ATXMEGA32A4-AU - 32KB Flash 32MHz 8/16-bit AVR XMEGA MCU
MPN: ATXMEGA32A4-AU ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.53 | $6.53 |
| 10 | $5.87 | $58.70 |
| 100 | $5.21 | $521.00 |
| 500 | $4.62 | $2,310.00 |
| 1,000 | $4.1 | $4,100.00 |
ATXMEGA32A4-AU Overview
An AVR XMEGA microcontroller is an advanced 8/16-bit RISC architecture MCU that extends the classic AVR core with a richer peripheral set, DMA-driven I/O, an event system for inter-peripheral signaling, and a more capable interrupt controller, while keeping the AVR instruction set and toolchain compatibility. XMEGA sits above classic ATmega in the Microchip (formerly Atmel) AVR taxonomy, between ATmega and the SAM Cortex-M families in terms of performance and peripheral depth. It targets low-power embedded designs that need deterministic I/O without leaving the AVR ecosystem.
Key features include 32 KB in-system programmable Flash with read-while-write support, 1 KB internal EEPROM for non-volatile data, five flexible 16-bit Timer/Counters with compare and PWM modes, two TWI (I2C-compatible) interfaces, five USARTs, two SPI ports, a 16-bit Real-Time Counter (RTC), a 12-channel 12-bit ADC, and AES/DES crypto accelerators. The DMA controller and event system offload repetitive I/O from the CPU, enabling efficient sensor and communication pipelines. The integrated bandgap reference and on-chip temperature sensor simplify analog designs.
Architecturally, the A4 series uses the XMEGA core with single-cycle ALU operations, hardware multiplier, and a peripheral event system that allows peripherals to trigger each other without CPU intervention. The result is deterministic low-latency I/O at very low active currents, making the A4 family well suited to battery-powered measurement, sensor hubs, and human-interface products.
Typical applications include industrial sensor nodes, smart metering, building automation controllers, low-power wireless sensor hubs (paired with an external radio), USB/HID peripherals, motor control edge nodes, and consumer human-interface devices. Choose the ATXMEGA32A4-AU when you need AVR toolchain continuity with XMEGA-grade peripherals in a 44-pin TQFP.
Designers should plan a stable 1.6 V to 3.6 V rail with sufficient decoupling near the AVDD pins, route the event system lines carefully to avoid noise coupling into ADC inputs, and verify the boundary scan / PDI programming interface is accessible for in-system firmware updates. Selecting the A4 family preserves AVR toolchain investment while adding modern peripherals.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for ATXMEGA32A4-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 ATXMEGA32A4-AU (same form factor and footprint) — differing in Program Memory (Flash), SRAM, EEPROM, ADC, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATXMEGA64A4-AU
✅ Drop-In📋 Reference alternative (not in catalog)
ATXMEGA32A4-AUR
✅ Drop-In📋 Reference alternative (not in catalog)
ATXMEGA32A4-AN
✅ Drop-In📋 Reference alternative (not in catalog)
ATXMEGA16A4U-AU
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$3.05 / Unit
View Datasheet →ATXMEGA128A4U-AUR
✅ Drop-In✓ In Stock
$5.45 / Unit
View Datasheet →ATXMEGA32A4-AU Maximum Ratings & Electrical Characteristics
| Core | AVR XMEGA A4 |
| CPU Architecture | 8/16-bit RISC |
| Program Memory (Flash) | 32 KB (16K x 16) |
| Boot Code Section | 4 KB |
| SRAM | 4 KB |
| EEPROM | 1 KB |
| Maximum Clock Frequency | 32 MHz |
| MIPS Throughput | 32 MIPS |
| Operating Voltage Range | 1.6 V to 3.6 V |
| I/O Pins | 34 |
| DMA Channels | 4 |
| Event System Channels | 8 |
| 16-bit Timer/Counters | 5 |
| USART | 5 |
| SPI | 2 |
| TWI (I2C) | 2 |
| ADC | 12-bit, 12-channel |
| Real-Time Counter | 16-bit |
| External Bus Interface | Yes |
| Package | 44-pin TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
ATXMEGA32A4-AU Pin Configuration
| Pin 1 | VCC — Digital supply voltage |
| Pin 2 | GND — Ground |
| Pin 3 | AVCC — Analog supply voltage |
| Pin 4 | AGND — Analog ground |
| Pin 5 | PA0 — Port A bit 0 / ADC0 input |
| Pin 6 | PA1 — Port A bit 1 / ADC1 input |
| Pin 7 | PA2 — Port A bit 2 / ADC2 input |
| Pin 8 | PA3 — Port A bit 3 / ADC3 input |
| Pin 9 | PA4 — Port A bit 4 / ADC4 input |
| Pin 10 | PA5 — Port A bit 5 / ADC5 input |
| Pin 11 | PA6 — Port A bit 6 / ADC6 input |
| Pin 12 | PA7 — Port A bit 7 / ADC7 input |
| Pin 13 | PB0 — Port B bit 0 |
| Pin 14 | PB1 — Port B bit 1 |
| Pin 15 | PB2 — Port B bit 2 |
| Pin 16 | PB3 — Port B bit 3 |
| Pin 17 | PC0 — Port C bit 0 |
| Pin 18 | PC1 — Port C bit 1 |
| Pin 19 | PC2 — Port C bit 2 |
| Pin 20 | PC3 — Port C bit 3 |
| Pin 21 | PC4 — Port C bit 4 |
| Pin 22 | PC5 — Port C bit 5 |
| Pin 23 | PC6 — Port C bit 6 |
| Pin 24 | PC7 — Port C bit 7 |
| Pin 25 | PD0 — Port D bit 0 |
| Pin 26 | PD1 — Port D bit 1 |
| Pin 27 | PD2 — Port D bit 2 |
| Pin 28 | PD3 — Port D bit 3 |
| Pin 29 | PD4 — Port D bit 4 |
| Pin 30 | PD5 — Port D bit 5 |
| Pin 31 | PD6 — Port D bit 6 |
| Pin 32 | PD7 — Port D bit 7 |
| Pin 33 | PE0 — Port E bit 0 |
| Pin 34 | PE1 — Port E bit 1 |
| Pin 35 | PE2 — Port E bit 2 / TDI |
| Pin 36 | PE3 — Port E bit 3 / TDO |
| Pin 37 | RESET — Reset input (active low) |
| Pin 38 | PDI_CLK — Program and Debug Interface clock |
| Pin 39 | PDI_DATA — Program and Debug Interface data |
| Pin 40 | XTAL1 — External crystal / clock input |
| Pin 41 | XTAL2 — External crystal output |
| Pin 42 | TOSC1 — 32.768 kHz crystal pin 1 (RTC) |
| Pin 43 | TOSC2 — 32.768 kHz crystal pin 2 (RTC) |
| Pin 44 | AREF — ADC reference voltage |
Typical Applications
ATXMEGA32A4-AU is suitable for 7 applications: Industrial Sensor Node, Smart Metering and Building Automation, Low-Power Wireless Sensor Hub, USB HID / Human-Interface Device, Motor Control Edge Node, Consumer Human-Interface Device, Data Logger with RTC.
Industrial Sensor Node
The ATXMEGA32A4-AU fits industrial sensor nodes where deterministic I/O, low active current, and 12-bit ADC precision are mandatory. Its 12-channel 12-bit ADC with internal PGA and bandgap reference handles thermocouple, RTD, and 4-20 mA front-ends without external signal conditioning, while the 4-channel DMA controller streams conversion results into SRAM without CPU intervention. The 8-channel event system lets timers trigger ADC conversions autonomously, holding timing jitter under 1 us - critical for power-line synchronized measurements. Compared with a discrete MCU plus external ADC, the A4 reduces BOM by one IC and ~5 passive parts. Use the device between 2.7 V and 3.6 V at 32 MHz for full 32 MIPS throughput; the 1.6 V lower bound supports slower battery-backed logging modes.
Recommended
Smart Metering and Building Automation
In smart electricity, water, and gas meters the ATXMEGA32A4-AU provides the metrology front-end, LCD drive logic, and communication stack in a single 44-pin TQFP. The 12-bit ADC plus PGA measures current shunt voltage to better than 0.5% accuracy, while the 16-bit RTC keeps wall-clock time across power cycles using an external 32.768 kHz crystal. AES/DES hardware accelerators encrypt DLMS/COSEM or wireless M-Bus payloads with negligible CPU overhead. The 1.6 V to 3.6 V supply window supports direct LiSOCl2 battery connection with no LDO required. The 32 KB Flash holds the metrology library plus a wireless M-Bus or LoRaWAN stack when paired with an external transceiver.
Recommended
Low-Power Wireless Sensor Hub
The ATXMEGA32A4-AU is a strong host MCU for sub-GHz or 2.4 GHz wireless sensor hubs that pair with an external transceiver such as SPI-attached LoRa or BLE modules. The 2 SPI ports allow simultaneous connection of a radio and a sensor front-end, while the 5 USARTs handle RS-485 or debug channels. The event system wakes the CPU only on a peripheral trigger, allowing deep-sleep currents around 1 uA with RTC running. The 32 KB Flash accommodates a small Contiki or lightweight proprietary MAC plus application code. Compared with a Cortex-M0+ alternative, the A4 delivers equivalent sleep current with simpler toolchain and faster interrupt latency for time-critical radio servicing.
Recommended
USB HID / Human-Interface Device
For HID-class peripherals that do not require USB, the ATXMEGA32A4-AU drives matrix key-scans, capacitive touch buttons, and LED indicators via DMA, leaving the CPU free to handle communication stacks. Five 16-bit Timer/Counters generate PWM for LED dimming and buzzer tones. When USB is required, design teams migrate to the ATXMEGA32A4U-AU (TQFP-44, pin-compatible) which integrates a USB 2.0 Full-Speed device peripheral. The 32 KB Flash holds USB stacks plus HID report descriptors and button debouncing logic, while 4 KB SRAM buffers HID reports with headroom for additional CDC channels.
Recommended
Motor Control Edge Node
In distributed motor-control systems the ATXMEGA32A4-AU serves as the commutation, current-sense, and communication controller at the edge of a CAN or RS-485 network. The 5 16-bit Timer/Counters produce center-aligned PWM up to 32 MHz, with dead-time insertion handled in hardware, allowing three-phase BLDC or stepper control with deterministic switching. The 12-bit ADC samples phase currents via the event system at the PWM center point for low-noise readings. The A4 communicates over USART (RS-485) or external CAN controller attached to SPI. Designers typically scale to the ATXMEGA64A4-AU (TQFP-44 pin-compatible) when field-oriented control firmware exceeds 32 KB.
Recommended
Consumer Human-Interface Device
The ATXMEGA32A4-AU is well matched to consumer HMI products such as remote controls, e-reader front panels, smart-home keypads, and small appliances with capacitive touch. The event system offloads touch scanning from the CPU, while DMA streams display data to SPI-attached LCD or LED drivers without jitter. The RTC drives wake-up at user-preset intervals for ultra-low standby power. The 1.6 V lower bound supports direct 2xAA battery operation, and the 32 KB Flash stores UI strings, fonts, and product firmware. Migrating to ATXMEGA32A4U-AU adds USB for tethered firmware update and CDC diagnostics.
Recommended
Data Logger with RTC
For battery-powered data loggers recording temperature, humidity, or vibration, the ATXMEGA32A4-AU combines a 16-bit RTC, 12-bit ADC, 4-channel DMA, and 1 KB EEPROM into a compact TQFP-44 solution. The RTC running from a 32.768 kHz crystal schedules wake-ups every minute, hour, or day while consuming microamp-level standby current. DMA moves ADC samples directly into SRAM buffers, allowing the CPU to remain in sleep between bursts. The EEPROM stores configuration and calibration data, while the 32 KB Flash holds the application plus a small file system. Compared with discrete RTC + MCU designs, the A4 cuts BOM cost and board area by ~30%.
Recommended
Recommended Products Summary
Engineering reference data for ATXMEGA32A4-AU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATXMEGA64A4-AU | ATXMEGA32A4-AUR | ATXMEGA32A4-AN | ATXMEGA16A4U-AU | ATXMEGA128A4U-AUR |
|---|---|---|---|---|---|---|
| Package | 44-TQFP (10x10) | 44-TQFP (10x10) - same | 44-TQFP (10x10) - same | 44-TQFP (10x10) - same | 44-TQFP (10x10) - same | 44-TQFP (10x10) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash | 32 KB | 64 KB | 32 KB | 32 KB | 16 KB | 128 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 4 KB | 2 KB | 8 KB |
| EEPROM | 1 KB | 2 KB | 1 KB | 1 KB | 1 KB | 2 KB |
| Max Clock | 32 MHz | 32 MHz | 32 MHz | 32 MHz | 32 MHz | 32 MHz |
| USB | No | No | No | No | Yes (Full-Speed) | Yes (Full-Speed) |
| I/O Pins | 34 | 34 | 34 | 34 | 34 | 34 |
| 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 | 1.6 V to 3.6 V | 1.6 V to 3.6 V |
Key Differentiators
- Highest code density per MHz in the A4 family at this pin count (vs ATMEGA32U4-AU)
- Pin-compatible Flash headroom via 64 KB variant (vs ATXMEGA64A4-AU)
- USB-equipped TQFP-44 sibling when connectivity is needed (vs ATXMEGA32A4U-AU)
Design Notes
Power the ATXMEGA32A4-AU from a clean 1.6 V to 3.6 V rail. Place a 100 nF X7R ceramic capacitor within 5 mm of each VCC/AVCC pin pair, plus a shared 4.7 uF bulk capacitor at the regulator output. Estimated: at 32 MHz, 3.3 V, and all peripherals active, typical active current is around 10 mA, so the 4.7 uF bulk sustains the rail during ADC burst sampling. Tie AREF to AVCC through a 10 nF capacitor unless using an external reference.
Route the PDI_CLK and PDI_DATA lines as a short matched pair to a 6-pin programming header to retain in-system programming access. Keep analog traces (ADC inputs, AREF) away from switching signals and add a ground guard ring around the AREF pin. Use a continuous ground plane on layer 2 with the TQFP-44 thermal pad tied to GND via multiple vias for low-impedance return paths. Estimated: with a 2 oz copper pour the package achieves roughly 60 C/W theta_JA, sufficient for the part's typical application power levels.
Do not exceed 3.6 V on any pin; the ATXMEGA32A4-AU is not 5 V tolerant. When migrating code from ATmega parts, note that the XMEGA uses the PDI interface (not ISP) for programming - retain a PDI header on prototype boards. Estimated: enabling all five USARTs and two SPI ports simultaneously requires verifying pin-mux conflicts in the datasheet's alternate-function table before final pin assignment. The internal bandgap reference is ratiometric, not absolute, so calibrate ADC readings against AVCC for precision measurements.
Compliance Information
RoHS compliant per Microchip product page; lead-free TQFP finish indicated by 'AU' ordering code suffix; halogen-free status not stated in the verified web data - marked unknown.