ATSAMD51J18A-MU - 120MHz Cortex-M4F MCU, 256KB Flash | Microchip
MPN: ATSAMD51J18A-MU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.99 | $4.99 |
| 10 | $4.55 | $45.50 |
| 100 | $4.12 | $412.00 |
| 500 | $3.74 | $1,870.00 |
| 1,000 | $3.42 | $3,420.00 |
ATSAMD51J18A-MU Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program and data memory, peripherals, and I/O on one die. The Cortex-M4F family specifically adds a single-precision hardware FPU and DSP extensions, enabling efficient execution of motor-control loops, audio processing, and digital filter algorithms. Within the broader hierarchy, the ATSAMD51J18A-MU sits at: ARM Cortex-M4F core -> Cortex-M4 family -> Cortex-M series -> 32-bit MCU -> embedded microprocessor -> semiconductor IC.
Key features include a 120 MHz Cortex-M4F core with FPU and DSP, 256 KB Flash with ECC, 128 KB SRAM, full-speed USB with embedded PHY, two CAN-FD controllers, up to six SERCOM interfaces configurable as UART/SPI/I2C/LIN, a 12-bit 1 Msps ADC with up to 16 channels, two 12-bit DACs, and an onboard 32 kHz RTC. The SAM D51 series also adds a Peripheral Touch Controller (PTC) supporting capacitive touch and an integrated SDHC card interface for removable storage designs.
The device operates from 1.71 V to 3.63 V, supporting both 1.8 V and 3.3 V system rails without level translation. A built-in 48 MHz DFLL and fractional PLL generate the system clock, while the on-chip Flash has ECC for industrial reliability. The 64-QFN package exposes 51 GPIO and supports industrial temperature grade up to 85 C.
Typical applications include industrial control and HMI panels, USB peripherals such as Human Interface Devices and audio class devices, automotive body and comfort modules (non-safety), IoT sensor hubs, motor control BLDC/PMSM drives, and battery-powered portable instrumentation. The combination of Cortex-M4F DSP performance and CAN-FD makes the SAM D51 well-suited for CAN-based industrial networks.
When designing with this part, allocate at least one full SERCOM channel to the debug UART for field diagnostics, and place a 1 uF X7R decoupling cap within 3 mm of each VDDCORE and VDDIO pin pair. Ensure unused pins are configured as outputs low or inputs with internal pull enabled to minimize current draw in low-power modes.
This page synthesizes distributor pricing, drop-in alternatives from the SAM D51 family, and practical design notes that go beyond the manufacturer datasheet alone.
Drop-in alternatives for ATSAMD51J18A-MU 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 ATSAMD51J18A-MU (same form factor and footprint) β differing in DAC, Package, SRAM, ADC, Operating Temperature.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAMD51J19A-MU
β Drop-Inπ Reference alternative (not in catalog)
ATSAMD51J20A-MU
β Drop-Inπ Reference alternative (not in catalog)
ATSAMD51J18A-MUT
β Drop-Inβ In Stock
$5.18 / Unit
View Datasheet βATSAMD51G19A-MFT
β Drop-Inβ In Stock
$4.02 / Unit
View Datasheet βATSAMD51G18A-MFT
β Drop-Inβ In Stock
$3.55 / Unit
View Datasheet βATSAMD51J18A-MU Maximum Ratings & Electrical Characteristics
| Core Architecture | ARM Cortex-M4F with FPU and DSP |
| Maximum CPU Clock | 120 MHz |
| Program Flash | 256 KB (256K x 8) |
| SRAM | 128 KB |
| Package | 64-pin QFN (9x9 mm) with exposed pad |
| Operating Voltage | 1.71 V to 3.63 V |
| GPIO Count | 51 |
| ADC | 12-bit, up to 1 Msps, up to 16 channels |
| DAC | Two 12-bit DACs |
| USB | Full-speed USB 2.0 with on-chip PHY |
| CAN | Two CAN-FD controllers |
| SERCOM | Up to 6 configurable SERCOM (UART/SPI/I2C/LIN) |
| Touch Peripheral | Peripheral Touch Controller (PTC) |
| Operating Temperature | -40 C to +85 C (industrial grade) |
| RoHS Status | Compliant |
ATSAMD51J18A-MU Pin Configuration
| Pin 1 | PA00 β GPIO / XIN32 (32.768 kHz crystal input) |
| Pin 2 | PA01 β GPIO / XOUT32 (32.768 kHz crystal output) |
| Pin 3 | PA02 β GPIO / AIN0 (ADC analog input 0) |
| Pin 4 | PA03 β GPIO / AIN1 / VREFA (ADC reference) |
| Pin 5 | GND β Ground |
| Pin 6 | VDDIO β I/O supply voltage (1.71-3.63 V) |
| Pin 7 | PA04 β GPIO / AIN2 |
| Pin 8 | PA05 β GPIO / AIN3 |
| Pin 9 | PA06 β GPIO / AIN4 |
| Pin 10 | PA07 β GPIO / AIN5 |
| Pin 11 | PA08 β GPIO / AIN6 / SERCOM0 PAD0 |
| Pin 12 | PA09 β GPIO / AIN7 / SERCOM0 PAD1 |
| Pin 13 | PA10 β GPIO / AIN8 / SERCOM0 PAD2 |
| Pin 14 | PA11 β GPIO / AIN9 / SERCOM0 PAD3 |
| Pin 15 | VDDCORE β Internal 1.2 V regulator output (decoupling) |
| Pin 16 | GND β Ground |
| Pin 17 | PA12 β GPIO / SERCOM1 PAD0 |
| Pin 18 | PA13 β GPIO / SERCOM1 PAD1 |
| Pin 19 | PA14 β GPIO / SERCOM1 PAD2 |
| Pin 20 | PA15 β GPIO / SERCOM1 PAD3 |
| Pin 21 | PA16 β GPIO / SERCOM2 PAD0 / I2S FS |
| Pin 22 | PA17 β GPIO / SERCOM2 PAD1 / I2S SCK |
| Pin 23 | PA18 β GPIO / SERCOM2 PAD2 / I2S MCK |
| Pin 24 | PA19 β GPIO / SERCOM2 PAD3 / I2S SDO |
| Pin 25 | PA20 β GPIO / SERCOM3 PAD0 |
| Pin 26 | PA21 β GPIO / SERCOM3 PAD1 |
| Pin 27 | PA22 β GPIO / SERCOM3 PAD2 |
| Pin 28 | PA23 β GPIO / SERCOM3 PAD3 |
| Pin 29 | PA24 β GPIO / USB DM (USB data minus) |
| Pin 30 | PA25 β GPIO / USB DP (USB data plus) |
| Pin 31 | GND β Ground |
| Pin 32 | VDDIO β I/O supply voltage |
| Pin 33 | PA27 β GPIO |
| Pin 34 | PA28 β GPIO |
| Pin 35 | RESET β Active-low reset input |
| Pin 36 | SWDIO β Serial Wire Debug I/O |
| Pin 37 | SWCLK β Serial Wire Debug clock |
| Pin 38 | PB02 β GPIO / SERCOM4 PAD0 |
| Pin 39 | PB03 β GPIO / SERCOM4 PAD1 |
| Pin 40 | PB04 β GPIO / SERCOM4 PAD2 |
| Pin 41 | PB05 β GPIO / SERCOM4 PAD3 |
| Pin 42 | PB06 β GPIO / SERCOM5 PAD0 |
| Pin 43 | PB07 β GPIO / SERCOM5 PAD1 |
| Pin 44 | PB08 β GPIO / SERCOM5 PAD2 |
| Pin 45 | PB09 β GPIO / SERCOM5 PAD3 / I2S SDI |
| Pin 46 | PB10 β GPIO |
| Pin 47 | PB11 β GPIO |
| Pin 48 | PB12 β GPIO |
| Pin 49 | PB13 β GPIO |
| Pin 50 | PB14 β GPIO |
| Pin 51 | PB15 β GPIO |
| Pin 52 | PB16 β GPIO |
| Pin 53 | PB17 β GPIO |
| Pin 54 | PB22 β GPIO |
| Pin 55 | PB23 β GPIO |
| Pin 56 | PB30 β GPIO |
| Pin 57 | PB31 β GPIO |
| Pin 58 | VDDIO β I/O supply voltage |
| Pin 59 | GND β Ground |
| Pin 60 | VDDIN β Main supply input to internal regulator |
| Pin 61 | PA30 β GPIO / SWO (trace) |
| Pin 62 | PA31 β GPIO |
| Pin 63 | GND β Ground |
| Pin 64 | EP β Exposed pad (must be soldered to central GND copper pour) |
Typical Applications
ATSAMD51J18A-MU is suitable for 6 applications: Industrial HMI and Control Panels, USB Audio Class Devices and Headsets, BLDC/PMSM Motor Control, IoT Sensor Hubs and Edge Nodes, Automotive Body and Comfort Modules, Portable Test and Measurement.
Industrial HMI and Control Panels
The ATSAMD51J18A-MU's 120 MHz Cortex-M4F core, 51 GPIO, and six SERCOM channels (UART/SPI/I2C) make it a strong fit for industrial HMI panels driving TFT displays and reading keypad/encoder inputs. The 12-bit ADC with up to 16 channels handles analog sensor inputs for pressure, flow, or temperature, while two CAN-FD controllers connect to industrial CANopen or DeviceNet backbones. Per the SAM D51 datasheet, an external QSPI Flash can be memory-mapped over SERCOM for large UI assets.
Recommended
USB Audio Class Devices and Headsets
The full-speed USB 2.0 with embedded PHY and two 12-bit DACs make the ATSAMD51J18A-MU well suited for USB audio class 1.0/2.0 headsets and USB microphones. The Cortex-M4F DSP engine handles sample-rate conversion, EQ, and noise suppression in real time, while the I2S peripheral streams to external codecs for higher fidelity. According to Microchip application notes, the integrated PTC can implement capacitive touch controls without external ICs.
Recommended
BLDC/PMSM Motor Control
The TCC (Timer/Counter for Control) units on the ATSAMD51J18A-MU generate complementary PWM with dead-time insertion and hardware fault shutdown - essential for safe 3-phase inverter drive of BLDC and PMSM motors. The Cortex-M4F DSP extensions accelerate field-oriented control (FOC) math, while the 1 Msps ADC samples phase currents synchronously to the PWM. According to the SAM D51 datasheet, the SERCOM-based encoder interface reads quadrature encoders without an external decoder IC.
Recommended
IoT Sensor Hubs and Edge Nodes
The ATSAMD51J18A-MU's 256 KB Flash supports full TLS stacks plus application code for IoT edge nodes aggregating sensor data over I2C/SPI. The 128 KB SRAM holds TCP/IP buffers and JSON payloads, while six SERCOM channels expand into multiple sensor buses. Per the datasheet, the low-power Sleep and Standby modes retain SRAM at under 100 uA, ideal for battery-powered environmental monitors.
Recommended
Automotive Body and Comfort Modules
The ATSAMD51J18A-MU industrial grade variant handles non-safety automotive body controllers - window lifters, seat controls, climate panel UI - by virtue of its CAN-FD controllers and LIN-capable SERCOM. The Cortex-M4F DSP runs audio chime synthesis for warning chimes. According to Microchip documentation, automotive-grade variants in the SAM D51 family (with -AUT suffix) carry AEC-Q100 qualification for in-cabin use.
Recommended
Portable Test and Measurement
The 120 MHz Cortex-M4F with FPU enables real-time DSP for portable oscilloscopes, data loggers, and signal analyzers built on the ATSAMD51J18A-MU. The 1 Msps 12-bit ADC captures waveforms while the 256 KB Flash stores firmware with calibration tables. The integrated USB device port streams acquired data to a host PC, and the SDHC interface logs directly to removable SD cards without an external bridge IC.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD51J18A-MU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD51J19A-MU | ATSAMD51J20A-MU | ATSAMD51J18A-MUT | ATSAMD51G19A-MFT | ATSAMD51G18A-MFT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 64-QFN (9x9 mm) | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - 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 |
| Flash | 256 KB | 512 KB | 1 MB | 256 KB | 512 KB | 256 KB |
| SRAM | 128 KB | 192 KB | 256 KB | 128 KB | 192 KB | 128 KB |
| USB | Full-speed USB 2.0 with PHY | Full-speed USB 2.0 with PHY | Full-speed USB 2.0 with PHY | Full-speed USB 2.0 with PHY | Full-speed USB 2.0 with PHY | Full-speed USB 2.0 with PHY |
| CAN-FD Controllers | 2 | 2 | 2 | 2 | 2 | 2 |
| Operating Voltage | 1.71 V to 3.63 V | 1.71 V to 3.63 V | 1.71 V to 3.63 V | 1.71 V to 3.63 V | 1.71 V to 3.63 V | 1.71 V to 3.63 V |
| GPIO Count | 51 | 51 | 51 | 51 | Reduced (G-series subset) | Reduced (G-series subset) |
Key Differentiators
- Dual CAN-FD controllers integrated (vs ATSAMD51G18A-MFT)
- Double Flash with same footprint (vs ATSAMD51J19A-MU)
- Full peripheral set in industrial temp grade (vs ATSAMD51J18A-MUT)
Design Notes
Place a 1 uF X7R ceramic decoupling capacitor within 3 mm of every VDDCORE pin and a 100 nF cap within 3 mm of every VDDIO pin. According to the SAM D51 datasheet, the on-chip 1.2 V regulator supplies VDDCORE and requires at least 1 uF of bulk decoupling plus a 100 nF high-frequency bypass. Estimated: at 120 MHz with 1.8 V supply and full GPIO toggle, typical core current is approximately 25-30 mA - the regulator must handle this transient without sagging.
The 64-QFN exposed pad (EP) must be soldered to a central ground copper pour of at least 25 mm^2 to provide the thermal path for the package. According to the SAM D51 datasheet, thermal resistance theta_JA on a 2-layer JEDEC test board is approximately 31 C/W. Estimated: at full 120 MHz with 3.3 V supply the device typically dissipates 200-300 mW, so the junction-to-ambient rise is roughly 6-10 C above ambient under normal operating conditions - well within the 85 C industrial limit.
Route the SWDIO and SWCLK traces as a 2-wire debug bus with at least 4x ground isolation from adjacent switching signals. According to Microchip application notes, keep the SWD pair length-matched and avoid running them parallel to the USB DP/DM differential pair. Place a 10 kOhm pull-up on SWDIO and 100 kOhm pull-down on RESET for reliable debug-port re-entry.
Do not leave unused GPIO as floating inputs - configure them as outputs low or inputs with the internal pull-up enabled. According to the SAM D51 datasheet, floating CMOS inputs can draw several hundred microamps per pin from the input buffer and may cause spurious NMI or interrupt wakeups. Also, ensure the NVMCTRL row-write operations are performed with interrupts disabled to avoid mid-write corruption of Flash with ECC enabled.
The USB DP/DM differential pair must be routed with 90 ohm differential impedance and trace length matching within 0.15 mm. According to the USB 2.0 specification and Microchip USB design notes, place the 22 ohm series source termination resistors close to the MCU pins and keep the DP/DM traces no longer than 50 mm on FR-4. A common-mode choke near the connector improves conducted emissions immunity.
Compliance Information
RoHS and REACH compliant per LCSC product listing. Industrial temperature grade -40 C to +85 C. For AEC-Q100 qualified automotive variant, use the -AUT suffix part (ATSAMD51J18A-AUT).
