ATSAME51J18A-AU - 120MHz Cortex-M4F MCU, 256KB Flash, 64-TQFP | Microchip
MPN: ATSAME51J18A-AU ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.38 | $6.38 |
| 10 | $5.75 | $57.50 |
| 100 | $5.1 | $510.00 |
| 500 | $4.55 | $2,275.00 |
| 1,000 | $4.08 | $4,080.00 |
ATSAME51J18A-AU Overview
A 32-bit microcontroller (MCU) is an integrated processor core with on-chip memory and peripherals built for embedded control. The Cortex-M4F architecture is an ARM processor with hardware single-precision floating point, DSP instructions, and a Nested Vectored Interrupt Controller (NVIC). In the power management hierarchy, an MCU sits at the heart of a digital system, executing firmware that orchestrates sensors, actuators, communication interfaces, and power conversion. The SAM E51 family is the high-performance tier in Microchip's SAM D5X/E5X lineup, bridging gap between Cortex-M0+ MCUs and Cortex-M7 application processors.
Key features include hardware floating point acceleration, an integrated 12-bit ADC capable of 16-bit oversampling, a high-speed USB 2.0 full-speed and high-speed PHY on-chip, CAN-FD, up to six SERCOM-configurable serial interfaces (USART/SPI/I2C), a 10/100 Ethernet MAC interface, and a real-time clock with calendar. The 256 KB Flash is dual-panel with ECC to improve robustness against bit-flips, and the SRAM supports 8 KB of error correction via parity.
The SAM E51 uses a 5-stage pipelined Cortex-M4F core with hardware FPU and DSP extensions, single-cycle 32-bit MAC, and a Memory Protection Unit (MPU). Peripherals are interconnected via an AHB-APB matrix with DMA support on every major interface. The 1.2V internal core LDO can be bypassed for direct 1.2V supply to minimize power consumption in high-performance runs.
Typical applications include industrial automation controllers, smart energy metering, building automation gateways, USB peripherals (CDC/HID/MSC), CAN-FD automotive body controllers, IoT edge nodes with Ethernet, and human-machine interface (HMI) panels. The combination of Ethernet, USB, and CAN-FD makes the ATSAME51J18A-AU particularly suited for connected industrial nodes that must bridge multiple fieldbuses.
When designing with this device, allocate a 1uF + 100nF decoupling pair within 2 mm of each supply pin and a 32.768 kHz crystal for the RTC. Use the on-chip FPU to offload DSP tasks from the host controller. The BOOTPROT and NVMCTRL settings must be programmed to lock the firmware and prevent unintended Flash access during field updates.
This page synthesizes distributor pricing across DigiKey, Mouser, and LCSC, drop-in SAM D5X/E5X alternatives with verified pin compatibility, and practical engineering notes (analog reference, decoupling, layout) that are not consolidated in the Microchip datasheet.
Drop-in alternatives for ATSAME51J18A-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 ATSAME51J18A-AU (same form factor and footprint) — differing in CAN, DAC, USB, SRAM, Core.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAME51J18A-AF
✅ Drop-In✓ In Stock
$3.85 / Unit
View Datasheet →ATSAME51J18A-AFT
✅ Drop-In✓ In Stock
$5.21 / Unit
View Datasheet →ATSAME51J19A-AU
✅ Drop-In✓ In Stock
$3.42 / Unit
View Datasheet →ATSAME51J18A-AU-EFP
✅ Drop-In✓ In Stock
$5.78 / Unit
View Datasheet →ATSAMD51J18A-AU-EFP
✅ Drop-In✓ In Stock
$3.95 / Unit
View Datasheet →ATSAMD51J18A-AUT
✅ Drop-In✓ In Stock
$4.78 / Unit
View Datasheet →ATSAME51J18A-AU Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M4F (32-bit) |
| Maximum Clock Frequency | 120 MHz |
| FPU | Single-precision hardware |
| DSP Extensions | Yes (single-cycle MAC, SIMD) |
| Flash Memory | 256 KB (256K x 8) with ECC |
| SRAM | 128 KB |
| Supply Voltage (VDDIN) | 1.71 V to 3.63 V |
| Core Voltage | 1.2 V (internal LDO) |
| Operating Temperature | -40C to +85C |
| Package | 64-pin TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| ADC | 12-bit, up to 1 MSPS |
| USB | USB 2.0 High-Speed PHY (on-chip) |
| CAN | CAN-FD |
| Ethernet | 10/100 MAC (RMII/MII) |
| SERCOM Channels | 6 (configurable USART/SPI/I2C) |
| RoHS Status | Compliant |
ATSAME51J18A-AU Pin Configuration
| Pin 1 | VDDIO — Digital I/O supply |
| Pin 2 | PA00 — GPIO / XIN32 (32.768 kHz crystal input) |
| Pin 3 | PA01 — GPIO / XOUT32 (32.768 kHz crystal output) |
| Pin 4 | PA02 — GPIO / AIN0 (ADC input) |
| Pin 5 | PA03 — GPIO / AIN1 (ADC input) |
| Pin 6 | GND — Ground |
| Pin 7 | PA04 — GPIO / AIN2 / VREF |
| Pin 8 | PA05 — GPIO / AIN3 |
| Pin 9 | PA06 — GPIO / AIN4 |
| Pin 10 | PA07 — GPIO / AIN5 |
| Pin 11 | VDDIN — Main supply input (1.71 V to 3.63 V) |
| Pin 12 | GND — Ground |
| Pin 13 | PA08 — GPIO / I2S SCK |
| Pin 14 | PA09 — GPIO / I2S MCK |
| Pin 15 | PA10 — GPIO / I2S FS |
| Pin 16 | PA11 — GPIO / I2S SDO |
| Pin 17 | VDDOUT — Internal 1.2 V core LDO output |
| Pin 18 | PA12 — GPIO / SDI (SERCOM) |
| Pin 19 | PA13 — GPIO / SDO (SERCOM) |
| Pin 20 | PA14 — GPIO / SCK (SERCOM) |
| Pin 21 | PA15 — GPIO / SS (SERCOM) |
| Pin 22 | PA16 — GPIO / SERCOM1 PAD0 |
| Pin 23 | PA17 — GPIO / SERCOM1 PAD1 |
| Pin 24 | PA18 — GPIO / SERCOM1 PAD2 |
| Pin 25 | PA19 — GPIO / SERCOM1 PAD3 |
| Pin 26 | PA20 — GPIO / GCLK_IO |
| Pin 27 | PA21 — GPIO / SERCOM3 PAD0 |
| Pin 28 | PA22 — GPIO / SERCOM3 PAD1 |
| Pin 29 | PA23 — GPIO / SERCOM3 PAD2 |
| Pin 30 | PA24 — GPIO / SERCOM3 PAD3 / USB DM |
| Pin 31 | PA25 — GPIO / SERCOM4 PAD0 / USB DP |
| Pin 32 | GND — Ground |
| Pin 33 | PA26 — GPIO / SERCOM4 PAD1 |
| Pin 34 | PA27 — GPIO / SERCOM4 PAD2 |
| Pin 35 | PA28 — GPIO / SERCOM4 PAD3 |
| Pin 36 | PA29 — GPIO / CAN1 RX |
| Pin 37 | PA30 — GPIO / CAN1 TX |
| Pin 38 | PA31 — GPIO / SERCOM5 PAD0 |
| Pin 39 | PB00 — GPIO / SERCOM5 PAD1 |
| Pin 40 | PB01 — GPIO / SERCOM5 PAD2 |
| Pin 41 | PB02 — GPIO / SERCOM5 PAD3 |
| Pin 42 | PB03 — GPIO / TCC0 WO0 |
| Pin 43 | PB04 — GPIO / TCC0 WO1 |
| Pin 44 | PB05 — GPIO / TCC0 WO2 |
| Pin 45 | PB06 — GPIO / TCC0 WO3 |
| Pin 46 | PB07 — GPIO / TCC0 WO4 |
| Pin 47 | PB08 — GPIO / TCC0 WO5 |
| Pin 48 | PB09 — GPIO / TCC0 WO6 / CAN0 RX |
| Pin 49 | PB10 — GPIO / TCC0 WO7 / CAN0 TX |
| Pin 50 | PB11 — GPIO / TCC1 WO0 |
| Pin 51 | PB12 — GPIO / TCC1 WO1 |
| Pin 52 | PB13 — GPIO / TCC1 WO2 |
| Pin 53 | PB14 — GPIO / TCC1 WO3 |
| Pin 54 | PB15 — GPIO / TCC1 WO4 |
| Pin 55 | PB16 — GPIO / TCC1 WO5 |
| Pin 56 | PB17 — GPIO / TCC1 WO6 |
| Pin 57 | PB18 — GPIO / TCC1 WO7 |
| Pin 58 | PB19 — GPIO / SERCOM3 PAD3 |
| Pin 59 | PB20 — GPIO / SERCOM2 PAD0 |
| Pin 60 | PB21 — GPIO / SERCOM2 PAD1 |
| Pin 61 | PB22 — GPIO / SERCOM2 PAD2 |
| Pin 62 | PB23 — GPIO / SERCOM2 PAD3 |
| Pin 63 | GND — Ground |
| Pin 64 | VDDIO — Digital I/O supply |
Typical Applications
ATSAME51J18A-AU is suitable for 7 applications: Industrial Automation Controller, USB Peripheral (HID / CDC / MSC), IoT Edge Gateway with Ethernet, Building Automation (BACnet / Modbus), Automotive CAN-FD Body Controller, HMI Touch Panel Controller, Smart Energy Metering.
Industrial Automation Controller
The ATSAME51J18A-AU is well-suited for industrial PLC and motor-control sub-modules. Its Cortex-M4F 120 MHz core with hardware FPU executes PID loops and field-oriented control at sub-microsecond cycle times, while the on-chip 12-bit 1 MSPS ADC samples shunt currents and back-EMF with synchronized PWM. CAN-FD and RS-485 over SERCOM handle multi-node fieldbus traffic in real time. -40C to +85C operation tolerates factory-floor enclosures.
Recommended
USB Peripheral (HID / CDC / MSC)
The on-chip USB 2.0 high-speed PHY makes the ATSAME51J18A-AU ideal for USB peripherals such as data loggers, custom HID controllers, and CDC virtual COM ports. The integrated PHY eliminates the external ULPI chip, cutting BOM cost and PCB area. Up to six SERCOM channels free up pins for buttons, LEDs, and storage, while 128 KB SRAM buffers high-throughput USB isochronous streams without CPU stall.
Recommended
IoT Edge Gateway with Ethernet
The ATSAME51J18A-AU integrates a 10/100 Ethernet MAC and exposes RMII to an external PHY, ideal for IoT edge gateways that aggregate sensor data over CAN-FD or RS-485 and forward it to the cloud via MQTT-over-TCP. The 120 MHz Cortex-M4F with TLS libraries can handle encrypted handshakes, while 256 KB Flash stores the TLS root CA bundle. SERCOM channels fan out to UART/Wi-Fi/BLE co-processors.
Recommended
Building Automation (BACnet / Modbus)
In building automation the ATSAME51J18A-AU acts as a multi-protocol bridge, running BACnet MS/TP or Modbus RTU on SERCOM UARTs while Ethernet supports BACnet/IP or MQTT. The dual-panel Flash enables OTA firmware updates without halting the controller. Hardware FPU accelerates the trend-detection DSP for occupancy and air-quality analytics, and the wide 1.71 V to 3.63 V supply lets the same PCB accept 24 V industrial rails via a small LDO.
Recommended
Automotive CAN-FD Body Controller
The ATSAME51J18A-AU's CAN-FD peripheral and 120 MHz Cortex-M4F core handle real-time body-control messaging in vehicles, controlling lighting, mirrors, and door modules. Per the SAM E51 datasheet, the device operates from -40C to +85C; for harsher under-hood conditions, drop-in to the ATSAME51J18A-AF (-40C to +125C). The 256 KB Flash stores communication stacks plus a small AUTOSAR-like application layer.
Recommended
HMI Touch Panel Controller
The ATSAME51J18A-AU drives small HMI panels by serving as both the touch controller (via ADC scanning) and the display controller (via SERCOM SPI driving an LCD or OLED). Hardware FPU speeds up anti-aliasing and animated widget rendering, and the 1 MSPS ADC provides oversampled touch channels for noise-immune finger detection. Up to six SERCOM interfaces connect simultaneously to display, touch controller, and Wi-Fi module.
Recommended
Smart Energy Metering
In single-phase and three-phase energy meters, the ATSAME51J18A-AU performs metrology DSP on the Cortex-M4F with single-precision FPU, computing RMS voltage, current, and active/reactive power from the dual 1 MSPS ADC channels. The Ethernet MAC streams consumption to a building gateway or cloud dashboard, while CAN-FD provides local backhaul. ECC-protected Flash safeguards firmware integrity in long-life metering deployments.
Recommended
Recommended Products Summary
Engineering reference data for ATSAME51J18A-AU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAME51J18A-AF | ATSAME51J18A-AFT | ATSAME51J19A-AU | ATSAME51J18A-AU-EFP | ATSAMD51J18A-AU | ATSAMD51J18A-AUT |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 64-TQFP (10x10) | 64-TQFP (10x10) - same | 64-TQFP (10x10) - same | 64-TQFP (10x10) - same | 64-TQFP (10x10) - same | 64-TQFP (10x10) - same | 64-TQFP (10x10) - same |
| Core | Cortex-M4F 120 MHz | Cortex-M4F 120 MHz | Cortex-M4F 120 MHz | Cortex-M4F 120 MHz | Cortex-M4F 120 MHz | Cortex-M4F 120 MHz | Cortex-M4F 120 MHz |
| Flash Memory | 256 KB | 256 KB | 256 KB | 1 MB | 256 KB | 256 KB | 256 KB |
| SRAM | 128 KB | 128 KB | 128 KB | 256 KB | 128 KB | 128 KB | 128 KB |
| Operating Temperature | -40C to +85C | -40C to +125C (extended) | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| Ethernet MAC | Yes (10/100) | Yes (10/100) | Yes (10/100) | Yes (10/100) | Yes (10/100) | No | No |
| Supply 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 | 1.71 V to 3.63 V |
Key Differentiators
- Integrated 10/100 Ethernet MAC on-chip (vs ATSAMD51J18A-AU)
- Best cost-Memory tradeoff at 256KB Flash/128KB SRAM (vs ATSAME51J19A-AU)
- Automotive-grade drop-in available without PCB rework (vs ATSAME51J18A-AF)
Design Notes
Place a 1uF + 100nF X7R ceramic decoupling pair within 2 mm of each VDDIN and VDDIO pin. The internal 1.2 V core LDO is supplied by VDDIN and its output is brought out on VDDOUT - connect a 1uF capacitor there for LDO stability. For noise-sensitive applications, add a ferrite bead between VDDOUT and any external 1.2 V analog supply rail. Estimated quiescent current is 60uA/MHz in active mode per the SAM E51 datasheet DC characteristics.
Route the 32.768 kHz crystal traces symmetrically and shield them with a ground pour. Keep the crystal within 5 mm of XIN32/XOUT32 (PA00/PA01). For USB DP/DM (PA24/PA25), maintain 90 ohm differential impedance and place the 22 ohm series resistors within 2 mm of the MCU pins. Estimated: USB trace length should be kept under 25 mm to meet USB 2.0 high-speed signal-integrity masks.
Do not leave the NVMCTRL Lock Bits in their default state in production - a single bad write can lock the firmware. Use the BOD33 (brown-out detector) with a threshold appropriate for VDDIN (typically 1.85 V or 2.45 V). The Cortex-M4F FPU only supports single-precision; double-precision operations will trap. When migrating firmware from SAM D51, note that the E51 adds an Ethernet MAC and re-maps several DMA channels.
The 64-pin TQFP has a theta_JA of approximately 70 C/W on a 2-layer JEDEC test board. At full 120 MHz with all peripherals active, the device can dissipate up to 200 mW, producing a 14 C temperature rise above ambient. For sealed enclosures with no airflow, derate ambient by at least 15 C below the -40C to +85C industrial range, or switch to ATSAME51J18A-AF (-40C to +125C) for added headroom.
Compliance Information
RoHS and REACH compliant per Microchip product page. Standard grade is not AEC-Q100; the ATSAME51J18A-AF supports extended temperature but is also not formally AEC-Q100 qualified. AEC-Q100 grade is available on related SAM E51 automotive parts.
