ATMEGA8A-MUR - AVR 8-bit MCU 16MHz 8KB Flash | Microchip
MPN: ATMEGA8A-MUR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.9471 | $0.95 |
| 10 | $0.88 | $8.80 |
| 100 | $0.81 | $81.00 |
| 500 | $0.76 | $380.00 |
| 1,000 | $0.7 | $700.00 |
ATMEGA8A-MUR Overview
A microcontroller unit (MCU) is a single-chip computer that integrates a processor core, program memory, data memory and peripherals such as timers, ADCs and serial interfaces. Within the embedded systems hierarchy, the ATmega8A belongs to the 8-bit AVR ATmega family from Atmel (now Microchip Technology), positioned below the larger ATmega88/328/64 families while covering the classic low-pin-count embedded control space.
Key features include the advanced RISC architecture with 130 powerful instructions, most executing in a single clock cycle, plus 32 general-purpose working registers. The device integrates three flexible timer/counters with compare modes, a 10-bit ADC with 6 multiplexed channels, a byte-oriented two-wire interface (I2C-compatible), an SPI serial port and a programmable USART. In-system programmable (ISP) flash with read-while-write support allows firmware updates in the final product.
Architecturally, the AVR core uses a Harvard structure with separate program and data buses, enabling single-cycle instruction fetch and execution. The ATMEGA8A operates from 4.5 V to 5.5 V at the full 16 MHz grade, with power-saving modes including idle and power-down to extend battery life. Internal and external interrupt sources, a watchdog timer and an on-chip debug capability via debugWIRE-style ICSP tools complete the feature set.
Typical applications include industrial control and automation nodes, motor and LED control, sensor interfaces and data loggers, home appliances, HVAC systems and hobby/embedded education platforms where the 10-bit ADC and serial ports simplify analog sensing and communication.
When designing with this part, note the 4.5 V to 5.5 V supply range of the 16 MHz M-grade: for 3.3 V systems, select the L-grade variant running at reduced clock, or the ATmega88PA family which supports 1.8 V operation. Decouple VCC and AVCC separately with 100 nF ceramic capacitors.
This page synthesizes distributor pricing, drop-in alternatives, pinout and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for ATMEGA8A-MUR — 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 ATMEGA8A-MUR (same form factor and footprint) — differing in Package, ADC Channels, Instructions, Mounting Type, ADC Resolution.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA88PA-CCUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.08 / Unit
View Datasheet →ATMEGA88-20MU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
Contact for price
View Datasheet →ATMEGA88V-10MJ
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.32 / Unit
View Datasheet →ATMEGA8A-MUR Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 16 MHz |
| Program Memory Type | FLASH |
| Program Memory Size | 8 KB (4K x 16) |
| EEPROM Size | 512 B |
| RAM Size | 1 KB |
| Number of I/O | 23 |
| Supply Voltage | 4.5 V to 5.5 V |
| ADC Resolution | 10-bit |
| ADC Channels | 6 |
| Connectivity | I2C, SPI, UART/USART |
| Peripherals | Brown-out Detect/Reset, POR, PWM, WDT |
| Timers/Counters | 3 (two 8-bit, one 16-bit) |
| Instructions | 130 (mostly single-cycle) |
| Operating Temperature | -40C to +85C |
| Package | 32-VQFN (5x5 mm) |
| Mounting Type | Surface Mount |
| Lifecycle Status | Active |
ATMEGA8A-MUR Pin Configuration
| Pin 1 | PC6 (RESET) — Port C bit 6 / active-low Reset input |
| Pin 2 | PD0 (RXD) — Port D bit 0 / USART receive input |
| Pin 3 | PD1 (TXD) — Port D bit 1 / USART transmit output |
| Pin 4 | PD2 (INT0) — Port D bit 2 / external interrupt 0 |
| Pin 5 | PD3 (INT1) — Port D bit 3 / external interrupt 1 |
| Pin 6 | PD4 (T0/XCK) — Port D bit 4 / Timer0 external clock, USART external clock |
| Pin 7 | VCC — Digital supply voltage (4.5 V to 5.5 V) |
| Pin 8 | GND — Ground |
| Pin 9 | PB6 (XTAL1/TOSC1) — Port B bit 6 / crystal oscillator input or Timer oscillator input |
| Pin 10 | PB7 (XTAL2/TOSC2) — Port B bit 7 / crystal oscillator output or Timer oscillator output |
| Pin 11 | PD5 (T1/OC0B) — Port D bit 5 / Timer1 external clock, Timer0 output compare B |
| Pin 12 | PD6 (AIN0) — Port D bit 6 / analog comparator positive input |
| Pin 13 | PD7 (AIN1) — Port D bit 7 / analog comparator negative input |
| Pin 14 | PB0 (ICP1/CLKO) — Port B bit 0 / Timer1 input capture, system clock output |
| Pin 15 | PB1 (OC1A) — Port B bit 1 / Timer1 output compare A (PWM) |
| Pin 16 | PB2 (SS/OC1B) — Port B bit 2 / SPI slave select, Timer1 output compare B (PWM) |
| Pin 17 | PB3 (MOSI/OC2) — Port B bit 3 / SPI master data out, Timer2 output compare (PWM) |
| Pin 18 | PB4 (MISO) — Port B bit 4 / SPI master data in |
| Pin 19 | PB5 (SCK) — Port B bit 5 / SPI serial clock |
| Pin 20 | AVCC — ADC supply voltage, connect to VCC via low-pass filter |
| Pin 21 | AREF — ADC analog reference input |
| Pin 22 | GND — Ground |
| Pin 23 | PC0 (ADC0) — Port C bit 0 / ADC channel 0 |
| Pin 24 | PC1 (ADC1) — Port C bit 1 / ADC channel 1 |
| Pin 25 | PC2 (ADC2) — Port C bit 2 / ADC channel 2 |
| Pin 26 | PC3 (ADC3) — Port C bit 3 / ADC channel 3 |
| Pin 27 | PC4 (ADC4/SDA) — Port C bit 4 / ADC channel 4, two-wire interface data |
| Pin 28 | PC5 (ADC5/SCL) — Port C bit 5 / ADC channel 5, two-wire interface clock |
| Pin 29 | GND — Ground pad (VQFN version) |
| Pin 30 | GND — Ground pad (VQFN version) |
| Pin 31 | GND — Ground pad (VQFN version) |
| Pin 32 | GND — Ground pad (VQFN version) |
Typical Applications
ATMEGA8A-MUR is suitable for 6 applications: Industrial Control Nodes, Sensor Interface and Data Logging, Motor and LED Control, Home Appliances and HVAC, Embedded Education and Prototyping, Consumer Remote Controls and Peripherals.
Industrial Control Nodes
The ATMEGA8A-MUR fits industrial control and automation nodes that require deterministic 8-bit control with modest program size. Its 16 MIPS AVR core, watchdog timer and brown-out reset provide robust operation on noisy factory floors, while the 10-bit ADC digitizes potentiometer, thermistor or current-shunt feedback with 6 multiplexed channels. The 4.5-5.5 V operating range matches legacy 5 V industrial rails directly, eliminating level shifting. Placed on a PLC daughter card or relay controller, the USART and SPI ports link to RS-485 transceivers and displays; three timer/counters generate PWM for actuators. Its compact 5x5 mm VQFN saves board area versus DIP predecessors while retaining the same proven peripheral map.
Recommended
Sensor Interface and Data Logging
For sensor front-ends, the ATMEGA8A-MUR combines a 10-bit ADC with 6 channels, an internal bandgap reference option and 1 KB of SRAM for buffering readings between log intervals. The three flexible timer/counters pace periodic sampling precisely, while the two-wire interface reads digital sensors (temperature, humidity, pressure) over I2C and the SPI port writes to SD or EEPROM storage. The 512 B EEPROM retains calibration constants across power cycles without external memory. Operating in power-down mode between samples extends battery life in remote loggers. At 16 MHz, post-processing such as filtering and unit conversion executes comfortably, making this MCU a compact, self-contained acquisition node in a 5x5 mm footprint.
Recommended
Motor and LED Control
The ATMEGA8A-MUR suits small motor and LED driver applications through its PWM capability on multiple timer channels: two 8-bit timers with compare modes plus one 16-bit timer deliver phase-correct or fast PWM at adjustable carrier frequencies for DC motor speed control and LED dimming. The 16 MHz clock allows fine PWM resolution at audible-frequency carriers, and the 23 I/O lines drive H-bridge logic or MOSFET gates directly through external driver ICs. ADC feedback closes current or brightness loops; the USART reports status on a control bus. The 5 V rail range matches standard driver logic families, simplifying gate-drive level compatibility in compact lighting and actuator boards.
Recommended
Home Appliances and HVAC
In appliance and HVAC controllers, the ATMEGA8A-MUR provides the essential mix of robust analog input, timer control and serial communication at minimal cost. The 10-bit ADC reads NTC temperature sensors on multiple channels - compressor, ambient, coil - while timer compare modes produce zero-cross-synchronized PWM or relay timing. Brown-out detection and watchdog reset guarantee recovery from mains disturbances, an important reliability factor in motor-driven appliances. The 512 B EEPROM stores user setpoints and fault histories across power cycles, and the USART or I2C bus connects to displays and remote-control receivers. The 4.5-5.5 V range ties directly to transformer-based 5 V supplies common in white goods.
Recommended
Embedded Education and Prototyping
The ATmega8A family is a staple in embedded systems education because its 130-instruction AVR RISC core, 32 working registers and transparent peripheral architecture teach fundamentals without vendor abstraction layers. The ATMEGA8A-MUR brings the classic DIP-friendly ATmega8 design into surface-mount course boards: students access 23 GPIOs, the 10-bit ADC, timers, PWM, I2C, SPI and USART, all documented in one datasheet. In-circuit serial programming via MPLAB SNAP with just two I/O pins plus RESET lets learners flash code repeatedly without removing the chip. At under one dollar in volume as of 2026-09-19, universities and maker kits can stock large quantities affordably while still using professional BGA-era packaging.
Recommended
Consumer Remote Controls and Peripherals
For cost-sensitive consumer peripherals - remote controls, keyboards, small displays, toy electronics - the ATMEGA8A-MUR offers the required integration in one sub-dollar device. The USART or SPI drives IR LED timing through timer compare outputs, the ADC reads battery voltage and button matrices with resistor ladders, and the internal RC oscillator option (calibrated) eliminates the external crystal where clock accuracy permits, saving two components. Power-down mode cuts current to microamp levels for battery shelf life. The compact 5x5 mm VQFN (5x5) fits ergonomic handheld PCBs, and the wide availability across 9 distributor channels as of 2026-09-19 keeps mass-production supply risk low for this active product family.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA8A-MUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA88PA-CCUR | ATMEGA88-20MU | ATMEGA88V-10MJ |
|---|---|---|---|---|
| Package | 32-VQFN (5x5 mm) | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core / Architecture | AVR 8-bit RISC | AVR 8-bit RISC (picoPower) | AVR 8-bit RISC | AVR 8-bit RISC |
| Max Clock Speed | 16 MHz | 20 MHz | 20 MHz | 10 MHz |
| Flash Memory | 8 KB | 8 KB | 8 KB | 8 KB |
| Supply Voltage | 4.5 V to 5.5 V | 1.8 V to 5.5 V | 4.5 V to 5.5 V | 1.8 V to 5.5 V |
| RAM / EEPROM | 1 KB / 512 B | 1 KB / 512 B | 1 KB / 512 B | 1 KB / 512 B |
| Lifecycle Status | Active | Active | Active | Active |
Key Differentiators
- Lowest-cost entry in the VQFN-32 ATmega footprint (vs ATMEGA88PA-CCUR)
- 16 MHz operation for single-cycle-peripheral timing (vs ATMEGA88V-10MJ)
- Compact 5x5 mm surface-mount package with same die as TQFP part (vs ATMEGA8A-AU)
Design Notes
Decouple VCC (pin 7) with a 100 nF ceramic capacitor placed within 5 mm of the pin, and connect AVCC (pin 20) to VCC through an LC low-pass filter (10 uH + 100 nF) when ADC accuracy matters - ATmega8A datasheet recommends AVCC within 50 mV of VCC even when the ADC is unused. Tie pins 29-32 ground pads of the VQFN package to the exposed center pad and a solid ground plane for both thermal and return-path performance.
The 32-pad VQFN (5x5 mm, 0.5 mm pitch) requires attention during reflow: use a 0.5 mm stencil with slightly reduced pad apertures, and enlarge the exposed center pad aperture by 50-70% with 4-6 vias to ground to solder the die paddle reliably. If hand assembly or rework is planned, keep the ATMEGA8A-AU (TQFP, 0.8 mm pitch) in mind as the same die in an easier-to-touch package.
The 16 MHz -M grade is only rated at 4.5-5.5 V: running it at 3.3 V violates the datasheet frequency-voltage envelope and causes marginal operation. Also note that PC6 is fused as RESET by default - if the pin is needed as GPIO, disabling RESET via fuse removes SPI programming capability, a one-way risk. Reserve PB3/PB4/PB5 (MOSI/MISO/SCK) plus RESET on a header for ICSP even in production layouts.
When using XTAL1/XTAL2 (pins 9-10) with a 16 MHz crystal, keep the crystal and its two 12-22 pF load capacitors within 10 mm of the pins and guard them with a ground pour to prevent the clock from coupling into the ADC or analog comparator inputs. Alternatively, use the factory-calibrated internal RC oscillator to free PB6/PB7 as GPIOs when clock accuracy of approximately 1-2% is acceptable.
Compliance Information
RoHS compliance and lead-free finish indicated by distributor listings (LCSC, DigiKey). Obtain formal REACH and conflict-minerals declarations from the Microchip product compliance portal.
