ATMEGA8A-AU - AVR 8-bit MCU 16MHz 8KB Flash TQFP-32 | Microchip
部品番号: ATMEGA8A-AU ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $2.45 | $2.45 |
| 10 | $2.15 | $21.50 |
| 100 | $1.78 | $178.00 |
| 500 | $1.52 | $760.00 |
| 1,000 | $1.31 | $1,310.00 |
ATMEGA8A-AU 概要
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a processor core, program memory, data memory, and peripherals such as timers, UART, SPI, I2C and ADC on one silicon die. Within the power management and embedded-systems hierarchy, the MCU sits at the top of the control chain, reading sensors and driving actuators; the ATmega8A belongs to the AVR family from Microchip Technology (formerly Atmel), one of the most widely deployed 8-bit MCU architectures in education and industry.
Key features include the advanced AVR RISC architecture with 130 powerful instructions, most executing in a single clock cycle; a 2-cycle on-chip hardware multiplier; 10-bit ADC with up to 8 single-ended channels; and high-endurance non-volatile memory segments rated for 10,000 Flash and 100,000 EEPROM write cycles. The device runs from 4.5 V to 5.5 V at full 16 MHz speed, per the datasheet supply range for the -16 speed grade.
Architecturally, the AVR core uses 32 x 8 general-purpose working registers directly connected to the ALU, achieving fully static operation and eliminating the accumulator bottleneck of classic 8051-style designs. Harvard memory architecture separates program and data buses for parallel instruction fetch.
Typical applications include industrial control panels, consumer appliance interfaces, motor control, sensor nodes, and legacy Arduino-compatible boards using the MiniCore hardware package.
Design consideration: at 16 MHz choose the 4.5-5.5 V supply window; for 3.3 V battery systems use the ATmega8L (8 MHz max) speed-grade variant instead.
This page synthesizes distributor pricing, drop-in alternatives such as the ATmega88A family, and practical design notes not found in the manufacturer datasheet.
ドロップイン代替品: ATMEGA8A-AU — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
このシリーズのバリエーション
同一シリーズでドロップイン互換のモデル: ATMEGA8A-AU （同一形状・フットプリント） — 相違点: Package, ADC, Operating Temperature, Maximum Clock Frequency, Timers.
クイック比較ツール — 並列比較する代替部品を選択:
ATMEGA8A-AN
✅ ドロップイン✓ 在庫あり
$1.58 / 個
データシートを見る →ATMEGA88A-AU
✅ ドロップイン✓ 在庫あり
$1.52 / 個
データシートを見る →ATMEGA88PA-AUR
✅ ドロップイン✓ 在庫あり
$0.82 / 個
データシートを見る →ATMEGA88V-10AU
✅ ドロップイン✓ 在庫あり
$1.58 / 個
データシートを見る →ATMEGA88PB-ANR
✅ ドロップイン✓ 在庫あり
$1.38 / 個
データシートを見る →ATMEGA8-16AI
✅ ドロップイン✓ 在庫あり
$2.46 / 個
データシートを見る →ATMEGA8A-AU 最大定格＆電気的特性
| Core Architecture | 8-bit AVR RISC |
| 最大クロック周波数 | 16 MHz |
| Flash Program Memory | 8 KB (4K x 16) |
| EEPROM | 512 B |
| SRAM | 1 KB |
| I/O Pins | 23 |
| Supply Voltage Range | 4.5 V to 5.5 V (at 16 MHz) |
| Throughput | Up to 16 MIPS at 16 MHz |
| Instructions | 130 instructions, most single-cycle |
| Hardware Multiplier | On-chip 2-cycle multiplier |
| ADC | 10-bit, 6 multiplexed channels (8 on TQFP/QFN incl. ADC6/ADC7) |
| Communication Interfaces | 1x USART, SPI, TWI (I2C) |
| Timers | 2x 8-bit, 1x 16-bit timer/counter |
| Analog Comparator | Yes, on-chip |
| Flash Endurance | 10,000 write cycles |
| EEPROM Endurance | 100,000 write cycles |
| パッケージ | 32-TQFP (7x7 mm, 0.8 mm pitch) |
| 実装タイプ | Surface Mount |
| Programming / Debug | In-Circuit Serial Programming (ICSP) via SPI, MPLAB SNAP supported |
| ライフサイクル状態 | Active |
ATMEGA8A-AU ピン構成
| ピン 1 | PD3 (INT1) — Port D bit 3 / External Interrupt 1 |
| ピン 2 | PD4 (XCK/T0) — Port D bit 4 / USART External Clock / Timer0 external clock |
| ピン 3 | GND — Ground |
| ピン 4 | VCC — Digital supply voltage |
| ピン 5 | GND — Ground |
| ピン 6 | VCC — Digital supply voltage |
| ピン 7 | PB6 (XTAL1/TOSC1) — Port B bit 6 / Crystal oscillator input / Timer oscillator input |
| ピン 8 | PB7 (XTAL2/TOSC2) — Port B bit 7 / Crystal oscillator output / Timer oscillator output |
| ピン 9 | PD5 (T1) — Port D bit 5 / Timer1 external counter input |
| ピン 10 | PD6 (AIN0) — Port D bit 6 / Analog comparator positive input |
| ピン 11 | PD7 (AIN1) — Port D bit 7 / Analog comparator negative input |
| ピン 12 | PB0 (ICP1) — Port B bit 0 / Timer1 input capture |
| ピン 13 | PB1 (OC1A) — Port B bit 1 / Timer1 PWM output A |
| ピン 14 | PB2 (SS/OC1B) — Port B bit 2 / SPI slave select / Timer1 PWM output B |
| ピン 15 | PB3 (MOSI/OC2) — Port B bit 3 / SPI master output / Timer2 PWM output |
| ピン 16 | PB4 (MISO) — Port B bit 4 / SPI master input |
| ピン 17 | PB5 (SCK) — Port B bit 5 / SPI serial clock |
| ピン 18 | AVCC — ADC supply voltage |
| ピン 19 | ADC6 — ADC input channel 6 (TQFP/QFN packages only) |
| ピン 20 | AREF — ADC analog reference voltage |
| ピン 21 | GND — Ground |
| ピン 22 | ADC7 — ADC input channel 7 (TQFP/QFN packages only) |
| ピン 23 | PC0 (ADC8) — Port C bit 0 / ADC channel 8 |
| ピン 24 | PC1 (ADC9) — Port C bit 1 / ADC channel 9 |
| ピン 25 | PC2 (ADC10) — Port C bit 2 / ADC channel 10 |
| ピン 26 | PC3 (ADC11) — Port C bit 3 / ADC channel 11 |
| ピン 27 | PC4 (SDA/ADC12) — Port C bit 4 / TWI data line / ADC channel 12 |
| ピン 28 | PC5 (SCL/ADC13) — Port C bit 5 / TWI clock line / ADC channel 13 |
| ピン 29 | PC6 (RESET) — Reset input (active low) / Port C bit 6 |
| ピン 30 | PD0 (RXD) — Port D bit 0 / USART receive |
| ピン 31 | PD1 (TXD) — Port D bit 1 / USART transmit |
| ピン 32 | PD2 (INT0) — Port D bit 2 / External Interrupt 0 |
主な用途
ATMEGA8A-AU の用途: 6 件s: Industrial Control and Automation, Consumer Appliance Control, Sensor Nodes and Data Acquisition, Hobby and Arduino-Compatible Education, Motor Control and Power Electronics, Communication Interfaces and Legacy Retrofit.
Industrial Control and Automation
The ATMEGA8A-AU fits industrial control panels because its 4.5-5.5 V supply matches standard 5 V logic rails, its 23 I/O lines drive relays and optocouplers directly, and its 10-bit ADC reads 0-5 V transducer signals without external conversion. The three timers generate PWM for actuator control, while SPI and TWI link HMI displays and EEPROM storage. Fully static operation across 0-16 MHz allows undervolting the clock to reduce emissions in noisy factory environments. With 10,000-cycle Flash endurance supporting field firmware updates and a 16 MIPS core handling scan loops in the microsecond range, it covers PLC auxiliary logic, motor start sequencers, and sensor hubs at a fraction of the cost of 32-bit MCUs.
おすすめ
Consumer Appliance Control
White goods, small kitchen appliances, and HVAC controllers benefit from the ATMEGA8A-AU's cost structure and robustness. The 8 KB Flash holds complete appliance state machines including button debouncing, buzzer melodies, and display multiplexing for 7-segment LED panels driven through the 23 I/O pins. The on-chip analog comparator provides zero-cross detection for triac-based heater and motor phase control without an external comparator IC. At 16 MHz the 2-cycle hardware multiplier accelerates PID temperature-control loops. Its active lifecycle status and multi-source distributor availability (Octopart lists 10 distributors) reduce end-of-life risk for products with 5-10 year service commitments, and the 5 V operation tolerates noisy appliance power environments well.
おすすめ
Sensor Nodes and Data Acquisition
The ATMEGA8A-AU integrates a 10-bit successive-approximation ADC with 6 multiplexed channels (8 including the dedicated ADC6/ADC7 pins on the TQFP-32), plus AVCC and AREF pins that enable clean analog reference design - well suited to multi-channel sensor acquisition. TWI (I2C) and SPI interfaces connect digital sensors such as temperature, pressure, and accelerometers, while the USART streams readings at up to 1 Mbps to a gateway. The 512 B EEPROM stores calibration constants that survive power loss, eliminating external NV memory. Because the ADC noise depends heavily on AVCC filtering, adding an RC filter on AVCC yields effective resolution near 10 bits in quiet designs, adequate for environmental monitoring, metering front-ends, and hobby instrumentation.
おすすめ
Hobby and Arduino-Compatible Education
The ATmega8A is a staple of electronics education and maker projects: the MCUdude MiniCore Arduino hardware package on GitHub provides first-class Arduino IDE support for ATmega8, ATmega48/88/168/328 devices. The ATMEGA8A-AU in TQFP-32 suits compact custom boards, while its DIP sibling ATmega8-16PU fits breadboards. With 16 MIPS at 16 MHz, it comfortably runs Arduino core functions, servo libraries, and NeoPixel drivers. Its low unit cost (around $2.45 as of 2026-09-19) makes classroom and club purchasing practical, and the enormous AVR documentation base, community tutorials, and ISP programmer compatibility (USBasp, MPLAB SNAP) shorten the learning curve for students transitioning from graphical to C/C++ embedded programming.
おすすめ
Motor Control and Power Electronics
The ATMEGA8A-AU generates up to three PWM channels from its two 8-bit timers and one 16-bit timer, supporting DC motor speed control, fan drivers, and basic BLDC trapezoidal commutation with Hall inputs on the interrupt-capable pins. The analog comparator with selectable reference handles overcurrent trip detection with microsecond-class response, and the 16-bit timer captures input pulses for tachometer feedback. Because the 5 V I/O drives standard MOSFET gate-driver inputs directly, the typical design pairs the MCU with an H-bridge driver IC. Firmware tables stored in Flash implement commutation lookup and ramp profiles, and the 8 KB code space is sufficient for complete closed-loop speed controllers in fans, pumps, and power tools.
おすすめ
Communication Interfaces and Legacy Retrofit
The ATMEGA8A-AU's full-duplex USART, hardware SPI, and TWI (I2C) make it an effective protocol bridge and legacy-system retrofit controller: converting RS-232 equipment to USB-adjacent TTL links, adding modem handling to aging machinery, or acting as an I2C-to-SPI translator between mismatched subsystems. The USART supports framing-error and parity detection for robust field communication, and the AVR's deterministic single-cycle core lets interrupt-driven UART servicing run alongside timing-critical tasks. In retrofit scenarios, its 5 V I/O tolerance connects directly to legacy TTL logic levels without level shifters. The 10,000-cycle Flash endurance supports on-site firmware re-flashing during equipment service cycles, which is valuable for long-lifetime industrial communication nodes.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: ATMEGA8A-AU — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | ATMEGA8A-AN | ATMEGA88A-AU | ATMEGA88PA-AUR | ATMEGA88V-10AU | ATMEGA88PB-ANR | ATMEGA8-16AI |
|---|---|---|---|---|---|---|---|
| Package | TQFP-32 (7x7 mm) | TQFP-32 (7x7 mm) - same | TQFP-32 (7x7 mm) - same | TQFP-32 (7x7 mm) - same | TQFP-32 (7x7 mm) - same | TQFP-32 (7x7 mm) - same | TQFP-32 (7x7 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max Clock / Throughput | 16 MHz / 16 MIPS | 16 MHz / 16 MIPS | 20 MHz / 20 MIPS | 20 MHz / 20 MIPS | 10 MHz / 10 MIPS | 20 MHz / 20 MIPS | 16 MHz / 16 MIPS |
| Flash Memory | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB |
| SRAM | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB |
| Firmware Compatibility | Baseline (ATmega8 register map) | Identical - same die | Migration required (AVR094) | Migration required (AVR094) | Migration required (AVR094) | Migration required | Identical register map |
| Lifecycle Status | Active | Active | Active | Active | Active | Active | Original die - availability declining |
主な差別化要因
- Zero-migration ATmega8 firmware compatibility （vs ATMEGA88A-AU)
- Lowest effective cost for legacy maintainers （vs ATMEGA88PB-ANR)
- 8 ADC channels on TQFP package （vs ATMEGA8-16PI (DIP-28))
設計ノート
Decouple both VCC pins (4 and 6) and AVCC (pin 18) individually with 100 nF ceramic capacitors placed within 5 mm of each pin, plus one bulk 10 uF per board section. AVCC must be connected to VCC even if the ADC is unused, per the Microchip datasheet - if ADC is used, filter AVCC through an LC network (10 uH + 100 nF) to reduce supply-coupled ADC noise. GND pins 3, 5 and 21 should connect to a solid ground plane to minimize ground bounce across the 23 switching I/O lines.
The TQFP-32 has a 0.8 mm pitch; specify a solder mask-defined pad of about 0.55 mm with 0.35 mm trace widths for reliable reflow. Keep the crystal (pins 7/8) within 10 mm of the package with 22 pF load capacitors matched to the crystal spec, and guard the XTAL traces with ground. Route the RESET line (pin 29) away from PWM outputs; a 10 kOhm pull-up on RESET is mandatory for stable ICSP programming and noise immunity during power ramp.
The most frequent ATmega8A design errors: (1) leaving PC6/RESET floating causes sporadic resets - always add the pull-up; (2) exceeding the 4.5-5.5 V speed window - running this -16 grade below 4.5 V at 16 MHz violates the guaranteed operating envelope, use the L or 88V grades for low voltage; (3) migrating firmware to pin-compatible ATmega88 without reviewing the different interrupt vector table and register names described in Microchip application note AVR094; (4) forgetting that ADC6/ADC7 exist only on TQFP/QFN packages - DIP designs have 6 ADC channels instead of 8.
コンプライアンス情報
Compliance status not stated in the provided web data; verify on the official Microchip ATmega8A product page compliance documentation.
