ATXMEGA128A1-AU - 8/16-bit AVR XMEGA MCU, 128KB Flash, TQFP-100
MPN: ATXMEGA128A1-AU ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.82 | $8.82 |
| 10 | $7.94 | $79.40 |
| 100 | $7.05 | $705.00 |
| 500 | $6.34 | $3,170.00 |
| 1,000 | $5.85 | $5,850.00 |
ATXMEGA128A1-AU Overview
What is an XMEGA microcontroller? The XMEGA family represents Atmel/Microchip's high-performance 8/16-bit AVR RISC architecture, sitting in the taxonomy: microcontroller -> embedded MCU -> 8/16-bit RISC MCU -> AVR XMEGA family -> A1 series. XMEGA devices execute most instructions in a single clock cycle, achieving throughput approaching 1 MIPS per MHz, and integrate rich peripherals such as DMA controllers, event systems, and multi-level interrupt controllers to reduce CPU load in real-time applications.
Key features of the ATXMEGA128A1-AU include four-channel DMA controller, eight-channel event system, programmable multi-level interrupt controller, 78 general-purpose I/O lines, 16-bit real-time counter (RTC), eight flexible 16-bit timer/counters with compare and PWM channels, eight USARTs, four SPI/serial interfaces, two I2C/TWI interfaces, 12-bit ADC and DAC, and a full-speed USB device interface. The wide 1.6 V to 3.6 V operating voltage range supports both 1.8 V and 3.3 V system designs.
The ATXMEGA128A1-AU uses a pipelined Harvard architecture with 32 working registers directly connected to the ALU, enabling high code density and deterministic interrupt latency. The peripheral event system allows peripherals to communicate without CPU intervention, while the four-channel DMA controller offloads data movement between memory and peripherals, ideal for high-throughput sensor aggregation or USB transfers.
Typical applications include industrial control systems, building automation, smart energy metering, motor control, USB human-interface devices, sensor hubs, and low-power wireless sensor nodes. Its high peripheral integration and rich connectivity make it well-suited for designs consolidating multiple discrete functions onto a single MCU.
When designing with this device, note that the A1 family is marked Not Recommended for New Designs by Microchip, with the AU series offered as the preferred successor. Designers should validate long-term availability before committing to new production. Decoupling with 100 nF ceramic capacitors near each supply pin is essential for clean ADC and DAC performance.
This page synthesizes distributor pricing, lifecycle status, drop-in alternative recommendations, and practical design notes that complement the manufacturer datasheet, enabling engineers to make informed sourcing and design decisions.
Drop-in alternatives for ATXMEGA128A1-AU — 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 ATXMEGA128A1-AU (same form factor and footprint) — differing in Core Architecture, Package, Operating Temperature, Mounting Type, SRAM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATXMEGA128A1-AUR
✅ Drop-In📋 Reference alternative (not in catalog)
ATXMEGA64A1-AU
✅ Drop-In📋 Reference alternative (not in catalog)
ATXMEGA128A1-MU
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ATSAM3U4EA-CU
✅ Drop-In✓ In Stock
$12.05 / Unit
View Datasheet →ATSAM3U4EA-AU
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$7.18 / Unit
View Datasheet →ATXMEGA128A1-AU Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR XMEGA (enhanced RISC), 8/16-bit |
| CPU Clock Speed | 32 MHz max |
| Program Memory (Flash) | 128 KB (64K x 16), in-system programmable with read-while-write |
| Boot Code Section | 8 KB |
| SRAM | 8 KB |
| EEPROM | 2 KB |
| Operating Voltage Range | 1.6 V to 3.6 V |
| General-Purpose I/O Pins | 78 |
| DMA Channels | 4 |
| Event System Channels | 8 |
| Timer/Counters | 8 x 16-bit with compare and PWM |
| USART Interfaces | 8 |
| SPI Interfaces | 4 |
| I2C/TWI Interfaces | 2 |
| ADC | 12-bit, multi-channel |
| DAC | 12-bit |
| USB Interface | Full-speed USB device |
| External Bus Interface | Yes |
| Package | TQFP-100 (14x14 mm, 0.5 mm pitch) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C (industrial) |
| RoHS Status | Compliant (Green, MS-026AED) |
ATXMEGA128A1-AU Pin Configuration
| Pin 1 | AVCC — Analog supply voltage |
| Pin 10 | PA0 — GPIO Port A bit 0 |
| Pin 20 | PA7 — GPIO Port A bit 7 |
| Pin 30 | PB6 — GPIO Port B bit 6 |
| Pin 40 | PC5 — GPIO Port C bit 5 |
| Pin 50 | PD4 — GPIO Port D bit 4 |
| Pin 60 | PE3 — GPIO Port E bit 3 |
| Pin 70 | PF2 — GPIO Port F bit 2 |
| Pin 80 | GND — Ground |
| Pin 90 | RESET — Reset input (active low) |
| Pin 100 | DVCC — Digital supply voltage |
Typical Applications
ATXMEGA128A1-AU is suitable for 6 applications: Industrial Control Systems, Smart Energy Metering, USB Human Interface Devices, Building Automation Hubs, Sensor Hub Aggregation, Motor Control and BLDC Drive.
Industrial Control Systems
The ATXMEGA128A1-AU fits industrial control applications because of its 78 GPIO lines, four-channel DMA controller, and eight 16-bit timer/counters with PWM outputs. Engineers can drive multiple stepper motors, BLDC motors, or solenoid banks while the DMA offloads encoder feedback and ADC sampling without CPU intervention. The 1.6-3.6 V supply tolerates 24 V industrial rails after step-down conversion, and the industrial temperature grade (-40C to +85C) handles factory floor conditions. Compared to a discrete MCU plus FPGA combination, the ATXMEGA128A1-AU consolidates logic, timers, and connectivity into a single TQFP-100 device.
Recommended
Smart Energy Metering
The ATXMEGA128A1-AU is well-suited for smart electricity, water, and gas metering thanks to its 12-bit ADC for accurate analog measurements, event system for zero-crossing detection, and RTC for time-of-use billing. The 128 KB Flash supports complex metering algorithms and communication stacks (DLMS/COSEM, M-Bus), while 8 KB SRAM buffers measurement data between transmissions. Its low-power sleep modes extend battery life in wireless meter deployments. The device's TQFP-100 footprint allows integration of multiple metering channels plus LCD interface on a single PCB.
Recommended
USB Human Interface Devices
The ATXMEGA128A1-AU integrates a full-speed USB 2.0 device controller, making it ideal for USB HID peripherals such as keyboards, mice, game controllers, and custom input devices. With 78 GPIO available, designers can scan large key matrices or capacitive touch arrays while the DMA and event system handle USB endpoint transfers autonomously. The 32 MHz CPU processes HID reports at sub-millisecond latency, and 128 KB Flash accommodates USB stacks plus application logic. Compared to discrete USB controller plus MCU designs, this single-chip solution reduces BOM cost and PCB area.
Recommended
Building Automation Hubs
The ATXMEGA128A1-AU serves as a building automation controller because it offers eight USARTs, four SPI ports, and two I2C/TWI interfaces for connecting to diverse field buses (Modbus, BACnet, KNX gateways). Its 128 KB Flash stores protocol stacks for multiple subsystems (HVAC, lighting, access control), and the four-channel DMA moves sensor data to communication buffers without CPU overhead. The 32 MHz core handles multi-protocol arbitration deterministically, while the RTC provides accurate time-stamping for event logs and scheduling.
Recommended
Sensor Hub Aggregation
The ATXMEGA128A1-AU aggregates data from multiple sensors via its event system and DMA controller, allowing low-latency sensor fusion in robotics, drones, and IoT edge nodes. Eight 16-bit timer/counters capture encoder and PWM inputs from motor controllers, while the 12-bit ADC reads analog sensors in parallel. Its 32 MHz throughput enables real-time sensor fusion algorithms such as complementary or Kalman filters. Compared to MCU + external FPGA solutions, the integrated event routing eliminates inter-chip latency and simplifies PCB layout.
Recommended
Motor Control and BLDC Drive
The ATXMEGA128A1-AU drives BLDC, stepper, and DC motors using its eight 16-bit timer/counters with complementary PWM outputs and configurable dead-time insertion. The event system synchronizes ADC sampling to PWM center points for accurate current sensing, while the four-channel DMA transfers ADC results to memory without CPU interrupts. Its 78 GPIO accommodate multiple motor phases, Hall sensor inputs, and encoder feedback. The 32 MHz CPU executes field-oriented control (FOC) loops within microseconds, and the wide 1.6-3.6 V supply simplifies integration with 3.3 V gate drivers.
Recommended
Recommended Products Summary
Engineering reference data for ATXMEGA128A1-AU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATXMEGA128A1-AUR | ATXMEGA64A1-AU | ATXMEGA128A1-MU | ATSAM3U4EA-CU | ATSAM3U4EA-AU |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | TQFP-100 (14x14 mm) | TQFP-100 - same | TQFP-100 - same | TQFP-100 - same | TQFP-100 - same | TQFP-100 - same |
| Core Architecture | AVR XMEGA 8/16-bit | AVR XMEGA 8/16-bit | AVR XMEGA 8/16-bit | AVR XMEGA 8/16-bit | ARM Cortex-M3 | ARM Cortex-M3 |
| Max Clock Speed | 32 MHz | 32 MHz | 32 MHz | 32 MHz | 96 MHz | 96 MHz |
| Flash Memory | 128 KB | 128 KB | 64 KB | 128 KB | 256 KB | 256 KB |
| SRAM | 8 KB | 8 KB | 4 KB | 8 KB | 52 KB | 52 KB |
| GPIO Count | 78 | 78 | 78 | 78 | 52 | 52 |
| 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 | 1.62 V to 3.6 V | 1.62 V to 3.6 V |
| Lifecycle Status | NRND | NRND | NRND | NRND | Active | Active |
Key Differentiators
- Highest GPIO count in TQFP-100 XMEGA family (vs ATXMEGA64A1-AU)
- ARM Cortex-M3 upgrade path in identical package (vs ATSAM3U4EA-AU)
- Integrated full-speed USB device controller (vs ATMEGA328P-AUR)
Design Notes
Place a 100 nF ceramic decoupling capacitor within 5 mm of each AVCC and DVCC pin pair, plus a bulk 4.7 uF to 10 uF tantalum or ceramic at the regulator output. The ATXMEGA128A1-AU separates analog and digital supplies; connect AVCC and DVCC through a ferrite bead or small resistor to suppress digital switching noise from coupling into the 12-bit ADC. For USB applications, ensure DVCC stays above 3.0 V for compliant USB signaling levels.
The ATXMEGA128A1-AU is marked Not Recommended for New Designs by Microchip. For new production, plan migration to the XMEGA AU series (e.g., ATXMEGA128A4U family) or ARM Cortex-M0+ SAM D20/D21 MCUs. Do not assume 10+ year availability for this NRND part in long-lifecycle industrial designs. Place safety stock orders if redesign is not feasible.
Route the 32 MHz external crystal traces symmetrically with matched length to GND and keep them short (under 5 mm). Place load capacitors within 2 mm of the crystal pins. For USB applications, the D+ and D+ traces must be 90 ohm differential with characteristic impedance matching. Avoid routing digital signals under the analog AVCC supply plane to prevent noise coupling into ADC measurements.
Compliance Information
RoHS compliant per Green package designation (MS-026AED) listed in FindIC and Heisener data. Not AEC-Q100 qualified - not intended for automotive safety applications. Reach compliance assumed per Microchip policy.
