ATMEGA328-AUR - 8-bit AVR MCU 20MHz 32KB Flash TQFP-32 | Microchip
料号： ATMEGA328-AUR ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $2.85 | $2.85 |
| 10 | $2.56 | $25.60 |
| 100 | $2.28 | $228.00 |
| 500 | $2.05 | $1,025.00 |
| 1,000 | $1.83 | $1,830.00 |
| 3,000 | $1.65 | $4,950.00 |
ATMEGA328-AUR 概述
An 8-bit microcontroller (MCU) is a single integrated circuit that combines a processor core, memory, and peripherals such as timers, UART, SPI, and I2C on one die. MCUs sit at the lowest level of the embedded systems hierarchy - below SoCs and application processors - and are the workhorses of industrial control, consumer appliances, and hobbyist platforms such as the Arduino UNO, which made the ATmega328 family the most recognized 8-bit MCU in the world.
Key features include the AVR enhanced RISC architecture executing most instructions in a single clock cycle, 32 general-purpose working registers, three flexible timer/counters, a 10-bit ADC with 8 multiplexed channels (6 differential with programmable gain), and hardware USART, SPI, and TWI (I2C) serial interfaces. The device supports both 2.5V to 5.5V operation across its speed grades, enabling battery-powered 3.3V designs as well as 5V industrial rails.
Technical depth: the Harvard architecture with separate program and data buses allows single-cycle instruction fetch and execution. In-System Programmable Flash with read-while-write support permits firmware updates in the field via SPI or a bootloader, while independent lock bits protect code IP. Power management includes idle, ADC noise reduction, power-save, power-down, standby, and extended standby modes, plus an on-chip brown-out detector and internal RC oscillator options.
Typical applications include Arduino-compatible boards, industrial sensor nodes, motor control panels, HVAC and appliance control, battery monitors, and consumer electronics - anywhere a low-cost, well-supported 8-bit controller with rich analog and serial peripherals is required.
Design consideration: decouple VCC/AVCC with 100 nF ceramics close to pins, and remember the TQFP-32 version exposes ADC6 and ADC7 (pins 19 and 22) that the 28-pin DIP variant lacks - useful for extra analog channels.
This page synthesizes distributor pricing, drop-in alternatives, pinout data, and practical design notes not found in the manufacturer datasheet, as of 2026-09-17.
直接替换替代料： ATMEGA328-AUR ——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： ATMEGA328-AUR （相同外形与封装尺寸） ——差异在于 Package, Supply Voltage Range, Timers, ADC, Communication Interfaces.
快速对比工具——选择替代料号进行并排对比：
ATMEGA328P-AUR
✅ 直接替换✓ 有现货
$2.18 / 个
查看数据手册 →ATMEGA328PB-AUR
✅ 直接替换✓ 有现货
$1.31 / 个
查看数据手册 →ATMEGA328-AU
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
ATMEGA328P-AU
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$1.74 / 个
查看数据手册 →ATMEGA325PA-AUR
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$3.9 / 个
查看数据手册 →ATMEGA328-AUR 最大额定值与电气特性
| Core Processor | AVR 8-bit RISC |
| Core Size | 8-bit |
| Speed | 20 MHz |
| Flash Memory | 32 KB (16K x 16) |
| EEPROM | 1 KB |
| SRAM | 2 KB |
| Number of I/O | 23 |
| ADC Resolution | 10-bit |
| Number of ADC Channels | 8 (TQFP-32) |
| Timers/Counters | 2 x 8-bit, 1 x 16-bit |
| Communication Interfaces | USART, SPI, TWI (I2C) |
| Supply Voltage Range | 2.5 V to 5.5 V |
| 工作温度 | -40C to +85C |
| 封装 | 32-TQFP (7x7 mm) |
| 安装类型 | Surface Mount |
| Packaging | Tape & Reel (R suffix) |
| Programmability | In-System Programmable (ISP), read-while-write |
| RoHS 状态 | Compliant |
ATMEGA328-AUR 引脚配置
| 引脚 1 | PD3 (PCINT19/OC2B/INT1) — Port D, GPIO / Timer2 output compare B / external interrupt 1 |
| 引脚 2 | PD4 (PCINT20/XCK/T0) — Port D, GPIO / USART external clock / Timer0 clock input |
| 引脚 3 | GND — Ground |
| 引脚 4 | VCC — Digital supply voltage |
| 引脚 5 | GND — Ground |
| 引脚 6 | VCC — Digital supply voltage |
| 引脚 7 | PB6 (PCINT6/XTAL1/TOSC1) — Port B / crystal oscillator input / Timer oscillator |
| 引脚 8 | PB7 (PCINT7/XTAL2/TOSC2) — Port B / crystal oscillator output |
| 引脚 9 | PD5 (PCINT21/OC0B/T1) — Port D, GPIO / Timer0 output compare B / Timer1 clock input |
| 引脚 10 | PD6 (PCINT22/OC0A/AIN0) — Port D, GPIO / Timer0 output compare A / analog comparator input |
| 引脚 11 | PD7 (PCINT23/AIN1) — Port D, GPIO / analog comparator input 1 |
| 引脚 12 | PB0 (PCINT8/CLKO/ICP1) — Port B, GPIO / clock output / Timer1 input capture |
| 引脚 13 | PB1 (PCINT9/OC1A) — Port B, GPIO / Timer1 output compare A |
| 引脚 14 | PB2 (PCINT10/OC1B/SS) — Port B, GPIO / Timer1 output compare B / SPI slave select |
| 引脚 15 | PB3 (PCINT11/OC2A/MOSI) — Port B, GPIO / Timer2 output compare A / SPI master out |
| 引脚 16 | PB4 (PCINT12/MISO) — Port B, GPIO / SPI master in |
| 引脚 17 | PB5 (PCINT13/SCK) — Port B, GPIO / SPI clock |
| 引脚 18 | AVCC — ADC supply voltage |
| 引脚 19 | ADC6 — ADC input channel 6 (TQFP-32 only) |
| 引脚 20 | AREF — Analog reference voltage |
| 引脚 21 | GND — Ground |
| 引脚 22 | ADC7 — ADC input channel 7 (TQFP-32 only) |
| 引脚 23 | PC0 (ADC8/PCINT16) — Port C, GPIO / ADC channel 0 |
| 引脚 24 | PC1 (ADC9/PCINT17) — Port C, GPIO / ADC channel 1 |
| 引脚 25 | PC2 (ADC10/PCINT18) — Port C, GPIO / ADC channel 2 |
| 引脚 26 | PC3 (ADC11/PCINT19) — Port C, GPIO / ADC channel 3 |
| 引脚 27 | PC4 (ADC12/SDA/PCINT20) — Port C, GPIO / ADC4 / I2C data |
| 引脚 28 | PC5 (ADC13/SCL/PCINT21) — Port C, GPIO / ADC5 / I2C clock |
| 引脚 29 | PC6 (RESET/PCINT22) — Reset input (active low) / GPIO after fuse programming |
| 引脚 30 | PD0 (PCINT16/RXD) — Port D, GPIO / USART receive |
| 引脚 31 | PD1 (PCINT17/TXD) — Port D, GPIO / USART transmit |
| 引脚 32 | PD2 (PCINT18/INT0) — Port D, GPIO / external interrupt 0 |
典型应用
ATMEGA328-AUR 适用于 6 应用s: Arduino-Compatible Boards, Industrial Sensor Nodes, Home Automation and Smart Devices, Motor Control and PWM Applications, Battery-Powered Instruments, Consumer Appliance Control.
Arduino-Compatible Boards
The ATMEGA328-AUR powers the classic Arduino ecosystem: with a 16 MHz crystal, 22 pF load capacitors, auto-reset capacitor, and the Optiboot bootloader, it becomes an Uno/Nano-compatible controller in a compact 7x7 mm TQFP. Its 32 KB Flash holds large sketches, and hardware USART/SPI/TWI map directly to Arduino pins. Because register maps match the ATmega328P, the full Arduino library ecosystem runs unchanged, making it the default choice for open-source hardware production runs where the DIP package is unnecessary and SMT assembly lowers cost.
推荐
Industrial Sensor Nodes
In factory sensor acquisition nodes, the ATMEGA328-AUR's 10-bit ADC with 8 channels digitizes thermistors, pressure bridges, and 4-20 mA-derived signals, while the USART links to RS-485 transceivers and the TWI bus reads I2C sensors. The 2.5V-5.5V supply range tolerates noisy industrial rails, and the -40C to +85C industrial grade suits control cabinets. Power-down sleep between samples cuts average current in battery-fed nodes, and the 1 KB EEPROM stores calibration constants that survive power loss without external memory.
推荐
Home Automation and Smart Devices
Smart plugs, thermostats, and lighting controllers use the ATMEGA328-AUR because its 23 GPIO directly drive relays and triac circuits via opto-isolators, while the ADC monitors mains-derived voltage samples for zero-cross detection. The three timer/counters generate PWM for dimming or motor speed, and the TWI interface reads touch or environmental sensors. At volume, its low cost in tape-and-reel supports consumer pricing pressure, and code compatibility with the huge ATmega community shortens firmware development cycles significantly.
推荐
Motor Control and PWM Applications
Fan, pump, and small DC motor controllers exploit the ATMEGA328-AUR's 16-bit Timer1 for high-resolution PWM and its 8-bit Timer0/Timer2 for tachometer input capture and phase-correct PWM. The ADC samples current-shunt voltages for overload detection, and the input-capture unit measures period precisely for closed-loop speed control. Operating from a 5V industrial rail with the brown-out detector enabled ensures safe PWM shutdown on supply dips, while the watchdog timer recovers firmware from transient faults in unattended equipment.
推荐
Battery-Powered Instruments
Portable meters and loggers benefit from the ATMEGA328-AUR's sleep architecture: power-down mode drops consumption below 1 uA, waking on the watchdog or external interrupt to sample, log to EEPROM, or transmit over UART. The 2.5V operation end-of-life threshold lets designs run directly from two alkaline cells through most of their discharge curve, and ADC noise-reduction mode improves measurement resolution during conversions. Designers needing the longest battery life should evaluate the picoPower ATMEGA328P-AUR, which shares this footprint exactly.
推荐
Consumer Appliance Control
Coffee makers, rice cookers, and small appliance boards use the ATMEGA328-AUR for keypad scanning, display driving (via SPI to LED/LCD drivers), relay control, and thermistor-based temperature regulation with PID firmware. The 20 MHz capability gives headroom for control loops, and the internal 8 MHz RC oscillator removes crystal cost in cost-sensitive products where timing tolerance is acceptable. Tape-and-reel supply supports automated SMT lines, and industrial temperature rating covers kitchen environments near heating elements.
推荐
推荐产品汇总
工程参考数据： ATMEGA328-AUR ——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 | ATMEGA328P-AUR | ATMEGA328PB-AUR | ATMEGA328-AU | ATMEGA325PA-AUR |
|---|---|---|---|---|---|
| Package | 32-TQFP (7x7 mm) | 32-TQFP (7x7 mm) - same | 32-TQFP (7x7 mm) - same | 32-TQFP (7x7 mm) - same | 32-TQFP - same footprint |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB |
| Max Clock Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 10 MHz |
| SRAM | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB |
| PicoPower / Low Sleep Current | No | Yes (picoPower) | Yes (XLP-style improvements) | No | Yes (picoPower) |
| Drop-in Compatibility Notes | - | Full pin-to-pin, firmware compatible | Same footprint, 2 pins reassigned, register deltas | Identical die, tray packaging | Different peripheral set - review required |
关键差异点
- Lowest cost within the pin-compatible family （对比 ATMEGA328P-AUR)
- Two extra ADC channels vs 28-pin DIP versions （对比 ATMEGA328-PU (DIP-28))
- Guaranteed legacy register compatibility （对比 ATMEGA328PB-AUR)
- Trade-off: higher sleep current （对比 ATMEGA328P-AUR)
设计说明
Place 100 nF ceramic decoupling capacitors directly across each VCC/GND pin pair (pins 4/3 and 6/5) plus one on AVCC (pin 18) to ground, with a 10 uF bulk capacitor near the IC. Tie AVCC to VCC through an LC filter (10 uH + 10 uF) when ADC accuracy matters. Route the AREF pin with its own 100 nF capacitor to ground; never connect AREF to a supply rail directly.
Respect the frequency-versus-voltage curve: 20 MHz requires 4.5V-5.5V; at 3.3V limit the clock to about 10 MHz. If your design uses an external 16 MHz crystal for Arduino compatibility, run the part from 5V to stay within specification. Estimated: at 20 MHz/5V active current of roughly 6 mA, power dissipation is about 30 mW - negligible thermally in the TQFP-32, no heatsinking ever needed.
PB6/PB7 (pins 7/8) default to the crystal function; to use them as GPIO you must program the CKOUT/fuse settings for internal RC oscillator. Enable the brown-out detector (BOD) fuse when running from mains-derived supplies, and set the watchdog in production firmware. When replacing a failed ATMEGA328P with this non-P part in the field, expect slightly higher sleep current - relevant only in battery products.
Keep the crystal within 10 mm of pins 7/8 with short traces and guard with a ground ring for reliable start-up across temperature. For SPI lines longer than 10 cm, add 33-ohm series resistors to reduce ringing. Unused PCINT-capable inputs should be pulled high or low (internal pull-ups suffice) to prevent floating-input oscillation of the input schmitt triggers.
合规信息
RoHS compliance per standard Microchip environmental policy for current AVR production; REACH and halogen-free status not stated in provided web data.