ATMEGA64L-8MJ - 8MHz, 64KB Flash AVR MCU | Microchip
MPN: ATMEGA64L-8MJ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.12 | $8.12 |
| 10 | $7.35 | $73.50 |
| 100 | $6.48 | $648.00 |
| 500 | $5.87 | $2,935.00 |
| 1,000 | $5.31 | $5,310.00 |
ATMEGA64L-8MJ Overview
An 8-bit AVR microcontroller is a Harvard-architecture processor that executes most instructions in a single clock cycle, combining a RISC CPU core with on-chip FLASH program memory, SRAM data memory, and EEPROM for non-volatile storage. Within the power-management hierarchy, it functions as a complete embedded system-on-chip, replacing discrete CPU, memory, and peripheral logic in cost- and power-sensitive designs.
Key differentiating features include 53 programmable I/O lines, an internal RC oscillator that simplifies system clock design, and connectivity through I2C (Two-Wire Interface), SPI, and UART/USART serial interfaces. The AVR core's single-cycle instruction execution provides roughly 8 MIPS throughput at the maximum 8MHz clock, and the device offers ATmega103 compatibility mode selected by a fuse, plus a global pull-up disable for I/O power optimization.
Architecturally, the ATmega64L pairs its AVR RISC core with a rich peripheral set including an 8-channel 10-bit ADC, timers with PWM outputs, and hardware serial ports. The L-suffix speed grade limits operation to 0-8MHz but enables the wide 2.7V-5.5V operating range, distinguishing it from the standard ATmega64 (4.5V-5.5V, up to 16MHz).
Typical applications include industrial automation controllers, HVAC and building management systems, sensor data-acquisition nodes, and 3.3V portable or battery-powered instruments where the low-voltage supply range and internal oscillator reduce board cost and component count.
When designing with this device, remember the 8MHz ceiling at reduced supply voltages: below 4.5V, clock frequency must stay within the L-grade envelope to guarantee margin. Decouple VCC and AVCC separately for clean ADC results.
This page synthesizes verified distributor data, drop-in alternatives, and practical design guidance not found in a single datasheet.
Drop-in alternatives for ATMEGA64L-8MJ — 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 ATMEGA64L-8MJ (same form factor and footprint) — differing in Package, EEPROM Size, Operating Temperature, Program Memory Size, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA64A-MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.42 / Unit
View Datasheet →ATMEGA64A-MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.42 / Unit
View Datasheet →ATMEGA64L-8MU
✅ Drop-In✓ In Stock
$3.72 / Unit
View Datasheet →ATMEGA64L-8MI
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA64-16MI
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.48 / Unit
View Datasheet →ATMEGA64L-8MJ Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Program Memory Size | 64KB (32K x 16) FLASH |
| SRAM Size | 4KB |
| EEPROM Size | 2KB |
| Maximum Clock Frequency | 8MHz |
| Operating Voltage Range | 2.7V to 5.5V |
| Number of I/O Lines | 53 Programmable I/O |
| Communication Interfaces | I2C, SPI, UART/USART |
| Internal Oscillator | Yes |
| Package | 64-QFN/MLF (9x9 mm) |
| Mounting Type | Surface Mount |
| ATmega103 Compatibility Mode | Yes (fuse-selectable) |
| Global Pull-up Disable | Yes |
| Throughput | up to 8 MIPS at 8MHz |
| Operating Temperature | -40C to +85C (industrial) |
| RoHS Status | Compliant (green, per distributor listing) |
| Speed Grade Series | ATmega64L: 0 - 8MHz |
ATMEGA64L-8MJ 64-qfn/mlf (9x9 mm) Pin Configuration Guide
Pin configuration for ATMEGA64L-8MJ (64-qfn/mlf (9x9 mm) 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 ATMEGA64L-8MJ.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA64L-8MJ is suitable for 6 applications: Industrial Automation Controllers, Sensor Data Acquisition Nodes, HVAC and Building Management Systems, Battery-Powered Portable Instruments, Consumer Appliance Control Boards, Embedded Communication and Gateway Modules.
Industrial Automation Controllers
The ATMEGA64L-8MJ fits industrial controller boards that need substantial program memory and multiple serial links in one device. Its 64KB FLASH holds protocol stacks and HMI logic, while two USARTs plus SPI and I2C drive fieldbus transceivers, operator displays, and sensors concurrently. The 53 programmable I/O lines interface relays, limit switches, and encoders directly, and the 8-channel 10-bit ADC reads analog process signals such as 4-20mA-derived voltages. The industrial temperature rating and QFN/MLF package withstand control-cabinet environments, and the internal oscillator removes clock-component cost in non-timing-critical sequences. Placed as the main controller with SPI-connected EEPROM or I2C I/O expanders, it delivers roughly 8 MIPS - sufficient for state machines and polling loops typical of PLC-lite and pump/valve sequencing applications.
Recommended
Sensor Data Acquisition Nodes
For distributed data-acquisition nodes, the ATMEGA64L-8MJ combines its 8-channel 10-bit ADC with the low-voltage 2.7V-5.5V supply range, letting one rail power the MCU and 3.3V sensors without level shifters. The 64KB FLASH accommodates local filtering, scaling, and burst-buffering firmware, while the 4KB SRAM holds sample buffers for interrupted acquisition. SPI links to precision ADCs or SD-card storage, and the USART streams results over RS-485 or wireless modules. The internal oscillator suits timestamp-tolerant logging, and the global pull-up disable trims leakage in battery-backed installations. Deployed as a remote node polling I2C humidity or pressure sensors at 100-400kHz, it balances cost, power, and I/O flexibility, with EEPROM storing calibration coefficients through power cycles.
Recommended
HVAC and Building Management Systems
Building automation controllers benefit from the ATMEGA64L-8MJ's combination of generous memory and multi-interface connectivity. The 64KB FLASH stores scheduling, PID control, and communication firmware, while the 2KB EEPROM keeps setpoints and schedules across power outages. UART/USART links to RS-485 building networks, I2C reads temperature and humidity sensors, and the ADC samples thermistors and pressure switches. The 2.7V-5.5V range simplifies designs powered from 3.3V standby rails, and the industrial temperature rating covers rooftop and mechanical-room environments. In typical deployments the device runs damper and valve sequencing from its 53 I/O lines, with the 8MHz clock providing ample headroom for multi-loop PID updates in the tens-of-milliseconds range expected by comfort-control algorithms.
Recommended
Battery-Powered Portable Instruments
The L-grade ATMEGA64L-8MJ operates directly from 2.7V supplies, allowing two-cell battery or single lithium-cell operation through an LDO without 5V conversion. The internal oscillator eliminates a crystal and its drive current, and the global pull-up disable plus fuse options reduce static consumption between measurements. Its 64KB FLASH supports menu-driven UI firmware, and the 4KB SRAM buffers data-logger sessions between EEPROM or card writes. The 8MHz clock is sufficient for sampling instruments such as handheld meters, environmental monitors, and portable test adapters, where the 10-bit ADC digitizes user-adjusted or sensor inputs. Designers should use sleep modes between conversions and clock the USART from a crystal only when precise baud rates are needed, trading slight power for timing accuracy.
Recommended
Consumer Appliance Control Boards
Appliance controllers - washers, ovens, and small HVAC units - use the ATMEGA64L-8MJ for its balance of program space and peripheral count. The 64KB FLASH hosts button debouncing, display multiplexing, and safety-interlock firmware with room for localization strings, while 53 I/O lines drive seven-segment stacks, relays, triac triggers, and encoder inputs. The 2KB EEPROM retains user preferences and cycle counters, and the industrial temperature range tolerates enclosed, warm compartments. The QFN/MLF 9x9 mm package suits compact single-board controllers, and ATmega103 compatibility mode eases migration of legacy appliance designs. Running at 8MHz from an internal RC oscillator, the device handles keypad scanning and PWM heater or motor control loops typical of appliance timing requirements without external timing components.
Recommended
Embedded Communication and Gateway Modules
The ATMEGA64L-8MJ serves as a protocol-conversion and gateway MCU where two USARTs, SPI, and I2C must coexist: bridging RS-232 service ports to RS-485 fieldbuses, or translating between I2C sensor clusters and SPI-connected radio modules. The 64KB FLASH fits buffer management plus multiple protocol parsers, and the 4KB SRAM provides FIFO space for burst traffic - critical when a 115200-baud link feeds a slower downstream bus. The internal oscillator suffices for tolerant links, while the L-grade supply range matches 3.3V radio modules directly. Designers typically attach the wireless or line transceiver via USART with flow control emulated in software, and use EEPROM to store node addresses and pairing data. The 8 MIPS budget comfortably handles framing, CRC, and queue logic for low-rate industrial telemetry.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA64L-8MJ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA64L-8MU | ATMEGA64A-MU | ATMEGA64L-8MI | ATMEGA64-16MI |
|---|---|---|---|---|---|
| Package | 64-QFN/MLF (9x9 mm) | 64-QFN/MLF (9x9 mm) - same | 64-QFN/MLF (9x9 mm) - same | 64-QFN/MLF (9x9 mm) - same | 64-QFN/MLF (9x9 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| FLASH Memory | 64KB (32K x 16) | 64KB | 64KB | 64KB | 64KB |
| SRAM | 4KB | 4KB | 4KB | 4KB | 4KB |
| Max Clock Frequency | 8MHz | 8MHz | 16MHz (at 5V) | 8MHz | 16MHz |
| Operating Voltage | 2.7V to 5.5V | 2.7V to 5.5V | 2.7V to 5.5V (L grade) / 4.5V-5.5V (16MHz grade) | 2.7V to 5.5V | 4.5V to 5.5V |
| I/O Lines | 53 | 53 | 53 | 53 | 53 |
| Interfaces | I2C, SPI, UART/USART | I2C, SPI, UART/USART | I2C, SPI, UART/USART | I2C, SPI, UART/USART | I2C, SPI, UART/USART |
| Lifecycle / Availability | Active (in stock at DigiKey as of 2026-09-18) | Active (listed on FindIC as replace part) | Active - recommended successor | Active | Active |
Key Differentiators
- True low-voltage operation down to 2.7V (vs ATMEGA64-16MI)
- Refreshed successor availability with same footprint (vs ATMEGA64A-MU)
- Internal oscillator reduces BOM and board area (vs ATMEGA64L-8AU)
Design Notes
The ATmega64L speed grade is clock-frequency dependent on supply voltage. Per the Atmel-2490 datasheet family structure, the L grade (0-8MHz) is guaranteed from 2.7V to 5.5V, while full-speed ATmega64 operation (up to 16MHz) requires 4.5V-5.5V. If your board runs at 3.3V, keep the system clock at or below 8MHz; if you need 16MHz, you must run at 5V or select a different part. Violating the frequency-versus-voltage derating causes marginal timing and unreliable FLASH execution.
Decouple VCC and AVCC independently. The QFN/MLF 64-pad package exposes power through pad 18-class supply pins and a die-attach pad, so place 100nF ceramic capacitors directly at each supply pin with a solid ground plane, and connect AVCC to VCC through an LC or RC filter (e.g., 10uH/100nF) when the 10-bit ADC is used. The exposed pad should be soldered to a grounded thermal array - leaving it floating degrades ground integrity and thermal performance. Estimated: a 100nF cap within 3mm of each supply pin keeps high-frequency rail noise below 50mV in typical 5V designs.
Do not confuse package variants when sourcing: ATMEGA64L-8AU/-8AQ are 64-lead TQFP, while -8MJ/-8MU/-8MI are 64-pad QFN/MLF - they are electrically identical but not footprint-compatible. Also remember the PEN pin (programming enable) is active-low sampled at reset and needs a pull-up on JTAG/ISP-programmed boards. For migration to ATmega64A, verify fuse defaults and the retained 2.7V low-voltage operating point, as A-series datasheet derating tables differ slightly from the original ATmega64L.
Compliance Information
Distributor listings (FindIC/DigiKey) describe the ATMEGA64L-8MJ family as GREEN/RoHS-compliant. REACH and halogen-free status not stated in provided data.
