ATMEGA1284-MUR - 8-bit AVR MCU, 128KB Flash, 20MHz | Microchip
MPN: ATMEGA1284-MUR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.22 | $2.22 |
| 10 | $2.1 | $21.00 |
| 100 | $1.98 | $198.00 |
| 500 | $1.85 | $925.00 |
| 1,000 | $1.72 | $1,720.00 |
ATMEGA1284-MUR Overview
An 8-bit AVR microcontroller is a single-chip computer built on the AVR enhanced RISC architecture, in which most of its instructions execute in a single clock cycle to deliver throughput approaching one MIPS per megahertz. Within the power-management and embedded-processing hierarchy, the ATmega family sits in the broad microcontroller (MCU) class, alongside competitors such as the PIC, STM8, and 8051 cores. The ATMEGA1284-MUR belongs to the ATmega164A/PA/324A/PA/644A/PA/1284/P family documented in the shared Microchip (Atmel) datasheet.
Key features include the 128KB self-programmable flash with read-while-write capability, 16KB of internal SRAM (the largest in the ATmega 44-pin family), 4KB EEPROM for non-volatile parameter storage, and 32 general-purpose I/O lines with 32 general-purpose working registers. Peripherals comprise two flexible USARTs, an SPI interface, a two-wire (I2C) interface, an 8-channel 10-bit ADC, a real-time counter, and three timer/counters with compare modes and PWM.
Technically, the device implements 133 powerful instructions, most executed in single clock cycle, with optional Harvard-architecture code and data buses. Operating voltage covers 2.5V, 3.3V, and 5V systems (per distributor parametric data), allowing direct interfacing with 5V industrial logic or battery-friendly 3.3V designs. ISP and parallel programming plus boot-section self-programming enable field firmware updates without removing the chip from the PCB.
Typical applications include industrial control and automation nodes, embedded systems requiring large SRAM buffers such as graphic LCD controllers and Ethernet-attached sensors, and hobbyist or educational platforms - the MightyCore Arduino hardware package explicitly supports the ATmega1284. The 44-VQFN footprint suits compact, two-layer and four-layer industrial PCBs.
When designing with this device, place a 100nF ceramic decoupling capacitor at each VCC/AVCC pin pair close to the package, and route the exposed pad to a solid ground plane for thermal and EMC performance. Remember that the ADC reference and AVCC supply should be filtered separately from digital VCC for best analog accuracy.
This page synthesizes distributor pricing (LCSC from $2.2196), drop-in alternatives within the ATmega 44-pin family, pinout guidance, and practical design notes not consolidated on the manufacturer datasheet alone. Pricing references are as of 2026-09-15.
Drop-in alternatives for ATMEGA1284-MUR β 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 ATMEGA1284-MUR (same form factor and footprint) β differing in Package, EEPROM, SRAM, ADC, Core Processor.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA1284P-MUR
β Drop-Inβ In Stock
Contact for price
View Datasheet βATMEGA644PA-MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA324PA-MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA164PA-MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$2.89 / Unit
View Datasheet βATMEGA1284-MUR Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 20 MHz |
| Flash Memory | 128 KB (64K x 16) |
| SRAM | 16 KB |
| EEPROM | 4 KB |
| Operating Voltage | 2.5 V / 3.3 V / 5 V |
| Number of I/O | 32 |
| Connectivity | I2C, SPI, UART/USART |
| USARTs | 2 |
| ADC Resolution | 10-bit |
| Timers | 3 x timer/counter with compare modes and PWM |
| Real-Time Counter | Yes |
| Package | 44-VQFN (7x7 mm) with exposed pad |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (TR) |
| Product Status | Active |
| Architecture | AVR enhanced RISC, 133 instructions, mostly single-cycle |
ATMEGA1284-MUR 44-vqfn (7x7 mm) with exposed pad Pin Configuration Guide
Pin configuration for ATMEGA1284-MUR (44-vqfn (7x7 mm) with exposed pad package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for ATMEGA1284-MUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA1284-MUR is suitable for 6 applications: Industrial Control and Automation, IoT Sensor Nodes and Gateways, Graphic LCD and HMI Controllers, Home Appliance Control, Battery-Powered Portable Instruments, Educational and Maker Embedded Systems.
Industrial Control and Automation
The ATMEGA1284-MUR fits industrial control nodes that must bridge multiple serial protocols: its two USARTs, SPI, and I2C interfaces allow simultaneous RS-485 fieldbus, sensor SPI, and HMI I2C communication, while 5V-tolerant GPIO logic directly drives PLC-style I/O. The 128KB flash accommodates larger protocol stacks and OTA-capable bootloaders, and the 16KB SRAM buffers telemetry frames that smaller ATmega parts cannot hold. Operating across 2.5V/3.3V/5V supplies, it integrates into legacy 5V cabinets without level shifting. Placed on a four-layer PCB with the exposed pad grounded, it delivers reliable operation in noisy factory environments where its watchdog timer and brown-out detection maintain system integrity through supply dips.
Recommended
IoT Sensor Nodes and Gateways
For IoT sensor nodes, the ATMEGA1284-MUR offers the SRAM headroom (16KB) that mesh-network and TCP/IP light stacks require - packet buffers, TLS-fragment staging, and JSON serialization often exceed the 2KB of an ATmega328P. Its 10-bit ADC samples up to eight analog sensors, and the two USARTs let one port serve a modem (cellular or LoRa) while the other services local diagnostics. At 3.3V operation it pairs cleanly with 3.3V radio modules without level shifters. Battery-powered variants should consider the picoPower ATMEGA1284P-MUR, which is pin-identical, for lower sleep currents; the base ATMEGA1284-MUR suits mains-powered gateways and line-powered hubs where its $2.22 unit price keeps BOM cost low.
Recommended
Graphic LCD and HMI Controllers
Graphic TFT and OLED HMIs demand frame and line buffers that strain small MCUs; the ATMEGA1284-MUR's 16KB SRAM and 128KB flash let it hold glyph tables, localized font sets, and screen-state machines that drop-in smaller ATmegas cannot. Its SPI interface drives common display controllers at multi-MHz clock rates, while a second USART keeps a touch controller or host MCU link independent. PWM timers support backlight dimming with smooth logarithmic curves. In a typical design the MCU is clocked at 16-20MHz from a crystal, with the ADC channel spare for a resistive touch divider. The 7x7mm VQFN keeps the HMI controller board compact enough to mount directly behind the display module.
Recommended
Home Appliance Control
Home appliances - coffee machines, air purifiers, dishwashers - benefit from the ATMEGA1284-MUR's combination of three timer/counters with PWM for heater, fan, and pump control, plus its real-time counter for clock and delayed-start functions. The 4KB EEPROM stores user settings and cycle counters across power cycles without external NVM, and the 10-bit ADC reads NTC temperature sensors and user potentiometers. Its 5V operation directly interfaces with triac-driver optocouplers and relay coils through simple drivers. Firmware safety logic, including watchdog supervision and brown-out reset, meets the robustness expectations of mains-powered white goods. Tape-and-reel packaging supports automated pick-and-place for volume appliance production.
Recommended
Battery-Powered Portable Instruments
Portable instruments - hand-held meters, dataloggers, test gadgets - use the ATMEGA1284-MUR's large SRAM to buffer thousands of ADC samples (16KB holds roughly 8000 x 16-bit readings) before writing to external flash or EEPROM, dramatically reducing write energy versus streaming. Running at 3.3V and reduced clock speeds (8MHz and below), it trades throughput for current in accordance with the AVR frequency-voltage derating curve. The two USARTs let a datalogger stream to both a Bluetooth module and a debug console. Designers targeting multi-year battery life should select the pin-compatible ATMEGA1284P-MUR whose picoPower power-down mode cuts sleep current, keeping the PCB layout unchanged between the two variants.
Recommended
Educational and Maker Embedded Systems
The ATMEGA1284-MUR is a favorite in education and the maker community because the MCUdude MightyCore Arduino hardware package on GitHub explicitly supports the ATmega1284, giving full Arduino IDE, bootloader, and library compatibility. With 128KB flash and 16KB SRAM, students can run larger sketches - Ethernet shields, complex sensor fusion, or multiple SoftwareSerial ports - that exhaust an ATmega328P's 2KB SRAM. The 44-pin VQFN can be adapted to breadboards via TQFP44-to-DIP40 adapter PCBs of the type shared on PCBWay. At roughly $2.22 per unit, it is an economical platform chip for university lab boards, robotics kits, and self-built retrocomputing projects that also need its dual hardware USARTs.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA1284-MUR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA1284P-MUR | ATMEGA644PA-MUR | ATMEGA324PA-MUR | ATMEGA164PA-MUR |
|---|---|---|---|---|---|
| Package | 44-VQFN (7x7 mm) EP, Tape & Reel | 44-VQFN (7x7 mm) EP - same | 44-VQFN (7x7 mm) EP - same | 44-VQFN (7x7 mm) EP - same | 44-VQFN (7x7 mm) EP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 128 KB | 128 KB | 64 KB | 32 KB | 16 KB |
| SRAM | 16 KB | 16 KB | 4 KB | 2 KB | 1 KB |
| EEPROM | 4 KB | 4 KB | 2 KB | 1 KB | 512 B |
| Max Clock Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Low-Power Technology | Standard ATmega | picoPower | picoPower | picoPower | picoPower |
| USART Count | 2 | 2 | 2 | 2 | 1 |
Key Differentiators
- Largest SRAM in the 44-pin ATmega family (vs ATMEGA324PA-MUR)
- More cost-effective than the picoPower variant for mains-powered designs (vs ATMEGA1284P-MUR)
- Dual hardware USARTs (vs ATMEGA164PA-MUR)
Design Notes
The ATMEGA1284-MUR comes in a 44-pin VQFN (7x7 mm) with an exposed pad. Solder the exposed pad to a grounded copper pour with an array of thermal vias - this is not optional for reliable reflow, as the pad also anchors the die. Place 100nF ceramic capacitors at every VCC and AVCC pin within 3mm of the pad, plus a 10uF bulk capacitor per supply domain. Keep the crystal within 10mm of the XTAL pins with short ground-guarded traces for stable 20MHz operation.
Supply the part at 5V when driving 5V industrial peripherals, or 3.3V for battery and 3.3V radio designs; note that the maximum safe clock frequency is derated at lower supply voltages per the AVR speed-versus-voltage curve in the family datasheet - do not run 20MHz at the low end of the voltage range. Separate AVCC from digital VCC through an RC or ferrite filter (e.g., 10 ohm + 100nF) to preserve 10-bit ADC accuracy, and connect AGND to a quiet analog ground island.
Do not confuse the suffix variants: -MUR is tape-and-reel VQFN, -MU is tray VQFN, and -AU is TQFP - the TQFP part will not fit the VQFN footprint. When substituting with ATmega644/324/164 family members, verify flash and SRAM headroom first, since code that fits 128KB will not link against 32KB parts. Enable the watchdog and brown-out detector fuses in production; AVR parts ship with BOD disabled by default, and unattended industrial nodes without watchdog protection can hang in the field.
Compliance Information
Compliance status was not stated in the provided verified web data; consult the official Microchip product page or environmental data sheet for RoHS/REACH confirmation.
