ATMEGA1284P-AU - 8-bit AVR MCU 128KB Flash 20MHz TQFP-44
MPN: ATMEGA1284P-AU ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.2 | $8.20 |
| 10 | $7.45 | $74.50 |
| 100 | $6.1 | $610.00 |
| 500 | $5.2 | $2,600.00 |
| 1,000 | $4.65 | $4,650.00 |
ATMEGA1284P-AU Overview
An 8-bit AVR microcontroller is a single-chip computer built around the AVR enhanced RISC architecture, executing most instructions in a single clock cycle to deliver throughputs approaching 1 MIPS per MHz. AVR microcontrollers sit within the broader hierarchy: 8-bit MCU -> microcontroller unit -> embedded processor -> semiconductor IC. They are widely used in hobbyist (Arduino), industrial, and consumer applications because the architecture is deterministic, low-power, and supported by a mature GCC toolchain (avr-gcc) and Atmel/Microchip Studio IDE.
Key features of the ATMEGA1284P-AU include 20 MHz maximum operating frequency, 1.8V-5.5V wide operating voltage, six sleep modes (Idle, ADC Noise Reduction, Power-save, Power-down, Standby, Extended Standby) with as little as 100 nA current draw at 1.8V, and QTouch library support for capacitive touch sensing. The advanced RISC core delivers 135 powerful instructions with most executing in one clock cycle.
The device supports In-System Programming (ISP) via SPI and self-programming via the boot block. The peripheral set includes two 8-bit timer/counters and two 16-bit timer/counters with separate prescalers and compare modes, an 8-channel 10-bit ADC, an analog comparator, a programmable watchdog timer with on-chip oscillator, and an interrupt controller with 31 vectored interrupts. The JTAG interface (IEEE 1149.1 compliant) enables on-chip debug.
Typical applications include industrial control systems, home automation gateways, sensor data loggers, automotive body and aftermarket modules, USB-to-UART bridges, hobbyist Arduino-compatible boards (MightyCore and bobuino variants), and low-power wireless sensor nodes. The 32 GPIO count combined with two hardware serial ports makes it a strong upgrade path for designs that outgrow the ATmega328P-based Arduino Uno.
When designing with this device, allocate PCB area for the 44-pin TQFP land pattern and ensure the decoupling network (100 nF plus 10 uF bulk) is placed within 5 mm of the AVCC and VCC pins. Programmers must apply the correct fuse settings: the default internal RC oscillator at 8 MHz may be replaced by an external crystal for time-critical UART or USB applications.
This page synthesizes distributor pricing, drop-in alternatives from the ATmega AVR family, and practical design notes not found in the standalone Atmel datasheet.
Drop-in alternatives for ATMEGA1284P-AU — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ATMEGA1284P-AU (same form factor and footprint) — differing in Package, ADC, Timer/Counters, Core Architecture, EEPROM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA1284P-AUR
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA1284-AUR
✅ Drop-In✓ In Stock
$4.61 / Unit
View Datasheet →ATMEGA164A-AU
✅ Drop-In✓ In Stock
$2.65 / Unit
View Datasheet →ATMEGA324P-15AT1
✅ Drop-In✓ In Stock
$4.21 / Unit
View Datasheet →ATMEGA1284P-MU
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →ATMEGA1284P-AU Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Program Memory (Flash) | 128 KB |
| EEPROM | 4 KB |
| SRAM | 16 KB |
| Maximum CPU Speed | 20 MHz |
| Operating Voltage Range | 1.8 V to 5.5 V |
| I/O Pins | 32 |
| General-Purpose Registers | 32 |
| ADC | 10-bit, 8-channel |
| USART | 2 |
| SPI | 1 |
| TWI (I2C) | 1 |
| Timer/Counters | 2x 8-bit, 2x 16-bit |
| PWM Channels | 6 |
| Package | TQFP-44 (10x10 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C (industrial) |
| In-System Programming | Yes (SPI) |
| JTAG Debug | Yes (IEEE 1149.1) |
| RoHS Status | Compliant |
| MSL Level | 3 (per JEDEC J-STD-020) |
ATMEGA1284P-AU Pin Configuration
| Pin 1 | VCC — Digital supply voltage |
| Pin 2 | GND — Ground |
| Pin 3 | XTAL2 — Crystal oscillator pin 2 |
| Pin 4 | XTAL1 — Crystal oscillator pin 1 |
| Pin 5 | PD0 — Digital I/O, RXD0 (USART0 receive) |
| Pin 6 | PD1 — Digital I/O, TXD0 (USART0 transmit) |
| Pin 7 | PD2 — Digital I/O, INT0/RXD1 |
| Pin 8 | PD3 — Digital I/O, INT1/TXD1 |
| Pin 9 | PD4 — Digital I/O, T0/PCINT20 |
| Pin 10 | PD5 — Digital I/O, T1/OC1A/PCINT21 |
| Pin 11 | PD6 — Digital I/O, AIN0/OC1B/PCINT22 |
| Pin 12 | PD7 — Digital I/O, AIN1/OC2A/PCINT23 |
| Pin 13 | PB0 — Digital I/O, PCINT0/SS |
| Pin 14 | PB1 — Digital I/O, PCINT1/SCK |
| Pin 15 | PB2 — Digital I/O, PCINT2/MOSI |
| Pin 16 | PB3 — Digital I/O, PCINT3/MISO |
| Pin 17 | PB4 — Digital I/O, PCINT4/OC0A |
| Pin 18 | PB5 — Digital I/O, PCINT5/OC0B |
| Pin 19 | PB6 — Digital I/O, PCINT6/OC1C |
| Pin 20 | PB7 — Digital I/O, PCINT7/OC0C |
| Pin 21 | VCC — Digital supply voltage |
| Pin 22 | GND — Ground |
| Pin 23 | PC0 — Digital I/O, ADC0 |
| Pin 24 | PC1 — Digital I/O, ADC1 |
| Pin 25 | PC2 — Digital I/O, ADC2 |
| Pin 26 | PC3 — Digital I/O, ADC3 |
| Pin 27 | PC4 — Digital I/O, ADC4/SDA |
| Pin 28 | PC5 — Digital I/O, ADC5/SCL |
| Pin 29 | PC6 — Digital I/O, ADC6/OC3A |
| Pin 30 | PC7 — Digital I/O, ADC7/OC3B |
| Pin 31 | AVCC — Analog supply voltage |
| Pin 32 | AGND — Analog ground |
| Pin 33 | AREF — ADC reference voltage |
| Pin 34 | PA0 — Digital I/O, ADC8 |
| Pin 35 | PA1 — Digital I/O, ADC9 |
| Pin 36 | PA2 — Digital I/O, ADC10 |
| Pin 37 | PA3 — Digital I/O, ADC11 |
| Pin 38 | PA4 — Digital I/O, ADC12/OC3C |
| Pin 39 | PA5 — Digital I/O, ADC13/OC3A |
| Pin 40 | PA6 — Digital I/O, ADC14 |
| Pin 41 | PA7 — Digital I/O, ADC15 |
| Pin 42 | RESET — Reset input (active low) |
| Pin 43 | VCC — Digital supply voltage |
| Pin 44 | GND — Ground |
Typical Applications
ATMEGA1284P-AU is suitable for 6 applications: Industrial Sensor Data Logger, Home Automation Gateway, Automotive Aftermarket Telematics, Hobbyist / MightyCore Arduino-Compatible Board, USB-to-UART Bridge / Serial Console Adapter, Low-Power Wireless Sensor Node.
Industrial Sensor Data Logger
The ATMEGA1284P-AU fits industrial sensor data loggers because the 128 KB Flash accommodates complex logging protocols and SD card file-system libraries, while the 16 KB SRAM buffers large data blocks before write. Its 1.8-5.5V supply range supports battery-backed RTC circuits and 24V industrial rails via LDO. The two USARTs allow simultaneous connection to a Modbus RTU sensor bus and a Bluetooth/GSM telemetry link, while the 8-channel 10-bit ADC reads multiple analog sensors. Unlike smaller ATmegas atmega328/32, the 1284P runs multi-task logging firmware without memory pressure.
Recommended
Home Automation Gateway
The ATMEGA1284P-AU suits home automation gateways because the 32 GPIO and dual USARTs enable parallel connection to multiple radio modules (Zigbee, LoRa, or 433 MHz ISM). The 128 KB Flash stores Z-Wave, Zigbee HA 1.2, and proprietary RF protocol stacks. The 16 KB SRAM buffers network discovery packets. Its industrial temperature range -40C to +85C supports installation in utility rooms. The TWI (I2C) interface connects to sensor front-ends and the JTAG debug enables production firmware tuning without ISP hassles.
Recommended
Automotive Aftermarket Telematics
The ATMEGA1284P-AU fits automotive aftermarket telematics because the 32 GPIO interface to GPS modules, accelerometer chips, OBD-II CAN transceivers (via SPI), and the 128 KB Flash supports custom CAN/J1850 protocol stacks. The 16 KB SRAM buffers CAN frames and GPS NMEA sentences for cloud upload. The industrial -40C to +85C operating temperature handles under-dash thermal environments. The dual USART splits GPS serial stream from Bluetooth HCI to a phone. Unlike smaller ATmegas, the 1284P's 4 KB EEPROM stores user settings and trip logs over many years.
Recommended
Hobbyist / MightyCore Arduino-Compatible Board
The ATMEGA1284P-AU powers Arduino-compatible boards using the MightyCore and bobuino variants, which are well-known to AVR enthusiasts. The 1284P delivers 4x the Flash and 8x the SRAM of the Arduino Uno's ATmega328P, removing memory constraints for projects like robotics controllers, LED matrices, and quadcopter flight controllers. The dual USARTs (the Uno's ATmega328P has only one) simplify Bluetooth serial bridges plus USB-serial debug. The TQFP-44 package and standard Arduino pinout enable drop-in board variants. Programming remains 100% compatible with avr-gcc and the Arduino IDE.
Recommended
USB-to-UART Bridge / Serial Console Adapter
The ATMEGA1284P-AU fits USB-to-UART bridge designs because the dual USARTs allow simultaneous conversion of two serial channels to USB CDC. The 128 KB Flash accommodates USB stack libraries (LUFA or V-USB) plus application logic, while the 16 KB SRAM supports HID and CDC endpoint buffers. The 5.5V supply tolerance directly powers from USB VBUS. The TQFP-44 package and small footprint suit compact USB-stick form factors. Its industrial temperature grade supports outdoor and industrial serial console use.
Recommended
Low-Power Wireless Sensor Node
The ATMEGA1284P-AU fits low-power wireless sensor nodes because its PicoPower technology delivers power-down currents as low as a few hundred nA with the 32.768 kHz watch crystal active, enabling years of battery life on 2xAA cells. The 16 KB SRAM buffers sensor samples for batch transmission, reducing wake-up time. The TWI (I2C) interface connects to low-power temperature/humidity sensors like the SHT3x. The 128 KB Flash stores LoRaWAN or Zigbee stack plus application firmware. The industrial temperature grade supports outdoor environmental monitoring deployments.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA1284P-AU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA1284P-AUR | ATMEGA1284-AU | ATMEGA164A-AU | ATMEGA324P-15AT1 | ATMEGA1284P-MU |
|---|---|---|---|---|---|---|
| Package | TQFP-44 (10x10 mm) | TQFP-44 (same) | TQFP-44 (same) | TQFP-44 (same) | TQFP-44 (same) | QFN-44 (different land pattern) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 128 KB | 128 KB | 128 KB | 16 KB (-87%) | 32 KB (-75%) | 128 KB |
| SRAM | 16 KB | 16 KB | 16 KB | 4 KB (-75%) | 8 KB (-50%) | 16 KB |
| EEPROM | 4 KB | 4 KB | 4 KB | 1 KB | 1 KB | 4 KB |
| Maximum Clock Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 15 MHz (-25%) | 20 MHz |
| GPIO Count | 32 | 32 | 32 | 32 | 32 | 32 |
| PicoPower (P-suffix) | Yes | Yes | No (non-P) | Yes | Yes | Yes |
Key Differentiators
- Largest SRAM in the ATmega AVR TQFP-44 family (16 KB) (vs ATMEGA164A-AU)
- PicoPower technology for battery-powered designs (vs ATMEGA1284-AU)
- Industrial -40C to +85C operating temperature range (vs ATMEGA324P-15AT1)
Design Notes
Power supply decoupling for the ATMEGA1284P-AU must include a 100 nF ceramic capacitor placed within 5 mm of each AVCC and VCC pin, plus a shared 10 uF bulk capacitor on each supply rail. The AVCC pin should be tied to VCC through an LC filter (10 ohm + 10 uF) if the ADC is used at >1 MSPS to keep digital switching noise out of the analog section. Decoupling isn't optional for stable ADC readings, and the Arduino-style Pro schema typically places capacitors on each side. Estimated: a typical 100 nF + 10 uF combination per rail provides adequate decoupling for 20 MHz operation.
PCB layout for the 44-pin TQFP-44 package requires a 10x10 mm land pattern with 0.8 mm pitch and 0.4 mm wide pads; use NSMD (non-solder-mask-defined) pads for best thermal cycling reliability. Route all four ground pins (pin 22, 32, GND, GND) directly to a single ground pour, and connect all three VCC pins (pin 1, 21, 43) to a single power pour. Place the ISP header (MOSI/MISO/SCK/RESET/VCC/GND) at the board edge for production programming access. Estimated: ground pour resistance under 5 milliohms across the die improves thermal and EMI performance.
Common pitfalls when bringing up the ATMEGA1284P-AU include: (1) forgetting to set the CKDIV8 fuse for 8 MHz internal RC operation - the device ships configured for 1 MHz; (2) tying RESET directly to VCC without a 10 kohm pull-up and 100 nF cap, which makes ISP programming unreliable; (3) using the internal 8 MHz RC for UART communication without calibration against a 32.768 kHz crystal, which yields baud rate errors >5%; (4) exceeding 5.5V on AVCC when using the ADC with internal reference. Always program fuses last and verify with an ISP programmer that reports the chip signature 0x1E9715.
Compliance Information
RoHS and REACH compliant per Microchip product page; not AEC-Q100 qualified - choose automotive-grade parts for AEC-Q100 requirements. MSL Level 3 per JEDEC J-STD-020.