ATMEGA16U4-MUR - 8-bit AVR USB MCU 16KB 16MHz VQFN-44 | Microchip
MPN: ATMEGA16U4-MUR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.12 | $4.12 |
| 10 | $3.7 | $37.00 |
| 100 | $3.24 | $324.00 |
| 500 | $2.88 | $1,440.00 |
| 1,000 | $2.56 | $2,560.00 |
| 3,000 | $2.35 | $7,050.00 |
ATMEGA16U4-MUR Overview
A USB microcontroller (USB MCU) is a microcontroller that integrates a USB transceiver and protocol engine on-chip, eliminating the need for an external USB interface chip. Within the power/performance hierarchy, the ATmega16U4 sits in the 8-bit AVR ATmega family, which is part of the broader microcontroller unit (MCU) class of embedded semiconductor devices.
Key differentiating features include single-cycle execution of most instructions delivering up to 1 MIPS per MHz throughput, an on-chip USB 2.0 device controller with 8 KB of boot code space for field firmware updates, and in-system programmable (ISP) flash that allows firmware reprogramming on the assembled PCB. The enhanced AVR RISC core combines a rich instruction set with 32 general-purpose working registers, all directly connected to the arithmetic logic unit.
Technically, the ATmega16U4/ATmega32U4 family is a low-power CMOS design based on the AVR enhanced RISC architecture, per the Atmel-7766 datasheet summary. Its 12-channel 10-bit ADC supports analog sensing, while high-speed PWM outputs suit motor control and LED dimming. The JTAG boundary-scan capability supports production test flows.
Typical applications include USB keyboards, mice and game controllers, custom USB HID devices, battery-powered instruments requiring both USB connectivity and low standby power, and embedded sensor nodes using the 10-bit ADC.
When designing with this device, budget the VQFN-44 (7x7 mm) land pattern carefully and note that the -MUR suffix indicates tape-and-reel industrial-temperature, green packaging.
This page synthesizes distributor pricing, drop-in alternative analysis, pin compatibility notes, and practical design guidance not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA16U4-MUR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA32U4-MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.86 / Unit
View Datasheet →ATMEGA16U4-MUR Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Maximum Clock Frequency | 16 MHz |
| Flash Memory | 16 KB (8K x 16) |
| Boot Code Section | 8 KB |
| SRAM | 2.5 KB |
| EEPROM | 1024 B |
| USB Interface | USB 2.0 full-speed/low-speed device |
| ADC Resolution | 10-bit, 12-channel |
| PWM | High-speed PWMs |
| Debug Interface | JTAG (on-chip-debug) |
| In-System Programming | Yes (ISP) |
| Package | 44-VQFN (7x7 mm) |
| Mounting Type | Surface Mount |
| Temperature Range | Industrial (per datasheet) |
| Processing Rate | Up to 1 MIPS per MHz |
| Packaging | Tape & Reel (MUR suffix) |
| RoHS Status | Green (per distributor listing) |
ATMEGA16U4-MUR 44-vqfn (7x7 mm) Pin Configuration Guide
Pin configuration for ATMEGA16U4-MUR (44-vqfn (7x7 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 ATMEGA16U4-MUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA16U4-MUR is suitable for 6 applications: USB HID Devices (Keyboards, Mice, Controllers), Custom USB Instruments and Test Adapters, Battery-Powered Portable Devices, Motor Control and LED Dimming, Industrial Sensor Nodes with USB Commissioning, Maker, Hobbyist and Rapid Prototyping Boards.
USB HID Devices (Keyboards, Mice, Controllers)
The ATMEGA16U4-MUR fits USB human-interface devices because its USB 2.0 full-speed/low-speed device controller is fully integrated on-chip, so no external USB interface chip or bridge is required. With a 16 MHz clock and the AVR core delivering up to 1 MIPS per MHz, the MCU scans key matrices and processes HID reports with substantial timing margin. The 8 KB boot code section lets manufacturers ship field-updatable firmware over the same USB cable, eliminating in-field programming fixtures. High-speed PWM outputs drive RGB indicator LEDs directly, and the 1024 B EEPROM stores calibration data such as key travel or joystick trim across power cycles. The 44-VQFN (7x7 mm) footprint keeps the PCB compact enough for slim peripheral enclosures.
Recommended
Custom USB Instruments and Test Adapters
Custom USB measurement adapters and instruments benefit from the ATMEGA16U4-MUR's combination of USB device connectivity and a 12-channel 10-bit ADC, allowing analog signals to be digitized and streamed over USB from a single chip. The 2.5 KB SRAM buffers sample batches before bulk transfers, and the JTAG interface supports on-chip-debug during firmware bring-up as well as boundary-scan production test. Because flash is in-system programmable, calibration routines and firmware revisions can be flashed on the assembled board without desoldering. Per the Atmel-7766 datasheet summary, the architecture sustains 1 MIPS per MHz throughput, so protocol handling and DSP-style filtering run comfortably at 16 MHz. The VQFN-44 industrial-temperature rating suits benchtop environments.
Recommended
Battery-Powered Portable Devices
Battery-powered portable devices use the ATMEGA16U4-MUR's low-power CMOS AVR design to combine USB charging/communication with long sleep-dominated runtime. Per the Atmel-7766 summary, this is a low-power microcontroller family, and the AVR's single-cycle instruction execution lets designers finish tasks at lower clock rates, then sleep between events. The 12-channel 10-bit ADC reads battery voltage and sensor inputs directly, removing external ADC ICs and their quiescent burden. The 1024 B EEPROM retains user settings without battery-backed RAM. When USB is unplugged, the same firmware can operate from a lower-speed internal clock to cut power. The compact 7x7 mm VQFN-44 package fits handheld and wearable form factors easily.
Recommended
Motor Control and LED Dimming
The high-speed PWM peripherals of the ATMEGA16U4-MUR make it appropriate for small motor control and precision LED dimming nodes that also need a USB configuration port. Per the Microchip product page, the device includes high-speed PWMs that can run at carrier frequencies well above audible range, avoiding LED flicker and motor whine. The 12-channel 10-bit ADC closes the loop by reading current-sense shunts or position potentiometers, while the AVR core's 1 MIPS per MHz throughput executes PID control loops at 16 MHz with headroom. A USB link allows PC-based tuning of speed or brightness profiles, and firmware updates over the 8 KB boot section simplify field servicing without reopening the enclosure.
Recommended
Industrial Sensor Nodes with USB Commissioning
Industrial sensor nodes deploy the ATMEGA16U4-MUR where a rugged 8-bit MCU with occasional USB commissioning is preferred over a larger 32-bit platform. The industrial temperature rating and green QFN/MLF packaging noted in distributor datasheets (FindIC, AiPCBA) suit factory-floor environments, while the 12-channel 10-bit ADC digitizes multiple analog sensors - temperature, pressure, or current loops - on one chip. In operation the node samples continuously at modest power; during installation or service, a technician connects USB to reconfigure thresholds or flash new firmware through the in-system programmable flash. The JTAG interface supports boundary-scan checks during board production, improving line yield on multi-layer industrial PCBs.
Recommended
Maker, Hobbyist and Rapid Prototyping Boards
The ATmega16U4/32U4 family is the silicon behind popular open-source USB microcontroller boards, making the ATMEGA16U4-MUR a natural choice for maker and prototype hardware. Its USB device controller plus 8 KB bootloader region reproduces the classic workflow of drag-and-drop firmware updates with no external programmer, and the 16 KB ISP flash with in-system programming supports iterative design. Rich onboard peripherals - high-speed PWMs for servos and LEDs, a 12-channel 10-bit ADC for analog inputs, and JTAG for serious debugging with standard tools - cover most hobby projects on one chip. Distribution through DigiKey, Mouser, and Newark with same-day shipping keeps prototype schedules short.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA16U4-MUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA32U4-MUR |
|---|---|---|
| Package | 44-VQFN (7x7 mm) | 44-VQFN (7x7 mm) - same |
| Brand | Microchip Technology | Microchip Technology |
| Flash Memory | 16 KB (8K x 16) | 32 KB |
| Boot Code Section | 8 KB | 8 KB |
| Max Clock Frequency | 16 MHz | 16 MHz |
| USB Interface | USB 2.0 full-speed/low-speed device | USB 2.0 full-speed/low-speed device |
| ADC | 12-channel 10-bit | 12-channel 10-bit |
| Debug Interface | JTAG on-chip-debug | JTAG on-chip-debug |
| Pin Compatibility | Reference (44-VQFN) | Pin-to-pin compatible, same footprint |
Key Differentiators
- Lower flash with identical pinout and USB subsystem (vs ATMEGA32U4-MUR)
- Integrated USB 2.0 full-speed device controller (vs ATMEGA16U4-AU (non-USB ATmega16A class parts))
- JTAG on-chip-debug in a 44-VQFN package (vs ATMEGA32U4-MUR)
Design Notes
The ATMEGA16U4-MUR comes in a 44-VQFN (7x7 mm) QFN/MLF package with a center ground pad. Per standard AVR QFN layout practice, connect the exposed pad to a solid ground plane through an array of thermal vias - this is the primary return path for the device and also the thermal relief. Define the land pattern exactly to the 7x7 mm QFN outline in the datasheet mechanical drawing; note that the -AU TQFP-44 variants use a different land pattern and are not footprint-compatible. Confirm stencil aperture design for the center pad to avoid excess solder causing tilting.
Decouple the ATmega16U4 supply pins with 100 nF ceramic capacitors placed as close as possible to each VCC/GND pair, plus bulk capacitance near the USB connector for VBUS transients. Estimated: at 16 MHz and typical activity, AVR core current is in the low-milliamp range per the AVR family supply-current curves, so a 5V-to-3.3V LDO sized at 100-150 mA usually suffices. USB 2.0 full-speed signaling requires D+/D- series termination per the USB spec as detailed in the Atmel-7766 datasheet USB chapter; keep the D+/D- traces length-matched and routed away from switching nodes.
Do not confuse ordering-code variants when sourcing: ATMEGA16U4-MUR is the VQFN tape-and-reel industrial part, ATMEGA16U4-MU is the same die in tray packing, and ATMEGA16U4-AU/AUR are TQFP-44 - only the MU/MUR family is footprint-identical. When migrating firmware to the ATMEGA32U4 pin-compatible drop-in, recheck bootloader address constants and linker scripts since the flash size doubles but the boot section remains 8 KB. Ensure the 16 MHz clock source (crystal or internal) matches fuse settings; wrong CKDIV8 fuse state is a common first-bring-up failure causing the chip to run at 2 MHz.
Compliance Information
Distributor datasheet listings (FindIC, AiPCBA) describe the ATMEGA16U4-MUR as 'QFN/MLF, Ind Temp, Green', indicating Microchip's green package designation consistent with RoHS compliance. Formal REACH and halogen-free certificates should be requested from Microchip.