ATMEGA324PA-MNR - 8-bit AVR MCU 20MHz 32KB Flash | Microchip
MPN： ATMEGA324PA-MNR ✓ 啟用中ATMEGA324PA-MNR 概覽
A microcontroller of this class integrates a processor core, program memory, data memory, and peripherals such as UART/USART, SPI, I2C (TWI), an ADC, and timers onto a single chip. Within the embedded systems hierarchy, the ATmega324PA sits in the 8-bit general-purpose MCU family, positioned below 32-bit ARM-based devices and above small 8-pin AVR parts, making it a mid-range workhorse for cost- and power-sensitive designs.
Key features include the picoPower technology for ultra-low sleep-mode consumption, read-while-write Flash operation for in-system self-programming, 1 KB of EEPROM for non-volatile parameter storage, and 32 general-purpose I/O lines with internal pull-ups. The enhanced RISC core with 32 general-purpose working registers enables efficient C-compiled code execution.
Architecturally, the ATmega324PA uses a Harvard structure with separate program and data buses. On-chip features include power-on reset, programmable brown-out detection, an internal calibrated RC oscillator, and multiple sleep modes including idle, power-save, power-down, and standby, allowing the designer to trade processing speed against current consumption. According to the ATmega324PA datasheet published by Microchip (Atmel), the device family spans 128 KB Flash maximum with up to 16 KB SRAM across 40/44-pin variants.
Typical applications include industrial sensor nodes and automation controllers, consumer appliances and HVAC controls, and battery-powered portable instruments where the picoPower sleep modes extend battery life. Its dual USARTs, SPI, and TWI interfaces also suit communication gateways and human-machine interface boards.
A key design consideration: operate within the 105C maximum ambient rating noted by distributors, and plan for the VQFN exposed pad providing a solid ground connection on the PCB.
This page synthesizes distributor pricing, drop-in family alternatives, and practical design notes not found in the manufacturer datasheet alone.
直接替換替代品，適用於 ATMEGA324PA-MNR — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： ATMEGA324PA-MNR （相同外形與佔位） — 差異在於 Package, Flash Memory, Packaging, EEPROM, Number of I/O.
ATMEGA324PB-MU
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA324PB-MNR
✅ 直接替換📋 參考替代品（不在目錄中）
ATMEGA324PA-MCHR
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA164PA-MNR
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ATMEGA644PA-MNR
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ATMEGA1284P-MNR
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
ATMEGA324PA-MNR 最大額定值與電氣特性
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 20 MHz |
| Flash Memory | 32 KB (16K x 16) |
| EEPROM | 1 KB |
| SRAM | 2 KB |
| GPIO Count | 32 |
| Connectivity | I2C, SPI, UART/USART |
| 供應電壓 | 5 V (nominal per Mouser listing) |
| 工作溫度 | -40C to +105C |
| 封裝 | 44-VQFN (7x7 mm) with exposed pad |
| 安裝類型 | Surface Mount |
| Packaging | Tape & Reel (T&R) |
| Technology | picoPower low-power CMOS |
| Program Memory Type | ISP FLASH with read-while-write |
| RoHS 狀態 | Green (RoHS compliant per Mouser listing) |
ATMEGA324PA-MNR 44-vqfn (7x7 mm) with exposed pad 腳位配置指南
ATMEGA324PA-MNR（44-vqfn (7x7 mm) with exposed pad 封裝）的腳位配置。 此數位 IC 包含 GPIO、通訊介面（UART、SPI、I2C）與電源腳位。替代腳位功能與配置選項請參閱製造商資料表。對嵌入式系統設計與 PCB 佈局至關重要。
無詳細腳位定義資料： ATMEGA324PA-MNR.
請參閱 資料表 以查看完整腳位配置。
典型應用
ATMEGA324PA-MNR 適用於 6 應用s: Industrial Sensor Nodes and Automation, Battery-Powered Portable Instruments, Consumer Appliances and HVAC Control, Communication Gateways and Protocol Bridges, Human-Machine Interface Boards, Hobby, Education, and Legacy AVR Designs.
Industrial Sensor Nodes and Automation
The ATMEGA324PA-MNR fits industrial sensing and control nodes because it combines 32 KB Flash, 2 KB SRAM, and a -40C to +105C temperature rating, covering both cold warehouses and hot panel enclosures. Its I2C, SPI, and UART/USART interfaces connect directly to ADCs, EEPROMs, and Modbus-style RS-485 links via external transceivers. In a typical node the MCU reads sensors over TWI, executes filtering in the 2 KB SRAM, and reports over USART while sleeping in picoPower power-down mode between samples to save energy. The 20 MHz core delivers roughly 20 MIPS of effective throughput for control loops, and 1 KB EEPROM stores calibration data through power cycles. The VQFN exposed pad provides a robust ground reference for noisy factory floors.
推薦
Battery-Powered Portable Instruments
For handheld meters, dataloggers, and portable test tools, the ATMEGA324PA-MNR's picoPower technology is the decisive parameter: power-down and power-save sleep modes keep RAM alive at microamp-class currents, while wake-up interrupts return to full-speed 20 MHz operation only when needed. Executing instructions in a single cycle at ~1 MIPS per MHz means measurement routines complete quickly, so the duty cycle stays sleep-dominated and battery life is maximized. The 32 GPIO lines drive an LCD segment driver or keypad matrix, and the ADC front end digitizes sensor channels, while the 1 KB EEPROM preserves user settings and calibration constants across battery swaps. Designers should budget wake-up latency of the selected sleep mode in timing-critical sampling loops.
推薦
Consumer Appliances and HVAC Control
White goods, thermostats, and fan controllers benefit from the ATMEGA324PA-MNR's balance of cost, memory, and robustness. The 105C ambient rating supports control boards mounted near motors or heating elements, and the internal calibrated RC oscillator eliminates an external crystal in cost-driven designs where timing precision permits. Typical firmware uses timers for phase-control or PWM outputs to drive triacs and fan circuits, TWI to read temperature and humidity sensors, and a USART for factory diagnostics. With 32 KB Flash there is headroom for communication stacks and fault-logging routines, while 2 KB SRAM holds state machines and look-up tables. Brown-out detection protects EEPROM writes and program flow during mains dips.
推薦
Communication Gateways and Protocol Bridges
The ATMEGA324PA-MNR serves as an economical protocol bridge because its dual USART/UART capability, SPI, and I2C (TWI) allow it to interconnect serial field devices with system buses. A common topology routes RS-485 traffic on one USART to a display or host on the second, while SPI handles external Flash buffering and TWI manages configuration EEPROMs or RTCs. The 20 MHz AVR core sustains throughput near 20 MIPS, sufficient for framing, CRC checking, and store-and-forward buffering within 2 KB SRAM when packet sizes are bounded. Because throughput scales linearly with clock per the single-cycle RISC architecture, designers can trade speed grade against power budget in mains-powered gateway hardware.
推薦
Human-Machine Interface Boards
Key panels, small displays, and controller front-ends use the ATMEGA324PA-MNR's 32 GPIO lines to scan button matrices, drive LED indicators, and communicate with serial character LCDs or OLED controllers. With 32 KB Flash there is space for multi-language string tables and menu frameworks, while the 1 KB EEPROM retains user preferences without external memory. The internal RC oscillator plus software-debounced interrupts handles touch-style inputs without a crystal, reducing BOM cost. Interfaces to the main controller are handled over TWI in slave mode or a USART, keeping the HMI electrically isolated from the power section. The 7x7 mm VQFN suits compact bezel-mounted PCBs, and the exposed pad aids EMI performance in electrically noisy enclosures.
推薦
Hobby, Education, and Legacy AVR Designs
The ATmega324PA remains popular for educational platforms and legacy AVR designs because it shares the well-documented AVR instruction set and toolchain (AVR-GCC, MPLAB X, AVRISP/UPDI-class programmers for ISP) with the wider ATmega family. Its 32 KB Flash and dual UARTs exceed the classic ATmega328 resources, enabling course projects with richer peripherals while retaining the same free toolchain and the shared ATmega164A/PA/324A/PA/644A/PA/1284/P datasheet. University labs and makers use the 44-VQFN on adapter boards to teach surface-mount assembly, and maintainers of shipped AVR products source the PA as a drop-in continuation of existing firmware images compiled years ago, minimizing requalification risk.
推薦
推薦產品摘要
工程參考資料，適用於 ATMEGA324PA-MNR — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | ATMEGA324PB-MU | ATMEGA324PB-MNR | ATMEGA324PA-MCHR | ATMEGA644PA-MNR | ATMEGA1284P-MNR |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-VQFN (7x7 mm) | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same |
| Core / Speed | 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 | AVR 8-bit, 20 MHz |
| Flash Memory | 32 KB | 32 KB | 32 KB | 32 KB | 64 KB | 128 KB |
| SRAM | 2 KB | 2 KB | 2 KB | 2 KB | 4 KB | 16 KB |
| EEPROM | 1 KB | 1 KB | 1 KB | 1 KB | 4 KB | 4 KB |
| GPIO Count | 32 | 32 | 32 | 32 | 32 | 32 |
| USART Count | 2 (UART/USART) | 3 | 3 | 2 | 2 | 2 |
| Temperature Range | -40C to +105C | -40C to +105C | -40C to +105C | -40C to +105C | -40C to +85C | -40C to +85C |
主要差異化特點
- picoPower low-power technology (對比ATMEGA324PB-MU)
- Higher temperature ceiling within drop-in options (對比ATMEGA644PA-MNR)
- Cost-effective 32 KB Flash midpoint (對比ATMEGA1284P-MNR)
- Fewer peripherals can mean simpler qualification (對比ATMEGA324PB-MU)
設計說明
The 44-VQFN 7x7 mm package has a central exposed pad that must be soldered to a grounded thermal land pattern. Follow the Microchip VQFN land-pattern recommendation in the datasheet package section: array of thermal vias under the pad connected to the ground plane for reliable solder joint inspection and EMI performance. Use no-clean flux profiles compatible with via-in-pad or ensure vacuum-assisted reflow to void out under the large pad. Pin 1 is identified by the dot marker on the package top.
Decouple every VCC pin with 100 nF ceramic capacitors placed within a few millimeters of the pins, plus one bulk 10 uF capacitor near the supply entry. The internal regulator oscillator start-up and brown-out detector require a stable supply; if using the programmable BOD, select a trip level consistent with your 5 V rail tolerance. When operating at 20 MHz near +105C ambient, verify the VCC-versus-frequency safe operating region in the datasheet before committing to the maximum clock grade.
Three common ATmega324PA pitfalls: (1) leaving RESET floating in noisy environments - enable the internal pull-up and add a 10 k external pull-up plus optional 100 nF to ground for robust reset behavior; (2) assuming the internal 8 MHz RC oscillator accuracy suffices for UART - calibrate or use an external crystal when baud rates exceed modest error budgets; (3) EEPROM corruption during brown-out - always enable BOD and follow the EEPROM write sequence in the datasheet. When migrating to ATMEGA324PB, re-verify register maps since peripheral instances increased.
Estimated: at 5 V and a typical active current of a few mA, self-heating of the VQFN-44 is low (tens of mW), so the package is rarely thermally limiting. The dominant thermal constraint is ambient: the part is rated to +105C, so in sealed enclosures verify that local air temperature near the MCU stays below the rating including heat from nearby power components such as regulators or motor drivers. Grounded exposed pad and thermal vias improve heat spreading to the PCB.
合規資訊
Listed as a Green (RoHS) part per Mouser listing. REACH, halogen-free, and conflict-minerals status not stated in retrieved data - verify on Microchip compliance portal.