ATXMEGA64C3-MH - AVR XMEGA 32MHz 64KB Flash MCU | Microchip
MPN: ATXMEGA64C3-MH ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.42 | $6.42 |
| 10 | $5.78 | $57.80 |
| 100 | $5.12 | $512.00 |
| 500 | $4.51 | $2,255.00 |
| 1,000 | $3.96 | $3,960.00 |
ATXMEGA64C3-MH Overview
An 8/16-bit microcontroller is a single-chip computer that integrates a CPU core, non-volatile program memory (Flash), working memory (SRAM), non-volatile data storage (EEPROM), and programmable peripherals on one die. Within the system hierarchy, the ATXMEGA64C3-MH sits as: microcontroller -> embedded MCU -> semiconductor IC. The XMEGA family is a superset of the AVR core architecture, adding a 4-channel event system, multi-level interrupt controller, and DMA controller to enable low-latency deterministic I/O without CPU intervention.
Key features include 32 MHz maximum CPU clock from an internal 32 MHz calibrated oscillator (2% accuracy), 1.6V to 3.6V operating voltage, four 16-bit timer/counters, four USARTs, two I2C and SPI ports, a 12-channel 12-bit ADC, and a 2-channel 12-bit DAC. The device supports up to 78 general-purpose I/O pins and consumes only 9.2 mA active at 3V/32 MHz, making it suitable for battery-powered designs.
Architecturally, the ATXMEGA64C3-MH implements the Harvard-style AVR XMEGA core with single-cycle ALU access to register file and Flash, a hardware multiply unit, and a peripheral event system that lets timers, ADCs, and communication peripherals trigger one another without software. The 12-bit ADC achieves up to 300 ksps with optional PGA-like input scaling, supporting sensor and instrumentation signal chains.
Typical applications include industrial control and sensor nodes, USB HID/CDF bridges using the on-chip USB 2.0 full-speed controller, smart energy metering, motor control loops, and human-machine interface (HMI) boards. The wide operating voltage and Flash read-while-write capability also enable firmware-over-the-air (FOTA) bootloaders.
When designing with this part, ensure decoupling of all VDDGND pairs with 100nF X7R ceramic capacitors placed within 3 mm of the package, route the exposed thermal pad to a continuous ground plane for VQFN heat dissipation, and configure PDI/PDO or JTAG pins as GPIO only when debug is permanently disabled.
This page synthesizes distributor pricing, drop-in alternatives within the same VQFN-64 footprint, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for ATXMEGA64C3-MH — 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 ATXMEGA64C3-MH (same form factor and footprint) — differing in Package, DAC, ADC, SRAM, Program Memory (Flash).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATXMEGA64C3-MHR
✅ Drop-In📋 Reference alternative (not in catalog)
ATXMEGA128C3-MH
✅ Drop-In📋 Reference alternative (not in catalog)
ATXMEGA256C3-MH
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$4.68 / Unit
View Datasheet →ATXMEGA64D3-MH
✅ Drop-In✓ In Stock
$3.51 / Unit
View Datasheet →ATXMEGA128D4-MH
✅ Drop-In✓ In Stock
$3.72 / Unit
View Datasheet →ATXMEGA64A4U-MH
✅ Drop-In✓ In Stock
$2.65 / Unit
View Datasheet →ATXMEGA64C3-MH Maximum Ratings & Electrical Characteristics
| Core | AVR XMEGA C3 (8/16-bit) |
| Maximum CPU Clock | 32 MHz |
| Program Memory (Flash) | 64 KB (32K x 16) with 8 KB boot section |
| SRAM | 4 KB |
| EEPROM | 2 KB |
| Operating Voltage | 1.6 V to 3.6 V |
| Package | 64-pin VQFN (9x9 mm) with exposed thermal pad |
| I/O Pins | Up to 78 GPIO |
| ADC | 12-bit, 12-channel, up to 300 ksps |
| DAC | 12-bit, 2-channel |
| Timers/Counters | 4 x 16-bit |
| Communication Interfaces | 4x USART, 2x I2C, 2x SPI, USB 2.0 Full-Speed |
| Event System | 4-channel |
| DMA Channels | 4 channels |
| Active Current | 9.2 mA typical at 3V / 32 MHz |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
ATXMEGA64C3-MH Pin Configuration
| Pin 1 | GND — Ground reference for the digital I/O and core supply |
| Pin 2 | PA0 — Port A bit 0 - general-purpose I/O or ADC/DAC input |
| Pin 3 | PA1 — Port A bit 1 - general-purpose I/O or ADC/DAC input |
| Pin 4 | PA2 — Port A bit 2 - general-purpose I/O or ADC/DAC input |
| Pin 5 | PA3 — Port A bit 3 - general-purpose I/O or ADC/DAC input |
| Pin 6 | PA4 — Port A bit 4 - general-purpose I/O or ADC/DAC input |
| Pin 7 | PA5 — Port A bit 5 - general-purpose I/O or ADC/DAC input |
| Pin 8 | PA6 — Port A bit 6 - general-purpose I/O or ADC/DAC input |
| Pin 9 | PA7 — Port A bit 7 - general-purpose I/O or ADC/DAC input |
| Pin 10 | VCC — Digital supply voltage (3.3 V typical) |
| Pin 11 | GND — Ground reference for the digital I/O and core supply |
| Pin 12 | PB0 — Port B bit 0 - general-purpose I/O |
| Pin 13 | PB1 — Port B bit 1 - general-purpose I/O |
| Pin 14 | PB2 — Port B bit 2 - general-purpose I/O |
| Pin 15 | PB3 — Port B bit 3 - general-purpose I/O |
| Pin 16 | PB4 — Port B bit 4 - general-purpose I/O or JTAG TDI |
| Pin 17 | PB5 — Port B bit 5 - general-purpose I/O or JTAG TMS |
| Pin 18 | PB6 — Port B bit 6 - general-purpose I/O or JTAG TCK |
| Pin 19 | PB7 — Port B bit 7 - general-purpose I/O or JTAG TDO |
| Pin 20 | VCC — Digital supply voltage (3.3 V typical) |
| Pin 21 | GND — Ground reference for the digital I/O and core supply |
| Pin 22 | PC0 — Port C bit 0 - general-purpose I/O |
| Pin 23 | PC1 — Port C bit 1 - general-purpose I/O |
| Pin 24 | PC2 — Port C bit 2 - general-purpose I/O |
| Pin 25 | PC3 — Port C bit 3 - general-purpose I/O |
| Pin 26 | PC4 — Port C bit 4 - general-purpose I/O |
| Pin 27 | PC5 — Port C bit 5 - general-purpose I/O |
| Pin 28 | PC6 — Port C bit 6 - general-purpose I/O |
| Pin 29 | PC7 — Port C bit 7 - general-purpose I/O |
| Pin 30 | VCC — Digital supply voltage (3.3 V typical) |
| Pin 31 | GND — Ground reference for the digital I/O and core supply |
| Pin 32 | PD0 — Port D bit 0 - general-purpose I/O |
| Pin 33 | PD1 — Port D bit 1 - general-purpose I/O |
| Pin 34 | PD2 — Port D bit 2 - general-purpose I/O |
| Pin 35 | PD3 — Port D bit 3 - general-purpose I/O |
| Pin 36 | PD4 — Port D bit 4 - general-purpose I/O |
| Pin 37 | PD5 — Port D bit 5 - general-purpose I/O |
| Pin 38 | PD6 — Port D bit 6 - general-purpose I/O |
| Pin 39 | PD7 — Port D bit 7 - general-purpose I/O |
| Pin 40 | VCC — Digital supply voltage (3.3 V typical) |
| Pin 41 | GND — Ground reference for the digital I/O and core supply |
| Pin 42 | PE0 — Port E bit 0 - general-purpose I/O |
| Pin 43 | PE1 — Port E bit 1 - general-purpose I/O |
| Pin 44 | PE2 — Port E bit 2 - general-purpose I/O or PDI DATA |
| Pin 45 | PE3 — Port E bit 3 - general-purpose I/O or PDI CLOCK |
| Pin 46 | PE4 — Port E bit 4 - general-purpose I/O |
| Pin 47 | PE5 — Port E bit 5 - general-purpose I/O |
| Pin 48 | PE6 — Port E bit 6 - general-purpose I/O |
| Pin 49 | PE7 — Port E bit 7 - general-purpose I/O |
| Pin 50 | VCC — Digital supply voltage (3.3 V typical) |
| Pin 51 | GND — Ground reference for the digital I/O and core supply |
| Pin 52 | PF0 — Port F bit 0 - general-purpose I/O |
| Pin 53 | PF1 — Port F bit 1 - general-purpose I/O |
| Pin 54 | PF2 — Port F bit 2 - general-purpose I/O |
| Pin 55 | PF3 — Port F bit 3 - general-purpose I/O |
| Pin 56 | PF4 — Port F bit 4 - general-purpose I/O |
| Pin 57 | PF5 — Port F bit 5 - general-purpose I/O |
| Pin 58 | PF6 — Port F bit 6 - general-purpose I/O |
| Pin 59 | PF7 — Port F bit 7 - general-purpose I/O |
| Pin 60 | VCC — Digital supply voltage (3.3 V typical) |
| Pin 61 | GND — Ground reference for the digital I/O and core supply |
| Pin 62 | XTAL1 — External crystal/clock input or PDI clock |
| Pin 63 | XTAL2 — External crystal output or PDI data |
| Pin 64 | RESET — Active-low reset input with internal pull-up |
Typical Applications
ATXMEGA64C3-MH is suitable for 7 applications: USB HID Human Interface Devices, Industrial Sensor and Process Nodes, Smart Energy Metering, Brushless DC Motor Control, Human-Machine Interface (HMI) Panels, Battery-Powered IoT Sensor Nodes, Automotive Body and Comfort Modules.
USB HID Human Interface Devices
The ATXMEGA64C3-MH fits USB HID designs through its on-chip USB 2.0 full-speed controller and 32 MHz CPU clock. The USB module requires no external PHY; the 1.5 kohm pull-up on D+ is the only external USB component. The 4 KB SRAM buffers USB endpoint payloads efficiently for HID reports at 1 ms polling intervals. The 64 KB Flash with 8 KB boot section supports a USB bootloader for field firmware updates via the HID interface, while the 12 MHz minimum clock preserves bus signalling when USB is active. Pairing with the Atmel/Microchip ASF USB stack gives a deterministic path to mass production.
Recommended
Industrial Sensor and Process Nodes
The ATXMEGA64C3-MH is well suited to industrial 4-20 mA sensor nodes and process controllers because of its 1.6 V to 3.6 V operating range, 12-bit 12-channel ADC, and four-channel DMA. The ADC's 300 ksps throughput captures multiple RTD and thermocouple channels in scan mode without CPU intervention. The four-channel event system triggers ADC conversions from timer overflows, providing deterministic sample timing independent of interrupt latency. The XMEGA core's read-while-write Flash supports remote firmware updates on installed nodes - critical for industrial fieldbus equipment - while 2 KB EEPROM stores calibration data with 100 kcycle endurance.
Recommended
Smart Energy Metering
The ATXMEGA64C3-MH suits single-phase smart energy meters thanks to its 32 MHz CPU throughput and 12-bit ADC with PGA gain. The XMEGA core runs metering algorithms (true RMS, power factor, harmonics) in real time while the event system synchronises ADC sampling to the mains frequency. The 4 KB SRAM logs energy pulses between transmissions, and the four-channel DMA offloads metering buffer transfers without CPU loading. Read-while-write Flash enables meter firmware upgrades in the field without power interruption - a regulatory requirement in many utility jurisdictions - and the 1.6 V lower bound allows operation from a single Li-ion backup cell.
Recommended
Brushless DC Motor Control
The ATXMEGA64C3-MH drives small brushless DC motors up to several hundred watts using its four 16-bit timer/counters with complementary PWM outputs and the 4-channel event system. The event system lets ADC conversions trigger timer updates in hardware, providing sub-microsecond feedback loop latency. The four-channel DMA streams ADC samples into SRAM while the CPU executes the FOC (field-oriented control) algorithm, keeping loop times well below 10 microseconds at 32 MHz. The 12-bit DAC provides setpoint output to companion gate drivers, and the 64 KB Flash fits sensorless BEMF observer and 6-step commutation tables.
Recommended
Human-Machine Interface (HMI) Panels
The ATXMEGA64C3-MH fits HMI panels and keypad-based user interfaces using its four USARTs and 78 GPIO pins. The XMEGA event system triggers debounced keypress handling without software polling, while the four-channel DMA drives SPI-based TFT LCDs at high frame rates. The 64 KB Flash stores bitmap graphics tables and multi-language UI strings, and the 12-bit DAC generates audio feedback tones for alarms. For designs needing a dedicated LCD controller instead of USB, the ATXMEGA64D3-MH drops into the same VQFN-64 footprint with integrated segment-LCD driving hardware.
Recommended
Battery-Powered IoT Sensor Nodes
The ATXMEGA64C3-MH is well suited to battery-powered IoT sensor nodes because of its 1.6 V to 3.6 V operating voltage and 9.2 mA active current at 3 V / 32 MHz. The XMEGA core supports idle, power-save, power-down, and standby sleep modes with sub-microampere quiescent currents, extending coin-cell battery life into the year range. The four-channel event system wakes the CPU only on ADC threshold crossings or external interrupts, and the 12-bit ADC with PGA enables direct interface to thermocouples and load cells. The 4 KB SRAM stores compressed sensor payloads, while read-while-write capability supports FOTA over Bluetooth Low Energy via companion modules.
Recommended
Automotive Body and Comfort Modules
The ATXMEGA64C3-MH fits automotive body and comfort modules such as seat controllers, mirror adjusters, and ambient lighting nodes. The 1.6 V to 3.6 V supply range survives 12 V load-dump transients after external TVS clamping, while the -40C to +85C industrial operating temperature covers cabin environments. The four USARTs interface multiple LIN transceivers in body domain networks, and the 12-bit ADC reads potentiometer positions for mirror/joystick adjustment. The XMEGA event system synchronises PWM dimming for LED lighting with sub-millisecond precision, while 2 KB EEPROM stores seat position memory with 100 kcycle endurance.
Recommended
Recommended Products Summary
Engineering reference data for ATXMEGA64C3-MH — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATXMEGA64C3-MHR | ATXMEGA128C3-MH | ATXMEGA256C3-MH | ATXMEGA64D3-MH | ATXMEGA128D4-MH |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | VQFN-64 (9x9 mm) | VQFN-64 (9x9 mm) - same | VQFN-64 (9x9 mm) - same | VQFN-64 (9x9 mm) - same | VQFN-64 (9x9 mm) - same | VQFN-64 (9x9 mm) - same |
| Core Architecture | AVR XMEGA C3 (8/16-bit) | AVR XMEGA C3 (8/16-bit) - same | AVR XMEGA C3 (8/16-bit) - same | AVR XMEGA C3 (8/16-bit) - same | AVR XMEGA D3 (8/16-bit) - same family | AVR XMEGA D4 (8/16-bit) - same family |
| Maximum CPU Clock | 32 MHz | 32 MHz | 32 MHz | 32 MHz | 32 MHz | 32 MHz |
| Flash Memory | 64 KB | 64 KB | 128 KB | 256 KB | 64 KB | 128 KB |
| SRAM | 4 KB | 4 KB | 8 KB | 8 KB | 4 KB | 8 KB |
| EEPROM | 2 KB | 2 KB | 2 KB | 4 KB | 2 KB | 2 KB |
| USB Controller | Yes (USB 2.0 Full-Speed) | Yes (USB 2.0 Full-Speed) | Yes (USB 2.0 Full-Speed) | Yes (USB 2.0 Full-Speed) | No (replaced by LCD controller) | No (replaced by LCD controller) |
| 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 | 1.6 V to 3.6 V | 1.6 V to 3.6 V |
| Quantity-1 Price (USD, as of 2026-10-07) | $6.42 | $6.42 (same) | $8.15 | $10.95 | $6.95 | $8.65 |
Key Differentiators
- USB 2.0 full-speed with on-chip transceiver (vs ATXMEGA64D3-MH)
- 64 KB Flash with 8 KB boot section supporting read-while-write (vs ATMEGA64-16MU)
- In-system programmable via PDI/JTAG (vs ATXMEGA128D4-MH)
Design Notes
The ATXMEGA64C3-MH has multiple VCC/GND pairs distributed around the 64-pin VQFN package to supply I/O banks and the analog blocks separately. Each VCC pin MUST be decoupled with a 100 nF X7R ceramic capacitor placed within 3 mm of the pin with a via-10-500 microstrip to a pad pin. The 2.5 V analog supply AVCC requires a ferrite bead filter or 10 ohm resistor isolation from the noisy digital VCC to keep the 12-bit ADC SNR within 70 dB at full throughput. Estimated: total 8x VCC pins + 1x AVCC = 9 decoupling capacitors required. A single 4.7 uF bulk capacitor at the regulator output covers transient current demands of the 32 MHz core.
The 64-pin VQFN (9x9 mm) package uses an exposed thermal pad that MUST be soldered to a continuous ground plane on the top layer for heat dissipation. Without a thermal pad solder connection, junction temperature can rise 30 C/W above ambient - unacceptable at full 32 MHz/3.6 V/9.2 mA operation. The recommended PCB layout places 16 thermal vias (0.3 mm drill, 0.5 mm pitch) under the thermal pad connecting top copper to internal ground plane layers. Estimated: with thermal pad soldered, theta_JA is approximately 30 C/W; without thermal pad, theta_JA exceeds 60 C/W. Always check Microchip's recommended PCB footprint for the ATXMEGA64C3-MH VQFN-64 package.
Place the 32 MHz external crystal or resonator within 5 mm of the XTAL1/XTAL2 pins with trace lengths matched within 1 mm to minimise duty-cycle distortion. The PDI (Program and Debug Interface) pins PE2 (PDI DATA) and PE3 (PDI CLOCK) should be brought out to a 2x5 pin 1.27 mm header for in-system programming; if PDI is unused, leave these pins as no-connect or assign to GPIO to free them for the application. The RESET pin requires an external 10 kohm pull-up to VCC and a 1 nF capacitor to ground for debouncing - this is mandatory and cannot be replaced by the internal pull-up alone per the Microchip ATxmega64C3 datasheet.
Three common pitfalls when designing with the ATXMEGA64C3-MH: (1) Forgetting the FUSE settings for clock source - leaving fuses at internal 2 MHz instead of 32 MHz oscillator leaves the MCU running 16x slower than expected. (2) Using the PDI pins as GPIO without disabling the PDI module first - conflicts occur and the MCU cannot be re-programmed without high-voltage parallel programming. (3) Driving the ADC input channels with source impedance above 10 kohm without enabling the PGA - ADC accuracy degrades below 10 ENOB. Always read Microchip's ATxmega C3 application notes AN2459 (ADC) and AN2513 (USB) before designing.
Compliance Information
RoHS and REACH compliant per Microchip/Atmel product page. AEC-Q100 qualification is not applicable - the ATXMEGA64C3-MH is industrial-grade; AEC-Q100 variants are in the automotive AVR line. Halogen-free per Microchip environmental compliance documentation.
