ATMEGA324PA-PN - 8-Bit AVR MCU 20MHz 32KB Flash DIP-40 | Microchip
MPN: ATMEGA324PA-PN ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.12 | $4.12 |
| 10 | $3.71 | $37.10 |
| 100 | $3.3 | $330.00 |
| 500 | $2.96 | $1,480.00 |
| 1,000 | $2.66 | $2,660.00 |
ATMEGA324PA-PN Overview
An 8-bit AVR microcontroller is a self-contained computer-on-a-chip that executes the Harvard-architecture AVR RISC instruction set, combining program Flash, data SRAM, EEPROM and peripherals such as timers, ADCs and serial interfaces in one package. Within the power-management hierarchy, it belongs to the ATmega family of embedded MCUs, which sit at the top level of Microchip's 8-bit AVR product line alongside the ATtiny low-pin-count series.
Key features include in-system programmable (ISP) Flash with read-while-write support, picoPower technology for low standby consumption, and three hardware serial interfaces: SPI, TWI (I2C) and USART. The 16K x 16 organized Flash delivers roughly 10,000 flash write/erase cycles per Microchip documentation, while the AVR core executes most instructions in a single clock cycle, achieving near 1 MIPS per MHz throughput at 20 MHz.
The 'A' suffix denotes the picoPower revision of the ATmega324P silicon, offering reduced sleep-mode currents versus the original ATmega324. The -PN speed/temperature grade specifies 20 MHz maximum frequency with an extended operating range to +105 C, distinguishing it from the standard -PU grade (85 C) in the identical 40-PDIP footprint. Input supply options span 2.5 V, 3.3 V and 5 V operation per distributor specification listings.
Typical applications include industrial control boards requiring through-hole serviceability, educational and hobbyist development boards, serial-communication bridges, and sensor acquisition nodes that use the USART, SPI or I2C interfaces.
When designing with this device, budget power rails at 5 V for maximum 20 MHz performance, and account for the through-hole package's larger board area versus TQFP equivalents when layout density matters.
This page synthesizes verified distributor data, same-footprint alternatives, and practical design guidance not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA324PA-PN — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ATMEGA324PA-PN (same form factor and footprint) — differing in Package, Mounting Type, Operating Temperature, Timers/Counters, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA324PA-PU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.55 / Unit
View Datasheet →ATMEGA324PA-MCHR
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →ATMEGA324PA-CU
✅ Drop-In✓ In Stock
$2.45 / Unit
View Datasheet →ATMEGA324PV-10PU
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA644PA-PU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA32A-PN
✅ Drop-In✓ In Stock
$4.15 / Unit
View Datasheet →ATMEGA324PA-PN Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Core Series | AVR ATmega (picoPower) |
| Max CPU Frequency | 20 MHz |
| Program Memory (Flash) | 32 KB (16K x 16), ISP, read-while-write |
| EEPROM | 1 KB |
| SRAM | 2 KB |
| General Purpose I/O | 32 lines |
| Working Registers | 32 x 8-bit general purpose |
| Communication Interfaces | I2C (TWI), SPI, UART/USART |
| Operating Supply Voltage | 2.5 V / 3.3 V / 5 V |
| Operating Temperature | up to +105 C (PN grade) |
| Package | 40-PDIP, 0.600 in (15.24 mm) width |
| Mounting Type | Through-Hole |
| Packaging | Tube |
| RoHS / Green Status | Green (RoHS compliant per Microchip listing) |
| Data Program Memory Size | 32KB FLASH, 1KB EE, 2KB RAM |
| Supplier Device Package | 40-DIP |
ATMEGA324PA-PN 40-dip Pin Configuration Guide
Pin configuration for ATMEGA324PA-PN (40-dip package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for ATMEGA324PA-PN.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA324PA-PN is suitable for 6 applications: Industrial Automation Control Boards, Hobbyist and Educational Prototyping, Embedded Instrumentation and Data Loggers, Serial Communication Bridges and Converters, Appliance and Consumer Product Control, Legacy System Maintenance and Repair.
Industrial Automation Control Boards
The ATMEGA324PA-PN fits industrial controller boards because its -PN grade is specified to +105 C, matching control-cabinet ambient conditions near drives and power supplies. The 32 KB Flash accommodates ladder-logic interpreters or Modus-RTU slaves implemented over its hardware USART, while 1 KB EEPROM retains configuration and calibration data across power cycles without external nonvolatile memory. Its through-hole PDIP-40 package can be socketed, enabling field replacement of the controller without soldering rework - a common requirement in long-service-life industrial equipment. Operating the AVR at 5 V and 20 MHz gives approximately 20 MIPS throughput, sufficient for polling dozens of digital I/O points and running PID loops at kHz rates. The SPI and TWI interfaces connect rotary encoders, isolated ADCs and local displays; picoPower sleep modes reduce standby current in battery-backed control panels.
Recommended
Hobbyist and Educational Prototyping
The ATMEGA324PA-PN is a favorite for hobby and education because the 40-pin DIP package inserts directly into solderless breadboards and 0.600-inch sockets, requiring no hot-air or reflow equipment. Community Arduino-core packages on GitHub (topic: atmega324) provide board definitions for ATmega164/324/644/1284, so students can program it with the Arduino IDE through a USBasp ISP programmer. Its 32 KB Flash holds generous sketches, while 32 GPIO lines out-muscle an ATmega328P (23 GPIO) for LED matrices, multiplexed keypads and multi-peripheral shields. The 20 MHz maximum clock delivers about 20 MIPS, roughly double the 16 MHz Arduino Uno, for timing-sensitive exercises. Distributor stock is deep - icDirectory reported 22,400 pieces as of February 2026 - keeping unit cost near 4 USD, ideal for classroom kits and student project budgets.
Recommended
Embedded Instrumentation and Data Loggers
For measurement and logging nodes, the ATMEGA324PA-PN combines a 10-bit ADC on its 8-channel PORTA with 2 KB of on-chip SRAM for sample buffering, letting it capture burst data before writing to external EEPROM or SD media over SPI. The picoPower 'A' silicon revision cuts active and sleep current, extending battery life in portable loggers; power-down sleep with periodic watchdog or timer wake is a proven AVR pattern. The 1 KB EEPROM stores calibration constants such as sensor offsets that survive firmware updates. Running from 2.5 V to 5 V supplies, it interfaces directly with 3.3 V sensor modules using level-appropriate clock speeds. The -PN grade's +105 C rating suits loggers mounted inside industrial machines or solar enclosures where ambient temperatures exceed the standard 85 C limit, and the DIP package simplifies one-off instrument prototyping and repair.
Recommended
Serial Communication Bridges and Converters
The ATMEGA324PA-PN hosts two hardware serial paths plus SPI and TWI, making it a compact protocol-translation node: for example USART-to-SPI gateways bridging a plant SCADA serial line to isolated peripheral buses. The hardware USART with its buffered shift register sustains reliable 115200-baud links at 20 MHz with minimal CPU load, while the AVR core handles framing, CRC and buffering in the 2 KB SRAM. Through-hole assembly suits converter boxes built in low volumes where hand soldering is acceptable, and the DIP package allows firmware re-flashing via the ISP header even after enclosure integration. Because the picoPower die handles wake-on-serial patterns, the bridge can sleep between transactions in energy-conscious installations. At approximately 20 MIPS, there is headroom to run both protocol stacks plus a simple diagnostic web of status LEDs driven from PORTB.
Recommended
Appliance and Consumer Product Control
White goods and consumer appliance control boards use the ATMEGA324PA-PN where firmware complexity - touch decoding, display multiplexing, motor sequencing - exceeds 8 KB-class MCUs but cost must stay under a few dollars. Its 32 KB Flash supports menu-driven UI code plus sensor compensation tables, and 1 KB EEPROM retains user settings through power interruption without a battery. The Green/RoHS listing satisfies consumer-market environmental requirements, and the +105 C PN grade tolerates the warm interior of dishwashers or oven-adjacent control compartments. The DIP-40 format suits low-volume appliance revisions assembled on contract lines without SMD capability. Peripherals cover the typical appliance bill of materials: PWM outputs for triac-based motor and heater control, TWI for membrane touch controllers, and ADC channels reading NTC temperature sensors directly.
Recommended
Legacy System Maintenance and Repair
Service organizations maintaining equipment designed around DIP-40 AVR or ATmega32 controllers depend on the ATMEGA324PA-PN for repair stock because the 40-PDIP footprint has remained stable across the ATmega32/324 families. When an original ATmega32 fails, the pin-compatible 324PA - with the same 32 KB Flash class and 2 KB SRAM - can restore function after a firmware port; conversely, 324PA-based boards can be revived from the same drawer of spares. Its extended +105 C rating also covers replacements in thermally stressed positions where the original consumer-grade device may have failed. Keeping this part in inventory mitigates obsolescence risk: channel stock remains deep (22,400 pieces reported by icDirectory as of February 2026), and Microchip has not issued end-of-life notices for the ATmega324PA family, providing a dependable continuity path for aging industrial assets.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA324PA-PN — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA324PA-PU | ATMEGA324PV-10PU | ATMEGA644PA-PU | ATMEGA32A-PN | ATMEGA324PA-MCHR |
|---|---|---|---|---|---|---|
| Package | 40-PDIP (0.600 in / 15.24 mm) | 40-PDIP (0.600 in) - same | 40-PDIP (0.600 in) - same | 40-PDIP (0.600 in) - same | 40-PDIP (0.600 in) - same | VQFN-44 (SMD) - different footprint |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max CPU Frequency | 20 MHz | 20 MHz | 10 MHz | 20 MHz | 16 MHz | 20 MHz |
| Flash Memory | 32 KB | 32 KB | 32 KB | 64 KB | 32 KB | 32 KB |
| SRAM | 2 KB | 2 KB | 2 KB | 4 KB | 2 KB | 2 KB |
| EEPROM | 1 KB | 1 KB | 1 KB | 2 KB | 1 KB | 1 KB |
| Silicon Revision / Features | picoPower (A revision) | picoPower (A revision) | picoPower, low-voltage | picoPower (A revision) | original ATmega32 (no picoPower) | picoPower (A revision) |
Key Differentiators
- Extended +105 C temperature grade in through-hole package (vs ATMEGA324PA-PU)
- Lower power via picoPower silicon revision (vs ATMEGA32A-PN)
- Cost-optimal memory point in pin-compatible family (vs ATMEGA644PA-PU)
- 20 MHz full-speed operation (vs ATMEGA324PV-10PU)
Design Notes
Design the 5 V rail with a 100 nF ceramic decoupling capacitor directly across VCC/GND plus 10 uF of bulk capacitance per AVR hardware design practice. At 20 MHz the ATMEGA324PA-PN requires a supply in the 4.5 V to 5.5 V region per the datasheet frequency-versus-voltage derating curve - running full speed at 3.3 V violates the safe operating envelope. The 'A' picoPower revision also requires correct fuse configuration of the BOD (brown-out detector) level: enable BOD at 4.3 V or 2.7 V depending on rail, since EEPROM writes during a brown-out can corrupt calibration data.
For through-hole layouts, keep the crystal within about 1 cm of XTAL1/XTAL2 with short ground returns for the 22 pF load capacitors; long DIP traces at 20 MHz invite start-up failures. If the board may be socketed, add a programming header for the SPI ISP signals (PB5/PB6/PB7/RESET) and avoid loading MISO/MOSI/SCK with strong pull-ups that fight the programmer. The RESET line needs a 10 k pull-up; never drive it below 0.3 VCC during normal operation or the chip enters programming mode unintentionally.
Do not confuse the -PN (+105 C) and -PU (+85 C) grades when stocking spares for a hot application - they are electrically identical but not thermally equivalent, and substituting PU in a 90 C enclosure causes field failures. Firmware written for the ATmega324PA will not run unmodified on the pin-compatible ATmega32A because peripheral register maps differ (second USART, revised timer units). Also note the 2 KB SRAM limit: buffer-heavy designs should watch stack/heap collision, which manifests as random resets rather than clean errors.
Compliance Information
Listed as Green (RoHS compliant) in Microchip and FindIC product listings for ATMEGA324PA-PN. REACH and conflict-minerals declarations not found in provided data - request formal certificates from Microchip.
