ATMEGA645-16MUR - 8-bit AVR MCU 64KB 16MHz 64-QFN | Microchip
MPN: ATMEGA645-16MUR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.12 | $5.12 |
| 10 | $4.62 | $46.20 |
| 100 | $4.1 | $410.00 |
| 500 | $3.72 | $1,860.00 |
| 1,000 | $3.35 | $3,350.00 |
ATMEGA645-16MUR Overview
An AVR ATmega microcontroller is an 8-bit reduced-instruction-set (RISC) processor that executes most of its 130 instructions in a single clock cycle, placing it in the broader hierarchy of microcontrollers -> embedded processors -> integrated circuits. The AVR architecture achieves near 1 MIPS per MHz throughput, allowing engineers to either maximize performance or run slower clocks to cut power consumption, which is why the ATmega family dominates cost-sensitive embedded designs.
Key features include 16 MIPS throughput at 16 MHz, an 8-channel 10-bit ADC for analog sensing, a JTAG interface for on-chip debugging and boundary scan, and 53 general-purpose I/O lines on this QFN variant. The device also integrates an LCD controller, making it one of the few ATmega parts with a built-in segment LCD driver, a differentiator against mainstream parts like the ATmega64A.
Technically, the ATMEGA645-16MUR uses the enhanced AVR RISC core with 32 general-purpose working registers directly connected to the ALU, delivering single-cycle execution. The 64KB self-programmable Flash supports ISP (In-System Programming) and boot-loader based firmware updates, while the 2KB EEPROM retains calibration data through power cycles.
Typical applications include industrial HMI panels with segment LCD displays, battery-powered metering products, building automation nodes, and consumer appliance controls, where the integrated LCD driver, ADC, and 5V tolerance reduce external component count.
Design consideration: at 16 MHz the part requires a 4.5V to 5.5V supply; derating to the ATMEGA645V-8MUR grade permits 2.7V to 5.5V operation at 8 MHz if lower voltage rails are needed.
This page synthesizes distributor availability data, drop-in family alternatives, and practical design guidance not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA645-16MUR — 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 ATMEGA645-16MUR (same form factor and footprint) — differing in Package, Supply Voltage Range, EEPROM Size, Debug Interface, Instructions.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA649-16MUR
✅ Drop-In✓ In Stock
$7.6 / Unit
View Datasheet →ATMEGA6450-16MUR
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA645V-8MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.98 / Unit
View Datasheet →ATMEGA645-16MUR Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Core Size | 8-Bit |
| Maximum Clock Frequency | 16 MHz |
| Program Memory Size | 64 KB (32K x 16) Flash |
| EEPROM Size | 2 KB |
| SRAM Size | 4 KB |
| Supply Voltage Range | 4.5 V to 5.5 V |
| Number of I/O | 53 |
| ADC Resolution | 10 bit |
| ADC Channels | 8 |
| Interfaces | JTAG, SPI, USART, I2C (TWI) |
| LCD Controller | Yes (segment LCD driver) |
| Throughput | 16 MIPS at 16 MHz |
| Package | 64-QFN (9 x 9 mm) |
| Operating Temperature | -40C to +85C (Industrial) |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel, Green/RoHS |
| Instructions | 130 (most single-cycle) |
ATMEGA645-16MUR 64-qfn (9 x 9 mm) Pin Configuration Guide
Pin configuration for ATMEGA645-16MUR (64-qfn (9 x 9 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 ATMEGA645-16MUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA645-16MUR is suitable for 6 applications: Industrial LCD HMI Panels, Utility Metering (Energy/Water/Gas), Building Automation Nodes, Appliance Control Boards, Portable Measurement Instruments, Access Control and Security Panels.
Industrial LCD HMI Panels
The ATMEGA645-16MUR fits industrial human-machine-interface panels because its integrated segment LCD controller drives glass displays directly without an external LCD driver IC, while the 10-bit 8-channel ADC reads potentiometers, thermistors, and analog transducer inputs. In a typical design the MCU runs at 16 MHz from a 5V industrial rail, multiplexing up to dozens of LCD segments while the 4KB SRAM buffers menu structures and the 2KB EEPROM stores user settings across power cycles. The JTAG interface enables on-chip debugging even after the 64-QFN is soldered, and ISP Flash programming allows field firmware updates. The 5V operation also provides superior noise immunity in electrically noisy factory environments versus 3.3V-only MCUs.
Recommended
Utility Metering (Energy/Water/Gas)
Metering products benefit directly from the ATMEGA645-16MUR combination of segment LCD, EEPROM, and low-power sleep modes. The 10-bit ADC samples current-shunt or transformer signals, the 64KB Flash holds multi-tariff firmware and accumulation tables in the 4KB SRAM, and the 2KB EEPROM preserves cumulative register values through outages. The LCD controller displays consumption figures on a low-cost segment glass, and power-save sleep keeps average current low between measurement intervals. Running from a 5V regulated supply at up to 16 MHz gives headroom for fast pulse processing, while slower clocking reduces consumption. ISP and boot-loader support permit on-site calibration firmware updates without desoldering the QFN device.
Recommended
Building Automation Nodes
In building automation - HVAC controllers, room units, and zone displays - the ATMEGA645-16MUR serves as the local control MCU. Its SPI and I2C (TWI) interfaces connect temperature/humidity sensors and EEPROM expansion, while a USART links to RS-485 transceivers for the building bus. The 8-channel 10-bit ADC monitors analog setpoint potentiometers and feedback signals, and the segment LCD shows setpoints and status locally. Industrial -40C to +85C operation covers rooftop and mechanical-room installations. The 53 GPIOs drive relays, dampers, and LEDs directly, and the 5V-tolerant 16 MHz core provides deterministic single-cycle instruction response for control loops without an RTOS.
Recommended
Appliance Control Boards
Consumer appliance controls - ovens, washing machines, dishwashers - use the ATMEGA645-16MUR to combine display, user interface, and actuator control in one 64-QFN device. The segment LCD controller drives the display, GPIOs and ADC channels read buttons and encoder inputs, and PWM-capable timers (via the 16 MHz core) drive triac or relay actuation of heaters and motors. The 64KB Flash accommodates multi-language UI strings and wash-cycle state machines in the 4KB SRAM, while the 2KB EEPROM stores last-used cycle settings. RoHS GREEN manufacturing meets appliance environmental requirements, and the 5V supply offers robust ESD and noise margins near mains-driven loads.
Recommended
Portable Measurement Instruments
Handheld and bench instruments - testers, calibrators, data loggers - leverage the ATMEGA645-16MUR ADC and JTAG debug. The 8-channel 10-bit ADC digitizes sensor bridges and user controls; results are shown on the integrated segment LCD. At 16 MIPS the AVR core handles scaling, filtering, and communication formatting in real time, and the 4KB SRAM holds logging buffers that upload via USART. JTAG on-chip debugging is decisive here: the 9x9 mm QFN pads are not hand-probable, so boundary-scan and breakpoint debugging on the assembled board shorten development cycles. Battery designs can clock the part slowly or use power-save sleep since the AVR offers near 1 MIPS per MHz efficiency.
Recommended
Access Control and Security Panels
Keypad-based access control panels use the ATMEGA645-16MUR for its combination of GPIO capacity, EEPROM credential storage, and local LCD feedback. The 53 I/O lines scan a key matrix and drive locks and alarm outputs; the 2KB EEPROM retains user codes and event pointers through power loss, and the 64KB Flash stores protocols and logging code with room for future features. The segment LCD displays entry prompts, and the USART interfaces to RS-485 network backbones. Industrial temperature rating supports unconditioned door-side enclosures, and the 5V 16 MHz operation delivers responsive keypad scanning and immediate actuator response within strict access-latency budgets.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA645-16MUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA649-16MUR | ATMEGA6450-16MUR | ATMEGA645V-8MUR |
|---|---|---|---|---|
| Package | 64-QFN (9x9 mm) | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max Clock Frequency | 16 MHz | 16 MHz | 16 MHz | 8 MHz |
| Flash Memory | 64 KB | 64 KB | 64 KB | 64 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 4 KB |
| Supply Voltage | 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 |
| LCD Controller | Yes (segment LCD) | Yes (larger segment allocation) | No | Yes (segment LCD) |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
Key Differentiators
- Integrated segment LCD controller (vs ATMEGA6450-16MUR)
- Full 16 MHz speed grade at 5V (vs ATMEGA645V-8MUR)
- LCD pin allocation differs within the same footprint (vs ATMEGA649-16MUR)
Design Notes
The ATMEGA645-16MUR requires 4.5V to 5.5V at the full 16 MHz speed grade; running below this violates the AVR frequency-versus-voltage derating curve and causes marginal core timing. Regulate a 5V rail with at least 100 nF decoupling per supply pin pair plus a 10 uF bulk capacitor near the QFN. If your system rail is 3.3V, redesign with the ATMEGA645V-8MUR grade (2.7V to 5.5V, 8 MHz max) rather than overclocking the -16 part.
The 64-pad QFN (9x9 mm) has a central exposed die paddle that must be soldered to a grounded thermal pad on the PCB for mechanical reliability and ground integrity - omitting the paddle solder paste pattern is a common cause of intermittent ground faults in QFN ATmega designs. Use an array of small vias under the paddle to the ground plane, and follow Microchip's QFN land-pattern application note for paste segmentation to avoid tombstoning and voiding.
When migrating from ATmega64 to ATmega645, consult Microchip application note AVR500 (doc2576): the parts are pin compatible for all but a few pins but Microchip explicitly does not design them as replacements for each other, and peripheral register maps differ. Also verify JTAG fuse settings - the JTAG port shares pins with GPIO, and leaving the JTAGEN fuse programmed reduces available I/O; disable it in production if those pins are needed.
Compliance Information
Distributor data (FindIC) lists GREEN, industrial temperature, Tape & Reel packaging. Automotive qualification not offered for this part.
