Microchip Technology

ATXMEGA128D4-AU - 128KB Flash XMEGA AVR MCU 32MHz 44TQFP | Microchip

MPN: ATXMEGA128D4-AU ✓ Active
In Stock Ships in 1-3 business days
1.6 V to 3.6 V Vdss 44-pin TQFP (10x10 mm) Package 32 MHz Speed 128 KB Memory
From $5.05 USD / Unit
MOQ: 1 |
Price updated: 2026-10-06
Volume Pricing
Qty Unit Price Extended
1 $7.85 $7.85
10 $7.07 $70.70
100 $6.3 $630.00
500 $5.65 $2,825.00
1,000 $5.05 $5,050.00
ℹ️ All prices are in USD

ATXMEGA128D4-AU Overview

The Microchip (Atmel) ATXMEGA128D4-AU is a high-performance, low-power 8/16-bit AVR XMEGA microcontroller integrating 128 KB of in-system programmable Flash with read-while-write support, 2 KB EEPROM, and 8 KB SRAM, housed in a 44-pin TQFP package. It executes instructions at up to 32 MHz from a 1.6-3.6 V supply, with 34 general-purpose I/O lines, two USARTs, two TWI (I2C) interfaces, four flexible 16-bit timer/counters with compare and PWM channels, a 16-bit real-time counter, a four-channel event system, and a programmable multi-level interrupt controller. An 8 KB boot-code section is dedicated for bootloader use, and the device supports AES and DES crypto accelerators plus a 12-bit, 2 MSPS ADC.

An 8/16-bit AVR XMEGA microcontroller is an advanced member of Microchip's AVR family combining 8-bit code density with 16-bit peripheral datapaths. It belongs to the broader class of microcontrollers (MCUs) within embedded processors and semiconductors, designed for deterministic real-time control with very low active and sleep-mode power. The XMEGA D4 sub-family specifically targets low-power mixed-signal applications requiring moderate pin counts and rich peripheral integration, sitting above tinyAVR and megaAVR in the Atmel/Microchip MCU hierarchy.

Key features include the four-channel event system for inter-peripheral signalling without CPU intervention, a programmable multi-level interrupt controller for deterministic response, a 12-bit 2 MSPS ADC with optional gain stage, and a hardware AES/DES cryptographic engine. The 8 KB boot section allows secure bootloader updates, while the read-while-write Flash enables live firmware upgrades without halting execution. Power-saving features include five sleep modes, a 1.5 µA real-time-counter backup mode, and a peripheral event system that can wake the CPU autonomously.

Typical applications include industrial control panels, sensor hubs, low-power wireless sensor nodes, motor control, smart metering, USB device peripherals, consumer white goods, and human-machine interface (HMI) touch panels. The wide 1.6-3.6 V operating range and integrated peripherals make it well suited to battery-powered and energy-harvesting designs.

Designers should provide a 0.1 µF decoupling capacitor adjacent to each VCC pin, route analog and digital grounds separately, and observe the 32 MHz maximum system clock. For firmware development, Microchip's Atmel Studio 7 and MPLAB X IDE with the AVR/GNU toolchain target this device directly.

Drop-in alternatives for ATXMEGA128D4-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 ATXMEGA128D4-AU (same form factor and footprint) — differing in Core Architecture, Package, ADC Resolution, Boot Code Section, EEPROM.

Microchip Technology
Core Architecture: 8-bit AVR RISC
Package: 100-TQFP (14x14 mm)
ADC Resolution: 10 bit
Compare with ATXMEGA128D4-AU →
Microchip Technology
Core Architecture: AVR XMEGA 8/16-bit RISC
ADC Resolution: 12-bit
Boot Code Section: 4 KB
Compare with ATXMEGA128D4-AU →

Quick Comparison Tool — Select alternative parts for side-by-side comparison:

ATXMEGA128A4U-AUR

✅ Drop-In
Microchip Technology
📦 TQFP-44
AVR XMEGA 8/16-bit RISC · ATxmega A4U · 128 KB (64K x 16) · 4 KB · 8 KB · 2 KB (2048 bytes) · 32 MHz · 32 MIPS

✓ In Stock

$5.45 / Unit

View Datasheet →

ATXMEGA64D4-AU

✅ Drop-In
📦 TQFP-44
same 44-pin TQFP, Flash 64 KB vs 128 KB (-50%), SRAM 4 KB vs 8 KB (-50%), identical peripherals

📋 Reference alternative (not in catalog)

ATXMEGA32D4-AU

✅ Drop-In
📦 TQFP-44
same 44-pin TQFP, Flash 32 KB vs 128 KB (-75%), SRAM 4 KB vs 8 KB (-50%), identical peripherals

📋 Reference alternative (not in catalog)

ATMEGA2560-16AU

✅ Drop-In
Microchip Technology
📦 TQFP-100
8-bit AVR RISC · 8-bit · 16 MHz · FLASH (ISP) · 256 KB (128K x 16) · 8 KB · 4 KB · 86

✓ In Stock

$8.87 / Unit

View Datasheet →

ATSAM3U4EA-CU

Microchip Technology
📦 LQFP-144
ARM Cortex-M3 (32-bit RISC) · 96 MHz · Thumb-2 · 256 KB Flash (dual-bank, 128-bit wide access) · 52 KB · 1.8 V / 3.3 V · 144-ball LFBGA (10x10 mm) · High-Speed USB 2.0 Device (480 Mbps, integrated transceiver)

✓ In Stock

$12.05 / Unit

View Datasheet →

ATXMEGA128D4-AU Maximum Ratings & Electrical Characteristics

Core Architecture AVR XMEGA (8/16-bit)
Program Memory (Flash) 128 KB
Boot Code Section 8 KB
EEPROM 2 KB
SRAM 8 KB
Maximum CPU Clock 32 MHz
Supply Voltage Range 1.6 V to 3.6 V
Operating Temperature -40C to +85C (industrial)
General-Purpose I/O Pins 34
Package 44-pin TQFP (10x10 mm)
Mounting Type Surface Mount
USART 2
TWI (I2C) Interfaces 2
SPI Interfaces 2
16-bit Timer/Counters 4
ADC 12-bit, up to 2 MSPS
Crypto Accelerator AES and DES
Event System Channels 4
RoHS Status Compliant
MSL Level 3

ATXMEGA128D4-AU 44-pin tqfp (10x10 mm) Pin Configuration Guide

Pin configuration for ATXMEGA128D4-AU (44-pin tqfp (10x10 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.

44-pin tqfp (10x10 mm) package pinout diagram for ATXMEGA128D4-AU

No detailed pinout data available for ATXMEGA128D4-AU.

Refer to the datasheet for full pin configuration.

Typical Applications

ATXMEGA128D4-AU is suitable for 6 applications: Industrial Sensor Hub, Smart Metering and Energy Monitoring, USB Human Interface Device (with companion), Battery-Powered Wearable Device, Motor Control and BLDC Driver, IoT Sensor Node with Secure Boot.

🏭

Industrial Sensor Hub

The ATXMEGA128D4-AU fits industrial sensor hubs through its 12-bit 2 MSPS ADC, two TWI (I2C) interfaces, and four 16-bit timer/counters, allowing simultaneous sampling of multiple analog sensors with deterministic timing. The 128 KB Flash hosts sensor-fusion firmware and protocol stacks (Modbus, IO-Link) while 8 KB SRAM holds time-series buffers. The 1.6-3.6 V supply range supports 3.3 V regulated industrial rails. The event system routes ADC conversions directly to DMA without CPU wakeup, cutting active duty cycle in battery-backed remote sensors.

⚡

Smart Metering and Energy Monitoring

The ATXMEGA128D4-AU's 128 KB Flash supports DLMS/COSEM or Open Smart Grid Protocol stacks while the hardware AES-128 accelerator secures communications. Its 12-bit ADC at 2 MSPS accurately samples current shunts and voltage dividers for class-0.5 metering accuracy. The four 16-bit timers drive tamper-detection inputs and metrology pulse outputs. Low-power sleep modes drop consumption below 1.5 µA with the RTC running, enabling 20+ year battery life on lithium cells used in gas and water meters.

🖥️

USB Human Interface Device (with companion)

Although the D4 lacks native USB, the ATXMEGA128D4-AU can implement low-speed USB via the on-chip USART in software-bitbang mode or by pairing with an external USB bridge like the AT42QT2120. The 8 KB SRAM and 128 KB Flash comfortably host HID stacks and capacitive-touch decoders. The event system wakes the CPU on touch events without polling, while AES hardware accelerates secure pairing for wireless HID bridges.

📱

Battery-Powered Wearable Device

The ATXMEGA128D4-AU suits wearables because of its deep-sleep current below 1.5 µA with RTC backup and the 1.6 V minimum supply that lets it run from nearly-depleted Li-ion cells. Its 34 GPIOs drive small OLEDs and capacitive-touch electrodes while two TWI ports interface to biometric sensors (heart-rate, SpO2). The 32 MHz peak performance executes DSP-style filtering for sensor fusion in real time. Compact 10x10 mm TQFP package fits wrist-worn form factors.

🏭

Motor Control and BLDC Driver

The ATXMEGA128D4-AU's four 16-bit timer/counters generate complementary PWM with dead-time insertion for BLDC and PMSM motors, while its 12-bit ADC samples back-EMF and phase currents synchronously. The event system triggers ADC conversions from timer compare events with zero CPU jitter, critical for field-oriented control loops. 8 KB SRAM holds observer state, and 128 KB Flash supports complex FOC and sensorless startup algorithms. Industrial -40C to +85C operation suits factory-floor deployments.

🧩

IoT Sensor Node with Secure Boot

The ATXMEGA128D4-AU's hardware AES/DES engine secures MQTT-SN or CoAP payloads over sub-GHz radios, while the 8 KB boot section enables secure bootloader updates for OTA firmware. Two USARTs drive an external LoRa or Sigfox transceiver and a debug console. With 1.6 V minimum supply, the device runs directly from energy-harvesting sources (solar, thermal). The event system wakes the CPU only when a transmission buffer is ready, maximizing battery life in remote IoT deployments.

What is the flash memory size of the ATXMEGA128D4-AU?
The ATXMEGA128D4-AU integrates 128 KB of in-system programmable Flash with read-while-write capability, plus an 8 KB dedicated boot-code section for bootloader use. According to the Microchip ATxmega D4 datasheet, the Flash is organized into two sections: the application section and the boot section, both of which can be reprogrammed while the CPU continues executing from the other section.
What is the maximum CPU clock speed of the ATXMEGA128D4-AU?
The ATXMEGA128D4-AU runs at up to 32 MHz system clock from a 1.6-3.6 V supply. The Microchip ATxmega D4 datasheet notes that throughput is approximately 32 MIPS at 32 MHz thanks to the single-cycle AVR XMEGA pipeline, with execution performance comparable to many 16-bit microcontrollers while retaining 8-bit code density.
Where can I buy the ATXMEGA128D4-AU and what is the current price?
The ATXMEGA128D4-AU is in stock at major distributors including Mouser, DigiKey, LCSC and Heisener, with a unit price of approximately $7.24 (LCSC) to $7.85 (break-quantity 1) as of 2026-10-07. Heisener lists 5,680 units immediately shippable. Verified Web Data confirms 12 distributors actively carry this part via Octopart.
What is the lead time for the ATXMEGA128D4-AU?
As of 2026-10-07, the ATXMEGA128D4-AU ships immediately from authorized distributors including Heisener (5,680 pieces in stock) and LCSC. Standard delivery is 3-7 business days from Heisener, with expedited options available for urgent orders. The Microchip part is currently in active production, so lead times remain short.
Is the ATXMEGA128D4-AU in stock right now?
Yes, the ATXMEGA128D4-AU is in stock as of 2026-10-07. Heisener reports 5,680 pieces available with immediate shipment, and the part is also available at Mouser, DigiKey, and LCSC. Octopart aggregates pricing and stock from 12 distributors for real-time availability checks.
What is the difference between the ATXMEGA128D4-AU and ATXMEGA64D4-AU?
The ATXMEGA128D4-AU has 128 KB Flash and 8 KB SRAM, while the ATXMEGA64D4-AU has 64 KB Flash and 4 KB SRAM. Both share the identical 44-pin TQFP package, the same AVR XMEGA core, identical peripherals (USARTs, TWIs, timers, ADC), and pin-for-pin compatibility. According to Microchip's XMEGA D4 datasheet, the 128D4 is a straightforward memory upgrade for designs originally targeted at the 64D4.
How does the ATXMEGA128D4-AU compare to the ATXMEGA16D4-AU?
The ATXMEGA128D4-AU offers 128 KB Flash, 8 KB SRAM, and 2 KB EEPROM, while the ATXMEGA16D4-AU provides 16 KB Flash, 2 KB SRAM, and 1 KB EEPROM. Both share the same 44-pin TQFP package, same peripheral set, and same 32 MHz maximum clock. The 128D4 is appropriate for code-rich applications, while the 16D4 is cost-optimized for simpler firmware.
When should I choose the ATXMEGA128D4-AU over the ATXMEGA64A4U-AU?
Choose the ATXMEGA128D4-AU when your design needs 128 KB Flash, the AES/DES crypto engine, and the D4 peripheral mix in a 44-pin TQFP. Choose the ATXMEGA64A4U-AU instead if you require USB 2.0 Full-Speed device support; the A4U series integrates a USB peripheral the D4 lacks. Both share the AVR XMEGA core and are firmware-portable with minor peripheral-driver changes.
What is the best drop-in replacement for the ATXMEGA128D4-AU?
The best drop-in replacement for the ATXMEGA128D4-AU in the same 44-pin TQFP package is the ATXMEGA128A4U-AUR, which adds integrated USB 2.0 Full-Speed at the cost of slightly different peripheral mapping. According to Microchip cross-reference tools, the ATXMEGA128A1-AU is another same-brand option in a 100-pin TQFP if you can rework the PCB, but for true drop-in replacement the 128A4U is the closest.
Can the ATXMEGA128A4U-AUR replace the ATXMEGA128D4-AU on my board?
The ATXMEGA128A4U-AUR is largely pin-compatible with the ATXMEGA128D4-AU in the 44-pin TQFP, both sharing 128 KB Flash, 8 KB SRAM, and the same AVR XMEGA core. Per Microchip documentation, the A4U series adds an integrated USB peripheral and a different ADC count, so firmware should be revalidated. For pure drop-in without USB the 128D4 itself remains the safest choice.
Where can I download the ATXMEGA128D4-AU datasheet PDF?
The official ATXMEGA128D4-AU datasheet PDF is hosted at Microchip's document library under part number Atmel-8135, covering the ATxmega16D4, 32D4, 64D4, and 128D4 devices. Verified Web Data confirms the URL: https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-8135-8-and-16-bit-AVR-microcontroller-ATxmega16D4-32D4-64D4-128D4_datasheet.pdf. Third-party mirrors also exist at abc-semi.com.
What is the pinout of the ATXMEGA128D4-AU in the 44-TQFP package?
The ATXMEGA128D4-AU pinout in the 44-pin TQFP package assigns pin 1 to the dot marker at top-left, with the AVR XMEGA D4 pin functions listed in the Microchip datasheet. The package exposes 34 GPIO pins grouped into multiple ports (PORTA through PORTD), plus VCC, GND, AVCC, AREF, RESET, and TDI/TDO/TMS/TCK for debug. Full pin mapping is in section 4 of the ATxmega D4 datasheet.
Does the ATXMEGA128D4-AU support AES hardware encryption?
Yes, the ATXMEGA128D4-AU integrates a hardware AES and DES cryptographic accelerator on-chip. According to the Microchip ATxmega D4 datasheet, this accelerator performs AES-128 encryption/decryption with minimal CPU overhead, freeing the core for application code. The accelerator is accessed via a memory-mapped register interface.
Which IDE and toolchain should I use to program the ATXMEGA128D4-AU?
The ATXMEGA128D4-AU is supported by Microchip's MPLAB X IDE and the legacy Atmel Studio 7 with the AVR/GNU C toolchain. Per Microchip's documentation, programming is done via the PDI (Program and Debug Interface) using tools such as the Atmel-ICE, AVR Dragon, or JTAGICE3. Microchip also ships the AVR-libc peripheral library for code portability across the XMEGA family.
What is the operating voltage range of the ATXMEGA128D4-AU?
The ATXMEGA128D4-AU operates from 1.6 V to 3.6 V supply voltage, making it compatible with 1.8 V, 2.5 V, and 3.3 V system rails. The Microchip ATxmega D4 datasheet specifies 1.6 V as the minimum for full 32 MHz operation, with reduced clock speeds down to lower voltages. This wide range supports both single-cell Li-ion and 3.3 V regulated designs.
What is the key fact engineers should know about the ATXMEGA128D4-AU?
The ATXMEGA128D4-AU is a 32 MHz 8/16-bit AVR XMEGA microcontroller with 128 KB Flash, 8 KB SRAM, 2 KB EEPROM, 34 GPIOs, two USARTs, two TWIs, four 16-bit timers, a 12-bit 2 MSPS ADC, and an AES/DES crypto engine in a 44-pin TQFP package, all operating from 1.6-3.6 V. It is pin-compatible with the ATXMEGA64D4-AU and ATXMEGA32D4-AU, allowing memory scaling without PCB rework.

Engineering reference data for ATXMEGA128D4-AU — comparison, design guidance, and compliance information.

Selection Guide

Choose the ATXMEGA128D4-AU when your embedded design needs 128 KB Flash for protocol stacks or application code in a 44-pin TQFP, requires hardware AES/DES for secure communications, and integrates 12-bit ADC sampling at up to 2 MSPS for sensor or metering applications. Choose the ATXMEGA128A4U-AUR instead if you need native USB 2.0 Full-Speed connectivity without an external bridge IC. Choose the ATXMEGA64D4-AU for cost-sensitive designs with smaller firmware footprints. The D4 family is firmware-portable across the 16D4/32D4/64D4/128D4 variants, simplifying last-minute memory scaling decisions.

Comparison with Alternatives

Parameter This Product ATXMEGA128A4U-AUR ATXMEGA64D4-AU ATXMEGA32D4-AU
Package TQFP-44 (10x10 mm) TQFP-44 - same TQFP-44 - same TQFP-44 - same
Brand Microchip Technology Microchip Technology - same Microchip Technology - same Microchip Technology - same
Flash Memory 128 KB 128 KB 64 KB (-50%) 32 KB (-75%)
SRAM 8 KB 8 KB 4 KB (-50%) 4 KB (-50%)
EEPROM 2 KB 2 KB 2 KB 1 KB (-50%)
Maximum Clock 32 MHz 32 MHz 32 MHz 32 MHz
Supply 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
USB Support No (external required) Yes (USB 2.0 FS) No No
GPIO Count 34 34 34 34

Key Differentiators

  • Largest Flash in 44-pin XMEGA D4 family (vs ATXMEGA64D4-AU)
  • Integrated hardware AES/DES crypto (vs ATMEGA328P-AUR)
  • Same-brand pin-compatible upgrade path (vs ATXMEGA128A4U-AUR)

Design Notes

Place a 0.1 µF decoupling capacitor within 5 mm of each VCC/AVCC pin, and add a 10 µF bulk capacitor on the main supply rail. The ATXMEGA128D4-AU has separate analog (AVCC) and digital (VCC) supplies; tie them together at the regulator output with a ferrite bead if the design mixes sensitive analog and noisy digital loads. AREF should be decoupled with 10 nF when using internal reference.

Route the PDI (Program and Debug Interface) signals to a 6-pin header with GND, VCC, PDI_DATA, PDI_CLK, and /RESET brought out for Atmel-ICE or JTAGICE3 in-circuit programming. Keep PDI traces short (under 50 mm) and shielded with ground. The 44-pin TQFP exposed pad (if present) should be soldered to a copper pour tied to GND for thermal dissipation and mechanical stability.

Do not exceed 32 MHz system clock or 3.6 V VCC. The brown-out detector (BOD) should be enabled in firmware with a threshold appropriate to the system clock (e.g., 2.7 V BOD for full-speed operation). The 8 KB SRAM is shared with the stack and heap; using -Os optimization and avoiding deep printf buffers is essential at high stack usage.

Compliance Information

RoHS
Compliant
REACH
Compliant
AEC-Q100
Not Qualified
Lead Free
Yes
Halogen Free
Unknown
Conflict Minerals
Compliant

RoHS and REACH compliance per Microchip product page; not AEC-Q100 qualified (commercial/industrial grade).

Data verified on: 2026-10-07 — data verified and curated by XAIPART's component engineering team

Related Searches

ATXMEGA128D4-AU datasheet ATXMEGA128D4-AU price ATXMEGA128D4-AU pinout Microchip ATXMEGA128D4 128KB flash TQFP-44 AVR XMEGA microcontroller ATXMEGA128D4-AU vs ATXMEGA64D4-AU ATXMEGA128D4-AU drop-in replacement ATXMEGA128D4-AU USB upgrade buy ATXMEGA128D4-AU in stock ATXMEGA128D4-AU industrial sensor hub ATXMEGA128D4-AU AES encryption 8/16-bit AVR XMEGA 32MHz MCU

Related Components & Terms

Microchip Technology ATXMEGA128D4-AU ATXMEGA128A4U-AUR ATXMEGA64D4-AU ATXMEGA32D4-AU AVR XMEGA 8/16-bit microcontroller TQFP-44 TQFP package family surface mount AES DES PDI Atmel-ICE MPLAB X IDE AVR-libc 12-bit ADC USART TWI RoHS REACH industrial sensor hub smart metering BLDC motor control
Quick Quote RFQ
Fill in complete details — our sales team will respond within 24 hours
Part Number Manufacturer Package QTY Target Price Extended
Total: $0.00 USD
✓
Quote submitted!

We will respond to your email within 24 hours

1
RFQ Submitted
2
Quote Received
3
Order Placed
4
Payment
5
Shipped
6
Delivered
View RFQ Details