ATMEGA640-16AUR - 8-bit AVR MCU 64KB Flash 16MHz | Microchip
MPN: ATMEGA640-16AUR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.85 | $7.85 |
| 10 | $7.2 | $72.00 |
| 100 | $6.81 | $681.00 |
| 500 | $6.35 | $3,175.00 |
| 1,000 | $5.9 | $5,900.00 |
ATMEGA640-16AUR Overview
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that executes most instructions in a single clock cycle, sitting within the broader hierarchy of microcontroller units (MCUs) under the semiconductor and embedded-system taxonomy. The AVR ATmega family from Microchip (originally Atmel) is widely used in industrial control, consumer electronics, and embedded products, and the ATmega640 shares its core with the well-known ATmega1280/2560 used on the Arduino Mega platform.
Key features include 86 general-purpose I/O lines, 32 general-purpose working registers, six flexible timer/counters with compare and PWM modes, a real-time counter, and an 8/16-channel 10-bit ADC. The device also integrates two programmable serial USARTs, a master/slave SPI interface, a byte-oriented 2-wire serial interface (I2C-compatible TWI), a programmable watchdog timer with a separate on-chip oscillator, an on-chip analog comparator, and an output-compare modulator.
Technical depth: the AVR core achieves close to 1 MIPS per MHz throughput, allowing the ATMEGA640-16AUR to deliver approximately 16 MIPS at its 16 MHz maximum frequency while remaining low-power. In-system programmable (ISP) Flash enables firmware updates on the final assembly, and the 4 KB EEPROM retains calibration data through power cycles.
Typical applications include industrial control systems, building automation and HVAC controllers, consumer appliances, and instrumentation requiring many I/O lines and multiple UART channels. Its Arduino Mega compatibility also makes it popular for rapid prototyping.
Design consideration: this is the 16 MHz / 5 V industrial grade variant (A = 4.5-5.5 V, U = industrial temperature, R = tape and reel); for 2.7-5.5 V or 8 MHz battery designs, select the ATmega640V-8AUR instead.
This page synthesizes distributor pricing, drop-in family alternatives, and practical design notes not found in the manufacturer datasheet, with data verified as of 2026-09-18.
Drop-in alternatives for ATMEGA640-16AUR 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 ATMEGA640-16AUR (same form factor and footprint) β differing in Package, Flash Memory, Watchdog Timer, ADC, Analog Comparator.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA1280-16AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA2560-16AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA1281-16AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA2561-16AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$15.98 / Unit
View Datasheet βATMEGA640V-8AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$9.6 / Unit
View Datasheet βATMEGA640-16AUR Maximum Ratings & Electrical Characteristics
| Core | AVR 8-bit RISC |
| Core Size | 8-bit |
| Max Clock Frequency | 16 MHz |
| Flash Memory | 64 KB (32K x 16) |
| SRAM | 8 KB |
| EEPROM | 4 KB |
| Supply Voltage Range | 4.5 V to 5.5 V |
| Operating Temperature | -40C to +85C (industrial) |
| GPIO Count | 86 |
| Timers/Counters | 6 (flexible timer/counters) |
| ADC Resolution | 10-bit |
| ADC Channels | 8/16-channel |
| USART | 2 (programmable serial USART) |
| SPI | Yes (master/slave SPI serial interface) |
| TWI (I2C) | Yes (byte-oriented 2-wire serial interface) |
| Watchdog Timer | Programmable, with separate on-chip oscillator |
| Package | 100-TQFP (14x14 mm) |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (R suffix) |
| RoHS Status | Compliant |
ATMEGA640-16AUR 100-tqfp (14x14 mm) Pin Configuration Guide
Pin configuration for ATMEGA640-16AUR (100-tqfp (14x14 mm) 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 ATMEGA640-16AUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA640-16AUR is suitable for 6 applications: Industrial Control Systems, Building Automation and HVAC, Consumer Appliances, Instrumentation and Data Loggers, Arduino Mega Prototyping and Education, Motor and Power Control Boards.
Industrial Control Systems
The ATMEGA640-16AUR fits industrial control because its 86 GPIO lines, six timer/counters, and two USARTs allow one MCU to drive relays, read limit switches, and communicate with HMIs and PLC backplanes simultaneously. Operating at 16 MHz from a 5 V industrial rail with -40C to +85C rating, it tolerates typical factory-floor temperature swings. In use, it runs the main scan loop reading digital and analog inputs through the 10-bit ADC, executes control logic in Flash-resident firmware, and outputs PWM via timer compare channels. A watchdog timer with a separate on-chip oscillator provides fail-safe recovery, a quantified reliability benefit in unattended installations.
Recommended
Building Automation and HVAC
HVAC controllers benefit from the ATMEGA640-16AUR's combination of a real-time counter, six timer/counters, and the byte-oriented 2-wire (TWI/I2C) interface used to poll temperature and humidity sensors. The 10-bit ADC with 8/16 channel options directly digitizes NTC thermistor and 0-10 V sensor inputs with external scaling, while two USARTs provide RS-485 (Modbus) and service-port connectivity. The 4 KB EEPROM stores setpoints, schedules, and calibration constants through power outages, eliminating external non-volatile memory. Its 5 V operation simplifies interfacing with industrial 24 V-derived I/O logic, and the programmable watchdog keeps the controller recovering from transient brownouts common in building electrical systems.
Recommended
Consumer Appliances
In appliance control boards, the ATMEGA640-16AUR drives segmented LCD or LED displays, touch or mechanical keypads, and motor control PWM outputs from a single 100-pin device, reducing BOM count. The output-compare modulator and six timer/counters generate precise PWM for heater triac firing and brushless fan speed control, while the 10-bit ADC reads thermistors and current-shunt feedback for closed-loop temperature regulation. Firmware fits in 64 KB Flash with room for OTA-style field updates via ISP bootloader. The industrial -40C to +85C rating covers unheated laundry and garage environments, and the on-chip analog comparator provides zero-cross detection for AC load switching without external components.
Recommended
Instrumentation and Data Loggers
Multi-channel data loggers exploit the ATMEGA640-16AUR's 10-bit ADC and 8 KB SRAM to sample many sensors into buffered records before writing to external storage over SPI. The 86 GPIO lines support parallel interfaces to character LCDs, keypads, and multiple chip-select lines for SPI Flash or SD-card media. Two USARTs allow simultaneous logging of external GPS or sensor streams and local RS-232 telemetry. Running at 16 MHz gives roughly 16 MIPS of headroom for filtering and scaling math on the 8-bit core. The 4 KB EEPROM holds calibration tables, and the separate on-chip watchdog oscillator keeps reset supervision independent of the main clock for long-term unattended accuracy.
Recommended
Arduino Mega Prototyping and Education
Because the ATmega640 shares its AVR core, peripheral layout, and 100-pin TQFP footprint with the ATmega2560 on the Arduino Mega 2560, it is a natural choice for educational and prototype designs. The MegaCore open-source package provides full Arduino IDE support for ATmega640, letting students and engineers reuse the extensive Mega library ecosystem including Servo, SPI, Wire, and UART libraries. Sixteen MHz operation with single-cycle instruction execution yields approximately 16 MIPS, ample for classroom robotics and instrumentation projects. Prototype boards designed around this part can migrate to ATMEGA1280 or ATMEGA2560 for larger sketches without any PCB change, protecting the design investment across iterations.
Recommended
Motor and Power Control Boards
The ATMEGA640-16AUR serves multi-motor control boards by providing independent PWM channels from its six timer/counters with compare units, controlling up to several motors or one multi-phase drive. The on-chip analog comparator and 10-bit ADC support current-limit feedback and bus-voltage monitoring; the output-compare modulator merges PWM and comparator events for hardware fault shutdown, reducing interrupt latency. The 5 V logic level interfaces cleanly with gate-driver ICs on 5 V-referenced boards. A programmable watchdog timer with a separate oscillator guarantees shutdown firmware runs even if the main crystal fails, a quantified safety benefit for thermal or over-current fault handling in appliances and industrial drives.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA640-16AUR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA1280-16AUR | ATMEGA2560-16AUR | ATMEGA1281-16AUR | ATMEGA2561-16AUR | ATMEGA640V-8AUR |
|---|---|---|---|---|---|---|
| Package | 100-TQFP (14x14 mm) | 100-TQFP (14x14 mm) - same | 100-TQFP (14x14 mm) - same | 100-TQFP (14x14 mm) - same | 100-TQFP (14x14 mm) - same | 100-TQFP (14x14 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 64 KB | 128 KB | 256 KB | 128 KB | 256 KB | 64 KB |
| SRAM | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB |
| Max Clock Frequency | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 8 MHz |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 2.7 V to 5.5 V |
| GPIO Count | 86 | 86 | 86 | 54 | 54 | 86 |
| USART Count | 2 | 2 | 4 | 2 | 2 | 2 |
Key Differentiators
- Highest GPIO density in the 100-pin ATmega family at this price point (vs ATMEGA1281-16AUR)
- Full 16 MHz speed at industrial temperature (vs ATMEGA640V-8AUR)
- Cost-optimized Flash size with identical footprint to larger siblings (vs ATMEGA2560-16AUR)
Design Notes
The ATMEGA640-16AUR requires 4.5 V to 5.5 V for guaranteed 16 MHz operation per the 16A speed grade. Do not run it from a nominal 3.3 V rail - the AVR datasheet derates maximum clock with falling VCC, so below 4.5 V the 16 MHz clock is out of specification and the MCU may misexecute code. Decouple each VCC/AVCC pair with 100 nF ceramics placed within a few millimeters of the pins, plus a 10 uF bulk capacitor near the supply entry.
For the 100-pin TQFP, connect AGND and AVCC to clean analog power: filter AVCC through an LC network (for example 10 uH + 10 uF) from the digital rail to keep ADC noise low, and never toggle digital outputs near the ADC reference pin during conversions. Provide a solid ground plane under the 14x14 mm body and connect all exposed GND pins directly with short vias. Place the 16 MHz crystal within 10 mm of XTAL1/XTAL2 with load capacitors matched to the crystal datasheet.
Enable the watchdog timer with its separate on-chip oscillator in production firmware - it is clock-independent and will catch crystal failure or code lockup, which single-oscillator supervisors miss. Also remember EEPROM endurance is finite; throttle writes of frequently changing calibration data, or wear levels across the 4 KB array. When migrating between ATmega640, 1280, and 2560 on the same board, verify fuse settings (clock source, BOD level) per device since factory fuse defaults differ.
Compliance Information
RoHS compliant per PartGenie compliance notes (RoHS Y). REACH status not confirmed in provided data. Not an AEC-Q100 automotive-marked part.
