ATMEGA8L-8MJ - 8MHz AVR MCU, 8KB Flash, 32-VQFN | Microchip
MPN: ATMEGA8L-8MJ ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
ATMEGA8L-8MJ Overview
A microcontroller unit (MCU) is a single integrated circuit that combines a processor core, program memory, data memory, and peripherals into one chip, forming the lowest tier of the embedded computing hierarchy (MCU -> embedded processor -> system-on-chip). The ATmega8 family is part of the AVR line, a modified Harvard-architecture 8-bit RISC family originally developed by Atmel, now owned by Microchip Technology after their 2016 acquisition.
The ATMEGA8L-8MJ executes 130 powerful instructions, most in a single clock cycle, achieving close to 1 MIPS per MHz. The L suffix denotes the low-voltage grade (operation below the standard 4.5V floor of the ATmega8), and the internal oscillator option removes the need for an external crystal in cost- or space-sensitive designs. On-chip peripherals include brown-out detection and reset, power-on reset, PWM outputs, and a watchdog timer.
Architecturally, the device provides 32 general-purpose working registers directly connected to the ALU, three flexible Timer/Counters with compare modes, a byte-oriented Two-wire Serial Interface (I2C/TWI), a serial programmable USART, and SPI. A 6-channel ADC and Read-While-Write FLASH programming round out the feature set, per the Atmel ATmega8/L datasheet (Atmel-2486).
Typical applications include industrial control nodes, sensor and instrumentation boards, hobby and educational embedded systems, and legacy replacement designs where a compact 5x5 mm QFN footprint and 3.3V-friendly operation are required.
Design consideration: because this part is obsolete, new designs should target the ATmega8A family or pin-compatible successors, and existing BOMs should secure stock or qualify a drop-in alternative such as ATMEGA8L-8MU before layout freeze.
This page synthesizes distributor cross-reference data, packaging details, drop-in alternative analysis, and practical sourcing guidance not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA8L-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 ATMEGA8L-8MJ (same form factor and footprint) — differing in EEPROM Size, Oscillator Type, Package, Program Memory Size, RAM Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA8L-8MU
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA8A-MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$0.7 / Unit
View Datasheet →ATMEGA8-16MJ
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.98 / Unit
View Datasheet →ATMEGA8L-8MJ Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 8 MHz |
| Program Memory Size | 8KB (4K x 16) |
| Program Memory Type | FLASH |
| EEPROM Size | 512 x 8 |
| RAM Size | 1K x 8 |
| Number of I/O | 23 |
| Connectivity | I2C, SPI, UART/USART |
| Peripherals | Brown-out Detect/Reset, POR, PWM, WDT |
| Oscillator Type | Internal |
| Package / Case | 32-VFQFN Exposed Pad (5x5 mm) |
| Mounting Type | Surface Mount |
| Packaging | Tray |
| Part Status | Obsolete |
| Series | AVR ATmega |
ATMEGA8L-8MJ 32-vfqfn exposed pad (5x5 mm) Pin Configuration Guide
Pin configuration for ATMEGA8L-8MJ (32-vfqfn exposed pad (5x5 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 ATMEGA8L-8MJ.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA8L-8MJ is suitable for 6 applications: Industrial Control Nodes, Sensor and Instrumentation Boards, Legacy Replacement and Repair, Embedded Education and Prototyping, Motor Control and PWM Loads, Communication Interface Bridges.
Industrial Control Nodes
The ATMEGA8L-8MJ fits industrial control and monitoring nodes where a compact 5x5 mm 32-VFQFN footprint, 23 GPIO lines, and on-chip brown-out detection plus watchdog timer are required. Its 8KB ISP FLASH with Read-While-Write supports field firmware updates over the TWI (I2C) or SPI bus, while the internal oscillator removes the cost and layout impact of an external crystal in noise-tolerant control loops. PWM peripherals directly drive actuators and dimming loads without additional companion ICs. Because the part is obsolete, use it for sustaining existing installations only; for new industrial designs, Microchip's ATmega8A or ATmega328PB families provide the same peripheral set with active lifecycle status and better availability.
Recommended
Sensor and Instrumentation Boards
Sensor acquisition boards benefit from the ATMEGA8L-8MJ's 6-channel ADC, TWI and SPI buses for connecting external converters, and 1KB SRAM for buffering samples. The low-voltage L-grade operation suits 3.3V battery-powered instruments, and the internal oscillator option keeps the BOM minimal in cost-sensitive designs. The USART provides a simple telemetry link to host systems, while brown-out reset guarantees deterministic recovery during supply dips. In such designs, the exposed ground pad of the QFN package also provides a low-inductance ground reference that benefits ADC noise performance. For new instrumentation projects, select ATMEGA8A-MU, which retains the footprint while adding improved analog characteristics documented in the ATmega8A datasheet.
Recommended
Legacy Replacement and Repair
Repair and sustaining engineering for legacy ATmega8-based equipment is the primary remaining use case for the ATMEGA8L-8MJ. Because the ATmega8 die has been in the field for two decades, a large installed base of industrial, automotive aftermarket, and consumer boards still depends on it. ATMEGA8L-8MJ, or its identical drop-in ATMEGA8L-8MU, restores function with zero firmware or layout changes. When only a 5V supply exists, ATMEGA8-16MJ is also pin-compatible. Buyers should verify date codes and authenticity through reputable broker channels since obsolete AVRs are a known counterfeit target, and Octopart currently lists three distributor sources for price comparison.
Recommended
Embedded Education and Prototyping
The AVR ATmega8 architecture is a staple of embedded-systems education: 130 mostly single-cycle RISC instructions, 32 working registers, and a well-documented register map make it an excellent teaching platform. The 32-VFQFN package, however, is harder to hand-solder than the DIP variant, so educational use of the -8MJ specifically targets pre-assembled modules and SMD assembly labs. Its I2C, SPI, and UART peripherals allow students to exercise all common embedded buses on one chip, and the ISP FLASH supports quick reprogramming without a socket. For new course material, base the curriculum on the ATmega8A to guarantee parts availability while keeping all existing lab code compatible.
Recommended
Motor Control and PWM Loads
The ATMEGA8L-8MJ's three Timer/Counters with compare modes generate PWM outputs for small motor drives, LED dimming, and heater control without external PWM ICs. Timer1 provides a 16-bit PWM channel suitable for fine-grained duty control, while the watchdog timer adds a safety layer for stalled-loop recovery in actuator applications. The 8MHz internal clock is sufficient for low-speed PWM work, and the 23 I/O lines leave headroom for limit switches and encoder inputs. Thermal design is simple at MCU power levels, but ensure the exposed QFN pad is grounded to sink die heat. For new motor-control nodes, the active ATMEGA8A-MU provides the same timers with a fully supported lifecycle.
Recommended
Communication Interface Bridges
With hardware I2C (Two-wire Serial Interface), SPI, and a USART on one chip, the ATMEGA8L-8MJ works well as a protocol bridge or gateway between subsystems - for example, translating UART telemetry from a modem to an I2C sensor bus, or buffering SPI flash data. The 1KB SRAM provides adequate packet buffering for low-speed links, and the byte-oriented TWI supports multi-master configurations per the Atmel-2486 datasheet. The 8MHz core executes roughly 1 MIPS per MHz, enough for software framing and checksums at modest data rates. New bridge designs should start on the ATMEGA88PA or ATmega328 family for larger RAM and PCINT flexibility, keeping the same MLF32 mechanical footprint where needed.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA8L-8MJ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA8L-8MU | ATMEGA8A-MU | ATMEGA8-16MJ |
|---|---|---|---|---|
| Package | 32-VFQFN Exposed Pad (5x5 mm) | 32-VFQFN Exposed Pad (5x5 mm) - same | 32-VFQFN Exposed Pad (5x5 mm) - same | 32-VFQFN Exposed Pad (5x5 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Lifecycle Status | Obsolete | Obsolete | Active | Obsolete |
| Max Speed | 8 MHz | 8 MHz | 8 MHz (L grade) | 16 MHz |
| Program Memory | 8KB (4K x 16) FLASH | 8KB (4K x 16) FLASH | 8KB (4K x 16) FLASH | 8KB (4K x 16) FLASH |
| SRAM | 1KB | 1KB | 1KB | 1KB |
| Number of I/O | 23 | 23 | 23 | 23 |
| Supply Voltage Class | Low-voltage L grade (3.3V-capable) | Low-voltage L grade (3.3V-capable) | Wide-range 8A grade (3.3V-capable) | Standard grade (5V systems) |
Key Differentiators
- Identical drop-in availability via ATMEGA8L-8MU (vs ATMEGA8L-8MU)
- Active lifecycle with ATMEGA8A-MU (vs ATMEGA8A-MU)
- 3.3V-capable L grade versus 5V-only standard grade (vs ATMEGA8-16MJ)
Design Notes
The 32-VFQFN exposed pad requires a centered ground land pattern with an array of thermal vias to the ground plane. The exposed pad is the primary ground connection and thermal path for the die; an ungrounded or poorly wetted pad is a leading cause of intermittent resets and ADC noise on MLF-package AVRs. Follow the MLF land-pattern recommendations in the Atmel-2486 ATmega8/L datasheet and inspect the pad joint with X-ray for critical builds.
Because this part is obsolete, every new purchase carries counterfeit and date-code risk: insist on certificates of conformance, buy from franchised distributors where stock remains, and plan a last-time-buy sized to your remaining product lifetime. Qualify ATMEGA8A-MU as the long-term drop-in now rather than after broker stock disappears - the ATmega8A is documented by Microchip as the successor device in the same 32-VQFN footprint.
As an L-grade (low-voltage) device, the ATMEGA8L-8MJ targets low-voltage rails, so verify your supply class before substituting: the standard-grade ATMEGA8-16MJ is not rated for the same low-voltage operation. Decouple VCC and AVCC with 100nF ceramics placed within a few millimeters of the pins, and tie AVCC to VCC through a low-pass filter if ADC accuracy matters. Enable brown-out detection via fuse settings to guarantee deterministic behavior during supply transients.
Keep the crystal (if used) within a few millimeters of the XTAL1/XTAL2 pins over a solid ground plane; the internal oscillator option can be fused instead to free two I/O-adjacent pins. Route the TWI (I2C) bus with pull-ups sized for bus capacitance and keep SPI clock lines away from the ADC reference routing. For ISP programming, reserve header access to MOSI, MISO, SCK, and RESET during layout so field firmware updates remain possible.
Compliance Information
Compliance status not explicitly stated in verified web data for this specific MPN. One third-party comparison describes the ATmega8L QFN family as GREEN, but no manufacturer certificate was retrieved; confirm per date code with the supplier.
