ATMEGA8L-8AU - 8-Bit AVR MCU 8KB Flash 8MHz | Microchip
MPN: ATMEGA8L-8AU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.85 | $2.85 |
| 10 | $2.56 | $25.60 |
| 100 | $2.28 | $228.00 |
| 500 | $2.05 | $1,025.00 |
| 1,000 | $1.82 | $1,820.00 |
ATMEGA8L-8AU Overview
An AVR microcontroller is a Harvard-architecture 8-bit MCU that executes most instructions in a single clock cycle, combining Flash program memory, SRAM data memory, and EEPROM non-volatile storage on one die. Within the product hierarchy, the ATmega8L sits under AVR 8-bit microcontrollers, which fall under general-purpose MCUs, which are part of the broader embedded processor and semiconductor category. The 'L' suffix denotes the low-voltage 2.7-5.5 V version, while '8' indicates 8 MHz maximum clock and 'AU' the TQFP package with industrial temperature range.
Key differentiators include 130 powerful instructions with most executing in a single clock cycle, 8 KB Flash with 10,000 write/erase cycles endurance, 512 bytes EEPROM with 100,000 cycles, and a programmable watchdog timer with on-chip oscillator. The device supports ISP programming via SPI and offers five sleep modes for power-sensitive designs.
Architecturally, the ATmega8L uses a single-cycle RISC core with 32 general-purpose working registers directly connected to the ALU, achieving throughput approaching 1 MIPS per MHz. This allows system designers to optimize power consumption versus processing speed - a critical trade-off in battery-powered embedded systems.
Typical applications include industrial control loops, IoT sensor nodes, motor control, metering equipment, embedded automation, and low-power board designs. The integrated 10-bit ADC and PWM channels make it well-suited for analog sensor interfacing and motor drive control without external components.
When designing with the ATMEGA8L-8AU, ensure the decoupling capacitors are placed within 5 mm of the VCC pins and use a 16 MHz crystal or ceramic resonator only if the 8 MHz internal calibrated oscillator accuracy is insufficient. The internal RC oscillator eliminates external components for cost-sensitive designs.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, providing engineers with a single reference for procurement and design decisions.
Drop-in alternatives for ATMEGA8L-8AU 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 ATMEGA8L-8AU (same form factor and footprint) β differing in Package, Maximum Clock Frequency, Core Architecture, Operating Temperature, ADC Resolution.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA8A-AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA88V-10AU
β Drop-Inβ In Stock
$1.58 / Unit
View Datasheet βATMEGA88PA-AUR
β Drop-Inβ In Stock
$0.82 / Unit
View Datasheet βATMEGA8-16AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA88A-AU
β Drop-Inβ In Stock
$1.52 / Unit
View Datasheet βATMEGA8L-8AU Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Program Memory Size | 8 KB Flash (4K x 16) |
| Flash Endurance | 10,000 write/erase cycles |
| SRAM | 1 KB |
| EEPROM | 512 bytes |
| EEPROM Endurance | 100,000 write/erase cycles |
| Maximum Clock Frequency | 8 MHz |
| Throughput | Up to 8 MIPS at 8 MHz |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Operating Temperature | -40 C to +85 C |
| Programmable I/O Lines | 23 |
| ADC Resolution | 10-bit, 8 channels |
| Timers | Two 8-bit, one 16-bit |
| PWM Channels | 3 (two 8-bit, one 16-bit) |
| Communication Interfaces | SPI, USART, TWI (I2C) |
| Package | 32-TQFP (7x7 mm) |
| Mounting Type | Surface Mount |
| Instruction Set | 130 powerful instructions |
| Sleep Modes | 5 (Idle, ADC Noise Reduction, Power-save, Power-down, Standby) |
| RoHS Status | Compliant |
ATMEGA8L-8AU Pin Configuration
| Pin 1 | PB0 β Port B, bit 0 (ICP1) |
| Pin 2 | PB1 β Port B, bit 1 (OC1A) |
| Pin 3 | PB2 β Port B, bit 2 (SS/OC1B) |
| Pin 4 | PB3 β Port B, bit 3 (MOSI/OC2) |
| Pin 5 | PB4 β Port B, bit 4 (MISO) |
| Pin 6 | PB5 β Port B, bit 5 (SCK) |
| Pin 7 | PB6 β Port B, bit 6 (XTAL1/TOSC1) |
| Pin 8 | PB7 β Port B, bit 7 (XTAL2/TOSC2) |
| Pin 9 | RESET β Reset input (active low) |
| Pin 10 | VCC β Digital supply voltage |
| Pin 11 | GND β Ground |
| Pin 12 | XTAL2 β Crystal oscillator output |
| Pin 13 | XTAL1 β Crystal oscillator input |
| Pin 14 | PD0 β Port D, bit 0 (RXD) |
| Pin 15 | PD1 β Port D, bit 1 (TXD) |
| Pin 16 | PD2 β Port D, bit 2 (INT0) |
| Pin 17 | PD3 β Port D, bit 3 (INT1) |
| Pin 18 | PD4 β Port D, bit 4 (OC1B) |
| Pin 19 | PD5 β Port D, bit 5 (OC1A) |
| Pin 20 | PD6 β Port D, bit 6 (OC0) |
| Pin 21 | PD7 β Port D, bit 7 |
| Pin 22 | PC0 β Port C, bit 0 (ADC0) |
| Pin 23 | PC1 β Port C, bit 1 (ADC1) |
| Pin 24 | PC2 β Port C, bit 2 (ADC2) |
| Pin 25 | PC3 β Port C, bit 3 (ADC3) |
| Pin 26 | PC4 β Port C, bit 4 (ADC4) |
| Pin 27 | PC5 β Port C, bit 5 (ADC5) |
| Pin 28 | PC6 β Port C, bit 6 (RESET) |
| Pin 29 | PC7 β Port C, bit 7 |
| Pin 30 | AVCC β Analog supply voltage |
| Pin 31 | GND β Ground |
| Pin 32 | AREF β Analog reference voltage |
Typical Applications
ATMEGA8L-8AU is suitable for 6 applications: Industrial Control Systems, IoT Sensor Nodes, Motor Control, Metering Equipment, Embedded Automation, Low-Power Board Designs.
Industrial Control Systems
The ATMEGA8L-8AU fits industrial control loops because its 8 KB Flash and 1 KB SRAM accommodate PLC ladder-logic interpreters and Modbus RTU stacks, while the 23 I/O lines directly drive opto-isolated relay outputs. Operating from 2.7-5.5 V, it interfaces with 24 V industrial sensors through simple resistor dividers and the integrated 8-channel 10-bit ADC. The 8 MHz clock provides 8 MIPS throughput, sufficient for 1 kHz PID control loops. Placed on a 4-layer PCB with ground plane, the device's 5 sleep modes reduce average current to under 1 mA in cyclic-sleep control applications, unlike always-on Cortex-M0 designs that consume 3-5 mA continuously.
Recommended
IoT Sensor Nodes
The ATMEGA8L-8AU suits battery-powered IoT sensor nodes because its 2.7 V minimum supply allows direct operation from 3.3 V Li-Ion cells without a boost converter, and Power-down mode draws under 1 uA to extend battery life to years. The 8-channel 10-bit ADC digitizes temperature, humidity, and pressure sensors directly, while the TWI (I2C) interface connects to external EEPROM or digital sensors. At 8 MHz and 3 V, active current is approximately 3.6 mA, so a 2000 mAh cell supports over 500 hours of continuous sampling. The 32-TQFP package occupies only 49 mm2, fitting compact wireless sensor enclosures.
Recommended
Motor Control
The ATMEGA8L-8AU handles brushed DC and stepper motor control because its 16-bit Timer1 generates precise PWM with 3 independent channels, and the 10-bit ADC reads current-sense shunts for closed-loop torque control. At 8 MHz, the PWM resolution at 20 kHz switching frequency is 8 bits, adequate for fan and pump drives. The 23 I/O lines drive H-bridge gate drivers directly through 10 ohm series resistors. Unlike dedicated motor-control MCUs, the ATMEGA8L adds no hardware dead-time insertion, so external gate drivers with built-in dead-time are recommended for half-bridge topologies to prevent shoot-through.
Recommended
Metering Equipment
The ATMEGA8L-8AU is used in utility metering because its 10-bit ADC and 8 MHz core sample voltage and current channels at 1 kHz for energy calculation, while the 512-byte EEPROM stores calibration coefficients and accumulated kWh readings with 100,000-cycle endurance. The 2.7-5.5 V supply supports both 3.3 V and 5 V metering front-ends. In a single-phase meter, the MCU multiplies instantaneous voltage and current samples to compute real power, then accumulates energy in SRAM. The integrated USART enables optical IrDA or RS-485 communication for AMR (automatic meter reading) without external UART bridges.
Recommended
Embedded Automation
The ATMEGA8L-8AU serves embedded automation controllers because its 130-instruction RISC core executes most operations in one clock cycle, delivering deterministic 125 ns instruction timing at 8 MHz for time-critical sequencing. The 23 I/O lines and three timers coordinate conveyor belts, solenoid valves, and limit switches. With 8 KB Flash, a compact state-machine firmware fits comfortably, and the 1 KB SRAM buffers sensor queues. The device's 5 sleep modes allow idle-current reduction between automation cycles. For 24 V factory floors, a 5 V LDO such as the MCP1700 powers the MCU from the 24 V bus through a buck pre-regulator.
Recommended
Low-Power Board Designs
The ATMEGA8L-8AU targets low-power board designs because its 2.7 V minimum supply and sub-1 uA Power-down current enable multi-year operation from coin cells. The internal 8 MHz calibrated RC oscillator eliminates external crystals, reducing BOM cost and board area in cost-sensitive designs. At 1 MHz (divided clock), active current drops to approximately 0.5 mA at 3 V, allowing continuous sensor polling from a CR2032 cell for months. The 32-TQFP package's 0.8 mm pitch is hand-solderable with drag-soldering techniques, unlike finer-pitch QFN packages, simplifying prototyping and small-batch production.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA8L-8AU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA8A-AU | ATMEGA88V-10AU | ATMEGA88PA-AU | ATMEGA8-16AU |
|---|---|---|---|---|---|
| Package | 32-TQFP (7x7) | 32-TQFP (7x7) - same | 32-TQFP (7x7) - same | 32-TQFP (7x7) - same | 32-TQFP (7x7) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Maximum Clock Frequency | 8 MHz | 16 MHz | 10 MHz | 20 MHz | 16 MHz |
| Supply Voltage Range | 2.7 V to 5.5 V | 4.5 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 4.5 V to 5.5 V |
| Flash Memory | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB |
| SRAM | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB |
| EEPROM | 512 bytes | 512 bytes | 512 bytes | 512 bytes | 512 bytes |
| Programmable I/O Lines | 23 | 23 | 23 | 23 | 23 |
| ADC Resolution | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
Key Differentiators
- Low-voltage operation down to 2.7 V (vs ATMEGA8A-AU)
- Pin-compatible upgrade path to 20 MHz (vs ATMEGA88PA-AU)
- Wide 1.8 V to 5.5 V supply flexibility (vs ATMEGA88V-10AU)
Design Notes
Place a 100 nF ceramic decoupling capacitor within 5 mm of each VCC pin (pins 10 and 30) and a 10 uF bulk capacitor within 20 mm of the package. The AVCC pin (pin 30) requires a separate 100 nF capacitor to GND and a 10 uH inductor or ferrite bead from VCC to AVCC to isolate digital switching noise from the ADC reference. According to the Microchip datasheet, ADC accuracy degrades if AVCC is not properly filtered. Estimated: at 8 MHz and 5 V, the core draws approximately 15 mA, so a 10 uF bulk capacitor provides adequate transient decoupling for 100 ns current steps.
Route the crystal or resonator traces as short as possible (under 10 mm) and keep them away from high-speed digital signals such as the SPI and USART lines. Place the load capacitors (typically 22 pF for a 16 MHz crystal) directly at the crystal pins with a solid ground plane beneath. For designs using the internal 8 MHz RC oscillator, leave XTAL1 and XTAL2 unconnected but do not route signals beneath them. The 32-TQFP's 0.8 mm pitch allows standard 6 mil trace/space design rules, simplifying PCB fabrication.
Do not exceed the absolute maximum rating of 6.0 V on any pin, and ensure the RESET pin (pin 9) has a 10 kOhm pull-up to VCC plus a 100 nF capacitor to GND for reliable power-on reset. The ATmega8L's Flash and EEPROM are programmed via SPI (MOSI, MISO, SCK) with the RESET pin held low; if the SPI pins are shared with application circuitry, isolate them during programming. Estimated: brown-out detection should be enabled at 2.7 V for 3.3 V systems to prevent Flash corruption during supply dips.
Compliance Information
RoHS compliant per Microchip product page. Industrial temperature grade (-40 C to +85 C), not AEC-Q100 automotive qualified. The 'AU' suffix indicates TQFP package with green/lead-free molding compound.
