ATMEGA324P-20AU - 8-bit AVR MCU 20MHz 32KB Flash | Microchip
MPN: ATMEGA324P-20AU ✓ Hoạt độngATMEGA324P-20AU Tóm tắt
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.
Bộ thay thế dễ dàng lắp đặt cho ATMEGA324P-20AU — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với ATMEGA324P-20AU (cùng hình factor và footprint) — khác nhau ở Package, Serial Interfaces, Supply Voltage Range, ADC, Flash Memory.
ATMEGA324PA-20AU
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
ATMEGA324PB-AU
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
ATMEGA324A-AU
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ATMEGA644P-20AU
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ATMEGA644PA-20AU
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
ATMEGA324P-20AU Tỷ lệ tối đa & tính chất điện
| Core Architecture | 8-bit AVR RISC |
| Tần số xung maksimum | 20 MHz |
| Flash Memory | 32 KB (16K x 16) ISP |
| EEPROM | 1 KB |
| SRAM | 2 KB |
| Điện áp cung cấp | 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) |
| Hộp | 44-TQFP (10x10 mm) |
| Kiểu lắp đặt | Surface Mount |
| Programming | In-System Programmable (ISP), read-while-write |
| Low Power Technology | picoPower |
| Working Registers | 32 general purpose |
Cấu hình chân ATMEGA324P-20AU
| Chân 1 | PB5 (OC1A) — Port B bit 5 / Timer1 Output Compare A |
| Chân 2 | PB6 (OC1B) — Port B bit 6 / Timer1 Output Compare B |
| Chân 3 | PB7 (OC2A/OC0A) — Port B bit 7 / Timer2 Output Compare A / Timer0 Output Compare A |
| Chân 4 | RESET — Reset input, active low |
| Chân 5 | VCC — Digital supply voltage |
| Chân 6 | GND — Ground |
| Chân 7 | XTAL1 — Crystal/oscillator input |
| Chân 8 | XTAL2 — Crystal/oscillator output |
| Chân 9 | PD0 (RXD0) — Port D bit 0 / USART0 receive |
| Chân 10 | PD1 (TXD0) — Port D bit 1 / USART0 transmit |
| Chân 11 | PD2 (INT0/RXD1) — Port D bit 2 / External interrupt 0 / USART1 receive |
| Chân 12 | PD3 (INT1/TXD1) — Port D bit 3 / External interrupt 1 / USART1 transmit |
| Chân 13 | PD4 (XCK/T0) — Port D bit 4 / USART0 external clock / Timer0 external clock |
| Chân 14 | VCC — Digital supply voltage |
| Chân 15 | GND — Ground |
| Chân 16 | PD5 (XCK1/OC1A) — Port D bit 5 / USART1 external clock / Timer1 Output Compare A |
| Chân 17 | PD6 (RT1/OC1B/OC2B) — Port D bit 6 / Timer1 Output Compare B / Timer2 Output Compare B |
| Chân 18 | PD7 (OC2A/OC0A) — Port D bit 7 / Timer2 Output Compare A / Timer0 Output Compare A |
| Chân 19 | PC0 (SCL) — Port C bit 0 / Two-Wire clock |
| Chân 20 | PC1 (SDA) — Port C bit 1 / Two-Wire data |
| Chân 21 | PC2 (TCK) — Port C bit 2 / JTAG test clock |
| Chân 22 | PC3 (TMS) — Port C bit 3 / JTAG test mode select |
| Chân 23 | PC4 (TDO) — Port C bit 4 / JTAG test data output |
| Chân 24 | PC5 (TDI) — Port C bit 5 / JTAG test data input |
| Chân 25 | PC6 (TOSC1) — Port C bit 6 / Timer oscillator input |
| Chân 26 | PC7 (TOSC2) — Port C bit 7 / Timer oscillator output |
| Chân 27 | PA7 (ADC7) — Port A bit 7 / ADC channel 7 |
| Chân 28 | PA6 (ADC6) — Port A bit 6 / ADC channel 6 |
| Chân 29 | PA5 (ADC5) — Port A bit 5 / ADC channel 5 |
| Chân 30 | PA4 (ADC4) — Port A bit 4 / ADC channel 4 |
| Chân 31 | PA3 (ADC3) — Port A bit 3 / ADC channel 3 |
| Chân 32 | PA2 (ADC2) — Port A bit 2 / ADC channel 2 |
| Chân 33 | PA1 (ADC1) — Port A bit 1 / ADC channel 1 |
| Chân 34 | PA0 (ADC0) — Port A bit 0 / ADC channel 0 |
| Chân 35 | GND — Ground |
| Chân 36 | AVCC — Analog supply voltage for ADC |
| Chân 37 | AREF — Analog reference voltage for ADC |
| Chân 38 | PB0 (XCK0/T0) — Port B bit 0 / USART0 external clock / Timer0 external clock |
| Chân 39 | PB1 (T1) — Port B bit 1 / Timer1 external clock |
| Chân 40 | PB2 (AIN0/INT2) — Port B bit 2 / Analog comparator positive input / External interrupt 2 |
| Chân 41 | PB3 (AIN1/OC0) — Port B bit 3 / Analog comparator negative input / Timer0 output compare |
| Chân 42 | PB4 (SS) — Port B bit 4 / SPI slave select |
| Chân 43 | GND — Ground |
| Chân 44 | VCC — Digital supply voltage |
Ứng dụng tiêu biểu
ATMEGA324P-20AU phù hợp cho 6 Áp dụngs: 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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho ATMEGA324P-20AU — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | 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 |
Bảo phân biệt quan trọng
- Lowest-risk sourcing: direct successor availability (vsATMEGA324PA-20AU)
- Simplest firmware migration in the family (vsATMEGA324PB-AU)
- Memory headroom trade-off (vsATMEGA644P-20AU)
- Cost advantage over larger siblings (vsATMEGA2560-16AU)
Ghi chú thiết kế
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.
Thông tin tuân thủ
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.