ATMEGA8-16MU - AVR 8-bit MCU 16MHz 8KB Flash | Microchip
MPN: ATMEGA8-16MU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.85 | $2.85 |
| 10 | $2.56 | $25.60 |
| 100 | $2.15 | $215.00 |
| 500 | $1.86 | $930.00 |
| 1,000 | $1.62 | $1,620.00 |
ATMEGA8-16MU Overview
An 8-bit microcontroller (MCU) is an integrated circuit that combines a processor core, program memory, data memory, and peripherals on a single chip. MCUs sit at the heart of the embedded-systems hierarchy - from raw silicon to the microcontroller unit to complete embedded control systems - executing dedicated control tasks in appliances, motors, sensors, and communication equipment.
Key features of the ATMEGA8-16MU include the advanced AVR RISC architecture with 130 powerful instructions, most executed in a single clock cycle, delivering up to 16 MIPS throughput at 16 MHz. On-chip memory comprises 8KB (4K x 16) ISP Flash, 512B EEPROM, and SRAM for data storage. Integrated analog and digital peripherals - including a 10-bit ADC, timers, USART, SPI, and TWI (I2C) - reduce external component count.
Technically, the AVR core's Harvard architecture separates program and data buses, allowing simultaneous access and single-cycle instruction execution. In-System Programmability (ICSP) via the SPI or bootloader enables firmware updates without removing the device from the PCB, while debugWIRE-style tool support through MPLAB SNAP programmers simplifies development.
Typical applications include industrial control and automation nodes, motor control and power-supply supervision, and consumer appliance interfaces. The 5V supply range and 23 I/O lines suit noise-tolerant industrial signal environments where 3.3V parts struggle.
For design, budget the flash carefully: 8KB fills quickly with floating-point or communication stacks, and the industrial temperature variant (suffix I) should be selected for -40C to +85C environments.
This page synthesizes verified distributor data, pin-compatible alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA8-16MU 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 ATMEGA8-16MU (same form factor and footprint) β differing in ADC, Instructions, Package, Core Architecture, EEPROM.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA8-16MI
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA8L-8MU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA8L-8MUR
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA88-20MU
β Drop-Inβ In Stock
Contact for price
View Datasheet βATMEGA8-16MU Maximum Ratings & Electrical Characteristics
| Core | AVR 8-bit RISC |
| Core Size | 8-bit |
| Maximum Clock Frequency | 16 MHz |
| Program Memory Type | Flash |
| Program Memory Size | 8KB (4K x 16) |
| Program Memory Type Detail | In-System Programmable (ISP) |
| EEPROM Size | 512B |
| Supply Voltage Range | 4.5 V to 5.5 V |
| I/O Count | 23 |
| Instructions | 130 (most single-cycle) |
| Package Type | 32-VQFN / MLF (5x5 mm) |
| Mounting Type | Surface Mount |
| Peripherals | 10-bit ADC, Timers, USART, SPI, TWI (I2C) |
| Programming Interface | ICSP (SPI), bootloader |
| Life Cycle Stage | Active |
ATMEGA8-16MU Pin Configuration
| Pin 1 | PC6 (/RESET) β Reset input (active low); also Port C bit 6 I/O when RSTDISBL fuse is programmed |
| Pin 2 | PD0 (RXD) β Port D bit 0; USART receive data input |
| Pin 3 | PD1 (TXD) β Port D bit 1; USART transmit data output |
| Pin 4 | PD2 (INT0) β Port D bit 2; external interrupt 0 input |
| Pin 5 | PD3 (INT1) β Port D bit 3; external interrupt 1 input |
| Pin 6 | PD4 (T0/XCK) β Port D bit 4; Timer0 counter input / USART external clock |
| Pin 7 | VCC β Digital supply voltage (4.5 V to 5.5 V) |
| Pin 8 | GND β Ground |
| Pin 9 | PB6 (XTAL1/TOSC1) β Port B bit 6; crystal/clock input; Timer oscillator input |
| Pin 10 | PB7 (XTAL2/TOSC2) β Port B bit 7; crystal/clock output; Timer oscillator output |
| Pin 11 | PD5 (T1/OC0B) β Port D bit 5; Timer1 counter input / Timer0 output compare |
| Pin 12 | PD6 (ICP1) β Port D bit 6; Timer1 input capture |
| Pin 13 | PD7 (OC2/AIN1) β Port D bit 7; Timer2 PWM output / analog comparator negative input |
| Pin 14 | PB0 (ICP1/CLKO) β Port B bit 0; Timer1 input capture / system clock output |
| Pin 15 | PB1 (OC1A) β Port B bit 1; Timer1 PWM output A |
| Pin 16 | PB2 (SS/OC1B) β Port B bit 2; SPI slave select / Timer1 PWM output B |
| Pin 17 | PB3 (MOSI/OC2) β Port B bit 3; SPI master data out / Timer2 PWM output |
| Pin 18 | PB4 (MISO) β Port B bit 4; SPI master data in |
| Pin 19 | PB5 (SCK) β Port B bit 5; SPI serial clock |
| Pin 20 | AVCC β ADC supply voltage; connect to VCC through low-pass filter |
| Pin 21 | AREF β ADC analog reference input |
| Pin 22 | GND β Ground |
| Pin 23 | PC0 (ADC0) β Port C bit 0; ADC channel 0 |
| Pin 24 | PC1 (ADC1) β Port C bit 1; ADC channel 1 |
| Pin 25 | PC2 (ADC2) β Port C bit 2; ADC channel 2 |
| Pin 26 | PC3 (ADC3) β Port C bit 3; ADC channel 3 |
| Pin 27 | PC4 (ADC4/SDA) β Port C bit 4; ADC channel 4 / TWI data line |
| Pin 28 | PC5 (ADC5/SCL) β Port C bit 5; ADC channel 5 / TWI clock line |
| Pin 29 | NC β Not connected (per datasheet) |
| Pin 30 | NC β Not connected (per datasheet) |
| Pin 31 | NC β Not connected (per datasheet) |
| Pin 32 | NC β Not connected (per datasheet) |
Typical Applications
ATMEGA8-16MU is suitable for 6 applications: Industrial Control and Automation, Switch-Mode Power Supply Supervision, Home Appliance Control Panels, Sensor Data Acquisition Nodes, Hobby, Education, and Maker Electronics, Lighting and Dimming Control.
Industrial Control and Automation
The ATMEGA8-16MU fits industrial control nodes because its 4.5V-5.5V native 5V operation tolerates noisy factory power rails, and its 23 I/O lines drive relays, optocouplers, and status LEDs directly. The 16 MHz AVR core executes 16 MIPS for deterministic polling loops and Modbus-style serial protocols over the integrated USART. The 512B EEPROM stores setpoints and configuration without external NVM. In a typical PLC-style slave node, the MCU reads sensors via the 10-bit ADC, executes ladder-logic-equivalent C code, and communicates over RS-485 through a transceiver such as the MAX485. Because the architecture is single-cycle RISC, interrupt latency is predictable, which matters for time-critical I/O scanning.
Recommended
Switch-Mode Power Supply Supervision
Digital supervision of switching power supplies is a natural fit for the ATMEGA8-16MU: its 10-bit ADC monitors output voltage and current sense signals across multiple channels, while timer PWM outputs (OC1A/OC1B) trim feedback or drive bias converters. The 16 MIPS throughput at 16 MHz supports software PID loops at several kHz update rates for secondary-side regulation. The 512B EEPROM retains fault logs and calibration constants across power cycles, and the USART reports telemetry to a system host. Compared with a dedicated digital-power DSP, the ATMEGA8-16MU costs a fraction as much and suffices for low-complexity supervision tasks such as battery-charger sequencing and hot-swap control where a 5V rail already exists in the system.
Recommended
Home Appliance Control Panels
Appliance control panels - washing machines, microwave ovens, coffee makers - use the ATMEGA8-16MU for its low cost, wide availability, and 5V noise immunity near relay and motor loads. The 23 GPIO lines scan a 4x4 key matrix, drive seven-segment or LCD drivers, and control triacs and relays through optocouplers. Timer PWM generates buzzer tones and fan-speed control, while the EEPROM memorizes user preferences. The 16 MHz clock provides headroom for debounce scanning and display refresh at low CPU load. Its MLF 5x5 mm footprint suits compact panel PCBs, and in-circuit serial programming allows final firmware flashing after assembly, simplifying manufacturing when product variants share one PCB layout.
Recommended
Sensor Data Acquisition Nodes
For distributed sensor nodes, the ATMEGA8-16MU combines an onboard 10-bit ADC (up to 6 multiplexed channels with internal reference) with TWI (I2C) and SPI masters for digital sensors such as temperature, pressure, and humidity devices. The 16 MHz core filters and scales readings fast enough for tens to hundreds of samples per second per channel. Averaging in the 1KB-class SRAM reduces noise before values are serialized over USART or TWI to a gateway. Low idle current and power-down sleep modes extend battery-backed operation where the 5V rail is generated locally. As an ICSP-programmable part, calibration coefficients stored in the 512B EEPROM can be updated in the field through a bootloader over the same serial link.
Recommended
Hobby, Education, and Maker Electronics
The ATmega8 family is a mainstay of embedded education and maker projects: the same AVR core powers the classic Arduino lineage, and the ATMEGA8-16MU runs the same open-source toolchain (AVR-GCC, avrdude) with a bootloader. Its 16 MIPS core is fast enough for robotics PWM, RC signal decoding, and small displays, while abundant community documentation shortens the learning curve. The MLF 5x5 mm package suits compact custom boards, and the ISP interface needs only a 6-pin header, an MPLAB SNAP, or a USBasp to program. Universities and training kits use it to teach registers, interrupts, and timers at the bare-metal level without vendor abstraction layers hiding the hardware.
Recommended
Lighting and Dimming Control
The ATMEGA8-16MU implements phase-cut and PWM lighting dimmers by using its 8/16-bit timers to generate PWM (up to 16-bit resolution on Timer1) or to synchronize to mains zero crossings through an input capture pin. The 5V-tolerant I/O drives MOSFET gate drivers or opto-triacs directly through current-limiting resistors, and the 10-bit ADC reads potentiometer or photodiode feedback for closed-loop brightness regulation. Its deterministic single-cycle RISC core keeps interrupt jitter low, which prevents visible flicker at dimming frequencies. The 512B EEPROM stores last-set brightness across power interruptions, a small feature that significantly improves user experience in residential dimmer retrofits.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA8-16MU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA8-16MI | ATMEGA8L-8MU | ATMEGA8L-8MUR | ATMEGA88-20MU |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 32-VQFN / MLF (5x5 mm) | 32-VQFN / MLF (5x5 mm) - same | 32-VQFN / MLF (5x5 mm) - same | 32-VQFN / MLF (5x5 mm) - same | 32-VQFN / MLF (5x5 mm) - same |
| Max Clock Frequency | 16 MHz | 16 MHz | 8 MHz | 8 MHz | 20 MHz |
| Program Flash | 8KB ISP Flash | 8KB ISP Flash | 8KB ISP Flash | 8KB ISP Flash | 8KB ISP Flash |
| I/O Pins | 23 | 23 | 23 | 23 | 23 |
| Firmware Compatibility | Reference (ATmega8) | Identical (same die) | Identical; F_CPU change to 8 MHz | Identical; F_CPU change to 8 MHz | Port required (register set differs per AVR094) |
Key Differentiators
- Full 16 MHz speed grade at 5V (vs ATMEGA8L-8MU)
- Zero-firmware-change industrial replacement (vs ATMEGA88-20MU)
- Trade-off: legacy peripheral set (vs ATMEGA88-20MU)
Design Notes
The MLF/VQFN 5x5 mm package requires an exposed ground pad on the PCB bottom side for both electrical ground return and thermal relief. Extend a matrix of 4x4 or 5x5 vias from the exposed pad to the internal/ground plane per Microchip MLF application guidelines. Land pattern dimensions should follow the datasheet mechanical drawing; do not assume the QFN land pattern from other vendors is compatible, as pad openings affect solder wicking and center-pad voiding during reflow.
Connect AVCC (pin 20) to VCC through a low-pass filter (typical 10 uH inductor or 100-ohm resistor with 100 nF capacitor) to keep ADC noise low; the datasheet notes AVCC must stay within 0.3V of VCC. Decouple VCC and AVCC each with 100 nF ceramic capacitors placed within 3 mm of the pins. If using the internal 2.56V ADC reference, add a 100 nF capacitor on AREF (pin 21) and do not drive it externally unless the REFS fuses permit it.
Verify the clock source fuses before first programming: the ATmega8 ships with the internal 1 MHz RC oscillator enabled, so a 16 MHz crystal will not run at 16 MHz until CKOPT/fuse bits are set for a full-swing crystal. Incorrect fuse settings (especially disabling RESET or SPIEN) can brick the device and require a high-voltage parallel programmer to recover. When migrating firmware to the pin-compatible ATMEGA88, remember AVR094 lists register-name differences - a direct hex-file transfer will not work.
Compliance Information
RoHS/lead-free status inferred from the MLF (MU) package suffix per standard Microchip ordering-code convention; verify against Microchip's official environmental datasheet for the specific date code before production release.
