ATMEGA324P-20AU - 8-bit AVR MCU 20MHz 32KB Flash | Microchip
料号： ATMEGA324P-20AU ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $8.42 | $8.42 |
| 10 | $7.58 | $75.80 |
| 100 | $7.11 | $711.00 |
| 500 | $6.68 | $3,340.00 |
| 1,000 | $6.24 | $6,240.00 |
ATMEGA324P-20AU 概述
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that executes most instructions in a single clock cycle, positioning it in the embedded control hierarchy between simple 8051-class MCUs and 32-bit ARM Cortex-M devices. The ATmega family is a workhorse for industrial control, hobby electronics, and appliance designs where 5V I/O tolerance and low cost matter more than raw processing power.
Key features include 32 general purpose I/O lines, two USARTs, a byte-oriented Two-Wire (I2C-compatible) interface, an SPI interface, an 8-channel 10-bit ADC, and three flexible timer/counters with compare modes and PWM. The picoPower technology enables aggressive sleep modes for battery-sensitive designs, while the AVR enhanced RISC instruction set achieves near 1 MIPS/MHz throughput.
Architecturally, the device pairs 32 general purpose working registers directly with the ALU, eliminating the accumulator bottleneck of classic 8-bit MCUs. Read-while-write Flash allows self-programming for bootloaders, and In-System Programming (ISP) via SPI simplifies production programming without removing the chip.
Typical applications include industrial automation nodes, HVAC and appliance control, sensor acquisition systems using the 10-bit ADC, and embedded designs requiring dual UART ports for modem and debug links.
A key design consideration is that this 5V part runs at 20 MHz only at 4.5V-5.5V; at lower VCC the maximum clock frequency derates per the datasheet frequency-versus-voltage curve.
This page synthesizes distributor pricing, drop-in family alternatives (ATMEGA324PA, ATMEGA324PB, ATMEGA644P), pinout data, and practical design notes not found in a single manufacturer source.
直接替换替代料： ATMEGA324P-20AU ——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： ATMEGA324P-20AU （相同外形与封装尺寸） ——差异在于 Package, Serial Interfaces, Supply Voltage Range, ADC, Flash Memory.
快速对比工具——选择替代料号进行并排对比：
ATMEGA324PA-20AU
✅ 直接替换📋 参考替代料（不在目录中）
ATMEGA324PB-AU
✅ 直接替换📋 参考替代料（不在目录中）
ATMEGA324A-AU
✅ 直接替换✓ 有现货
$2.09 / 个
查看数据手册 →ATMEGA644P-20AU
✅ 直接替换✓ 有现货
$3.95 / 个
查看数据手册 →ATMEGA644PA-20AU
✅ 直接替换📋 参考替代料（不在目录中）
ATMEGA324P-20AU 最大额定值与电气特性
| Core Architecture | 8-bit AVR RISC |
| 最大时钟频率 | 20 MHz |
| Flash Memory | 32 KB (16K x 16) ISP |
| EEPROM | 1 KB |
| SRAM | 2 KB |
| 电源电压 | 4.5 V to 5.5 V (20 MHz rating) |
| Number of I/O Lines | 32 |
| USARTs | 2 |
| Timers | 3 timer/counters with compare modes and PWM |
| ADC | 8-channel, 10-bit |
| Serial Interfaces | 2x USART, SPI, Two-Wire (I2C-compatible) |
| 封装 | 44-TQFP (10x10 mm) |
| 安装类型 | Surface Mount |
| Programming | In-System Programmable (ISP), read-while-write |
| Low Power Technology | picoPower |
| Working Registers | 32 general purpose |
ATMEGA324P-20AU 引脚配置
| 引脚 1 | PB5 (OC1A) — Port B bit 5 / Timer1 Output Compare A |
| 引脚 2 | PB6 (OC1B) — Port B bit 6 / Timer1 Output Compare B |
| 引脚 3 | PB7 (OC2A/OC0A) — Port B bit 7 / Timer2 Output Compare A / Timer0 Output Compare A |
| 引脚 4 | RESET — Reset input, active low |
| 引脚 5 | VCC — Digital supply voltage |
| 引脚 6 | GND — Ground |
| 引脚 7 | XTAL1 — Crystal/oscillator input |
| 引脚 8 | XTAL2 — Crystal/oscillator output |
| 引脚 9 | PD0 (RXD0) — Port D bit 0 / USART0 receive |
| 引脚 10 | PD1 (TXD0) — Port D bit 1 / USART0 transmit |
| 引脚 11 | PD2 (INT0/RXD1) — Port D bit 2 / External interrupt 0 / USART1 receive |
| 引脚 12 | PD3 (INT1/TXD1) — Port D bit 3 / External interrupt 1 / USART1 transmit |
| 引脚 13 | PD4 (XCK/T0) — Port D bit 4 / USART0 external clock / Timer0 external clock |
| 引脚 14 | VCC — Digital supply voltage |
| 引脚 15 | GND — Ground |
| 引脚 16 | PD5 (XCK1/OC1A) — Port D bit 5 / USART1 external clock / Timer1 Output Compare A |
| 引脚 17 | PD6 (RT1/OC1B/OC2B) — Port D bit 6 / Timer1 Output Compare B / Timer2 Output Compare B |
| 引脚 18 | PD7 (OC2A/OC0A) — Port D bit 7 / Timer2 Output Compare A / Timer0 Output Compare A |
| 引脚 19 | PC0 (SCL) — Port C bit 0 / Two-Wire clock |
| 引脚 20 | PC1 (SDA) — Port C bit 1 / Two-Wire data |
| 引脚 21 | PC2 (TCK) — Port C bit 2 / JTAG test clock |
| 引脚 22 | PC3 (TMS) — Port C bit 3 / JTAG test mode select |
| 引脚 23 | PC4 (TDO) — Port C bit 4 / JTAG test data output |
| 引脚 24 | PC5 (TDI) — Port C bit 5 / JTAG test data input |
| 引脚 25 | PC6 (TOSC1) — Port C bit 6 / Timer oscillator input |
| 引脚 26 | PC7 (TOSC2) — Port C bit 7 / Timer oscillator output |
| 引脚 27 | PA7 (ADC7) — Port A bit 7 / ADC channel 7 |
| 引脚 28 | PA6 (ADC6) — Port A bit 6 / ADC channel 6 |
| 引脚 29 | PA5 (ADC5) — Port A bit 5 / ADC channel 5 |
| 引脚 30 | PA4 (ADC4) — Port A bit 4 / ADC channel 4 |
| 引脚 31 | PA3 (ADC3) — Port A bit 3 / ADC channel 3 |
| 引脚 32 | PA2 (ADC2) — Port A bit 2 / ADC channel 2 |
| 引脚 33 | PA1 (ADC1) — Port A bit 1 / ADC channel 1 |
| 引脚 34 | PA0 (ADC0) — Port A bit 0 / ADC channel 0 |
| 引脚 35 | GND — Ground |
| 引脚 36 | AVCC — Analog supply voltage for ADC |
| 引脚 37 | AREF — Analog reference voltage for ADC |
| 引脚 38 | PB0 (XCK0/T0) — Port B bit 0 / USART0 external clock / Timer0 external clock |
| 引脚 39 | PB1 (T1) — Port B bit 1 / Timer1 external clock |
| 引脚 40 | PB2 (AIN0/INT2) — Port B bit 2 / Analog comparator positive input / External interrupt 2 |
| 引脚 41 | PB3 (AIN1/OC0) — Port B bit 3 / Analog comparator negative input / Timer0 output compare |
| 引脚 42 | PB4 (SS) — Port B bit 4 / SPI slave select |
| 引脚 43 | GND — Ground |
| 引脚 44 | VCC — Digital supply voltage |
典型应用
ATMEGA324P-20AU 适用于 6 应用s: Industrial Automation Control Nodes, Embedded Sensor Acquisition Systems, HVAC and Appliance Control, Communication and Telemetry Devices, Hobby, Education and Maker Platforms, Automotive Aftermarket and Off-Highway Electronics.
Industrial Automation Control Nodes
The ATMEGA324P-20AU fits industrial control nodes because its 5V-tolerant 32 GPIO lines interface directly with legacy 24V-buffered sensor inputs and relay drivers without level translation, and its 20 MHz AVR core delivers roughly 20 MIPS for deterministic polling loops. Dual USARTs allow one port for a Modbus RTU fieldbus link and a second for local diagnostics, while the hardware SPI and Two-Wire interface connect isolated ADC front ends or EEPROM configuration storage. The 10-bit, 8-channel ADC samples analog setpoints and feedback at up to 15 kSPS, sufficient for temperature and process monitoring. The industrial temperature designation (GREEN, per FindIC data) supports cabinet-mounted controllers, and ISP Flash enables field firmware updates through the existing serial link without disassembling equipment.
推荐
Embedded Sensor Acquisition Systems
For data acquisition designs, the ATMEGA324P-20AU's 8-channel 10-bit ADC with internal 2.56V reference option covers multi-sensor boards such as thermistor arrays, pressure bridges via external amplifiers, and potentiometer position feedback. The AVR core keeps sample servicing deterministic, and 2 KB SRAM buffers several hundred 10-bit readings before transmission. The Two-Wire interface reads digital sensors (humidity, RTC) while the first USART streams data to a host or radio module; the second USART remains available for configuration. picoPower sleep modes drop consumption between sample intervals, extending battery life in remote loggers. Because all analog inputs share Port A (pins 27-34) adjacent to AVCC and AREF (pins 36-37), a clean analog ground layout around that corner of the 44-TQFP yields measurably lower ADC noise.
推荐
HVAC and Appliance Control
White-goods and HVAC controllers benefit from the ATMEGA324P-20AU's combination of 5V robustness, three timers with PWM for blower or compressor drive, and dual USARTs for display panels plus communication. Timer compare channels generate phase-correct PWM for motor speed control, while the watchdog and brown-out features (documented in the ATmega324 datasheet) protect against mains-transient lockups common in appliance environments. The 1 KB EEPROM retains calibration and fault-log data through power cycles, and read-while-write Flash permits logging to the program array without halting execution. Industrial temperature range and the widely supported AVR toolchain shorten certification and production bring-up. The 44-TQFP 10x10 mm footprint suits two-layer control boards, keeping the bill of materials cost-sensitive appliance designs require.
推荐
Communication and Telemetry Devices
The ATMEGA324P-20AU's two independent hardware USARTs make it a natural fit for telemetry gateways: one UART connects a GSM/NB-IoT or LoRa modem while the second services a local RS-485/RS-232 diagnostic port, eliminating software UART bit-banging and its timing jitter. At 20 MHz, baud rates well beyond 115200 are achieved with low error from the datasheet baud-rate tables, and the SPI interface drives SD-card logging at compact-flash speeds adequate for text telemetry. The 32 KB Flash accommodates protocol stacks with headroom for OTA-capable bootloaders enabled by read-while-write self-programming. picoPower idle modes keep the radio poll cycle efficient in battery-backed installations. Designers should budget the 2 KB SRAM carefully, as modem buffers plus protocol state consume several hundred bytes.
推荐
Hobby, Education and Maker Platforms
The ATmega family underpins the Arduino ecosystem, and the ATMEGA324P-20AU extends that familiarity to projects needing more I/O than an ATmega328P: 32 GPIO, dual UARTs, and 44-pin TQFP versatility at hobby-friendly 5V levels. The AVR instruction set is fully supported by avr-gcc, Microchip Studio, and the open-source Arduino core forks for ATmega324 targets, so firmware reuse from ATmega328 designs is straightforward. ISP programming needs only a 6-pin header and a USBasp-class programmer, and bootloaders via either USART allow serial reprogramming from a laptop. The 10-bit ADC and hardware PWM support robotics, LED matrices, and instrument projects directly. Through-hole-style prototyping is possible using TQFP-44 breakout boards before committing to a production PCB.
推荐
Automotive Aftermarket and Off-Highway Electronics
In non-safety automotive aftermarket products such as gauge clusters, add-on controllers, and off-highway equipment accessories, the ATMEGA324P-20AU provides 5V logic compatible with vehicle sensor outputs through simple dividers, and the 10-bit ADC digitizes throttle, temperature, and battery-voltage signals. Timers generate PWM for gauges and backlighting, while a USART handles CAN-adapter modules or LIN transceiver daughterboards via SPI framing. The wide industrial temperature designation and robust AVR core tolerate engine-bay-adjacent environments when paired with proper transient suppression. EEPROM stores learned calibrations across ignition cycles. Designers must add load-dump protection externally, as the MCU itself is not automotive-qualified; for AEC-Q-qualified designs select Microchip's automotive AVR portfolio instead of this classic part.
推荐
推荐产品汇总
工程参考数据： ATMEGA324P-20AU ——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 | ATMEGA324PA-20AU | ATMEGA324PB-AU | ATMEGA324A-AU | ATMEGA644P-20AU | ATMEGA644PA-20AU |
|---|---|---|---|---|---|---|
| Package | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 32 KB | 32 KB | 32 KB | 32 KB | 64 KB | 64 KB |
| SRAM | 2 KB | 2 KB | 2 KB | 2 KB | 4 KB | 4 KB |
| EEPROM | 1 KB | 1 KB | 1 KB | 1 KB | 2 KB | 2 KB |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Supply Voltage | 4.5 V to 5.5 V | 1.8 V to 5.5 V (speed derated below 4.5 V) | 1.8 V to 5.5 V (speed derated below 4.5 V) | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 1.8 V to 5.5 V (speed derated below 4.5 V) |
| picoPower Low-Power | Yes | Yes (improved) | Yes (lowest of family) | No | No | Yes |
| USARTs | 2 | 2 | 2 | 2 | 2 | 2 |
| Firmware Compatibility | Baseline (classic ATmega324P) | Binary/AT compatible - none needed | Recompile required (register differences) | Binary compatible | Recompile for larger memory map | Recompile for larger memory map |
关键差异点
- Lowest-risk sourcing: direct successor availability （对比 ATMEGA324PA-20AU)
- Simplest firmware migration in the family （对比 ATMEGA324PB-AU)
- Memory headroom trade-off （对比 ATMEGA644P-20AU)
- Cost advantage over larger siblings （对比 ATMEGA2560-16AU)
设计说明
Decouple each of the three VCC pins (5, 14, 44) with 100 nF ceramic capacitors placed within 3 mm of the pin, plus one bulk 10 uF capacitor near the supply entry. Connect AVCC (pin 36) to VCC through an LC filter (10 uH + 100 nF) when ADC accuracy matters, and never leave AVCC unconnected even if the ADC is unused. Ground pins 6, 15, 35, and 43 should all be tied to a solid ground plane - the 44-TQFP center is the ideal via field for this.
Keep the AREF (pin 37) network short: a 100 nF capacitor to ground when using the internal reference, and do not drive AREF while the internal reference is selected - this damages the reference. Route analog Port A traces (pins 27-34) away from XTAL and USART lines to minimize crosstalk into ADC conversions. Place the 16 MHz or 20 MHz crystal within 10 mm of XTAL1/XTAL2 (pins 7-8) with load capacitors grounded directly to the ground plane per the clock-source section of the Microchip datasheet.
The '-20' speed grade is only valid at 4.5V-5.5V; running at 3.3V violates the frequency-versus-voltage derating curve and causes marginal operation that appears intermittently with temperature. Set the CKOPT/fuse configuration correctly for a 20 MHz crystal - incorrect low-frequency crystal fuses are the most common cause of boards that 'do not start'. Also verify brown-out detector fusing: enabling BOD around 4.3V protects Flash writes during 5V rail sag events.
At 20 MHz with fast GPIO slew settings, limit series resistance (33-100 ohm) on long unshielded output traces to reduce ringing and EMI. For the two USARTs, especially the modem-facing UART, add transient protection (TVS diodes) on any line leaving the PCB. JTAG pins PC2-PC5 double as GPIO; if JTAG is disabled via the JTAGEN fuse, confirm the pull-up state of PC2-PC5 at reset to avoid floating inputs during power-up sequences.
合规信息
Distributor data (FindIC) describes the part as GREEN industrial-temperature product; AU suffix denotes lead-free TQFP finish. REACH/halogen/conflict-minerals declarations not present in provided data - confirm via Microchip compliance portal.