ATXMEGA16A4U-AUR - 16KB Flash 32MHz 8/16-bit AVR XMEGA MCU | Microchip
MPN: ATXMEGA16A4U-AUR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.4 | $6.40 |
| 10 | $5.76 | $57.60 |
| 100 | $5.12 | $512.00 |
| 500 | $4.61 | $2,305.00 |
| 1,000 | $4.1 | $4,100.00 |
ATXMEGA16A4U-AUR Overview
An XMEGA A4U microcontroller is a high-performance, low-power 8/16-bit AVR RISC core member of the Atmel/Microchip AVR XMEGA family, which itself sits within the broader hierarchy of microcontrollers (MCU) -> embedded processors -> integrated circuits -> semiconductors. XMEGA parts combine a 2-cycle hardware multiplier, a peripheral event system, and a multi-channel DMA to deliver deterministic, low-overhead I/O that is well suited to battery-powered and signal-conditioning designs. The 'U' suffix specifically denotes a USB 2.0 full-speed (12 Mbps) transceiver, while the 'A4U' series provides 4-channel DMA, 8-channel event system, and an external bus interface for SRAM, SDRAM and NAND expansions.
Key differentiators of the ATXMEGA16A4U-AUR include 16KB Flash (vs 8/4KB on smaller XMEGA A-series siblings), on-chip USB 2.0 full-speed transceiver supporting device, host, and OTG roles, AES and DES crypto accelerators for secure firmware updates, an integrated 12-bit 1 MSPS ADC, a 12-bit 1 MSPS DAC, four USARTs, two TWI (I2C) ports, and two SPI ports. The peripheral event system allows direct hardware triggering between timers, ADC, DAC, DMA, and I/O without CPU intervention, while the 4-channel DMA controller offloads repetitive data moves to maintain real-time responsiveness.
Typical applications include USB HID/mass-storage peripherals, industrial sensor front-ends with USB logging, secure IoT edge nodes with AES encryption, portable data loggers, and battery-powered human-interface devices (HID) such as custom keyboards, mice, or capacitive-touch control panels. The wide 1.6V to 3.6V supply range and picoPower sleep modes support designs that spend long periods in standby and wake on USB events.
Design considerations include careful decoupling of the analog and digital VCC rails, provision for a 12 MHz crystal or external clock for USB full-speed operation, and reserving PA0/PA1 for the USB D-/D+ pins since the on-chip transceiver is bonded to those pads. The 4KB bootloader section with independent lock bits enables in-field firmware upgrades.
Drop-in alternatives for ATXMEGA16A4U-AUR — 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 ATXMEGA16A4U-AUR (same form factor and footprint) — differing in Core Architecture, SRAM, ADC, Operating Temperature, EEPROM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATXMEGA16A4U-AU
✅ Drop-In✓ In Stock
$3.05 / Unit
View Datasheet →ATXMEGA32A4U-AUR
✅ Drop-In📋 Reference alternative (not in catalog)
ATXMEGA128A4U-AUR
✅ Drop-In✓ In Stock
$5.45 / Unit
View Datasheet →ATMEGA32U4-AU
✅ Drop-In✓ In Stock
$4.25 / Unit
View Datasheet →ATXMEGA16A4U-AUR Maximum Ratings & Electrical Characteristics
| Core Architecture | 8/16-bit AVR XMEGA RISC |
| Core Series | XMEGA A4U |
| Program Memory (Flash) | 16 KB (8K x 16) |
| Boot Code Section | 4 KB with Independent Lock Bits |
| SRAM | 2 KB |
| EEPROM | 1 KB |
| Maximum CPU Speed | 32 MHz (up to 32 MIPS) |
| Operating Voltage | 1.6 V to 3.6 V |
| Operating Temperature (Industrial) | -40C to +85C |
| USB Interface | USB 2.0 Full-Speed (12 Mbps) Device/Host/OTG |
| DMA Channels | 4 |
| Event System Channels | 8 |
| ADC | 12-bit, 1 MSPS |
| DAC | 12-bit, 1 MSPS |
| USART | 4 channels |
| TWI (I2C) | 2 channels |
| SPI | 2 channels |
| Crypto Accelerator | AES and DES |
| External Bus Interface | Yes (SRAM, SDRAM, NAND) |
| Package | 44-pin TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (AUR) |
| RoHS Status | Compliant |
ATXMEGA16A4U-AUR Pin Configuration
| Pin 1 | VCC — Digital supply voltage |
| Pin 2 | PA0 — Port A bit 0 / USB D+ (USB transceiver data) |
| Pin 3 | PA1 — Port A bit 1 / USB D- (USB transceiver data) |
| Pin 4 | PA2 — Port A bit 2 |
| Pin 5 | PA3 — Port A bit 3 |
| Pin 6 | PA4 — Port A bit 4 |
| Pin 7 | PA5 — Port A bit 5 |
| Pin 8 | PA6 — Port A bit 6 |
| Pin 9 | PA7 — Port A bit 7 |
| Pin 10 | GND — Ground |
| Pin 11 | PB0 — Port B bit 0 |
| Pin 12 | PB1 — Port B bit 1 |
| Pin 13 | PB2 — Port B bit 2 |
| Pin 14 | PB3 — Port B bit 3 |
| Pin 15 | PB4 — Port B bit 4 |
| Pin 16 | PB5 — Port B bit 5 |
| Pin 17 | PB6 — Port B bit 6 |
| Pin 18 | PB7 — Port B bit 7 |
| Pin 19 | GND — Ground |
| Pin 20 | VCC — Digital supply voltage |
| Pin 21 | PC0 — Port C bit 0 |
| Pin 22 | PC1 — Port C bit 1 |
| Pin 23 | PC2 — Port C bit 2 |
| Pin 24 | PC3 — Port C bit 3 |
| Pin 25 | PC4 — Port C bit 4 |
| Pin 26 | PC5 — Port C bit 5 |
| Pin 27 | PC6 — Port C bit 6 |
| Pin 28 | PC7 — Port C bit 7 |
| Pin 29 | PD0 — Port D bit 0 |
| Pin 30 | PD1 — Port D bit 1 |
| Pin 31 | PD2 — Port D bit 2 |
| Pin 32 | PD3 — Port D bit 3 |
| Pin 33 | PD4 — Port D bit 4 |
| Pin 34 | PD5 — Port D bit 5 |
| Pin 35 | PD6 — Port D bit 6 |
| Pin 36 | PD7 — Port D bit 7 |
| Pin 37 | PE0 — Port E bit 0 |
| Pin 38 | PE1 — Port E bit 1 |
| Pin 39 | PE2 — Port E bit 2 / XTAL2 |
| Pin 40 | PE3 — Port E bit 3 / XTAL1 |
| Pin 41 | RESET — Reset input (active low) |
| Pin 42 | VCC — Digital supply voltage |
| Pin 43 | AVCC — Analog supply voltage |
| Pin 44 | GND — Ground |
Typical Applications
ATXMEGA16A4U-AUR is suitable for 6 applications: USB Human Interface Device (HID), Industrial Sensor Data Logger, Secure IoT Edge Node, Battery-Powered Portable Instrument, Automotive Body Control Module, Educational / Maker Development Platform.
USB Human Interface Device (HID)
The ATXMEGA16A4U-AUR's integrated USB 2.0 full-speed (12 Mbps) transceiver on PA0/PA1 and 4-channel DMA make it well suited to USB HID peripherals such as custom keyboards, mice, and capacitive touch panels. The on-chip 3.3V regulator removes the need for an external LDO on VBUS, while the event system delivers sub-millisecond interrupt latency for low-latency HID reports. Dedicated DMA channels on the USB endpoint banks double-buffer packets without CPU intervention, freeing 16KB Flash / 32 MIPS for application code and HID descriptors.
Recommended
Industrial Sensor Data Logger
The 12-bit 1 MSPS ADC, 4-channel DMA, 8-channel event system, and 1.6V to 3.6V supply range of the ATXMEGA16A4U-AUR support industrial sensor front-ends with sample-and-store logging. DMA moves ADC samples directly to SRAM without CPU intervention, freeing the AVR core to handle sensor calibration, while the 1KB EEPROM stores non-volatile configuration. picoPower sleep modes drop quiescent current below 100 nA between scans, enabling 2xAA battery operation for field-deployed sensor loggers.
Recommended
Secure IoT Edge Node
The ATXMEGA16A4U-AUR integrates AES and DES crypto accelerators alongside USB for secure IoT edge nodes that require encrypted firmware updates and authenticated cloud connectivity. The 4KB boot section with independent lock bits supports secure bootloader and signed-firmware workflows, while the 32 MIPS core runs TLS handshakes in reasonable time at USB data rates. The 2 KB SRAM buffers TLS records, and the wide 1.6V to 3.6V supply range allows direct Li-ion battery connection with an LDO.
Recommended
Battery-Powered Portable Instrument
The ATXMEGA16A4U-AUR's wide 1.6V to 3.6V operating range, picoPower sleep modes, integrated 12-bit DAC for stimulus generation, and USB charging interface make it ideal for portable instrumentation. Battery voltages from a single Li-ion cell can power the part directly through an LDO, while USB VBUS powers charging logic. The 32 MIPS throughput executes DSP-style FIR filtering on incoming sensor data in real time, and DMA offloads repetitive waveform generation from the CPU.
Recommended
Automotive Body Control Module
Although automotive-grade XMEGA variants exist, the ATXMEGA16A4U-AUR's industrial -40C to +85C range, 32 MIPS throughput, 4-channel DMA, and multiple USART/TWI/SPI ports support LIN and CAN body-control network nodes. The 12-bit ADC and DAC drive analog sensor readouts and PWM-actuated loads, while the 4KB boot section enables in-field firmware updates via CAN or USB. The 44-pin TQFP footprint is suitable for hand-soldered prototype or low-volume production modules.
Recommended
Educational / Maker Development Platform
The ATXMEGA16A4U-AUR's USB 2.0 full-speed, 32 MIPS, 16 KB Flash, and Atmel Studio / Microchip Studio toolchain support make it a strong educational MCU for advanced 8/16-bit designs. Developers can prototype USB, ADC/DAC, and event-system tutorials without external PHYs, while the 44-pin TQFP (10x10 mm) breaks out to standard 0.1-inch headers on development boards. The AVR GCC compiler and Atmel-ICE debug interface provide a low-cost path into RISC microcontroller development.
Recommended
Recommended Products Summary
Engineering reference data for ATXMEGA16A4U-AUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATXMEGA16A4U-AU | ATXMEGA32A4U-AUR | ATXMEGA128A4U-AUR | ATMEGA32U4-AU |
|---|---|---|---|---|---|
| Package | 44-pin TQFP (10x10 mm) | 44-pin TQFP (10x10 mm) - same | 44-pin TQFP (10x10 mm) - same | 44-pin TQFP (10x10 mm) - same | 44-pin TQFP - same footprint, different core |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core Architecture | 8/16-bit AVR XMEGA | 8/16-bit AVR XMEGA | 8/16-bit AVR XMEGA | 8/16-bit AVR XMEGA | 8-bit megaAVR (not XMEGA) |
| Program Memory (Flash) | 16 KB | 16 KB | 32 KB (+100%) | 128 KB (+700%) | 32 KB (+100%) |
| SRAM | 2 KB | 2 KB | 2 KB | 2 KB | 2.5 KB |
| EEPROM | 1 KB | 1 KB | 1 KB | 2 KB | 1 KB |
| Maximum CPU Speed | 32 MHz (32 MIPS) | 32 MHz | 32 MHz | 32 MHz | 16 MHz (-50%) |
| USB Interface | USB 2.0 Full-Speed OTG | USB 2.0 Full-Speed OTG | USB 2.0 Full-Speed OTG | USB 2.0 Full-Speed OTG | USB 2.0 Full-Speed (device only) |
| AES/DES Crypto | Yes (AES + DES) | Yes | Yes | Yes | No |
| Operating Voltage | 1.6 V to 3.6 V | 1.6 V to 3.6 V | 1.6 V to 3.6 V | 1.6 V to 3.6 V | 2.7 V to 5.5 V |
Key Differentiators
- On-chip USB 2.0 full-speed OTG transceiver removes external PHY (vs ATXMEGA16D4-MH)
- Drop-in Flash scalability across the A4U family (vs ATXMEGA16A4-AU (non-USB A4))
- XMEGA event system + DMA outperforms megaAVR peripherals (vs ATMEGA32U4-AU)
Design Notes
Decouple VCC, AVCC, and the USB VBUS regulator output separately. Place 100 nF ceramics as close as possible to each pin pair (VCC/GND and AVCC/GND), and add a 4.7 uF bulk capacitor on AVCC to suppress ADC reference noise. The on-chip USB 3.3V regulator still requires a 4.7 uF bulk on its output; failing to decouple this regulator raises noise on the analog supply and degrades ADC SNR by 6 to 10 dB at 1 MSPS sampling rates.
Route PA0 (USB D+) and PA1 (USB D-) as a 90-ohm differential pair with matched length within 0.5 mm and continuous ground reference. Keep the pair away from switching regulator inductors and oscillator traces to meet USB 2.0 full-speed radiated-emissions margins. The 44-pin TQFP (10x10 mm) exposes all USB pins, so an external ESD protection diode array (such as USBLC6-2) is recommended for production designs that touch commercial USB ports.
Use a 12 MHz crystal or external clock source on PE2 (XTAL2) / PE3 (XTAL1) for USB full-speed operation; the internal 32 MHz oscillator is not accurate enough for the 12 Mbps USB data-rate. The PLL multiplies the 12 MHz reference to the 32 MHz CPU clock, and the USB module derives its 12 MHz sample clock directly from the crystal. An incorrect crystal load capacitance (specified in the datasheet) shifts frequency and causes USB enumeration failures.
Do not assume that any 44-pin TQFP ATXMEGA is pin-compatible across A4U, D4, and E5 series - only A4U parts have the on-chip USB transceiver on PA0/PA1; D4 and E5 variants use those pins as general GPIO or analog inputs. Verify the full ordering code, including the 'U' suffix for USB and 'AU/AUR' packaging suffix, before routing the PCB. Lock bits and boot section configuration also differ; consult the ATxmega128-64-32-16A4U datasheet (DS40002166A) for the security lock sequence.
Compliance Information
RoHS and lead-free per Microchip product page (microchip.com/en-us/product/ATxmega16A4U). Industrial temperature -40C to +85C; the ATXMEGA16A4U-AUR is not AEC-Q100 qualified - consult Microchip automotive XMEGA variants for vehicle applications.