ATMEGA809-AU - 8-Bit AVR MCU 20MHz 8KB Flash | Microchip
料号： ATMEGA809-AU ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $1.58 | $1.58 |
| 10 | $1.44 | $14.40 |
| 100 | $1.25 | $125.00 |
| 500 | $1.1 | $550.00 |
| 1,000 | $0.98 | $980.00 |
ATMEGA809-AU 概述
An 8-bit microcontroller is an integrated circuit that executes program code on a CPU with an 8-bit-wide data bus, combining flash program memory, SRAM data memory, EEPROM, peripherals, and clocking into a single chip. In the embedded-systems hierarchy, the ATMEGA809-AU sits within the megaAVR family of general-purpose MCUs, which in turn belongs to the broader microcontroller unit (MCU) category of semiconductor devices. Microcontrollers replace multi-chip processor-plus-peripheral designs, reducing board area, bill-of-materials cost, and system power consumption.
Key features include the megaAVR 0-series Core Independent Peripherals (CIPs), which include the Event System allowing peripherals to communicate directly without CPU intervention, intelligent analog modules, and advanced low-power features. Connectivity is provided by I2C (TWI), SPI, and UART/USART serial interfaces, supporting multi-drop sensor networks and host communication. Peripheral functions include Brown-out Detect/Reset and Power-on Reset for supply supervision, ensuring reliable startup and operation in noisy electrical environments.
Architecturally, the ATMEGA809-AU uses the AVR RISC core with a hardware multiplier, enabling single-cycle arithmetic for digital control and signal-processing tasks while executing code from 8 KB of flash. The 1 KB SRAM provides workspace for program variables and communication buffers, while the 256-byte EEPROM retains calibration data and configuration through power cycles. Supply supervision peripherals such as BOD keep the core within safe operating margins across the full voltage and temperature range.
Typical applications include industrial automation nodes, home-appliance control boards, IoT sensor endpoints, and motor-control or LED-lighting systems where an efficient 8-bit MCU with robust analog and safety supervision is required at low cost.
When designing with the ATMEGA809-AU, use the single-pin UPDI interface (shared with PORTF) for programming and debugging to minimize external tooling overhead, and configure Brown-out Detection to match the supply rail's droop characteristics. Decouple VDD pins with 100 nF ceramics placed close to the package.
This page synthesizes distributor pricing, drop-in family alternatives, pinout data, and practical design guidance not consolidated in the manufacturer datasheet, verified against DigiKey, Mouser, LCSC, and Microchip sources as of 2026-09-18.
直接替换替代料： ATMEGA809-AU ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： ATMEGA809-AU （相同外形与封装尺寸） ——差异在于 Core Processor, Peripherals, Series, Connectivity, Operating Temperature.
快速对比工具——选择替代料号进行并排对比：
ATMEGA1609-AU
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$1.15 / 个
查看数据手册 →ATMEGA3209-AU
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$0.93 / 个
查看数据手册 →ATMEGA4809-AU
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
ATMEGA809-AFR
✅ 直接替换✓ 有现货
$1.55 / 个
查看数据手册 →ATMEGA1609-AFR
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$1.87 / 个
查看数据手册 →ATMEGA4809-AFR
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$1.36 / 个
查看数据手册 →ATMEGA809-AU 最大额定值与电气特性
| Core Processor | AVR (8-bit) |
| Core Size | 8-Bit |
| 最大时钟频率 | 20 MHz |
| Flash Memory | 8 KB (8K x 8) |
| SRAM | 1 KB |
| EEPROM | 256 bytes |
| Connectivity | I2C, SPI, UART/USART |
| Peripherals | Brown-out Detect/Reset, Power-on Reset, Event System |
| 封装 | 48-TQFP (7x7 mm) |
| 安装类型 | Surface Mount |
| Series | megaAVR 0, Functional Safety (FuSa) |
| Program Memory Type | FLASH |
| Hardware Multiplier | Yes |
| RoHS 状态 | Compliant |
ATMEGA809-AU 引脚配置
| 引脚 1 | PA5 — General-purpose I/O, Port A bit 5 |
| 引脚 2 | PA4 — General-purpose I/O, Port A bit 4 |
| 引脚 3 | PA3 — General-purpose I/O, Port A bit 3 |
| 引脚 4 | PA2 — General-purpose I/O, Port A bit 2 |
| 引脚 5 | PA1 — General-purpose I/O, Port A bit 1 |
| 引脚 6 | PA0 — General-purpose I/O, Port A bit 0 |
| 引脚 7 | GND — Ground |
| 引脚 8 | VDD — Power supply |
| 引脚 9 | PA7 — General-purpose I/O, Port A bit 7 |
| 引脚 10 | PA6 — General-purpose I/O, Port A bit 6 |
| 引脚 11 | PB5 — General-purpose I/O, Port B bit 5 |
| 引脚 12 | PB4 — General-purpose I/O, Port B bit 4 |
| 引脚 13 | PB3 — General-purpose I/O, Port B bit 3 |
| 引脚 14 | PB2 — General-purpose I/O, Port B bit 2 |
| 引脚 15 | PB1 — General-purpose I/O, Port B bit 1 |
| 引脚 16 | PB0 — General-purpose I/O, Port B bit 0 |
| 引脚 17 | GND — Ground |
| 引脚 18 | VDD — Power supply |
| 引脚 19 | PC7 — General-purpose I/O, Port C bit 7 |
| 引脚 20 | PC6 — General-purpose I/O, Port C bit 6 |
| 引脚 21 | PC5 — General-purpose I/O, Port C bit 5 |
| 引脚 22 | PC4 — General-purpose I/O, Port C bit 4 |
| 引脚 23 | PC3 — General-purpose I/O, Port C bit 3 |
| 引脚 24 | PC2 — General-purpose I/O, Port C bit 2 |
| 引脚 25 | PC1 — General-purpose I/O, Port C bit 1 |
| 引脚 26 | PC0 — General-purpose I/O, Port C bit 0 |
| 引脚 27 | PD7 — General-purpose I/O, Port D bit 7 |
| 引脚 28 | PD6 — General-purpose I/O, Port D bit 6 |
| 引脚 29 | PD5 — General-purpose I/O, Port D bit 5 |
| 引脚 30 | PD4 — General-purpose I/O, Port D bit 4 |
| 引脚 31 | GND — Ground |
| 引脚 32 | VDD — Power supply |
| 引脚 33 | PD3 — General-purpose I/O, Port D bit 3 |
| 引脚 34 | PD2 — General-purpose I/O, Port D bit 2 |
| 引脚 35 | PD1 — General-purpose I/O, Port D bit 1 |
| 引脚 36 | PD0 — General-purpose I/O, Port D bit 0 |
| 引脚 37 | PE3 — General-purpose I/O, Port E bit 3 |
| 引脚 38 | PE2 — General-purpose I/O, Port E bit 2 |
| 引脚 39 | PE1 — General-purpose I/O, Port E bit 1 |
| 引脚 40 | PE0 — General-purpose I/O, Port E bit 0 |
| 引脚 41 | PF5 — General-purpose I/O, Port F bit 5 |
| 引脚 42 | PF4 — General-purpose I/O, Port F bit 4 |
| 引脚 43 | PF3 — General-purpose I/O, Port F bit 3 |
| 引脚 44 | PF2 — General-purpose I/O, Port F bit 2 |
| 引脚 45 | PF1 — General-purpose I/O, Port F bit 1 |
| 引脚 46 | PF0 — General-purpose I/O, Port F bit 0 |
| 引脚 47 | GND — Ground |
| 引脚 48 | VDD — Power supply (UPDI is multiplexed on Port F per datasheet) |
典型应用
ATMEGA809-AU 适用于 6 应用s: Industrial Automation Nodes, Home Appliance Control, IoT Sensor Endpoints, Motor Control and Lighting, Educational and Hobbyist Platforms, Safety-Relevant Embedded Systems.
Industrial Automation Nodes
The ATMEGA809-AU fits industrial automation nodes where an 8-bit MCU must coordinate sensors and actuators over I2C, SPI, or UART/USART at up to 20 MHz. The megaAVR 0-series Core Independent Peripherals and Event System let timers, analog comparators, and communication modules react to events without CPU intervention, keeping deterministic timing in polling-heavy control loops. Brown-out Detect/Reset and Power-on Reset supervise the supply rail during brownouts caused by inductive loads or motor inrush. With 8 KB Flash and 1 KB SRAM, firmware for Modbus-style serial slaves or CAN-gateway glue logic fits comfortably. The 48-TQFP (7x7 mm) surface-mount package offers enough GPIO for optocoupler-driven I/O racks while remaining hand-solderable for prototype revisions.
推荐
Home Appliance Control
Home-appliance control boards benefit from the ATMEGA809-AU's combination of low unit cost (about $1.58 in single quantities at LCSC as of 2026-09-18), robust supply supervision, and rich GPIO count in the 48-TQFP footprint. User interfaces with rotary encoders, seven-segment displays, and touch or mechanical buttons map directly onto PORTA-PORTF banks. The hardware multiplier accelerates PID control for temperature regulation in ovens and refrigerators at a 20 MHz core rate. UART/USART links to inverter or display modules, while EEPROM storage retains user settings and fault logs across power cycles. Brown-out Detect/Reset prevents corrupted EEPROM writes when mains sags occur, a common field failure in appliance electronics.
推荐
IoT Sensor Endpoints
For battery- and mains-powered IoT sensor endpoints, the ATMEGA809-AU provides the megaAVR 0-series low-power architecture with intelligent analog and Core Independent Peripherals. The Event System allows a periodic timer to trigger ADC conversions and push results to a UART/USART radio link while the CPU sleeps, dramatically extending battery life. 8 KB Flash accommodates firmware including a serial protocol stack, and 256 bytes of EEPROM stores device identity and calibration constants. I2C and SPI interfaces connect humidity, pressure, and light sensors directly. Engineers can prototype rapidly using the MegaCoreX Arduino hardware package on GitHub, which explicitly supports the ATmega809, then deploy production code compiled with the AVR-GCC toolchain.
推荐
Motor Control and Lighting
Motor-control and LED-lighting applications exploit the ATMEGA809-AU's 20 MHz AVR core with hardware multiplier for fast PID and PWM duty-cycle computation. Core Independent Peripherals can tie timers directly to output compare pins through the Event System, generating glitch-free PWM for BLDC phases or dimmable LED strings even during ISR latency. Intelligent analog blocks monitor current-sense inputs without external comparators in many designs. The 48-TQFP package exposes sufficient GPIO for gate-driver enables, fault inputs, and encoder interfaces, while UART/USART links the controller to a supervisory board. Brown-out supervision prevents runaway PWM outputs during supply transients, protecting power stages from shoot-through failures.
推荐
Educational and Hobbyist Platforms
The ATMEGA809-AU is attractive for education and maker platforms because the open-source MegaCoreX Arduino hardware package on GitHub supports ATmega809, ATmega1609, ATmega3209, and ATmega4809 directly. Students program through the single-pin UPDI interface using low-cost Microchip SNAP or PICkit 4 tools, or via a serial bootloader, avoiding expensive debug probes. The AVR instruction set with hardware multiplier teaches both assembly fundamentals and C embedded development at a 20 MHz clock rate. The 48-TQFP (7x7 mm) package is solderable on simple two-layer boards, and 48 GPIO pins support robotics, sensor-lab, and display projects. Community documentation and forum threads on the Arduino forum lower the learning curve substantially.
推荐
Safety-Relevant Embedded Systems
The ATMEGA809-AU is classified on DigiKey as a megaAVR 0-series Functional Safety (FuSa) microcontroller, making it a candidate for safety-relevant embedded systems such as machine-guard controllers, e-stop monitors, and building-safety sensing. Microchip provides safety-collateral documentation supporting IEC 61508-oriented developments for this family. The built-in Brown-out Detect/Reset and Power-on Reset reduce external supervision components, while the Event System enables redundant, CPU-independent signal paths that simplify diagnostic coverage arguments. With 8 KB Flash, safety firmware including self-test routines remains compact and auditable. Always obtain Microchip's current FuSa package and certificates to confirm qualification scope for your target safety integrity level before committing the design.
推荐
推荐产品汇总
工程参考数据： ATMEGA809-AU ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | ATMEGA1609-AU | ATMEGA3209-AU | ATMEGA4809-AU | ATMEGA809-AFR |
|---|---|---|---|---|---|
| Package | 48-TQFP (7x7) | 48-TQFP (7x7) - same | 48-TQFP (7x7) - same | 48-TQFP (7x7) - same | 48-TQFP (7x7) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core / Clock | AVR 8-bit, 20 MHz | AVR 8-bit, 20 MHz | AVR 8-bit, 20 MHz | AVR 8-bit, 20 MHz | AVR 8-bit, 20 MHz |
| Flash | 8 KB | 16 KB | 32 KB | 48 KB | 8 KB |
| SRAM | 1 KB | 2 KB | 4 KB | 6 KB | 1 KB |
| EEPROM | 256 bytes | 256 bytes | 256 bytes | 256 bytes | 256 bytes |
| Connectivity | I2C, SPI, UART/USART | I2C, SPI, UART/USART | I2C, SPI, UART/USART | I2C, SPI, UART/USART | I2C, SPI, UART/USART |
| Qualification | Standard, FuSa classification | Standard | Standard | Standard | Automotive grade |
关键差异点
- Lowest-cost entry point of the 48-pin megaAVR 0-series （对比 ATMEGA4809-AU)
- Functional Safety (FuSa) product classification （对比 ATMEGA1609-AU)
- Identical-die automotive option （对比 ATMEGA809-AFR)
设计说明
Decouple every VDD pin (pins 8, 18, 32, 48) with a 100 nF ceramic capacitor placed within 2 mm of the pin and returned to the nearest GND pin (7, 17, 31, 47). The 48-TQFP exposes a large center area - use it for a solid ground plane via array rather than a thermal pad. Route the UPDI pin trace to a standard 1x3 or Tag-Connect footprint on every production board; retrofitting a programming header after layout freeze is a common and costly mistake on megaAVR 0-series designs.
Configure Brown-out Detection (BOD) level to sit below the minimum operating voltage of your regulator's regulation band but above the MCU's minimum safe operating voltage for the chosen clock frequency, using the datasheet voltage-versus-frequency derating curve. Enable the BOD in continuous mode during flash/EEPROM writes and sampled mode elsewhere to reduce supply current. Neglecting BOD configuration is the most common cause of corrupted EEPROM contents on AVR designs operating near the voltage limit.
The megaAVR 0-series differs significantly from classic ATmega328P-era parts: fuse semantics, register maps, and the programming interface (UPDI instead of ISP) are all new, so legacy ISP programmers and classic Arduino bootloaders will not work. Use MPLAB X with SNAP, PICkit 4, or Atmel-ICE, or the community MegaCoreX package for Arduino IDE support. When migrating code from ATmega328P, budget time to re-map peripherals to the Event System rather than assuming register-level compatibility.
合规信息
RoHS compliant per current Microchip active-product status on DigiKey/LCSC listings; use ATMEGA809-AFR for AEC-Q100 automotive qualification. Formal REACH and halogen-free declarations should be obtained from Microchip's material declaration documents.
