ATMEGA128A-AN - 8-bit AVR MCU 128KB Flash 16MHz | Microchip
部品番号: ATMEGA128A-AN ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $2.75 | $2.75 |
| 10 | $2.55 | $25.50 |
| 100 | $2.35 | $235.00 |
| 500 | $2.15 | $1,075.00 |
| 1,000 | $1.95 | $1,950.00 |
ATMEGA128A-AN 概要
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that executes most instructions in a single clock cycle. Within the power-management hierarchy, MCUs such as the ATmega128A integrate CPU, program memory, data memory, timers and peripherals on one die, replacing multi-chip solutions in embedded control systems. The ATmega128A belongs to the AVR ATmega family and the broader microcontroller unit (MCU) category.
Key features include 135 powerful RISC instructions, 32 general-purpose working registers, four flexible Timer/Counters with compare modes and PWM, a Real Time Counter, and 2 USARTs. Per the Microchip datasheet summary (Atmel-8151S), the device also provides one byte-oriented Two-Wire Interface (I2C), SPI, an 8-channel 10-bit ADC, and JTAG boundary-scan and on-chip debugging.
Architecturally, the AVR core uses single-cycle instruction execution with a deep pipeline, achieving near-1 MIPS per MHz throughput. Read-while-write Flash allows code updates during operation. The improved manufacturing process of the A-variant delivers significantly lower power consumption than the original ATmega128.
Typical applications include legacy industrial control upgrade, embedded instrumentation, motor-control front ends, and building automation nodes. Its 100% pin compatibility with ATmega103 and ATmega128 makes it ideal for PCB redesign-free refreshes.
Design consideration: at 16MHz and 5V, keep decoupling close to all VCC pins and observe XTAL1/XTAL2 layout; use the Migration application note AVR525 when replacing ATmega128.
This page adds value beyond the datasheet by synthesizing distributor pricing, drop-in alternatives, a full 64-pin pinout table, and practical design notes.
ドロップイン代替品: ATMEGA128A-AN — 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: ATMEGA128A-AN （同一形状・フットプリント） — 相違点: Flash Memory, Timers/Counters, Operating Temperature, Package, ADC.
クイック比較ツール — 並列比較する代替部品を選択:
ATMEGA128-16AN
✅ ドロップイン✓ 在庫あり
$7.44 / 個
データシートを見る →ATMEGA128A-AU
✅ ドロップイン ⚠️ 仕様未検証✓ 在庫あり
$4.3 / 個
データシートを見る →ATMEGA128L-8AN
✅ ドロップイン📋 参考代替品（カタログ未掲載）
ATMEGA128-16AI
✅ ドロップイン ⚠️ 仕様未検証✓ 在庫あり
$5.9 / 個
データシートを見る →ATMEGA128A-AN 最大定格＆電気的特性
| Core | AVR 8-bit RISC |
| Flash Memory | 128 KB (In-System Programmable, read-while-write) |
| EEPROM | 4 KB |
| SRAM | 4 KB |
| 最大クロック周波数 | 16 MHz |
| General Purpose I/O | 53 lines |
| Working Registers | 32 general purpose |
| Timers/Counters | 4 flexible Timer/Counters with compare modes and PWM |
| USART | 2 |
| Real Time Counter | Yes (RTC) |
| パッケージ | TQFP-64 |
| 動作温度 | -40C to +105C |
| 実装タイプ | Surface Mount |
| RoHS ステータス | Green (per LCSC/Mouser listing) |
ATMEGA128A-AN ピン構成
| ピン 1 | PEN — Programming enable (per datasheet) |
| ピン 2 | PE0 — RXD0/PDI - USART0 receive |
| ピン 3 | PE1 — TXD0/PDO - USART0 transmit |
| ピン 4 | PE2 — XCK0/AIN0 |
| ピン 5 | PE3 — AIN1/OC3A |
| ピン 6 | PE4 — OC3B/INT4 |
| ピン 7 | PE5 — OC3C/INT5 |
| ピン 8 | PE6 — T3/INT6 |
| ピン 9 | PE7 — ICP3/INT7/CLKO |
| ピン 10 | VCC — Digital supply voltage |
| ピン 11 | GND — Ground |
| ピン 12 | PG0 — WR - external memory write strobe |
| ピン 13 | PG1 — RD - external memory read strobe |
| ピン 14 | PG2 — ALE - external memory address latch enable |
| ピン 15 | PC0 — A8 - external memory address bus |
| ピン 16 | PC1 — A9 |
| ピン 17 | PC2 — A10 |
| ピン 18 | PC3 — A11 |
| ピン 19 | PC4 — A12 |
| ピン 20 | PC5 — A13 |
| ピン 21 | PC6 — A14 |
| ピン 22 | PC7 — A15 |
| ピン 23 | AREF — ADC reference voltage |
| ピン 24 | AGND — Analog ground |
| ピン 25 | AVCC — Analog supply voltage |
| ピン 26 | PA7 — AD7 - address/data bus, ADC7 |
| ピン 27 | PA6 — AD6, ADC6 |
| ピン 28 | PA5 — AD5, ADC5 |
| ピン 29 | PA4 — AD4, ADC4 |
| ピン 30 | PA3 — AD3, ADC3 |
| ピン 31 | PA2 — AD2, ADC2 |
| ピン 32 | PA1 — AD1, ADC1 |
| ピン 33 | PA0 — AD0, ADC0 |
| ピン 34 | PB0 — SS - SPI slave select |
| ピン 35 | PB1 — SCK - SPI clock |
| ピン 36 | PB2 — MOSI - SPI master out |
| ピン 37 | PB3 — MISO - SPI master in |
| ピン 38 | PB4 — OC0/PWM0 |
| ピン 39 | PB5 — OC1A - PWM output |
| ピン 40 | PB6 — OC1B - PWM output |
| ピン 41 | PB7 — OC2/OC1C - PWM output |
| ピン 42 | PF0 — ADC0 |
| ピン 43 | PF1 — ADC1 |
| ピン 44 | PF2 — ADC2 |
| ピン 45 | PF3 — ADC3 |
| ピン 46 | PF4 — ADC4/TCK - JTAG test clock |
| ピン 47 | PF5 — ADC5/TMS - JTAG test mode select |
| ピン 48 | PF6 — ADC6/TDO - JTAG test data out |
| ピン 49 | PF7 — ADC7/TDI - JTAG test data in |
| ピン 50 | GND — Ground |
| ピン 51 | VCC — Digital supply voltage |
| ピン 52 | GND — Ground |
| ピン 53 | VCC — Digital supply voltage |
| ピン 54 | PD0 — SCL/INT0 - TWI clock, external interrupt 0 |
| ピン 55 | PD1 — SDA/INT1 - TWI data, external interrupt 1 |
| ピン 56 | PD2 — RXD1/INT2 - USART1 receive |
| ピン 57 | PD3 — TXD1/INT3 - USART1 transmit |
| ピン 58 | PD4 — ICP1 - Timer1 input capture |
| ピン 59 | PD5 — XCK1 - USART1 external clock |
| ピン 60 | PD6 — T1 - Timer1 external clock input |
| ピン 61 | PD7 — T2 - Timer2 external clock input |
| ピン 62 | RESET — Reset input |
| ピン 63 | XTAL2 — Oscillator output |
| ピン 64 | XTAL1 — Oscillator input |
主な用途
ATMEGA128A-AN の用途: 6 件s: Legacy Industrial Control Board Refresh, Embedded Instrumentation and Data Loggers, Multi-Protocol Communication Nodes, Motor Control and PWM Actuator Drive, Educational and Maker Platforms, ATmega103 Replacement in Existing Designs.
Legacy Industrial Control Board Refresh
The ATMEGA128A-AN is a functionally identical drop-in replacement for the ATmega128, per Microchip application note AVR525, allowing production lines running the original ATmega128 to be refreshed without PCB redesign or firmware changes. The improved process delivers significantly lower power consumption, which reduces thermal load in sealed industrial enclosures. With 128KB read-while-write Flash, 4KB EEPROM for parameter storage and two USARTs for fieldbus links, it maintains the memory map and peripheral set legacy code expects. Verify only the minor electrical characteristic differences documented in the separate ATmega128A datasheet before mass production.
おすすめ
Embedded Instrumentation and Data Loggers
Instrumentation front ends benefit from the ATMEGA128A-AN's combination of 128KB program Flash, 4KB EEPROM for calibration constants and 53 GPIO lines for multiplexed sensor interfaces. Four Timer/Counters with compare modes and PWM support precise sampling triggers and actuator drive, while the Real Time Counter keeps timestamps during low-power operation. The 16MHz AVR core provides roughly 16 MIPS, sufficient for filtering and protocol handling without an external coprocessor. JTAG on-chip debugging through PF4-PF7 shortens field-firmware validation cycles during development of measurement products.
おすすめ
Multi-Protocol Communication Nodes
With two independent USARTs, an SPI port and a byte-oriented Two-Wire Interface (I2C) per the Microchip datasheet, the ATMEGA128A-AN bridges RS-232/RS-485 links with sensor buses in building automation and telemetry nodes. At 16MHz the core sustains simultaneous full-duplex UART traffic and TWI transactions while retaining headroom for application logic. 53 GPIO lines handle addressable I/O expansion, and 4KB EEPROM stores node addresses and configuration persistently. Read-while-write Flash allows field firmware updates over the communication link without halting the running application - a practical benefit for remotely deployed nodes.
おすすめ
Motor Control and PWM Actuator Drive
The four flexible Timer/Counters with compare modes and PWM outputs - including OC0, OC1A/OC1B/OC1C and OC3A/OC3B/OC3C - give the ATMEGA128A-AN up to seven hardware PWM channels suitable for DC motor speed control, LED dimming and servo actuation. External memory pins PA0-PA7 and PC0-PC7 plus WR/RD/ALE (PG0-PG2) support expanded addressing in motion controllers needing external RAM or memory-mapped peripherals. INT4-INT7 external interrupts on PE4-PE7 capture quadrature encoder edges with low latency. The -40C to +105C rating supports thermally demanding drive cabinets.
おすすめ
Educational and Maker Platforms
The ATmega128 family remains popular in education because the AVR RISC core executes most of its 135 instructions in a single cycle, making assembly and C timing behavior transparent to students. The open-source MegaCore Arduino hardware package explicitly supports the ATmega128 family, enabling Arduino-style development on this part. With 53 GPIO lines, on-chip 10-bit sensing via the ADC pins PF0-PF3/PA pins, and JTAG for classroom debug probes, a single TQFP-64 board covers digital, analog and communication labs. The 128KB Flash accommodates larger projects without the memory ceiling of smaller ATmega parts.
おすすめ
ATmega103 Replacement in Existing Designs
According to the Microchip datasheet summary, the ATmega128A is 100% pin compatible with the ATmega103 and can replace it on current printed circuit boards, making the ATMEGA128A-AN the standard migration path for designs built around the discontinued ATmega103. The application note 'Replacing ATmega103 by ATmega128A' documents fuse, register and behavioral differences the designer must address in firmware. Because the footprint and pinout are unchanged, a soldering operation alone completes the hardware migration, while the doubled Flash and added peripherals (second USART, extra timers) become available for feature growth.
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: ATMEGA128A-AN — 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 | ATMEGA128-16AN | ATMEGA128A-AU | ATMEGA128L-8AN | ATMEGA128-16AI |
|---|---|---|---|---|---|
| Package | TQFP-64 | TQFP-64 - same | TQFP-64 - same | TQFP-64 - same | TQFP-64 - same |
| Brand | Microchip Technology | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) |
| Flash | 128 KB | 128 KB | 128 KB | 128 KB | 128 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB |
| Max Clock | 16 MHz | 16 MHz | 16 MHz | 8 MHz (-50%) | 16 MHz |
| Process Generation | A (improved, lower power) | Original ATmega128 | A (improved) | L (low voltage) | Original ATmega128 |
| Drop-in Compatibility | Reference part | Functionally identical per AVR525 | Same die, pin-to-pin | Pin-compatible, clock/voltage derated | Pin-to-pin, same family |
主な差別化要因
- Lower power consumption via improved process （vs ATMEGA128-16AN)
- Full-speed 16MHz operation （vs ATMEGA128L-8AN)
- ATmega103 board compatibility （vs ATMEGA128A-AU)
設計ノート
Decouple every VCC pin (10, 51, 53) with 100nF ceramic capacitors placed within 2-3mm of the pin, plus one 4.7-10uF bulk capacitor per supply rail. Connect AVCC (pin 25) to VCC through a low-pass LC filter when using the ADC, and tie AREF (pin 23) to ground via 100nF unless an external reference is used. The A-process die draws less current than the original ATmega128, so existing designs may see slightly lower rail loading after substitution.
Keep XTAL1 (pin 64) and XTAL2 (pin 63) traces as short as possible with the crystal and load capacitors placed directly adjacent; guard them with ground pour away from switching signals. PEN (pin 1) must be handled per the datasheet programming-enable requirements - do not leave floating in production boards if ISP is used. Route the JTAG chain (PF4-PF7) to a 2x5 header for on-chip debug access; retrofitting JTAG later is difficult on dense TQFP-64 layouts.
When migrating from ATmega128 to ATmega128A, consult Microchip application note AVR525 (doc8166): although the part is a functionally identical drop-in, some electrical characteristics differ due to the new process, and the devices have separate datasheets. When migrating from ATmega103, note the application note 'Replacing ATmega103 by ATmega128A' - fuse defaults, register addresses and MCU control behavior differ even though the pinout is 100% compatible.
コンプライアンス情報
Listed as 'Green' by LCSC and Mouser, indicating RoHS/halogen-free compliance. Full REACH and conflict-minerals declarations not found in provided data.
