ATMEGA645-16MU - 8-bit AVR MCU, 64KB Flash, 16MHz | Microchip
N.º da peça: ATMEGA645-16MU ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $6.85 | $6,85 |
| 10 | $6.2 | $62,00 |
| 100 | $5.55 | $555,00 |
| 500 | $5.1 | $2.550,00 |
| 1.000 | $4.65 | $4.650,00 |
ATMEGA645-16MU Visão geral
A microcontroller is a single-chip computer that integrates a processor core, program memory, data memory, and peripherals such as timers, ADCs, and communication interfaces. Within the embedded-systems hierarchy, the 8-bit ATmega family sits in the cost- and power-sensitive segment below 32-bit ARM MCUs, and the ATmega645 belongs to the megaAVR branch, which targets applications needing 32KB to 256KB of Flash with mature, well-documented peripherals.
Key features include 130 powerful RISC instructions with mostly single-cycle execution, delivering 16 MIPS throughput at 16MHz; 64KB ISP Flash, 4KB SRAM, and 2KB EEPROM; 68 programmable I/O lines; and an 8-channel 10-bit ADC. An on-chip JTAG interface supports boundary-scan testing and on-chip debugging, which shortens development cycles on densely populated boards.
Architecturally, the AVR core uses a Harvard structure with separate program and data buses, allowing one instruction to be fetched while another executes. The ATMEGA645-16MU is rated for the industrial temperature range and is offered in a GREEN, RoHS-conscious package; supply voltage tolerance of 2.7V to 5.5V allows direct operation from 3.3V or 5V rails, with full 16MHz speed specified for 4.5V to 5.5V operation.
Typical applications include industrial control and automation nodes, consumer appliances and HVAC controllers, and battery-powered instrumentation where the 2.7V low-voltage operation and low-power idle/power-down modes extend battery life. The large I/O count suits keypad, display, and relay-matrix-heavy designs.
A key design consideration is clock-versus-voltage derating: below 4.5V the safe maximum clock frequency decreases, so designs running at 3.3V should target 8MHz-class operation or use the V-graded speed variants.
This page synthesizes distributor availability data, pin-compatible family alternatives, and practical design guidance not found on the manufacturer product page alone.
Alternativas drop-in para ATMEGA645-16MU — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Variantes desta série
Modelos da mesma série compatíveis como drop-in com ATMEGA645-16MU (mesmo formato e footprint) — diferindo em Package, Number of I/O, Program Memory Size, EEPROM, EEPROM Size.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
ATMEGA649-16MU
✅ Drop-In✓ Em estoque
$4.8 / unidade
Ver ficha técnica →ATMEGA64A-MU
✅ Drop-In✓ Em estoque
$4.24 / unidade
Ver ficha técnica →ATMEGA6450-16MU
✅ Drop-In ⚠️ Especificações não verificadas📋 Alternativa de referência (fora do catálogo)
ATMEGA325-16MUR
✅ Drop-In ⚠️ Especificações não verificadas✓ Em estoque
$3.28 / unidade
Ver ficha técnica →ATMEGA3250-16MU
✅ Drop-In ⚠️ Especificações não verificadas📋 Alternativa de referência (fora do catálogo)
ATMEGA645-16MU Classificações máximas e características elétricas
| Core Architecture | 8-bit AVR RISC |
| Program Memory Size | 64 KB (32K x 16) Flash, ISP |
| SRAM Size | 4 KB |
| EEPROM Size | 2 KB |
| Frequência máxima de clock | 16 MHz |
| Throughput | 16 MIPS at 16 MHz |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Number of I/O Lines | 68 |
| ADC Resolution | 10-bit |
| ADC Channels | 8 channels |
| Debug Interface | JTAG (on-chip debugging and boundary scan) |
| Encapsulamento | 64-QFN (9x9 mm) |
| Tipo de montagem | Surface Mount |
| Speed Grade Class | 16 (industrial, GREEN) |
| Status RoHS | GREEN package (per FindIC listing) |
| Core Supply | Single supply |
Guia de Configuração de Pinos do ATMEGA645-16MU 64-qfn (9x9 mm)
Configuração de pinos para ATMEGA645-16MU (pacote 64-qfn (9x9 mm)). Este CI digital inclui GPIO, interfaces de comunicação (UART, SPI, I2C) e pinos de alimentação. Consulte o datasheet do fabricante para funções alternativas dos pinos e opções de configuração. Essencial para projeto de sistemas embarcados e layout de PCB.
Nenhum dado detalhado de pinagem disponível para ATMEGA645-16MU.
Consulte a ficha técnica para a configuração completa dos pinos.
Aplicações típicas
ATMEGA645-16MU é adequado para 6 aplicaçãos: Industrial Control and Automation, Consumer Appliances and HVAC Control, Battery-Powered Portable Instrumentation, Motorized Equipment and Robotics, Lighting and Display Control Systems, Educational and Development Platforms.
Industrial Control and Automation
The ATMEGA645-16MU fits industrial control nodes because 68 programmable I/O lines cover relay, contactor, and valve-driving output matrices plus multi-button operator panels without external port expanders. The 16MHz/16MIPS AVR core executes control loops and Modbus-style serial protocols in single-cycle instruction time, while the 8-channel 10-bit ADC digitizes analog transducer signals (0-10V scaled or 4-20mA via shunt) directly on-chip. Its 2.7V to 5.5V supply range tolerates unregulated industrial supply droop, and the JTAG interface permits boundary-scan test of densely populated control boards during production. In this role the MCU typically sits between a power supply front end and relay driver stages, with the 64KB Flash hosting protocol stacks, calibration tables, and OTA-style firmware stored in the 2KB EEPROM.
Recomendado
Consumer Appliances and HVAC Control
Appliance and HVAC controllers favor the ATMEGA645-16MU because it integrates everything a white-goods control board needs in one 64-QFN die: a 10-bit ADC for NTC temperature sensing across 8 channels (multi-zone systems), 68 I/O for display segments, relays, and keypads, and 2KB EEPROM for storing user settings that must survive power cycles. Running at 16MHz from a 5V rail gives 16MIPS of headroom for PID loops and rotary-encoder UI handling, while low-power idle modes cut consumption in standby. The single-chip integration reduces BOM count versus discrete MCU-plus-ADC-plus-driver designs, and the GREEN industrial-grade package suits the extended ambient environments of refrigerator and boiler enclosures.
Recomendado
Battery-Powered Portable Instrumentation
Handheld instruments such as cable testers, environmental meters, and field gauges benefit from the ATMEGA645-16MU's 2.7V low-voltage operation, which allows direct powering from two alkaline cells or a 3V lithium coin cell without a boost converter. The megaAVR sleep architecture lets the core idle between measurements while the ADC and interrupt system stay available for wake-on-event, stretching battery runtimes substantially. The 64KB Flash is ample for menu-driven UIs, logging tables, and data export routines, and the JTAG port accelerates debugging of the analog front-end firmware during development. Designers should run 8MHz clocks in 3V systems to respect the AVR frequency-versus-voltage derating curve.
Recomendado
Motorized Equipment and Robotics
In motorized equipment and small robotics platforms, the ATMEGA645-16MU acts as the supervisory controller generating PWM signals for H-bridge drivers while reading quadrature encoders and current shunts through its 10-bit ADC channels. The 16MIPS core handles nested control loops at kHz update rates with margin left for communications and safety interlocks, and the generous I/O count directly interfaces limit switches, bump sensors, and status LEDs. Because megaAVR timers feature hardware PWM and input-capture, encoder counting and PWM generation impose little CPU load. The 2.7V to 5.5V supply range lets a single 5V rail serve both the MCU and logic-side driver inputs, simplifying power-tree design on compact robot boards.
Recomendado
Lighting and Display Control Systems
LED lighting engines and display controllers use the ATMEGA645-16MU for its combination of 64KB firmware space and dense I/O: DMX512 lighting fixtures store show data and protocols comfortably in Flash, while the many port pins drive multiplexed LED columns and read touch or button inputs. The 10-bit ADC supports mains-dimming feedback and thermal monitoring of LED arrays, letting firmware derate drive current when junction temperatures approach limits. Operating from a single 5V rail at 16MHz, the part sequences hardware PWM timers for flicker-free dimming. The 2KB EEPROM holds fixture address and curve calibration data across power cycles, and JTAG simplifies bring-up of multi-board lighting racks.
Recomendado
Educational and Development Platforms
The ATMEGA645-16MU is attractive for training boards and university lab platforms because the megaAVR architecture is exhaustively documented, the MegaCore Arduino package on GitHub supports the ATmega645 directly, and the JTAG interface allows teaching on-chip debugging with Atmel-ICE hardware. Students encounter a complete peripheral set in one chip - 8-channel 10-bit ADC, multiple timers, USART, SPI, TWI, and 68 GPIO - without needing external converters. The 64KB Flash tolerates large example projects and bootloader experimentation, and the 2.7V to 5.5V range makes the device forgiving of student wiring mistakes on bench supplies. 64-QFN hand soldering is harder than DIP, so lab boards typically mount the chip with castellations or use a socket carrier.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para ATMEGA645-16MU — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | ATMEGA649-16MU | ATMEGA64A-MU | ATMEGA6450-16MU | ATMEGA325-16MU | ATMEGA3250-16MU |
|---|---|---|---|---|---|---|
| Package | 64-QFN (9x9 mm) | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 64 KB | 64 KB | 64 KB | 64 KB | 32 KB | 32 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 4 KB | 2 KB | 4 KB |
| Max Clock Frequency | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz |
| LCD Controller | No | Yes (segment LCD) | No | No | No | No |
| JTAG Debug/Boundary Scan | Yes | Yes | Yes | Yes | Yes | Yes |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V |
| Pin Compatibility Notes | Reference | Same footprint; LCD pins shared with port functions | Pin compatible for all but a few pins (AVR500) | Same footprint; port mapping differs | Same footprint; memory halved | Same footprint; port mapping and memory differ |
Principais diferenciais
- No LCD controller overhead for non-display designs (vs ATMEGA649-16MU)
- Identical memory class with ATmega64 migration path (vs ATMEGA64A-MU)
- Double the memory of the 325-class alternatives (vs ATMEGA325-16MU)
- JTAG on-chip debugging in QFN (vs ATMEGA3250-16MU)
Notas de projeto
Respect the AVR frequency-versus-voltage derating curve: the ATMEGA645-16MU is a 16MHz speed-grade part, but full 16MHz operation is only guaranteed at the upper end of the 2.7V-5.5V supply range (approximately 4.5V and above). In 3.3V systems, run the core at 8MHz or use an ATmega645V variant. Add 100nF ceramic decoupling on each VCC/AVCC pair plus a bulk 10uF, and keep AVCC connected to VCC through a low-pass filter when ADC accuracy matters - the 10-bit ADC reference quality directly tracks AVCC cleanliness.
The 64-QFN (9x9 mm) package has a peripheral lead ring with a central die paddle that must be soldered to a grounded or tied thermal pad for mechanical reliability and thermal performance. Design the land pattern per the datasheet recommended footprint, with via arrays under the paddle to spread heat and reduce inductance. Because QFN leads cannot be visually inspected after reflow, specify X-ray or AOI sampling in production, and note that hand rework of a 64-lead 0.5mm-pitch QFN requires hot-air tooling - plan for rework difficulty in prototype iterations.
Three recurring mistakes when migrating between megaAVR variants: (1) assuming full pin compatibility with ATmega64A - Microchip application note AVR500 (doc2576) documents the few pins that differ between ATmega64 and ATmega645, so check those first; (2) leaving the JTAG interface enabled when those pins are needed as port I/O - the JTAGEN fuse must be cleared to free pins PORTC[7:4]; (3) ignoring EEPROM wear - the 2KB EEPROM is endurance-rated per cell, so log data to SRAM and batch-write EEPROM at power-down rather than writing every cycle.
With 68 I/O and up to 16MHz toggle activity, ground bounce on the QFN package becomes visible on analog measurements. Use multiple ground return vias, route ADC sensor inputs away from fast-switching port banks, and enable the ADC noise canceler sleep mode for precision conversions. Add series termination (33-100 ohm) on long clock or reset traces and keep the 16MHz crystal within 10mm of the XTAL pins with proper load capacitors per crystal specification.
Informações de conformidade
Listed as GREEN package per FindIC specification summary (green/RoHS-conscious packaging). No AEC-Q100 qualification published for this industrial-grade part. Formal RoHS/REACH certificates should be requested from Microchip's environmental compliance portal.
