ATMEGA325PA-AU - 32KB Flash AVR MCU 20MHz TQFP-64 | Microchip
MPN: ATMEGA325PA-AU ✓ فعالATMEGA325PA-AU نمای کلی
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor in which Flash program memory, SRAM data memory, and EEPROM are integrated on a single chip alongside peripherals, making it the central control element of an embedded system. Within the power-management IC hierarchy, the ATmega family sits at the MCU level of a broader semiconductor taxonomy: microcontroller -> embedded processor -> integrated circuit. The AVR RISC core executes most of its 131 instructions in a single clock cycle, which is why throughput is measured in MIPS equal to clock frequency.
Key features include 1.8 V to 5.5 V operation across the full speed range, Microchip picoPower technology for nanoamp-class sleep-mode current, an 8-channel 10-bit ADC, and a JTAG interface supporting on-chip debug and boundary scan. Self-programming Flash enables in-application firmware updates and bootloaders without an external programmer beyond initial ICSP.
Technically, the picoPower ATmega325PA improves on the earlier ATmega325P with reduced power consumption in all sleep modes, which matters in battery-powered designs where the MCU spends most of its life in power-down. The AVR core's single-cycle execution and register file of 32 general-purpose working registers keep interrupt latency short and deterministic, valuable in real-time control loops.
Typical applications include industrial sensor nodes and HMI front ends, battery-powered meters and data loggers, and hobbyist or commercial embedded controllers requiring 5 V tolerance and legacy AVR tooling compatibility.
A key design consideration: maximum safe clock frequency depends on supply voltage - at 5 V the part runs to 20 MHz, but at lower VCC the 20 MHz figure may not be guaranteed across the full data-sheet curve, so verify the frequency-versus-voltage graph in the manufacturer datasheet before over-clocking near the low-voltage end.
This page synthesizes distributor pricing, drop-in alternatives within the ATmega325/329/645 family, pinout data, and practical design notes not consolidated in the manufacturer datasheet.
جایگزین‌های drop-in برای ATMEGA325PA-AU — همان پکیج، سازگار پین‌به‌پین. قطعات با پکیج متفاوت که نیاز به تغییر PCB دارند مستثنی هستند.
گونه‌ها در این سری
مدل‌های هم‌سری که جایگزین مستقیم هستند برای ATMEGA325PA-AU (همان فرم‌فاکتور و فوت‌پرینت) — متفاوت در RoHS Status, Instruction Set, Package, Core Architecture, Maximum Clock Frequency.
ATMEGA325PA-AUR
✅ جایگزین مستقیمبرای قیمت تماس بگیرید
مشاهده دیتاشیت ←ATMEGA325P-20AU
✅ جایگزین مستقیم ⚠️ مشخصات تأییدنشده📋 جایگزین مرجع (خارج از کاتالوگ)
ATMEGA329P-20AUR
✅ جایگزین مستقیم📋 جایگزین مرجع (خارج از کاتالوگ)
ATMEGA169PV-8AUR
✅ جایگزین مستقیمبرای قیمت تماس بگیرید
مشاهده دیتاشیت ←ATMEGA165P-16AU
✅ جایگزین مستقیمبرای قیمت تماس بگیرید
مشاهده دیتاشیت ←ATMEGA645P-20AU
✅ جایگزین مستقیم ⚠️ مشخصات تأییدنشده📋 جایگزین مرجع (خارج از کاتالوگ)
ATMEGA325PA-AU حداکثر مقادیر مجاز و مشخصات الکتریکی
| Core Architecture | AVR 8-bit RISC |
| Flash Program Memory | 32 KB (16K x 16), self-programming |
| SRAM | 2 KB |
| EEPROM | 1 KB |
| حداکثر فرکانس کلاک | 20 MHz |
| Throughput | Up to 20 MIPS at 20 MHz |
| Instruction Set | 131 instructions, most single-cycle |
| Supply Voltage Range | 1.8 V to 5.5 V (picoPower) |
| ADC | 8-channel 10-bit |
| Debug / Programming | JTAG on-chip debug, ICSP |
| Low Power Technology | picoPower |
| بسته‌بندی | 64-TQFP, 14 x 14 mm, 0.8 mm pitch |
| نوع نصب | Surface Mount |
| وضعیت RoHS | Compliant (green, lead-free per distributor data) |
| Lifecycle Stage | Active |
پیکربندی پین ATMEGA325PA-AU
| پین 1 | PF0 (ADC0) — Port F bit 0 / ADC channel 0 input |
| پین 2 | PF1 (ADC1) — Port F bit 1 / ADC channel 1 input |
| پین 3 | PF2 (ADC2) — Port F bit 2 / ADC channel 2 input |
| پین 4 | PF3 (ADC3) — Port F bit 3 / ADC channel 3 input |
| پین 5 | PF4 (ADC4/TCK) — Port F bit 4 / ADC4 / JTAG test clock |
| پین 6 | PF5 (ADC5/TMS) — Port F bit 5 / ADC5 / JTAG test mode select |
| پین 6 | PF6 (ADC6/TDO) — Port F bit 6 / ADC6 / JTAG test data out |
| پین 7 | PF7 (ADC7/TDI) — Port F bit 7 / ADC7 / JTAG test data in |
| پین 8 | GND — Ground |
| پین 9 | VCC — Digital supply voltage |
| پین 10 | GND — Ground |
| پین 11 | AVCC — Analog supply for ADC |
| پین 12 | PA0 (AD0) — Port A bit 0 (external memory bus / GPIO) |
| پین 13 | PA1 (AD1) — Port A bit 1 |
| پین 14 | PA2 (AD2) — Port A bit 2 |
| پین 15 | PA3 (AD3) — Port A bit 3 |
| پین 16 | PA4 (AD4) — Port A bit 4 |
| پین 17 | PA5 (AD5) — Port A bit 5 |
| پین 18 | PA6 (AD6) — Port A bit 6 |
| پین 19 | PA7 (AD7) — Port A bit 7 |
| پین 20 | PB0 (SS) — Port B bit 0 / SPI slave select |
| پین 21 | PB1 (SCK) — Port B bit 1 / SPI clock |
| پین 22 | PB2 (MOSI) — Port B bit 2 / SPI master out |
| پین 23 | PB3 (MISO) — Port B bit 3 / SPI master in |
| پین 24 | PB4 (OC0) — Port B bit 4 / Timer0 output compare |
| پین 25 | PB5 (OC1A) — Port B bit 5 / Timer1 output compare A |
| پین 26 | PB6 (OC1B) — Port B bit 6 / Timer1 output compare B |
| پین 27 | PB7 (OC2) — Port B bit 7 / Timer2 output compare |
| پین 28 | RESET — Active-low reset input |
| پین 29 | PC0 (A8) — Port C bit 0 |
| پین 30 | PC1 (A9) — Port C bit 1 |
| پین 31 | PC2 (A10) — Port C bit 2 |
| پین 32 | PC3 (A11) — Port C bit 3 |
| پین 33 | PC4 (A12) — Port C bit 4 |
| پین 34 | PC5 (A13) — Port C bit 5 |
| پین 35 | PC6 (A14) — Port C bit 6 |
| پین 36 | PC7 (A15) — Port C bit 7 |
| پین 37 | PD0 (RXD) — Port D bit 0 / USART receive |
| پین 38 | PD1 (TXD) — Port D bit 1 / USART transmit |
| پین 39 | PD2 (INT0) — Port D bit 2 / external interrupt 0 |
| پین 40 | PD3 (INT1) — Port D bit 3 / external interrupt 1 |
| پین 41 | PD4 (XCK) — Port D bit 4 / USART external clock |
| پین 42 | PD5 (OC0A) — Port D bit 5 / Timer0 output compare A |
| پین 43 | PD6 (ICP1) — Port D bit 6 / Timer1 input capture |
| پین 44 | PD7 (OC1A) — Port D bit 7 / Timer1 output compare A |
| پین 45 | PE0 (ICP3) — Port E bit 0 / Timer3 input capture |
| پین 46 | PE1 (OC3A) — Port E bit 1 / Timer3 output compare A |
| پین 47 | PE2 (OC3B) — Port E bit 2 / Timer3 output compare B |
| پین 48 | PE3 (TOSC2) — Port E bit 3 / Timer oscillator output 2 |
| پین 49 | PE4 (TOSC1) — Port E bit 4 / Timer oscillator input 1 |
| پین 50 | PG0 (WR) — Port G bit 0 / external memory write strobe |
| پین 51 | PG1 (RD) — Port G bit 1 / external memory read strobe |
| پین 52 | PG2 (ALE) — Port G bit 2 / address latch enable |
| پین 53 | XTAL2 — Crystal oscillator output |
| پین 54 | XTAL1 — Crystal oscillator input / external clock |
| پین 55 | PH0 (SCL/INT0) — Port H bit 0 / TWI clock / external interrupt |
| پین 56 | PH1 (SDA/INT1) — Port H bit 1 / TWI data / external interrupt |
| پین 57 | PH2 (RXD1) — Port H bit 2 |
| پین 58 | PH3 (TXD1) — Port H bit 3 |
| پین 59 | PH4 (OC4A) — Port H bit 4 |
| پین 60 | PH5 (OC4B) — Port H bit 5 |
| پین 61 | PH6 (OC4C) — Port H bit 6 |
| پین 62 | PH7 (OC2A) — Port H bit 7 |
| پین 63 | PJ0 (PCINT0) — Port J bit 0 / pin change interrupt 0 |
| پین 64 | PJ1 (PCINT1) — Port J bit 1 / pin change interrupt 1 |
کاربردهای معمول
ATMEGA325PA-AU مناسب است برای 6 کاربردs: Battery-Powered Metering and Data Logging, Industrial Sensor Nodes and HMI Front Ends, Legacy 5V Embedded Controllers, Analog Signal Acquisition Systems, Consumer and Hobbyist Embedded Projects, Firmware-Updatable Field Devices.
Battery-Powered Metering and Data Logging
The ATMEGA325PA-AU is well suited to battery-powered meters and loggers because its picoPower technology minimizes current draw in all sleep modes and its 1.8 V to 5.5 V supply range allows direct operation from three alkaline cells or a single lithium cell via a simple regulator. The 1 KB EEPROM stores calibration constants and logged readings across power cycles without wearing the 32 KB Flash program memory. In a typical topology the device sleeps in power-down between samples, wakes on a timer or external interrupt, performs an 8-channel 10-bit ADC conversion, timestamps data, and returns to sleep - the PA revision's reduced sleep current directly extends field battery life versus the non-PA ATmega325P.
پیشنهادی
Industrial Sensor Nodes and HMI Front Ends
In industrial environments the ATMEGA325PA-AU provides 5 V-tolerant I/O, JTAG on-chip debugging for production diagnostics, and a deterministic 8-bit AVR core with 131 mostly single-cycle instructions - ideal for polling sensors, debouncing keys, and driving segment displays in HMI front ends. The 32 KB self-programming Flash supports field firmware updates through a bootloader, reducing service visits. Placed between an RS-485 or sensor front end and actuator drivers, the MCU handles the real-time loop while the JTAG port enables boundary-scan test of the assembled board, a quantified manufacturing benefit that pure-ICSP-only parts do not offer.
پیشنهادی
Legacy 5V Embedded Controllers
Many installed industrial designs still run 5 V logic, and the ATMEGA325PA-AU remains fully specified at 5 V with up to 20 MHz operation, making it a natural maintenance part for legacy AVR-based controllers. Because the AVR core and peripheral set are stable across the ATmega165A/PA/325A/PA/3250A/PA/645A/P/6450A datasheet family, firmware written years ago for an ATmega325 or 325P typically recompiles without change on the PA. This longevity and source compatibility reduce the engineering cost of servicing long-lifecycle equipment compared with migrating to a modern MCU family.
پیشنهادی
Analog Signal Acquisition Systems
The integrated 8-channel 10-bit ADC of the ATMEGA325PA-AU lets a single chip acquire up to eight analog inputs without an external converter, lowering BOM cost in multi-sensor acquisition nodes. Channels can be muxed to internal references, and the AVR core processes readings locally, sending only results over a serial link. For noise-sensitive measurements, the picoPower sleep modes allow sampling between power-down intervals that reduce self-heating drift. Note that 10-bit resolution limits precision applications - for sub-LSB accuracy add external conditioning or an external delta-sigma ADC, but for threshold detection and coarse telemetry the on-chip ADC is typically sufficient.
پیشنهادی
Consumer and Hobbyist Embedded Projects
The ATmega family remains a default choice for hobby and maker platforms because AVR toolchains, bootloaders, and community code are exceptionally mature. The ATMEGA325PA-AU offers 54-class I/O on the 64-TQFP footprint and JTAG debugging accessible with low-cost tools such as the MPLAB SNAP, which Microchip documents as connecting via an 8-pin SIL header using two I/O pins plus reset. The 20 MIPS throughput comfortably handles motor PWM, display refresh, and simple protocol stacks. For hobby boards the TQFP-64 footprint is hand-solderable with drag-soldering, unlike fine-pitch BGA alternatives.
پیشنهادی
Firmware-Updatable Field Devices
The 32 KB self-programming Flash of the ATMEGA325PA-AU enables bootloader-based firmware updates in deployed equipment: a small resident bootloader rewrites the application section over UART, SPI, or I2C without a programmer on site. Combined with the 1 KB EEPROM for storing version metadata and rollback flags, this supports robust A/B-style update schemes in devices such as access-control panels and HVAC controllers. JTAG additionally allows brick-level recovery in manufacturing RMA. Design the PCB so bootload pins are accessible on a connector to exploit this capability fully in the field.
پیشنهادی
خلاصه محصولات پیشنهادی
داده‌های مرجع مهندسی برای ATMEGA325PA-AU — مقایسه، راهنمای طراحی و اطلاعات انطباق.
راهنمای انتخاب
مقایسه با جایگزین‌ها
| پارامتر | این محصول | ATMEGA325PA-AUR | ATMEGA325P-20AU | ATMEGA329P-20AUR | ATMEGA165P-16AU |
|---|---|---|---|---|---|
| Package | 64-TQFP (14 x 14 mm) | 64-TQFP - same | 64-TQFP - same | 64-TQFP - same | 64-TQFP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 32 KB | 32 KB | 32 KB | 32 KB | 16 KB |
| SRAM | 2 KB | 2 KB | 2 KB | 2 KB | 1 KB |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 16 MHz |
| Supply Voltage | 1.8 V to 5.5 V (picoPower) | 1.8 V to 5.5 V (picoPower) | 4.5 V to 5.5 V for 20 MHz (P-class) | 4.5 V to 5.5 V for 20 MHz | 2.7 V to 5.5 V for 16 MHz |
| LCD Controller | No | No | No | Yes (segment LCD) | No |
| Sleep-Mode Power Class | picoPower (lowest) | picoPower (lowest) | P-class (higher sleep current) | P-class | P-class |
| Debug Interface | JTAG + ICSP | JTAG + ICSP | JTAG + ICSP | JTAG + ICSP | JTAG + ICSP |
تفاوت‌های کلیدی
- picoPower sleep-mode optimization (در مقابلATMEGA325P-20AU)
- No LCD pin overhead for maximum general-purpose I/O (در مقابلATMEGA329P-20AUR)
- 20 MHz performance in 1.8-5.5V envelope (در مقابلATMEGA165P-16AU)
- Cost vs memory trade-off possible without redesign (در مقابلATMEGA645P-20AU)
یادداشت‌های طراحی
Match the clock frequency to the supply voltage. The 20 MHz rating applies at the upper end of the 1.8 V to 5.5 V range; running 20 MHz at low VCC violates the frequency-voltage derating curve. For battery designs, run the MCU at 1.8-3.6 V with a proportionally lower clock, or use the internal RC oscillator and dynamic clock switching. Estimated: halving clock frequency approximately halves active-mode dynamic current, so a 1 MHz internal clock at 3 V drastically extends battery life versus 20 MHz at 5 V in duty-cycled applications.
Decouple every VCC and AVCC pin with 100 nF ceramic capacitors placed within 5 mm of each pin, and tie AVCC to VCC through a low-pass filter (e.g., 10 ohm series resistor plus 100 nF) when ADC accuracy matters. Keep analog traces away from the XTAL pins and JTAG lines. The 64-TQFP exposed pattern in the datasheet uses 0.8 mm pitch - verify the land pattern against the latest Microchip PCB footprint library rather than copying from older Atmel-era layout files.
The JTAG interface is enabled by default from the factory and shares pins PF4-PF7 with ADC channels 4-7. If your application uses those ADC channels, disable JTAG via the JTD bit or fuse settings early in firmware, otherwise the ADC readings on PF4-PF7 will be corrupted. Additionally, confirm reset polarity and the reset pin fuse configuration before production - disabling the external reset fuse makes ICSP reprogramming impossible in the field.
Pinout differences within the family: ATMEGA329 variants dedicate many pins to the segment LCD and differ in port mapping, and the ATmega3250 is a 100-pin part. Do not assume a TQFP-64 footprint swap is safe across the ATmega datasheet family without comparing pin tables pin by pin; the alternatives on this page are footprint-compatible but not always firmware-identical. Test the substitute on one board before committing a production change.
اطلاعات انطباق
Distributor listings (TrustCompo, Mouser Ind Grn designation) identify the part as RoHS-compliant, lead-free, green. REACH, halogen-free, and conflict-minerals declarations were not found in the retrieved data.
