ATMEGA8-16AC - 8-bit AVR MCU, 8KB Flash, 16MHz | Microchip
MPN: ATMEGA8-16AC ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.09 | $3.09 |
| 10 | $2.78 | $27.80 |
| 100 | $2.47 | $247.00 |
| 500 | $2.22 | $1,110.00 |
| 1,000 | $1.98 | $1,980.00 |
ATMEGA8-16AC Overview
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that executes most instructions in a single clock cycle, positioning it within the broader hierarchy of microcontrollers -> embedded processors -> semiconductors. MCUs of this class integrate program Flash, data SRAM, nonvolatile EEPROM, timers, ADC, and communication peripherals on a single die, replacing multi-chip solutions in cost-sensitive embedded systems.
Key features include the Advanced RISC architecture with 130 powerful instructions, 32 general-purpose working registers, and fully static operation to 16MHz. The -16A suffix denotes the 16MHz maximum clock; the -C suffix denotes the commercial 0C to +70C temperature range with 4.5V to 5.5V supply. Peripherals include two 8-bit timers, one 16-bit timer with input capture and dual PWM outputs, USART, SPI, and TWI (I2C-compatible) interfaces.
The ATmega8 AVR core pairs the Flash program memory with a separate SRAM data path and an on-chip boot-capable self-programming Flash, allowing firmware updates over UART or other links without external programmers. Brown-out reset, internal RC oscillator options, and six sleep modes support robust, low-power designs. The 10-bit ADC supports both single-ended and differential inputs with a selectable 2.56V internal reference.
Typical applications include industrial control panels, sensor interfaces and data loggers, motor and LED control, hobby and educational platforms (the classic Arduino heritage), and small consumer appliances where 8KB of code space and 5V I/O are sufficient.
When designing with the ATMEGA8-16AC, remember that 16MHz operation requires a 4.5V to 5.5V supply; the 8MHz ATMEGA8L variants are needed for 2.7V to 5.5V designs.
This page synthesizes distributor pricing, drop-in alternatives, pinout data, and practical design notes not found in a single manufacturer datasheet.
Drop-in alternatives for ATMEGA8-16AC — 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 ATMEGA8-16AC (same form factor and footprint) — differing in Package, ADC, Maximum Clock Frequency, Operating Temperature, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA8-16AU
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →ATMEGA8A-AU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.31 / Unit
View Datasheet →ATMEGA8-16AI
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.46 / Unit
View Datasheet →ATMEGA8L-8AU
✅ Drop-In✓ In Stock
$1.82 / Unit
View Datasheet →ATMEGA88A-AU
✅ Drop-In✓ In Stock
$1.52 / Unit
View Datasheet →ATMEGA8-16AC Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Flash Program Memory | 8 KB In-System Programmable |
| SRAM | 1 KB |
| EEPROM | 512 Bytes |
| Max CPU Speed | 16 MHz (16 MIPS) |
| Supply Voltage Range | 4.5 V to 5.5 V |
| ADC | 6 or 8-channel, 10-bit |
| Timers | Two 8-bit, one 16-bit |
| Communication Interfaces | USART, SPI, TWI (I2C-compatible) |
| PWM Channels | 3 PWM (OC1A, OC1B, OC2) |
| Instructions | 130 instructions, most single-cycle |
| General Purpose Registers | 32 x 8-bit |
| Operating Temperature | 0C to +70C (commercial) |
| Package | 32-TQFP |
| Mounting Type | Surface Mount |
| Brown-out Reset | Yes (selectable) |
| Packaging | Tray |
ATMEGA8-16AC Pin Configuration
| Pin 1 | PC6 (RESET) — Reset input / Port C bit 6 |
| Pin 2 | PD0 (RXD) — USART receive / Port D bit 0 |
| Pin 3 | PD1 (TXD) — USART transmit / Port D bit 1 |
| Pin 4 | PD2 (INT0) — External interrupt 0 / Port D bit 2 |
| Pin 5 | PD3 (INT1) — External interrupt 1 / Port D bit 3 |
| Pin 6 | PD4 (T0/XCK) — Timer0 counter input / USART clock / Port D bit 4 |
| Pin 7 | VCC — Digital supply voltage |
| Pin 8 | GND — Ground |
| Pin 9 | PB6 (XTAL1/TOSC1) — Crystal oscillator input / Timer oscillator / Port B bit 6 |
| Pin 10 | PB7 (XTAL2/TOSC2) — Crystal oscillator output / Timer oscillator / Port B bit 7 |
| Pin 11 | PD5 (T1) — Timer1 counter input / Port D bit 5 |
| Pin 12 | PD6 (AIN0) — Analog comparator positive input / Port D bit 6 |
| Pin 13 | PD7 (AIN1) — Analog comparator negative input / Port D bit 7 |
| Pin 14 | PB0 (ICP1) — Timer1 input capture / Port B bit 0 |
| Pin 15 | PB1 (OC1A) — Timer1 PWM output A / Port B bit 1 |
| Pin 16 | PB2 (SS/OC1B) — SPI slave select / Timer1 PWM output B / Port B bit 2 |
| Pin 17 | PB3 (MOSI/OC2) — SPI master output / Timer2 PWM output / Port B bit 3 |
| Pin 18 | PB4 (MISO) — SPI master input / Port B bit 4 |
| Pin 19 | PB5 (SCK) — SPI serial clock / Port B bit 5 |
| Pin 20 | AVCC — ADC supply voltage |
| Pin 21 | AREF — ADC analog reference input |
| Pin 22 | GND — Ground |
| Pin 23 | PC0 (ADC0) — ADC input 0 / Port C bit 0 |
| Pin 24 | PC1 (ADC1) — ADC input 1 / Port C bit 1 |
| Pin 25 | PC2 (ADC2) — ADC input 2 / Port C bit 2 |
| Pin 26 | PC3 (ADC3) — ADC input 3 / Port C bit 3 |
| Pin 27 | PC4 (ADC4/SDA) — ADC input 4 / TWI data / Port C bit 4 |
| Pin 28 | PC5 (ADC5/SCL) — ADC input 5 / TWI clock / Port C bit 5 |
| Pin 29 | ADC6 — ADC input 6 (TQFP only) |
| Pin 30 | ADC7 — ADC input 7 (TQFP only) |
| Pin 31 | GND — Ground (TQFP only) |
| Pin 32 | VCC — Digital supply voltage (TQFP only) |
Typical Applications
ATMEGA8-16AC is suitable for 6 applications: Industrial Control Panels, Sensor Interfaces and Data Logging, Motor and LED Control, Hobby, Education and Arduino-Compatible Boards, Consumer Appliances, Serial Communication Bridges.
Industrial Control Panels
The ATMEGA8-16AC fits industrial panel controllers that read buttons, drive relays, and display status over long 5V signal runs. Its 4.5V-5.5V supply tolerance absorbs noisy industrial rail excursions, the 16MHz/16MIPS core executes PID and sequencing logic with headroom, and the TWI (I2C-compatible) plus USART interfaces link to EEPROMs, displays, and modems. Brown-out reset keeps state machines safe during sag events. Placed with a 16MHz crystal and 0.1uF decoupling on each supply pin, it replaces discrete logic while the 512B EEPROM stores calibration and setpoints through power cycles without external nonvolatile memory.
Recommended
Sensor Interfaces and Data Logging
The 10-bit ADC of the ATMEGA8-16AC, with 6 single-ended channels in TQFP (8 including ADC6/ADC7) and a selectable 2.56V internal reference, makes it a compact analog front-end logger. Differential ADC modes reject common-mode noise on bridge and thermocouple front ends, while Timer/Counter1 input capture timestamps external pulse events at crystal accuracy. Sampled data streams to a host over USART or stores in the 1KB SRAM between writes to external EEPROM. Because the ADC shares VCC through AVCC, placing an LC filter on AVCC measurably improves effective noise-free resolution in sensor applications.
Recommended
Motor and LED Control
Three hardware PWM outputs (OC1A, OC1B on the 16-bit Timer/Counter1 and OC2 on the 8-bit Timer/Counter2) let the ATMEGA8-16AC drive H-bridge inputs, brushed-DC drivers, and constant-current LED strings without software bit-banging. At 16MHz, 8-bit PWM runs at roughly 15.6kHz on Timer1, above audible range for fan and motor noise. The 10-bit ADC closes the loop with current or back-EMF feedback, and the 16MIPS core executes PI control at kilohertz rates. This makes the part well suited to 5V fan controllers, small actuator drivers, and intelligent LED luminaires needing analog dimming curves.
Hobby, Education and Arduino-Compatible Boards
The ATmega8 is the original heart of the classic Arduino heritage, and community cores such as MCUdude MiniCore keep full Arduino IDE support alive for ATmega8 devices. The ATMEGA8-16AC suits educational boards, robotics kits, and maker prototypes: 32 general-purpose registers and 130 mostly single-cycle instructions make assembly teaching approachable, while SPI and the ISP interface allow programming with inexpensive USBasp tools. A 16MHz crystal yields the familiar 16MIPS headroom, and the 23 programmable I/O lines interface servos, sensors, and displays directly, making it a durable teaching platform.
Recommended
Consumer Appliances
Cost-sensitive appliance controls - coffee makers, fans, small heaters, chargers - benefit from the ATMEGA8-16AC combination of integrated Flash, ADC, and timers in one TQFP-32 device, cutting bill-of-materials count versus discrete logic plus comparators. The internal RC oscillator option eliminates the crystal on non-timing-critical products, saving two components, while the ADC reads NTC thermistors and user potentiometers directly. The 5V commercial temperature rating of 0C to +70C matches indoor appliance environments, and the 512B EEPROM preserves user settings such as timers and temperature presets across power interruptions without battery backup.
Recommended
Serial Communication Bridges
With hardware USART, SPI, and TWI on board, the ATMEGA8-16AC serves as a protocol converter between legacy RS-232 equipment and modern I2C or SPI peripherals. The USART runs reliably to 115200 baud at 16MHz with 0.2% clock error using a crystal, while the SPI master clocks up to fosc/2 for fast peripheral access. Typical bridges translate MODBUS-style UART frames to I2C sensor buses or buffer UART data through the 1KB SRAM as a small FIFO. Running the AVR core solely as a data mover consumes little of the 16MIPS budget, leaving margin for framing and checksum processing.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA8-16AC — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA8-16AU | ATMEGA8A-AU | ATMEGA8-16AI | ATMEGA8L-8AU | ATMEGA88A-AU |
|---|---|---|---|---|---|---|
| Package | TQFP-32 | TQFP-32 - same | TQFP-32 - same | TQFP-32 - same | TQFP-32 - same | TQFP-32 - same |
| Brand | Microchip Technology (Atmel) | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB |
| Max Clock | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 8 MHz | 20 MHz |
| Supply Voltage | 4.5 V - 5.5 V | 4.5 V - 5.5 V | 4.5 V - 5.5 V | 4.5 V - 5.5 V | 2.7 V - 5.5 V | 1.8 V - 5.5 V |
| Firmware Compatibility | Baseline (ATmega8) | Identical | Identical | Identical | Identical (timing changes at 8MHz) | Requires recompile (AVR094) |
Key Differentiators
- Full 16MHz speed grade at commercial cost (vs ATMEGA8L-8AU)
- Zero-change drop-in continuity (vs ATMEGA88A-AU)
- Cost advantage over larger AVRs (vs ATMEGA88A-AU)
Design Notes
The ATMEGA8-16AC requires 4.5V to 5.5V for 16MHz operation per the ATmega8 datasheet. Do not run this speed grade at 3.3V - timing violations are not guaranteed below 4.5V at 16MHz; use ATMEGA8L parts for low-voltage designs. Place 0.1uF ceramic decoupling on both VCC (pin 7/32) and AVCC (pin 20), and power AVCC through an LC filter (10uH + 10uF) so ADC switching noise from the digital core does not degrade the 10-bit converter's effective resolution.
Route the crystal (16MHz on XTAL1/XTAL2, pins 9-10) with short traces and ground guard, loading capacitors typically 12-22pF depending on crystal spec. Keep AREF (pin 21) clean: connect a 100nF capacitor to ground when using the internal 2.56V reference, and never drive AREF while the internal reference is enabled. Fan out ADC ground returns to the GND pin 22 rather than pin 8 to separate analog return current from digital switching paths.
Fuse misconfiguration is the most common ATmega8 field failure: selecting the wrong clock source fuse (e.g., external clock vs crystal) bricks programming access until a 1MHz+ clock is injected into XTAL1 for recovery. Also verify RESET (PC6, pin 1) has a 10k pull-up when not using the internal pull-up, since ISP programming fails with a floating reset. When migrating firmware to ATMEGA88A, remember register names and fuse defaults change - consult Microchip application note AVR094 before assuming compatibility.
Compliance Information
Compliance attributes for the -AC suffix were not present in the retrieved web data; verify against the official Microchip product page before production release.
