ATMEGA325-16AUR - AVR 8-Bit MCU 32KB 16MHz TQFP-64 | Microchip
MPN: ATMEGA325-16AUR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.57 | $6.57 |
| 10 | $6.1 | $61.00 |
| 100 | $5.65 | $565.00 |
| 500 | $5.22 | $2,610.00 |
| 1,000 | $4.8 | $4,800.00 |
ATMEGA325-16AUR Overview
An 8-bit microcontroller (MCU) is a single integrated circuit that combines a processor core, non-volatile program memory, data RAM, and peripheral functions such as timers, UART serial ports, and analog-to-digital converters. Within the semiconductor hierarchy, the ATMEGA325-16AUR belongs to the AVR ATmega family of enhanced RISC MCUs, which sits inside the broader categories of microcontrollers, embedded processors, and semiconductors.
Key features of the ATMEGA325-16AUR include the AVR enhanced RISC architecture executing most instructions in a single clock cycle, which yields throughput of up to 16 MIPS at 16MHz; 32KB of self-programmable Flash organized as 16K x 16 words, supporting 10,000 Flash write cycles; 1KB of EEPROM with a separate lockable boot section capability; and 2KB of on-chip SRAM for data buffering. The integrated ADC allows direct connection of analog sensors without an external converter, reducing bill-of-material cost in measurement applications.
The technical architecture follows the classic Harvard model, with separate buses for program and data memory that allow simultaneous instruction fetch and data access. The industrial temperature grade (-40C to +85C per distributor classification) and gull-wing TQFP terminals support automated surface-mount assembly on standard FR4 processes.
Typical applications include embedded control in industrial automation nodes, IoT sensor endpoints and gateways, and general-purpose consumer appliance control boards where 32KB of code space and rich I/O are sufficient.
A key design consideration is clock-versus-voltage derating: the 16MHz maximum speed is rated at 5V operation, so designs that drop VCC for power savings must correspondingly reduce system frequency.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA325-16AUR β 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 ATMEGA325-16AUR (same form factor and footprint) β differing in Package, Operating Temperature, Instructions, Packaging, RoHS Status.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA325P-16AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA325V-8AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA3250-16AU
β Drop-Inβ In Stock
$5.74 / Unit
View Datasheet βATMEGA3250PA-AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$2.98 / Unit
View Datasheet βATMEGA329-16AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$2.15 / Unit
View Datasheet βATMEGA645-16AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA325-16AUR Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Flash Memory | 32KB (16K x 16) |
| EEPROM | 1KB |
| SRAM | 2KB |
| Maximum Clock Frequency | 16MHz |
| Supply Voltage | 5V |
| ADC | Yes, integrated |
| Package | 64-TQFP (14 x 14 mm) |
| Number of Terminals | 64 |
| Terminal Form | Gull Wing |
| Package Shape | Square |
| Temperature Grade | Industrial |
| Operating Temperature | -40C to +85C |
| Mounting Type | Surface Mount |
| Packaging | Tape and Reel (R suffix) |
| Product Series | AVR ATmega |
| RoHS Status | Compliant (RoHS R suffix per Microchip part numbering) |
ATMEGA325-16AUR square Pin Configuration Guide
Pin configuration for ATMEGA325-16AUR (square 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 ATMEGA325-16AUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA325-16AUR is suitable for 6 applications: Industrial Automation Nodes, IoT Sensor Endpoints, Consumer Appliance Control, Measurement and Data Loggers, Motor and Actuator Control, Legacy AVR System Maintenance.
Industrial Automation Nodes
The ATMEGA325-16AUR fits industrial control nodes because its industrial temperature grade (-40C to +85C), 5V-tolerant I/O structure, and 16MHz/16 MIPS AVR core handle sensor polling, relay actuation, and Modbus-style UART communication in noisy factory environments. The 32KB Flash stores protocol handling and state machines, the 1KB EEPROM retains calibration and configuration data across power cycles, and the integrated ADC digitizes 0-5V transducer signals without an external converter. Place the MCU on a board with an isolated RS-485 transceiver for fieldbus networks; the 16MHz clock supports baud rates well above standard fieldbus speeds with timing margin.
Recommended
IoT Sensor Endpoints
Distributor data explicitly positions the ATMEGA325-16AUR as ideal for IoT and embedded systems development. Its 32KB (16K x 16) Flash accommodates sensor drivers plus a lightweight mesh or serial protocol stack, while the 2KB SRAM buffers radio payloads and ring-buffered samples. The integrated ADC reads analog temperature, humidity, or current sensors directly, and the AVR architecture wakes quickly from sleep for battery-powered duty cycling. Pair the MCU with a UART-based wireless module: the 16MHz system clock at 5V provides ample baud-rate accuracy for reliable serial links, keeping total endpoint cost low without sacrificing code headroom.
Recommended
Consumer Appliance Control
White-goods and small-appliance control boards benefit from the ATMEGA325-16AUR's balance of memory and I/O: the 64-pin TQFP exposes multiple 8-bit ports for keypad scanning, LED/LCD driving, and motor or heater relay control, while the 32KB Flash holds UI logic, safety interlocks, and configuration menus. The 5V supply level matches legacy appliance power rails, simplifying power-tree design with a basic buck or linear regulator. The 1KB EEPROM stores user settings and fault logs through power interruptions, and the RoHS-compliant tape-and-reel packaging supports high-volume automated assembly lines typical of appliance manufacturing.
Recommended
Measurement and Data Loggers
The integrated ADC and 1KB EEPROM make the ATMEGA325-16AUR well suited for battery-powered data loggers and portable measurement instruments. Analog channels from thermistors, strain gauges, or current shunts feed the on-chip converter, removing external ADC cost, while the 2KB SRAM sustains sample buffering between writes to external non-volatile storage. The AVR executes single-cycle instructions, so time-stamping and filtering routines close within the 16MHz budget. For precision front ends, add a dedicated reference and instrumentation amplifier ahead of the ADC input; the MCU's flexible port mapping on the 64-TQFP leaves ample pins for SPI or I2C peripheral expansion.
Recommended
Motor and Actuator Control
DC motor and actuator control is a natural fit: the AVR core generates PWM via hardware timers, reads position or current feedback through the ADC, and closes control loops at the 16MHz maximum rate (up to 16 MIPS of single-cycle throughput). The 5V I/O directly interfaces gate drivers and H-bridge modules, and the industrial -40C to +85C rating covers enclosed drive environments. The 64-TQFP provides enough pins for multi-motor coordination plus limit-switch and encoder inputs. Keep high-current switching ground returns separated from the MCU ground to protect ADC accuracy and prevent reset glitches during load transients.
Recommended
Legacy AVR System Maintenance
The ATMEGA325-16AUR is widely used to sustain legacy ATmega-based products - industrial meters, access-control panels, and instrument platforms designed on the Atmel AVR architecture. Because the ATmega325 remains in active production with distributor stock (DigiKey ships same day; more than 6,300 pieces were listed at Heisener as of September 2026), it serves both new builds and repair-and-continue-manufacturing programs. Its picoPower successor, the ATMEGA325P-16AUR, is pin- and code-compatible, so maintenance engineers can dual-source the same footprint against allocation risk without firmware changes or PCB respins, protecting long-lived product lines.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA325-16AUR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA325P-16AUR | ATMEGA325V-8AUR | ATMEGA3250-16AU | ATMEGA329-16AUR | ATMEGA645-16AUR |
|---|---|---|---|---|---|---|
| Package | 64-TQFP (14 x 14 mm) | 64-TQFP (14 x 14 mm) - same | 64-TQFP (14 x 14 mm) - same | 64-TQFP (14 x 14 mm) - same | 64-TQFP (14 x 14 mm) - same | 64-TQFP (14 x 14 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 32KB (16K x 16) | 32KB | 32KB | 32KB | 32KB | 64KB |
| EEPROM | 1KB | 1KB | 1KB | 1KB | 1KB | 2KB |
| SRAM | 2KB | 2KB | 2KB | 2KB | 2KB | 4KB |
| Maximum Clock Frequency | 16MHz | 16MHz | 8MHz | 16MHz | 16MHz | 16MHz |
| Special Peripherals | ADC | ADC (picoPower) | ADC (low-voltage V grade) | ADC, expanded port mapping | ADC, LCD segment driver | ADC, larger memory |
| Temperature Grade | Industrial (-40C to +85C) | Industrial | Industrial | Industrial | Industrial | Industrial |
Key Differentiators
- Full 16MHz performance class at 5V (vs ATMEGA325V-8AUR)
- Standard generation availability at scale (vs ATMEGA325P-16AUR)
- Predictable migration path to 64KB (vs ATMEGA645-16AUR)
- Pure general-purpose I/O mapping (vs ATMEGA329-16AUR)
Design Notes
The -16 speed grade is rated for full 16MHz operation at 5V per distributor data. If your design lowers VCC for power savings, derate the maximum clock frequency accordingly - running 16MHz below the rated voltage risks marginal timing and field failures. Estimated: a 5V rail at 16MHz with all I/O active can push total consumption well above sleep-mode figures, so size your 5V regulator with headroom and verify against the datasheet current-consumption tables rather than assuming typical-only values.
For the 64-TQFP (14 x 14 mm), place a 100nF ceramic decoupling capacitor at each VCC pin pair as close to the package as possible, plus a bulk 10uF near the power entry. Connect AVCC to VCC through an RC filter (e.g., 10 ohm + 100nF, estimate - verify in the manufacturer datasheet) when ADC accuracy matters, and keep analog routing away from switching traces. Provide a solid ground pour under the QFP to reduce loop area and improve EMI performance in industrial environments.
Flash write endurance is finite - do not place frequently updated variables in EEPROM without wear-leveling, and reserve the self-programmable Flash bootloader for true field updates rather than routine data storage. The industrial temperature grade is -40C to +85C per the distributor classification (Vyrian); do not extend to automotive 125C ambient without a Q-grade part. Finally, when substituting ATMEGA3250 family parts on the same footprint, confirm the port/pin mapping against the datasheet pinout diagram - the packages match but terminal functions differ.
Compliance Information
RoHS compliance and lead-free status inferred from the Microchip R (RoHS tape-and-reel) suffix convention; formal REACH, halogen-free, and conflict-minerals declarations should be obtained from the manufacturer product page.