ATSAMD51N20A-AU - 120MHz Cortex-M4F MCU 1MB Flash 100-TQFP | Microchip
MPN: ATSAMD51N20A-AU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $13.54 | $13.54 |
| 10 | $12.18 | $121.80 |
| 100 | $10.85 | $1,085.00 |
| 500 | $9.62 | $4,810.00 |
| 1,000 | $8.49 | $8,490.00 |
ATSAMD51N20A-AU Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, memory, and programmable peripherals on one silicon die, forming the embedded intelligence in countless products. Within the broader taxonomy, the ATSAMD51N20A-AU is an ARM Cortex-M4F MCU, belongs to the Cortex-M4 class of 32-bit microcontrollers, falls under the microcontroller (MCU) category, and finally under the integrated circuit (IC) family of semiconductors. Microchip's SAM D5x/E5x family extends the lower-pin-count SAM D2x/D1x line with higher performance, more memory, and richer peripherals while maintaining peripheral IP compatibility via SERCOM and Event System.
Key features include: ARM Cortex-M4F core with FPU and DSP extensions at up to 120 MHz; 1 MB dual-panel Flash with ECC and 256 KB SRAM with ECC; full-speed and high-speed USB 2.0 with on-chip PHY; six SERCOM serial channels (UART/SPI/I2C/LIN); I2S audio interface, SD/MMC host, and Quad-SPI memory interface; 12-bit 1 MSPS ADC with up to 32 channels, two 12-bit DACs, and three analog comparators; 16-bit and 24-bit timers with PWM, capture, and quadrature decode; 1.71V to 3.6V single supply; and AEC-Q100 qualification on the -AUT suffix variants.
The ATSAMD51 uses Microchip's Event System and SERCOM peripherals to route signals directly between peripherals and configurable serial engines, offloading I/O handling from the CPU. The Cortex-M4F with FPU delivers 1.25 DMIPS/MHz and supports single-precision IEEE 754 floating-point in hardware. The dual-panel Flash and ECC-protected SRAM enable safety-critical firmware reliability, while TrustZone-M is supported on the E5x variants but not on the D51 family. Cache and Prefetch buffers accelerate instruction throughput from Flash.
Typical applications include: industrial HMI and control panels, USB-equipped embedded devices, IoT edge nodes with crypto, audio playback and processing systems, motor control and FOC motor drives, and home automation hubs. In each, the combination of USB PHY, FPU, large Flash, and ECC memory uniquely fits scenarios requiring deterministic response plus connected peripherals.
Design consideration - the ATSAMD51N20A-AU's -AU suffix indicates the 100-pin TQFP package with -40C to +85C industrial temperature range; for AEC-Q100 automotive grade, select the -AUT variant. Use a 10uF plus 100nF decoupling pair close to each VDD pin and keep the 32.768 kHz crystal traces short.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for ATSAMD51N20A-AU β 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 ATSAMD51N20A-AU (same form factor and footprint) β differing in ADC, DAC, Operating Temperature, Package, SRAM.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAMD51N20A-AUT
β Drop-Inπ Reference alternative (not in catalog)
ATSAMD51N20A-AU-EFP
β Drop-Inβ In Stock
$9.42 / Unit
View Datasheet βATSAMD51N20A-AUT-EFP
β Drop-Inβ In Stock
$6.43 / Unit
View Datasheet βATSAMD51N20A-AFT
β Drop-Inπ Reference alternative (not in catalog)
ATSAMD51N19A-AUT-EFP
β Drop-Inβ In Stock
$3.65 / Unit
View Datasheet βATSAME51N20A-AU
β Drop-Inπ Reference alternative (not in catalog)
ATSAMD51N20A-AU Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M4F with FPU |
| Maximum Clock Frequency | 120 MHz |
| Flash Memory | 1 MB (1M x 8) dual-panel with ECC |
| SRAM | 256 KB with ECC |
| Operating Voltage | 1.71 V to 3.6 V |
| ADC | 12-bit, up to 1 MSPS, up to 32 channels |
| DAC | Dual 12-bit DAC |
| USB | USB 2.0 Full-/High-Speed with on-chip PHY |
| Serial Interfaces | 6x SERCOM (UART/SPI/I2C/LIN) |
| Audio Interface | I2S |
| Memory Card Interface | SD/MMC host controller |
| Timers | 16-bit and 24-bit, with PWM/capture/quadrature |
| Analog Comparators | 3 |
| Operating Temperature | -40C to +85C (industrial) |
| Package | 100-pin TQFP (14x14 mm) |
| Mounting Type | Surface Mount |
| MSL Level | 3 (168 hours) |
| RoHS Status | Compliant |
ATSAMD51N20A-AU Pin Configuration
| Pin 1 | PB04 β GPIO PB04 / I2S MCK1 |
| Pin 2 | PB05 β GPIO PB05 / I2S SCK1 |
| Pin 3 | PB06 β GPIO PB06 / I2S FS1 |
| Pin 4 | PB07 β GPIO PB07 / I2S DATA1 output |
| Pin 5 | PB08 β GPIO PB08 / I2S DATA1 input |
| Pin 6 | PB09 β GPIO PB09 / I2S MCK0 |
| Pin 7 | PA00 β GPIO PA00 / XIN32 |
| Pin 8 | PA01 β GPIO PA01 / XOUT32 |
| Pin 9 | PA02 β GPIO PA02 / AIN0 / DAC0 |
| Pin 10 | PA03 β GPIO PA03 / AIN1 / DAC1 / VREFA |
| Pin 11 | GND β Ground |
| Pin 12 | VDDANA β Analog supply voltage |
| Pin 13 | PA04 β GPIO PA04 / AIN2 |
| Pin 14 | PA05 β GPIO PA05 / AIN3 |
| Pin 15 | PA06 β GPIO PA06 / AIN4 |
| Pin 16 | PA07 β GPIO PA07 / AIN5 |
| Pin 17 | PA08 β GPIO PA08 / AIN6 |
| Pin 18 | PA09 β GPIO PA09 / AIN7 |
| Pin 19 | PA10 β GPIO PA10 / AIN8 |
| Pin 20 | PA11 β GPIO PA11 / AIN9 |
| Pin 21 | GND β Ground |
| Pin 22 | VDDIO β I/O supply voltage |
| Pin 23 | PB10 β GPIO PB10 |
| Pin 24 | PB11 β GPIO PB11 |
| Pin 25 | PB12 β GPIO PB12 |
| Pin 26 | PB13 β GPIO PB13 |
| Pin 27 | PB14 β GPIO PB14 |
| Pin 28 | PB15 β GPIO PB15 |
| Pin 29 | PA12 β GPIO PA12 |
| Pin 30 | PA13 β GPIO PA13 |
| Pin 31 | PA14 β GPIO PA14 |
| Pin 32 | PA15 β GPIO PA15 |
| Pin 33 | GND β Ground |
| Pin 34 | VDDIO β I/O supply voltage |
| Pin 35 | PA16 β GPIO PA16 |
| Pin 36 | PA17 β GPIO PA17 |
| Pin 37 | PA18 β GPIO PA18 |
| Pin 38 | PA19 β GPIO PA19 |
| Pin 39 | PB16 β GPIO PB16 |
| Pin 40 | PB17 β GPIO PB17 |
| Pin 41 | PB18 β GPIO PB18 |
| Pin 42 | PB19 β GPIO PB19 |
| Pin 43 | PB20 β GPIO PB20 |
| Pin 44 | PB21 β GPIO PB21 |
| Pin 45 | PA20 β GPIO PA20 |
| Pin 46 | PA21 β GPIO PA21 |
| Pin 47 | PA22 β GPIO PA22 |
| Pin 48 | PA23 β GPIO PA23 |
| Pin 49 | GND β Ground |
| Pin 50 | VDDIO β I/O supply voltage |
| Pin 51 | PA24 β GPIO PA24 / USB_DM |
| Pin 52 | PA25 β GPIO PA25 / USB_DP |
| Pin 53 | PB22 β GPIO PB22 |
| Pin 54 | PB23 β GPIO PB23 |
| Pin 55 | PB24 β GPIO PB24 |
| Pin 56 | PB25 β GPIO PB25 |
| Pin 57 | PB26 β GPIO PB26 / AIN14 |
| Pin 58 | PB27 β GPIO PB27 / AIN15 |
| Pin 59 | PB28 β GPIO PB28 / AIN16 |
| Pin 60 | PB29 β GPIO PB29 / AIN17 |
| Pin 61 | PA30 β GPIO PA30 / SWCLK |
| Pin 62 | PA31 β GPIO PA31 / SWDIO |
| Pin 63 | PB30 β GPIO PB30 / TDI |
| Pin 64 | PB31 β GPIO PB31 / TDO |
| Pin 65 | GND β Ground |
| Pin 66 | VDDIO β I/O supply voltage |
| Pin 67 | PC00 β GPIO PC00 |
| Pin 68 | PC01 β GPIO PC01 |
| Pin 69 | PC02 β GPIO PC02 |
| Pin 70 | PC03 β GPIO PC03 |
| Pin 71 | PC04 β GPIO PC04 |
| Pin 72 | PC05 β GPIO PC05 |
| Pin 73 | PC06 β GPIO PC06 |
| Pin 74 | PC07 β GPIO PC07 |
| Pin 75 | PC08 β GPIO PC08 / SD HC DETECT |
| Pin 76 | PC09 β GPIO PC09 / SD HC WRITE PROTECT |
| Pin 77 | PC10 β GPIO PC10 / SD HC CMD |
| Pin 78 | PC11 β GPIO PC11 / SD HC CK |
| Pin 79 | PA10 β GPIO PA10 alt / SD HC DATA0 (duplicated) |
| Pin 80 | PD00 β GPIO PD00 / SD HC DATA1 |
| Pin 81 | PD01 β GPIO PD01 / SD HC DATA2 |
| Pin 82 | PD02 β GPIO PD02 / SD HC DATA3 |
| Pin 83 | PD03 β GPIO PD03 |
| Pin 84 | PD04 β GPIO PD04 |
| Pin 85 | PD05 β GPIO PD05 |
| Pin 86 | PD06 β GPIO PD06 |
| Pin 87 | PD07 β GPIO PD07 |
| Pin 88 | PD08 β GPIO PD08 |
| Pin 89 | PD09 β GPIO PD09 |
| Pin 90 | PD10 β GPIO PD10 |
| Pin 91 | PD11 β GPIO PD11 |
| Pin 92 | PD12 β GPIO PD12 |
| Pin 93 | GND β Ground |
| Pin 94 | VDDIO β I/O supply voltage |
| Pin 95 | XIN β Crystal oscillator input (12 MHz) |
| Pin 96 | XOUT β Crystal oscillator output (12 MHz) |
| Pin 97 | GND β Ground |
| Pin 98 | RESET β Reset (active low) |
| Pin 99 | VDDIO β I/O supply voltage |
| Pin 100 | PB00 β GPIO PB00 |
Typical Applications
ATSAMD51N20A-AU is suitable for 6 applications: Industrial Human-Machine Interface (HMI) Controller, USB-Equipped Embedded Device, Audio Playback and Processing System, IoT Edge Node with Crypto Acceleration, Motor Control and FOC Motor Drive, Home Automation Hub and Gateway.
Industrial Human-Machine Interface (HMI) Controller
The ATSAMD51N20A-AU is well-suited as the central MCU behind industrial HMI panels combining touch input, a TFT LCD display, and USB connectivity. Its Cortex-M4F at 120 MHz executes LVGL/MODM graphics stacks in real time without frame drops, while the 1 MB Flash holds both the UI assets and the application firmware with ECC safety. The dual 12-bit DACs drive contrast/backlight PWM via op-amps, and six SERCOM channels connect SPI displays, I2C touch controllers, and UART/RS-485 fieldbuses simultaneously. Compared with SAM D2x family MCUs, the ATSAMD51N20A-AU doubles performance and adds USB High-Speed with on-chip PHY, eliminating the external ULPI transceiver and saving BOM cost in every HMI panel.
Recommended
USB-Equipped Embedded Device
The ATSAMD51N20A-AU integrates a USB 2.0 High-Speed PHY on-chip with device, host, and OTG modes, removing the need for an external ULPI transceiver and reducing BOM by $1-$2 per unit. At 120 MHz the Cortex-M4F handles USB CDC/MSC/HID class stacks concurrently with application firmware, while 256 KB ECC SRAM buffers high-bandwidth USB isochronous transfers. Connect the DP/DM pins directly to the USB-C connector through 39 ohm series resistors and ESD protection per the SAM D51 datasheet DS40001881G. Compared with PIC32MK MCUs, the ATSAMD51N20A-AU offers more SERCOM flexibility and better floating-point performance for DSP-style data processing over USB.
Recommended
Audio Playback and Processing System
The ATSAMD51N20A-AU combines a Cortex-M4F DSP-extended core, a hardware I2S interface, and dual 12-bit DACs - the right mix for audio playback, tone prompting, and basic DSP processing. The M4F's single-cycle MAC instructions accelerate MP3/AAC/Opus decoding in firmware, while I2S drives external 24-bit codecs like the TLV320AIC3106 over 4 wires. ECC SRAM buffers uncompressed WAV streams without dropouts, and the 1 MB Flash stores firmware plus compressed audio assets. Compared with MMA796 boards using SAM S70, the ATSAMD51N20A-AU fits smaller form factors while keeping sufficient audio performance for toys, doorbells, and industrial annunciators.
Recommended
IoT Edge Node with Crypto Acceleration
The ATSAMD51N20A-AU fits as the central MCU in IoT edge nodes requiring TLS/DTLS handshake, secure firmware storage, and OTA update capability. Its 120 MHz Cortex-M4F runs mbedTLS/X.509 handshakes in milliseconds, while ECC-protected Flash and SRAM safeguard firmware integrity in the field. Six SERCOM channels connect Wi-Fi/BLE modules (e.g., ATWINC1500 or RN4871) plus sensor I2C/SPI buses. The -AU 100-pin TQFP package exposes all peripheral pins for breadboard-friendly prototypes. Compared with SAM D2x, the N20A's larger 1 MB Flash supports dual-bank OTA with rollback safety.
Recommended
Motor Control and FOC Motor Drive
The ATSAMD51N20A-AU's Cortex-M4F core, 120 MHz speed, hardware FPU, and PWM-capable 24-bit timers make it well-suited for sensorless field-oriented control (FOC) of BLDC and PMSM motors. The 1 MSPS 12-bit ADC samples three-phase currents synchronously to PWM, while dual 12-bit DACs output reference waveforms for self-test. SERCOM channels connect to the gate driver SPI, isolated UART, and CAN-FD controller. Compared with dsPIC33 dedicated motor-control DSPs, the ATSAMD51N20A-AU sacrifices a few MIPS but gains the broader ARM ecosystem and easier migration to ATSAME51 with TrustZone for secure motor firmware.
Recommended
Home Automation Hub and Gateway
The ATSAMD51N20A-AU functions as the main controller inside a home automation hub that aggregates Zigbee, Wi-Fi, Z-Wave, and wired sensors, presents a local web UI, and bridges to cloud APIs. Its USB High-Speed PHY provides a 480 Mbps upstream link to a Raspberry Pi-class host or directly to a Wi-Fi module, while 256 KB ECC SRAM buffers simultaneous TLS sessions. The I2S interface drives a local speaker for voice feedback, and the SD/MMC host logs sensor history. Compared with ESP32-based hubs, the ATSAMD51N20A-AU offers more deterministic response and industrial-grade reliability for always-on service.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD51N20A-AU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD51N20A-AUT | ATSAMD51N20A-AU-EFP | ATSAMD51N20A-AUT-EFP | ATSAMD51N20A-AFT | ATSAMD51N19A-AUT-EFP | ATSAME51N20A-AU |
|---|---|---|---|---|---|---|---|
| Package | 100-TQFP (14x14) | 100-TQFP (14x14) - same | 100-TQFP (14x14) - same | 100-TQFP (14x14) - same | 100-TQFP (14x14) - same | 100-TQFP (14x14) - same | 100-TQFP (14x14) - same |
| Brand | Microchip Technology | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same |
| Core | ARM Cortex-M4F @ 120 MHz | ARM Cortex-M4F @ 120 MHz | ARM Cortex-M4F @ 120 MHz | ARM Cortex-M4F @ 120 MHz | ARM Cortex-M4F @ 120 MHz | ARM Cortex-M4F @ 120 MHz | ARM Cortex-M4F @ 120 MHz + TrustZone-M |
| Flash | 1 MB | 1 MB | 1 MB | 1 MB | 1 MB | 512 KB (-50%) | 1 MB |
| SRAM | 256 KB | 256 KB | 256 KB | 256 KB | 256 KB | 256 KB | 256 KB |
| Temperature Range | -40C to +85C (industrial) | -40C to +125C (automotive) | -40C to +85C (industrial) | -40C to +125C (automotive) | -40C to +125C (automotive) | -40C to +125C (automotive) | -40C to +85C (industrial) |
| AEC-Q100 Qualification | No | Yes | No | Yes | Yes | Yes | No |
| SERCOM Channels | 6 | 6 | 6 | 6 | 6 | 6 | 7 (+1) |
| TrustZone-M Security | No | No | No | No | No | No | Yes |
Key Differentiators
- On-chip USB High-Speed PHY eliminates external ULPI transceiver (vs ATSAMD21J18A-AU)
- Hardware FPU at 120 MHz Cortex-M4F for DSP and floating point (vs ATSAMD51J19A-AU)
- 1 MB dual-panel Flash with ECC for safe firmware updates (vs ATSAMD51N19A-AUT-EFP)
Design Notes
Decouple every VDDIO and VDDANA pin pair with 100 nF ceramic capacitors placed within 2 mm of the pin, and add a single 10 uF bulk capacitor per supply rail. The SAM D51 datasheet DS40001881G specifies that the digital and analog supplies may be tied together for simplicity, but separating them with a ferrite bead and dedicated regulator for VDDANA reduces ADC noise floor by approximately 6-8 dB. Use a low-noise LDO such as the AP2112-3.3 for VDDANA in ADC-intensive designs. Bring VDDIO up before VDDANA to avoid latch-up; the on-chip power-on-reset circuit monitors both rails.
The 100-pin TQFP package of the ATSAMD51N20A-AU has typical thermal resistance theta_JA of approximately 50 C/W with standard JEDEC 2s2p test PCB. At 120 MHz full activity across all peripherals, internal power dissipation rarely exceeds 200-300 mW, yielding junction temperature rise of 10-15 C above ambient - well within the -40C to +85C industrial range. For high-ambient enclosures above 60 C, design a copper pour of at least 0.5 square inches on the top layer under the TQFP exposed pad-adjacent ground area to keep junction below 100 C during continuous USB High-Speed operation.
Route the USB DP/DM differential pair with 90 ohm differential impedance and equal length matching within 150 mil of each other. Place the ESD protection array USBLC6 within 5 mm of the USB-C connector, not at the MCU. For the 12 MHz main crystal, keep traces short (under 6 mm) and surround them with a ground pour; route the 32.768 kHz crystal traces similarly to minimize jitter. SERCOM signals can be routed as needed, but use ground-via stitching every 100 mil along their length to control EMI. Verify clearance between the TQFP pad and inner-layer ground fill to prevent manufacturing shorts.
Avoid the common mistake of leaving the I2S peripheral misconfigured - the SAM D51 datasheet DS40001881G warns that I2S MCK must be enabled explicitly in the I2S CTRLA register before clocks appear on the pin. When migrating from SAM D2x to D51, note that SERCOM pad multiplexing has been remapped for several pins; do not assume the D21/D20 firmware pin assignments work directly on D51. Also, ECC-protected Flash and SRAM must be initialized by the startup code or the first read may return corrected errors that flag an interrupt - call NVMCTRL.CTRLA and configure RAMECC before main().
Compliance Information
RoHS compliant per Microchip product page DS40001881G. ATSAMD51N20A-AU is the industrial grade variant (not AEC-Q100) - select the -AUT suffix for AEC-Q100 automotive qualification.