
الطرازات في هذه السلسلة
طرازات من نفس السلسلة متوافقة تمامًا مع ATMEGA2561-16MU (نفس عامل الشكل والبصمة) — يختلف في Package, USART, Timers/Counters, ADC, Operating Temperature.
ATMEGA2561-16MUR
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
ATMEGA2561-16AU
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←ATMEGA2561-16AI
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
ATMEGA1281-16MUR
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←ATMEGA1281-16MUR
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←ATMEGA1281-16AU
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←ATMEGA2561-16MU الحدود القصوى والخصائص الكهربائية
| 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 |
| العلبة | 64-VFQFN (9x9 mm) with exposed pad |
| درجة حرارة التشغيل | -40 C to +85 C (industrial) |
| نوع التركيب | Surface Mount |
| Lead-Free / RoHS | Yes / Compliant |
تكوين أطراف ATMEGA2561-16MU
| دبوس 1 | VCC — Digital supply voltage |
| دبوس 2 | PE0 (RXD0/PCINT8) — Port E bit 0, USART0 RXD, pin-change interrupt |
| دبوس 3 | PE1 (TXD0) — Port E bit 1, USART0 TXD |
| دبوس 4 | PE2 (AIN0/XCK0) — Port E bit 2, analog comparator input, USART0 XCK |
| دبوس 5 | PE3 (AIN1/OC3A) — Port E bit 3, analog comparator input, timer output compare |
| دبوس 6 | PE4 (INT4/OC3B) — Port E bit 4, external interrupt, timer output compare |
| دبوس 7 | PE5 (INT5/OC3C) — Port E bit 5, external interrupt, timer output compare |
| دبوس 8 | PE6 (INT6/TCLK3) — Port E bit 6, external interrupt, timer clock input |
| دبوس 9 | PE7 (INT7/ICP3) — Port E bit 7, external interrupt, timer input capture |
| دبوس 10 | VCC — Digital supply voltage |
| دبوس 11 | GND — Ground |
| دبوس 12 | PH0 (RXD2) — Port H bit 0, USART2 RXD |
| دبوس 13 | PH1 (TXD2) — Port H bit 1, USART2 TXD |
| دبوس 14 | PH2 (XCK2) — Port H bit 2, USART2 XCK |
| دبوس 15 | PH3 (OC4A) — Port H bit 3, timer output compare |
| دبوس 16 | PH4 (OC4B) — Port H bit 4, timer output compare |
| دبوس 17 | PH5 (OC4C) — Port H bit 5, timer output compare |
| دبوس 18 | PH6 (OC2B) — Port H bit 6, timer output compare |
| دبوس 19 | PH7 (OC2A) — Port H bit 7, timer output compare |
| دبوس 20 | PB0 (SS/PCINT0) — Port B bit 0, SPI slave select, pin-change interrupt |
| دبوس 21 | PB1 (SCK/PCINT1) — Port B bit 1, SPI clock, pin-change interrupt |
| دبوس 22 | PB2 (MOSI/PCINT2) — Port B bit 2, SPI MOSI, pin-change interrupt |
| دبوس 23 | PB3 (MISO/PCINT3) — Port B bit 3, SPI MISO, pin-change interrupt |
| دبوس 24 | PB4 (OC0A/PCINT4) — Port B bit 4, timer output compare, pin-change interrupt |
| دبوس 25 | PB5 (OC1A/PCINT5) — Port B bit 5, timer output compare, pin-change interrupt |
| دبوس 26 | PB6 (OC1B/PCINT6) — Port B bit 6, timer output compare, pin-change interrupt |
| دبوس 27 | PB7 (OC0B/OC1C/PCINT7) — Port B bit 7, timer output compare, pin-change interrupt |
| دبوس 28 | VCC — Digital supply voltage |
| دبوس 29 | GND — Ground |
| دبوس 30 | AVCC — Analog supply voltage (for ADC) |
| دبوس 31 | AREF — ADC reference voltage |
| دبوس 32 | GND — Ground |
| دبوس 33 | PF0 (ADC0) — Port F bit 0, ADC input channel 0 |
| دبوس 34 | PF1 (ADC1) — Port F bit 1, ADC input channel 1 |
| دبوس 35 | PF2 (ADC2) — Port F bit 2, ADC input channel 2 |
| دبوس 36 | PF3 (ADC3) — Port F bit 3, ADC input channel 3 |
| دبوس 37 | PF4 (ADC4/TCK) — Port F bit 4, ADC input, JTAG TCK |
| دبوس 38 | PF5 (ADC5/TMS) — Port F bit 5, ADC input, JTAG TMS |
| دبوس 39 | PF6 (ADC6/TDO) — Port F bit 6, ADC input, JTAG TDO |
| دبوس 40 | PF7 (ADC7/TDI) — Port F bit 7, ADC input, JTAG TDI |
| دبوس 41 | PA0 (AD0) — Port A bit 0, external memory address/data |
| دبوس 42 | PA1 (AD1) — Port A bit 1, external memory address/data |
| دبوس 43 | PA2 (AD2) — Port A bit 2, external memory address/data |
| دبوس 44 | PA3 (AD3) — Port A bit 3, external memory address/data |
| دبوس 45 | PA4 (AD4) — Port A bit 4, external memory address/data |
| دبوس 46 | PA5 (AD5) — Port A bit 5, external memory address/data |
| دبوس 47 | PA6 (AD6) — Port A bit 6, external memory address/data |
| دبوس 48 | PA7 (AD7) — Port A bit 7, external memory address/data |
| دبوس 49 | PG2 (ALE) — Port G bit 2, external memory address latch enable |
| دبوس 50 | VCC — Digital supply voltage |
| دبوس 51 | GND — Ground |
| دبوس 52 | PG1 (RD) — Port G bit 1, external memory read strobe |
| دبوس 53 | PG0 (WR) — Port G bit 0, external memory write strobe |
| دبوس 54 | PD7 (SDA) — Port D bit 7, TWI I2C data |
| دبوس 55 | PD6 (SCL) — Port D bit 6, TWI I2C clock |
| دبوس 56 | PD5 (XCK1) — Port D bit 5, USART1 XCK |
| دبوس 57 | PD4 (ICP1) — Port D bit 4, timer1 input capture |
| دبوس 58 | PD3 (INT3/TXD1) — Port D bit 3, external interrupt, USART1 TXD |
| دبوس 59 | PD2 (INT2/RXD1) — Port D bit 2, external interrupt, USART1 RXD |
| دبوس 60 | PD1 (INT1/SDA) — Port D bit 1, external interrupt, I2C data alt |
| دبوس 61 | PD0 (INT0/SCL) — Port D bit 0, external interrupt, I2C clock alt |
| دبوس 62 | RESET — Reset input, active low |
| دبوس 63 | VCC — Digital supply voltage |
| دبوس 64 | GND — Ground |
| دبوس 65 | EPAD — Exposed thermal pad (connect to ground for thermal dissipation) |
التطبيقات النموذجية
ATMEGA2561-16MU مناسب لـ 6 التطبيقs: 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.
موصى به
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.
موصى به
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.
موصى به
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.
موصى به
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.
موصى به
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.
موصى به
ملخص المنتجات الموصى بها
بيانات مرجعية هندسية لـ ATMEGA2561-16MU — المقارنة وإرشادات التصميم ومعلومات الامتثال.
دليل الاختيار
المقارنة مع البدائل
| المعامل | هذا المنتج | 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 |
أبرز الفروقات
- Highest-density Flash in 64-VFQFN family (مقابلATMEGA1281-16MU)
- Pin-compatible 100% spec match (مقابلATMEGA2561-16MUR)
- Quad-USART bridge capability (مقابلATMEGA1281-16MU)
ملاحظات التصميم
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.
معلومات الامتثال
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.
