ATMEGA644A-AUR - 8-bit AVR MCU 64KB Flash 20MHz TQFP-44 | Microchip
N.º de pieza: ATMEGA644A-AUR ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $4.3 | $4,30 |
| 10 | $3.85 | $38,50 |
| 100 | $3.35 | $335,00 |
| 500 | $3 | $1.500,00 |
| 1.000 | $2.75 | $2.750,00 |
ATMEGA644A-AUR Descripción general
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that fetches and executes most instructions in a single clock cycle, making it a core building block of the embedded controller hierarchy (MCU -> microcontroller -> semiconductor). The ATmega644A belongs to the ATmega family that spans the ATmega164A, ATmega324A, ATmega644A, and ATmega1284 devices, all sharing an identical peripheral set and pinout across different Flash densities.
Key features include 32 general purpose I/O lines, two programmable serial USARTs, one byte-oriented 2-wire serial interface (TWI/I2C), one SPI interface, an 8-channel 10-bit ADC with optional differential input stage, and three flexible Timer/Counters with compare modes and PWM. A Real Time Counter (RTC) with separate oscillator supports battery-backed timekeeping, and read-while-write Flash allows firmware updates while executing code.
Architecturally, the device pairs 64 KB of In-System Programmable Flash with 32 general purpose working registers directly connected to the ALU, so a single-cycle instruction achieves throughput approaching 1 MIPS per MHz. Low-power CMOS process technology plus multiple sleep modes allow system designers to optimize power consumption against processing speed, which is why the family remains popular for cost-sensitive embedded designs.
Typical applications include industrial automation controllers, sensor data loggers, motor control interfaces, and hobbyist or Maker boards such as Arduino-compatible systems supported by MCUdude MightyCore. The 20 MHz speed and 4 KB SRAM comfortably handle protocol bridging and display driving tasks.
A key design consideration is clock sourcing: the ATmega644A supports an external crystal via XTAL1/XTAL2 pins, and fuse configuration determines clock source and brown-out thresholds, so verify fuses before switching clock schemes. Budget ADC accuracy margin by using a quiet AVCC supply and AREF filtering.
This page synthesizes distributor pricing, drop-in family alternatives, comparison tables, and practical design notes not found in the manufacturer datasheet, giving engineers a complete single-source reference. Pricing references are as of 2026-09-18 from distributor data.
Alternativas directas para ATMEGA644A-AUR — 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 ATMEGA644A-AUR (mismo factor de forma y huella) — difiere en ADC, Package, Timer/Counters, Core Architecture, EEPROM.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
ATMEGA644PA-AUR
✅ Sustitución directa✓ En stock
$1.78 / unidad
Ver hoja de datos →ATMEGA644-20AU
✅ Sustitución directa✓ En stock
$4.96 / unidad
Ver hoja de datos →ATMEGA1284P-AUR
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
ATMEGA324A-AUR
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
ATMEGA164A-AUR
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
ATMEGA644A-AUR Valores máximos y características eléctricas
| Core Architecture | 8-bit AVR RISC |
| Max Clock Frequency | 20 MHz |
| Flash Memory | 64 KB (32K x 16), In-System Programmable, Read-While-Write |
| SRAM | 4 KB |
| EEPROM | 2 KB |
| I/O Lines | 32 general purpose |
| USART | 2 programmable serial USARTs |
| Timer/Counters | 3 with compare modes and PWM |
| ADC | 8-channel, 10-bit, optional differential input |
| Serial Interfaces | 2-wire (TWI/I2C), SPI, 2x USART |
| Real Time Counter | Yes (RTC) |
| Encapsulado | 44-TQFP (10x10 mm) |
| Tipo de montaje | Surface Mount |
| Temperatura de funcionamiento | Industrial temperature range |
| Estado RoHS | Compliant |
| Life Cycle Stage | ACTIVE |
Guía de configuración de pines de ATMEGA644A-AUR 44-tqfp (10x10 mm)
Configuración de pines para ATMEGA644A-AUR (encapsulado 44-tqfp (10x10 mm)). Este CI digital incluye GPIO, interfaces de comunicación (UART, SPI, I2C) y pines de alimentación. Consulte la hoja de datos del fabricante para conocer las funciones alternativas de los pines y las opciones de configuración. Esencial para el diseño de sistemas embebidos y el diseño de PCB.
No hay datos detallados de patillaje disponibles para ATMEGA644A-AUR.
Consulte la hoja de datos para ver la configuración completa de patillas.
Aplicaciones típicas
ATMEGA644A-AUR es adecuado para 6 aplicacións: Industrial Automation Controllers, Sensor Data Loggers, Motor Control and PWM Actuator Interfaces, Arduino-Compatible Maker Boards, Embedded Communication Bridges, Measurement and Test Instrumentation Front-Ends.
Industrial Automation Controllers
The ATMEGA644A-AUR fits industrial control nodes that need reliable serial communication and moderate processing: its two USARTs support Modbus RTU master/slave links, while the 10-bit ADC acquires analog sensor feedback such as pressure and temperature. With 64 KB Flash, there is ample room for protocol stacks plus HMI logic, and the 4 KB SRAM buffers communication frames and control states. The three Timer/Counters generate PWM outputs for actuator or heater control with hardware precision, and the industrial temperature rating ensures operation in factory environments. Place the MCU between an RS-485 transceiver and relay/SSR drivers with optocoupler isolation; the 20 MHz clock executes near 20 MIPS, leaving headroom for both control loops and diagnostics logging in EEPROM.
Recomendado
Sensor Data Loggers
For battery-powered data logging, the ATMEGA644A-AUR combines an 8-channel 10-bit ADC with the Real Time Counter, allowing timestamped acquisition of multiple analog channels. The 2 KB EEPROM stores calibration constants and configuration that must survive power loss, while 64 KB Flash accommodates FAT-style logging code and filtering algorithms. Sleep modes let the MCU idle between samples, extending battery life in remote installations. Typical topology: analog sensors into the ADC input multiplexer, an SD card or external EEPROM on the SPI or TWI bus for bulk storage, and a USART streaming data on demand. The 4 KB SRAM holds ring buffers so bursts of high-rate samples are not lost between write cycles, and the separate RTC oscillator keeps time with minimal standby current.
Recomendado
Motor Control and PWM Actuator Interfaces
The ATMEGA644A-AUR's three flexible Timer/Counters with compare modes deliver multi-channel hardware PWM without CPU loading, suiting DC motor speed control, servo driving, and heater or lamp dimming. The 20 MHz clock yields fine PWM resolution (up to 16-bit on Timer/Counter1), and the differential ADC inputs read current-sense shunts for closed-loop torque or speed regulation. With 64 KB Flash there is room for field-oriented or PID control algorithms plus a host communication task on one of two USARTs. Design practice: drive MOSFET gate drivers from the PWM outputs, place a current sense resistor in the low side, and feed the amplified signal into a differential ADC channel; the ADC's optional differential stage with gain improves small-signal resolution for current feedback.
Recomendado
Arduino-Compatible Maker Boards
The ATmega644 family is directly supported by the MCUdude MightyCore Arduino hardware package, which covers ATmega1284, ATmega644, ATmega324, ATmega164, and related parts, so the ATMEGA644A-AUR can be programmed with the familiar Arduino IDE toolchain. Compared with the classic ATmega328 (32 KB/2 KB), the 644A doubles Flash to 64 KB and doubles SRAM to 4 KB while keeping the same AVR instruction set, allowing larger sketches, more libraries, and deeper buffers on the same low-cost 8-bit platform. The 44-TQFP package exposes 32 GPIO across four ports, enough for LCD shields plus multiple sensor buses. Bootloader firmware for the family is open source, and ISP programming uses the standard 6-pin header, making this MCU a natural choice for upgraded DIY boards and educational kits.
Recomendado
Embedded Communication Bridges
With two independent USARTs plus SPI and TWI, the ATMEGA644A-AUR is well suited as a protocol converter or gateway: translate RS-232 field device traffic to I2C sensor buses, or bridge SPI peripherals to a USB-to-serial upstream link. The 4 KB SRAM accommodates message framing and retransmission buffers, while 64 KB Flash holds multiple protocol stacks. The byte-oriented 2-wire interface supports both master and slave modes, and the SPI runs at high clock rates derived from the 20 MHz system clock. A practical implementation pairs each USART with an external transceiver (RS-485 or RS-232) and uses one timer for timeout supervision; hardware flow control is implemented in firmware. Read-while-write Flash allows field firmware updates without interrupting the communication service loop, an important feature for deployed gateways.
Recomendado
Measurement and Test Instrumentation Front-Ends
The 8-channel 10-bit ADC with optional differential input stage and internal reference makes the ATMEGA644A-AUR effective for low-cost measurement instruments: multimeter front-ends, thermal probes, and bench-top sensor readers. Differential mode with programmable gain improves small-signal measurement of bridge sensors such as strain gauges and thermocouple amplifiers, and averaging in the 4 KB SRAM raises effective resolution beyond 10 bits at reduced bandwidth. Results are displayed on a character LCD driven by GPIO or communicated over USART to a PC. The RTC provides timestamping for logged readings. Design tip: filter AVCC with an RC network and route analog traces away from the PWM outputs; ADC accuracy in this family depends strongly on supply noise, so allocate PCB area for a quiet analog island near the AREF pin.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para ATMEGA644A-AUR — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | ATMEGA644PA-AUR | ATMEGA644-20AU | ATMEGA1284P-AUR | ATMEGA324A-AUR |
|---|---|---|---|---|---|
| Package | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 64 KB | 64 KB | 64 KB | 128 KB | 32 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 16 KB | 2 KB |
| EEPROM | 2 KB | 2 KB | 2 KB | 4 KB | 1 KB |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Power Consumption | Standard power (A version) | picoPower, lowest | Standard power | picoPower | Standard power |
Diferenciadores clave
- Twice the memory of ATMEGA324A-AUR at the same pinout and speed (frente a ATMEGA324A-AUR)
- Lower power option available pin-to-pin (frente a ATMEGA644PA-AUR)
- Upgrade path to 128 KB without footprint change (frente a ATMEGA1284P-AUR)
Notas de diseño
Decouple each VCC/AVCC pin pair with 100 nF ceramic capacitors placed within a few millimeters of the pins, plus a 4.7-10 uF bulk capacitor near the MCU. AVCC must be connected to VCC even if the ADC is unused (per the family datasheet). If ADC accuracy matters, filter AVCC through an LC or RC network and keep AREF decoupled with a dedicated capacitor; switching noise on AVCC is the most common cause of ADC LSB jitter in AVR designs.
Fuse settings are the top migration pitfall: clock source, brown-out detector level, and JTAG enable are all fuse-configured and survive chip swaps, but firmware compiled for one family member may assume different fuse defaults. After replacing an ATmega644A with an ATmega644PA or ATmega1284P, verify the CKOUT, BODLEVEL, and BOOTRST fuses before first power-up. Also confirm that bootloader offset addresses match the Flash size when moving between 32 KB, 64 KB, and 128 KB members.
On a 44-TQFP (10x10 mm) footprint, use a standard 0.5 mm pitch land pattern and route the four GPIO ports symmetrically to connector headers to keep crystal, reset, and ISP header traces short. Keep XTAL1/XTAL2 traces under 10 mm with guard ground, and place the 6-pin ISP header so it does not conflict with high-current PWM routing. A solid ground plane under the device improves ADC performance and EMI; avoid crossing the analog island with digital return currents.
Información de cumplimiento
RoHS compliant per DigiKey/Mouser distributor listings. Formal REACH, halogen-free, and conflict minerals declarations must be obtained from Microchip compliance documentation.