ATMEGA644PA-AU - 8-bit AVR MCU, 20MHz, 64KB Flash | Microchip
Référence : ATMEGA644PA-AU ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $7.2 | $7,20 |
| 10 | $6.48 | $64,80 |
| 100 | $5.76 | $576,00 |
| 500 | $5.18 | $2 590,00 |
| 1 000 | $4.61 | $4 610,00 |
ATMEGA644PA-AU Présentation
An 8-bit AVR microcontroller is a reduced-instruction-set computing (RISC) device in the microcontroller unit (MCU) hierarchy of embedded processors, integrating a CPU core, program memory, data memory, and peripherals on a single chip. Microcontrollers sit below application processors and above ASICs in the embedded system taxonomy, making them the workhorse of industrial control, consumer devices, and IoT nodes. The AVR family is distinguished by its single-cycle instruction execution through 32 general-purpose working registers, achieving up to 20 MIPS throughput at 20 MHz.
Key features include 32 general purpose I/O lines, two USARTs for asynchronous serial communication, a byte-oriented Two-Wire serial interface (TWI/I2C), an SPI serial port, an 8-channel 10-bit ADC with up to 15 kSps throughput, and three flexible timer/counters with compare modes and PWM. The picoPower technology achieves very low power consumption in active and sleep modes, extending battery life in portable designs through six software-selectable power-saving modes.
The 64 KB Flash supports In-System Programming (ISP) with read-while-write, enabling firmware field updates without external programmers. The device supports boot loader programming through any interface and operates across 1.8V-5.5V supply range, allowing direct interface with both 3.3V and 5V logic. Peripherals include a real-time counter with separate oscillator, programmable watchdog timer with on-chip oscillator, and JTAG/OCD/debugWIRE on-chip debug interface.
Typical applications include industrial control systems, sensor nodes, battery-powered instrumentation, motor control boards using PWM channels, and Arduino-compatible hobby projects where the 644P variant is widely supported. The wide operating voltage also suits solar-powered remote sensing nodes.
For design, decouple VCC and AVCC separately with 100 nF ceramic capacitors, and reserve the RESET pin for ISP programming access. The device programs via ICSP using only two I/O pins plus reset. Supply voltage determines maximum safe clock frequency, so verify speed-grade derating at low VCC (10 MHz max at 2.7V).
This page synthesizes distributor pricing, drop-in alternatives, pinout data, and practical design notes not consolidated in the manufacturer datasheet.
Alternatives de remplacement direct pour ATMEGA644PA-AU — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec ATMEGA644PA-AU (même facteur de forme et même empreinte) — différant par ADC, Package, Serial Interfaces, EEPROM, RoHS Status.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
ATMEGA644P-20AU
✅ Remplacement direct✓ En stock
$3.95 / unité
Voir la fiche technique →ATMEGA644PV-10AU
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
ATMEGA1284P-AU
✅ Remplacement direct✓ En stock
$4.65 / unité
Voir la fiche technique →ATMEGA644PA-AU Valeurs maximales et caractéristiques électriques
| Core Architecture | AVR 8-bit RISC |
| Family | ATmega |
| Series | ATmega644P / picoPower |
| Fréquence d'horloge maximale | 20 MHz |
| Program Memory (Flash) | 64 KB (32K x 16) |
| SRAM | 4 KB |
| EEPROM | 2 KB |
| Supply Voltage Range | 1.8 V to 5.5 V |
| Température de fonctionnement | -40C to +85C (industrial) |
| GPIO Pins | 32 |
| ADC | 8-channel, 10-bit |
| USART | 2 |
| I2C (TWI) | 1 |
| SPI | 1 |
| Timer/Counters | 3 (with PWM and compare modes) |
| Boîtier | 44-pin TQFP (10x10 mm) |
| Type de montage | Surface Mount |
| MIPS | 20 MIPS at 20 MHz |
| Programming Interface | ISP / ICSP / JTAG / debugWIRE |
| Statut RoHS | Compliant |
Configuration des broches de ATMEGA644PA-AU
| Broche 1 | PA3 — Port A bit 3 (ADC3) |
| Broche 2 | PA2 — Port A bit 2 (ADC2) |
| Broche 3 | PA1 — Port A bit 1 (ADC1) |
| Broche 4 | PA0 — Port A bit 0 (ADC0) |
| Broche 5 | VCC — Digital supply voltage |
| Broche 6 | GND — Digital ground |
| Broche 7 | VCC — Digital supply voltage |
| Broche 8 | GND — Digital ground |
| Broche 9 | XTAL2 — Crystal oscillator output |
| Broche 10 | XTAL1 — Crystal oscillator input |
| Broche 11 | RXD0 — USART0 receive (PDI) |
| Broche 12 | TXD0 — USART0 transmit (PDO) |
| Broche 13 | INT0 — External interrupt 0 (PD2) |
| Broche 14 | INT1 — External interrupt 1 (PD3) |
| Broche 15 | ICP1 — Timer1 input capture (PD4) |
| Broche 16 | XCK0 — USART0 clock (PD5) |
| Broche 17 | TOSC1 — Timer0 oscillator (PD6) |
| Broche 18 | TOSC2 — Timer0 oscillator (PD7) |
| Broche 19 | AVCC — Analog supply voltage |
| Broche 20 | AREF — ADC reference voltage |
| Broche 21 | AGND — Analog ground |
| Broche 22 | ADC7 — ADC input channel 7 (PA7) |
| Broche 23 | ADC6 — ADC input channel 6 (PA6) |
| Broche 24 | ADC5 — ADC input channel 5 (PA5) |
| Broche 25 | ADC4 — ADC input channel 4 (PA4) |
| Broche 26 | SCL — TWI clock (PC0) |
| Broche 27 | SDA — TWI data (PC1) |
| Broche 28 | TCK — JTAG test clock (PC2) |
| Broche 29 | TMS — JTAG test mode select (PC3) |
| Broche 30 | TDO — JTAG test data out (PC4) |
| Broche 31 | TDI — JTAG test data in (PC5) |
| Broche 32 | PC6 — Port C bit 6 |
| Broche 33 | PC7 — Port C bit 7 |
| Broche 34 | RXD1 — USART1 receive (PD0) |
| Broche 35 | TXD1 — USART1 transmit (PD1) |
| Broche 36 | OC0B — Timer0 output compare B (PB0) |
| Broche 37 | OC0A — Timer0 output compare A (PB1) |
| Broche 38 | SS — SPI slave select (PB2) |
| Broche 39 | MOSI — SPI master out / slave in (PB3) |
| Broche 40 | MISO — SPI master in / slave out (PB4) |
| Broche 41 | SCK — SPI clock (PB5) |
| Broche 42 | OC1A — Timer1 output compare A (PB6) |
| Broche 43 | OC1B — Timer1 output compare B (PB7) |
| Broche 44 | RESET — Reset input, active low |
Applications typiques
ATMEGA644PA-AU convient pour 7 applications: Industrial Control Systems, Sensor Nodes and IoT Edge Devices, Motor Control and PWM Drivers, Battery-Powered Instrumentation, Arduino-Compatible Embedded Boards, Human-Machine Interface (HMI) Panels, Data Logging and Embedded Storage.
Industrial Control Systems
The ATMEGA644PA-AU fits industrial control applications because its 64 KB Flash with read-while-write ISP enables field firmware updates without external programmers, while the 8-channel 10-bit ADC and three PWM-capable timer/counters handle sensor acquisition and actuator drive simultaneously. The 32 GPIO lines multiplex keypad inputs, relay drivers, and display interfaces typical of PLC-style controllers. picoPower sleep modes drop current to microampere levels for battery-backed control panels. Operating from 1.8V to 5.5V with industrial -40C to +85C temperature range, the device tolerates harsh factory environments and direct 5V sensor interfaces.
Recommandé
Sensor Nodes and IoT Edge Devices
The ATMEGA644PA-AU serves wireless sensor nodes because picoPower technology delivers six software-selectable sleep modes reducing quiescent current to single-digit microamperes, enabling multi-year battery life on 2x AA cells. The two USARTs and one SPI port interface simultaneously with LoRa/Sigfox modules and local sensors, while the I2C/TWI bus connects temperature, humidity, and motion sensors. 64 KB Flash accommodates over-the-air update bootloaders. The wide 1.8V-5.5V supply range lets designers use lithium cells (3.7V nominal) or 3.3V regulated rails without level shifters.
Recommandé
Motor Control and PWM Drivers
The ATMEGA644PA-AU drives brushed DC and stepper motors through its three flexible timer/counters with PWM output channels, while the 8-channel 10-bit ADC samples feedback currents and position encoders in real time. 32 GPIO lines enable multi-axis stepper control and H-bridge driver interfaces. The 20 MHz clock rate delivers deterministic PWM frequency generation suitable for closed-loop speed control. The 44-pin TQFP package exposes nearly all peripherals, leaving headroom for additional safety interlocks and encoder inputs in robotics or CNC accessory designs.
Recommandé
Battery-Powered Instrumentation
The ATMEGA644PA-AU is well-matched to portable test and measurement instruments because its picoPower active mode draws only a few hundred microamperes at low clock rates, and its deep-sleep modes drop consumption to sub-microampere levels between measurements. The 8-channel ADC with internal 1.1V reference digitizes multiple sensor inputs without external references. 64 KB Flash stores calibration tables and logged data, while the TWI/I2C and SPI buses drive LCD displays and EEPROM storage. Operates directly from 2x AA alkaline or single Li-Ion cells across 1.8V-5.5V input range.
Recommandé
Arduino-Compatible Embedded Boards
The ATMEGA644PA-AU is a popular Arduino-compatible MCU through third-party cores (MightyCore, jackrabrel) because it delivers 64 KB Flash, 4 KB SRAM, and 32 GPIO - all doubled compared to the ATmega328P - while maintaining the familiar AVR toolchain. Hobbyists and educators use it for advanced projects like 3D printer controllers, retro computing, and LED matrix displays. The ISP programming interface aligns with standard AVR programmers, and the bootloader occupies only 512 bytes leaving ample room for application code. Wide voltage tolerance supports both 3.3V and 5V shields.
Recommandé
Human-Machine Interface (HMI) Panels
The ATMEGA644PA-AU drives HMI panels with character or graphic LCDs because its two USARTs handle touchscreen controllers and external communications simultaneously, while 32 GPIO lines scan keypads and drive LED indicators. The 8-channel ADC reads analog potentiometers and ambient light sensors for automatic backlight control. 64 KB Flash stores multi-language UI strings and bitmaps, and the SPI bus drives TFT-LED panels up to small QVGA resolutions. picoPower sleep modes reduce standby panel consumption for battery-backed operator panels in industrial HMIs.
Recommandé
Data Logging and Embedded Storage
The ATMEGA644PA-AU logs data to external EEPROM or SD cards because its SPI bus transfers data at full clock-divided rates to memory cards, and its two USARTs bridge GPS receivers and modems concurrently. The 4 KB SRAM buffers incoming measurements while the 64 KB Flash holds local processing algorithms and file system drivers. The real-time counter with separate oscillator timestamps each record accurately even during sleep periods. The 8-channel ADC samples environmental sensors at programmable rates up to 15 kSps for high-resolution logging.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour ATMEGA644PA-AU — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | ATMEGA644P-20AU | ATMEGA644PV-10AU | ATMEGA1284P-AU |
|---|---|---|---|---|
| Package | TQFP-44 (10x10 mm) | TQFP-44 (10x10 mm) - same | TQFP-44 (10x10 mm) - same | TQFP-44 - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 10 MHz | 20 MHz |
| Flash Memory | 64 KB | 64 KB | 64 KB | 128 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 16 KB |
| EEPROM | 2 KB | 2 KB | 2 KB | 4 KB |
| GPIO Pins | 32 | 32 | 32 | 32 |
| Supply Voltage Range | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| picoPower Technology | Yes (PA variant) | No (P variant) | Yes (PV variant) | Yes (P variant) |
Principaux différenciateurs
- picoPower sleep modes reduce sleep current to <2 uA (vs ATMEGA644P-20AU)
- 20 MHz operation vs 10 MHz ceiling (vs ATMEGA644PV-10AU)
- Arduino-compatible core support via MightyCore (vs ATMEGA1284P-AU)
Notes de conception
Estimated: The ATMEGA644PA-AU draws approximately 12 mA active at 20 MHz and 5V, dropping to <2 uA in power-down sleep mode. Decouple VCC and AVCC separately with 100 nF ceramic capacitors placed within 5 mm of their respective pins; AVCC additionally needs a 10 uH inductor or ferrite bead from VCC if the ADC is used for accurate measurements. Tie unused AVCC to VCC if analog peripherals are disabled.
Route the crystal traces (XTAL1, XTAL2) symmetrically and keep them short (<10 mm) with grounded guard traces. Place the crystal within 5 mm of the MCU. For ISP programming, expose the RESET, SCK, MOSI, MISO pins to a 2x3 or 2x5 header. Keep ADC analog traces away from switching nodes and digital clock lines to preserve ADC SNR.
Do not exceed 20 MHz clock rate unless VCC is 4.5V or higher; at lower voltages the maximum clock is derated (10 MHz at 2.7V, 4 MHz at 1.8V). The JTAG pins (PC2-PC5) cannot be used as GPIO while JTAG is enabled in fuses; disable JTAG via fuse bits if these pins are needed. The RESET pin requires a 10 kohm pullup to VCC and should not be left floating during operation.
When using SPI at high speeds (>4 MHz), keep MISO/MOSI/SCK traces short and matched in length within 5 mm. Add 33 ohm source termination on SCK for SPI peripherals located >50 mm from the MCU. For TWI/I2C buses, use 4.6 kohm pullups at 3.3V or 3.0 kohm at 5V to achieve standard-mode 100 kHz operation reliably.
Informations de conformité
RoHS compliant per Microchip product page. Industrial temperature grade -40C to +85C. Not AEC-Q100 qualified; not applicable for MCU category. Conflict minerals declaration compliant per Microchip policy.