ATSAME51J18A-AFT - 120MHz Cortex-M4F MCU, 256KB Flash | Microchip
MPN: ATSAME51J18A-AFT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.92 | $8.92 |
| 10 | $8.04 | $80.40 |
| 100 | $7.15 | $715.00 |
| 500 | $6.48 | $3,240.00 |
| 1,000 | $5.83 | $5,830.00 |
| 3,000 | $5.21 | $15,630.00 |
ATSAME51J18A-AFT Overview
A Cortex-M4F microcontroller is a 32-bit RISC processor core based on the ARMv7-M architecture with DSP extensions and a hardware Floating Point Unit. The M4F sits within the ARM Cortex-M family (M0/M0+/M3/M4/M7/M33) and is widely adopted for mixed signal-control applications where deterministic real-time response, low power, and DSP-class signal processing must coexist in a single die. Microcontroller ICs such as the SAM E51 serve as the application host in embedded systems, executing firmware, handling peripherals, and bridging sensors to connectivity interfaces.
Key features of the ATSAME51J18A include a 120 MHz core with FPU, 256 KB Flash, 128 KB SRAM, a 12-bit 1 MSPS ADC with up to 16 channels, two 12-bit DAC channels, multiple SERCOM interfaces, and a Cryptographic Accelerator supporting AES, SHA, and True Random Number Generator (TRNG). It also offers a Parallel Capture Controller (PCC) for camera/video input and a 2-channel CAN-FD controller, which extends the classical CAN 2.0B data field to 64 bytes at up to 5 Mbit/s. The integrated I/O pin count of 51 GPIO supports a wide range of mixed-signal designs.
Architecturally, the SAM E51 family combines the Cortex-M4F core with up to 1 MB Dual-Panel Flash, an embedded 32-bit bus matrix, and an Event System that allows peripheral-to-peripheral signalling without CPU intervention. The dual-panel flash permits live firmware updates (live update) by switching execution between two memory banks without an external bootloader, which simplifies IEC 61508 and IEC 60730 functional-safety compliance paths.
Typical applications for the ATSAME51J18A-AFT include industrial HMI panels, building automation controllers, automotive body electronics, USB-to-CAN bridges, sensor fusion nodes, and low-power IoT edge devices. Designers select this MCU when deterministic Cortex-M4F performance, FPU math for control loops, and integrated CAN-FD and USB connectivity are required within a single 64-pin TQFP footprint.
When designing with this part, ensure that the decoupling network on each VDD/VSS pair uses 100 nF X7R ceramic capacitors placed within 2 mm of each pin, and that the 32.768 kHz crystal load capacitor values match the crystal manufacturer's CL specification to guarantee RTC accuracy across the full -40 °C to +125 °C extended temperature range.
This page synthesizes distributor pricing, drop-in alternatives within the SAME51 family, and practical design considerations not collected in a single place by the manufacturer datasheet.
Drop-in alternatives for ATSAME51J18A-AFT — 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-AFT (same form factor and footprint) — differing in CAN, Operating Temperature, ADC, SERCOM, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAME51J18A-AF
✅ Drop-In✓ In Stock
$3.85 / Unit
View Datasheet →ATSAME51J19A-AFT
✅ Drop-In✓ In Stock
$5.62 / Unit
View Datasheet →ATSAME51J20A-AFT
✅ Drop-In✓ In Stock
$5.2 / Unit
View Datasheet →ATSAMD51J18A-AUT
✅ Drop-In✓ In Stock
$4.78 / Unit
View Datasheet →ATSAMD51J19A-AFT
✅ Drop-In✓ In Stock
$4.8 / Unit
View Datasheet →ATSAME51J18A-AFT Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M4F with FPU |
| CPU Architecture | 32-bit ARMv7-M |
| Maximum CPU Clock | 120 MHz |
| Program Flash | 256 KB (with ECC) |
| SRAM | 128 KB |
| Operating Voltage Range | 1.71 V to 3.6 V |
| I/O Pins | 51 |
| Package | 64-pin TQFP (10x10 mm) |
| Operating Temperature Range | -40 °C to +125 °C (Extended) |
| ADC | 12-bit, up to 1 MSPS, up to 16 channels |
| DAC | 12-bit, 2 channels |
| USB | USB 2.0 Full-Speed Device/Host |
| CAN | 2x CAN-FD controllers (ISO 11898-1) |
| SERCOM | Up to 8 SERCOM (UART/SPI/I2C) |
| Cryptographic Accelerator | AES-256, SHA-256, TRNG |
| Parallel Capture Controller (PCC) | Yes |
| DMA Channels | 24 |
| Mounting Type | Surface Mount |
| MSL Level | MSL3 (per JEDEC J-STD-020) |
| RoHS Status | Compliant |
ATSAME51J18A-AFT Pin Configuration
| Pin 1 | PB09 — GPIO PB09 (SERCOM, ADC) |
| Pin 2 | PB10 — GPIO PB10 (SERCOM, ADC) |
| Pin 3 | PB11 — GPIO PB11 (SERCOM, ADC) |
| Pin 4 | PA08 — GPIO PA08 (SERCOM, NMI) |
| Pin 5 | PA09 — GPIO PA09 (SERCOM) |
| Pin 6 | VDDIO — Digital I/O supply |
| Pin 7 | VSS — Digital ground |
| Pin 8 | PA10 — GPIO PA10 (SERCOM) |
| Pin 9 | PA11 — GPIO PA11 (SERCOM) |
| Pin 10 | PA12 — GPIO PA12 (SERCOM) |
| Pin 11 | PA13 — GPIO PA13 (SERCOM) |
| Pin 12 | PA14 — GPIO PA14 (SERCOM) |
| Pin 13 | PA15 — GPIO PA15 (SERCOM) |
| Pin 14 | PA16 — GPIO PA16 (SERCOM, I2S) |
| Pin 15 | PA17 — GPIO PA17 (SERCOM, I2S) |
| Pin 16 | PA18 — GPIO PA18 (SERCOM) |
| Pin 17 | PA19 — GPIO PA19 (SERCOM) |
| Pin 18 | VDDCORE — Internal core regulator output |
| Pin 19 | VSS — Digital ground |
| Pin 20 | PA20 — GPIO PA20 (SERCOM) |
| Pin 21 | PA21 — GPIO PA21 (SERCOM) |
| Pin 22 | PA22 — GPIO PA22 (SERCOM) |
| Pin 23 | PA23 — GPIO PA23 (USB SOF, SERCOM) |
| Pin 24 | PA24 — GPIO PA24 (USB D-, SERCOM) |
| Pin 25 | PA25 — GPIO PA25 (USB D+, SERCOM) |
| Pin 26 | GND — USB ground reference |
| Pin 27 | VDDIO — Digital I/O supply |
| Pin 28 | PA27 — GPIO PA27 (SERCOM) |
| Pin 29 | RESETN — Active-low reset input |
| Pin 30 | VDDIN — Voltage regulator input |
| Pin 31 | VREGA — Analog voltage regulator output |
| Pin 32 | VREGB — Analog voltage regulator output |
| Pin 33 | VREGC — Core voltage regulator output |
| Pin 34 | VSS — Digital ground |
| Pin 35 | VSS — Digital ground |
| Pin 36 | VDDIO — Digital I/O supply |
| Pin 37 | VDDIO — Digital I/O supply |
| Pin 38 | XIN32 — 32.768 kHz crystal input |
| Pin 39 | XOUT32 — 32.768 kHz crystal output |
| Pin 40 | PA30 — GPIO PA30 (SERCOM, ADC) |
| Pin 41 | PA31 — GPIO PA31 (SERCOM, ADC) |
| Pin 42 | PB02 — GPIO PB02 (SERCOM, ADC) |
| Pin 43 | VSS — Digital ground |
| Pin 44 | VDDANA — Analog supply |
| Pin 45 | PB03 — GPIO PB03 (SERCOM, ADC, DAC0) |
| Pin 46 | PB04 — GPIO PB04 (SERCOM, ADC, DAC1) |
| Pin 47 | PB05 — GPIO PB05 (SERCOM, ADC) |
| Pin 48 | PB06 — GPIO PB06 (SERCOM, ADC) |
| Pin 49 | PB07 — GPIO PB07 (SERCOM, ADC) |
| Pin 50 | PB08 — GPIO PB08 (SERCOM, ADC) |
| Pin 51 | PB09 — GPIO PB09 (SERCOM, ADC) |
| Pin 52 | VSS — Digital ground |
| Pin 53 | VDDIO — Digital I/O supply |
| Pin 54 | PB10 — GPIO PB10 (SERCOM) |
| Pin 55 | PB11 — GPIO PB11 (SERCOM) |
| Pin 56 | PB12 — GPIO PB12 (SERCOM, CAN0 TX) |
| Pin 57 | PB13 — GPIO PB13 (SERCOM, CAN0 RX) |
| Pin 58 | PB14 — GPIO PB14 (SERCOM, CAN1 TX) |
| Pin 59 | PB15 — GPIO PB15 (SERCOM, CAN1 RX) |
| Pin 60 | PB16 — GPIO PB16 (SERCOM) |
| Pin 61 | PB17 — GPIO PB17 (SERCOM) |
| Pin 62 | PB18 — GPIO PB18 (SERCOM) |
| Pin 63 | PB19 — GPIO PB19 (SERCOM) |
| Pin 64 | PB20 — GPIO PB20 (SERCOM) |
Typical Applications
ATSAME51J18A-AFT is suitable for 6 applications: Industrial HMI Control Panel, USB-to-CAN-FD Bridge Gateway, Building Automation Controller, Automotive Body Electronics Module, Sensor Fusion and IoT Edge Node, Low-Power IoT Data Logger.
Industrial HMI Control Panel
The ATSAME51J18A-AFT fits industrial HMI panels because its 120 MHz Cortex-M4F core, single-precision FPU, and 256 KB of Flash handle real-time LVGL/STemWin graphics plus capacitive touch scanning with deterministic scheduling. The 12-bit 1 MSPS ADC can sample backlight temperature and supply rails, while the eight SERCOM interfaces drive SPI displays, I2C sensors, and UART peripherals simultaneously. The 1.71-3.6 V supply simplifies integration with 3.3 V-only backlight drivers and 24 V industrial bus power rails, and the -40 °C to +125 °C temperature range supports cabinet installations at the warm edge of the enclosure. Place the MCU near the SPI display connector with a 4-layer stack-up and a continuous ground plane under the 64-pin TQFP for EMI robustness.
Recommended
USB-to-CAN-FD Bridge Gateway
The ATSAME51J18A-AFT is well suited as a USB-to-CAN-FD gateway for industrial PCs and edge controllers. Its USB 2.0 Full-Speed device port enumerates as a CDC-ACM or vendor-class device on the host side, while the two on-chip CAN-FD controllers push up to 5 Mbit/s over the bus with the extended 64-byte data field. The 256 KB Flash fits slcan/socketcan firmware plus a WebUSB configuration UI, and the Cryptographic Accelerator can secure firmware upgrades with AES-256. Use the SAME51's 32 kHz RTC for time-stamping CAN frames in IEC 61131-3 industrial networks, and buffer high-throughput bursts in the 128 KB SRAM before forwarding them over USB CDC.
Recommended
Building Automation Controller
The ATSAME51J18A-AFT powers building automation controllers that combine HVAC, lighting, and shading control in a single DIN-rail enclosure. The Cortex-M4F FPU executes fractional PID loops for damper/valve actuators with deterministic latency, while the two CAN-FD controllers carry BACnet MS/TP traffic or proprietary RS-485 framing through external transceivers. The integrated AES-256/SHA-256/TRNG accelerator secures commissioning tokens and OTA firmware against tampering. The 1.71-3.6 V supply tolerates PoE-derived 3.3 V rails and the -40 °C to +125 °C rating covers unheated mechanical rooms, while 51 GPIO exposes ample headroom for relay drivers, 0-10 V dimmers, and isolated digital inputs.
Recommended
Automotive Body Electronics Module
The ATSAME51J18A-AFT suits body electronics such as HVAC control units, seat controllers, and mirror adjusters where deterministic 120 MHz Cortex-M4F compute, 256 KB Flash, and CAN-FD bus connectivity are required in a 64-pin TQFP. The hardware AES-256/SHA-256 engine accelerates secure UDS services (0x27, 0x29) for OEM-level diagnostic authentication, and the SDHC controller logs driving events to removable media. Although the standard part is NOT AEC-Q100 qualified, the same die is offered as an automotive variant by Microchip; consult the latest PCN database for the -AZT/EK suffix ordering code. The -40 °C to +125 °C extended temperature grade supports under-dash mounting.
Recommended
Sensor Fusion and IoT Edge Node
The ATSAME51J18A-AFT acts as the application processor in IoT edge nodes that fuse IMU, pressure, and environmental data before forwarding to the cloud. The Cortex-M4F FPU executes sensor-fusion algorithms (Madgwick/Mahony) at 120 MHz while the SERCOM interfaces stream I2C/SPI sensor data through DMA, leaving the CPU headroom for application logic. The 12-bit 1 MSPS ADC samples analog channels such as battery voltage and thermistor dividers, and the integrated TRNG seeds TLS handshake keys for MQTT over Wi-Fi companion radios. With 128 KB SRAM the SAME51 buffers multi-sensor packets during radio sleep windows, and the 1.71-3.6 V supply operates from a single Li-ion cell via a buck-boost converter.
Recommended
Low-Power IoT Data Logger
The ATSAME51J18A-AFT is a strong fit for industrial data loggers that record slow-changing process variables onto SD cards or external flash. The on-chip SDHC controller plus SERCOM SPI extends to high-capacity SDXC cards (up to 32 GB with FAT32/exFAT firmware), and the RTC with 32.768 kHz crystal enables time-stamped logging across long deployment intervals. The 256 KB Flash accommodates a modular logging application plus a USB device stack for retrieval, while the AES-256 engine can sign log files for tamper-evident audits. Operating from 1.71-3.6 V with multiple Sleep modes (IDLE, STANDBY, OFF) the SAME51 can run from a small solar/battery pack for remote SCADA telemetry.
Recommended
Recommended Products Summary
Engineering reference data for ATSAME51J18A-AFT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAME51J18A-AF | ATSAME51J19A-AFT | ATSAME51J20A-AFT | ATSAMD51J18A-AUT | ATSAMD51J19A-AFT |
|---|---|---|---|---|---|---|
| Package | 64-TQFP (10x10 mm) | 64-TQFP (10x10 mm) - same | 64-TQFP (10x10 mm) - same | 64-TQFP (10x10 mm) - same | 64-TQFP (10x10 mm) - same | 64-TQFP (10x10 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Flash | 256 KB | 256 KB | 512 KB | 1 MB | 256 KB | 512 KB |
| SRAM | 128 KB | 128 KB | 128 KB | 256 KB | 128 KB | 128 KB |
| Maximum CPU Clock | 120 MHz | 120 MHz | 120 MHz | 120 MHz | 120 MHz | 120 MHz |
| CAN-FD Controllers | 2 | 2 | 2 | 2 | 0 (CAN 2.0B only) | 0 (CAN 2.0B only) |
| Crypto Accelerator | AES-256 / SHA-256 / TRNG | AES-256 / SHA-256 / TRNG | AES-256 / SHA-256 / TRNG | AES-256 / SHA-256 / TRNG | Not present | Not present |
| Operating Voltage | 1.71 V to 3.6 V | 1.71 V to 3.6 V | 1.71 V to 3.6 V | 1.71 V to 3.6 V | 1.71 V to 3.6 V | 1.71 V to 3.6 V |
| Approx. Price @ 1pc | USD 8.92 | USD 8.92 (similar) | USD ~9.50 | USD ~11.20 | USD ~7.50 | USD ~8.30 |
Key Differentiators
- Integrates two CAN-FD controllers and a hardware crypto accelerator in 64-pin TQFP (vs ATSAMD51J18A-AUT)
- Live-update dual-panel flash option at the SAME51 family tier (vs ATSAME51J18A-AF)
- Tape & Reel packaging for high-volume SMT assembly (vs ATSAME51J18A-AF)
- Extended temperature grade for industrial/automotive deployments (vs ATSAMD51J18A-AUT)
Design Notes
Decouple every VDD/VSS and VDDIO/VSS pair with a 100 nF X7R 0402 ceramic capacitor placed within 2 mm of the corresponding pin. Add a bulk 4.7 µF X5R capacitor at the VDDIN pin and a 1 µF X7R capacitor at the VDDCORE pin. The on-chip voltage regulators (VREGA/VREGB/VREGC) each need their own 1 µF X7R capacitor to the dedicated VSS pin to prevent analog/digital cross-talk. Estimated: assuming the SAME51 runs at 120 MHz with all peripherals enabled, peak transient current on VDDIO is ~80 mA per pin pair; a single shared 100 nF decoupling network is therefore insufficient.
At 120 MHz with all peripherals active, the ATSAME51J18A-AFT typically consumes ~70 mW from VDDIO/VDDIN, which is well within the 64-pin TQFP thermal envelope of approximately 80 °C/W (theta_JA on a standard 2S2P JEDEC test board). No external heatsink is required for industrial HMI, sensor fusion, and CAN-FD gateway designs. However, in fully sealed enclosures at +85 °C ambient with the USB PHY continuously active, confirm via direct measurement that the case temperature remains below +105 °C to preserve Flash data retention.
Use a 4-layer PCB with continuous ground plane beneath the TQFP footprint, and route the 32.768 kHz crystal traces (XIN32/XOUT32) within 5 mm of the MCU using a guard ring tied to analog ground. Place the 32.768 kHz crystal load capacitors (CLOAD1/CLOAD2) so their common node ties to the MCU's analog ground rather than digital ground to minimize RTC jitter. For USB applications, the 90 Ω differential pair on D+/D- must be 50 Ω single-ended to ground and length-matched to within 0.5 mm; route over a continuous ground plane and avoid vias on the differential pair.
Do NOT apply 5 V to any GPIO of the ATSAME51J18A-AFT. The maximum Vih is VDDIO + 0.3 V (3.6 V absolute maximum). Always include a bidirectional level shifter (TXS0108E or 74LVC8T245) when interfacing to 5 V peripherals. Forgetting the BOOTPROT fuse settings can leave the device unable to recover from a bad firmware update; configure NVMCTRL, BOOTPROT, and DSU fields in the fuse area during production programming. The ATSAME51 does NOT auto-detect 32 kHz crystal vs external reference; you must configure FUSES.OSC32KCTRL accordingly in Atmel START / MPLAB Harmony.
When the SAME51 drives an SPI display at 50 MHz or above, place a 33 Ω source-series resistor within 5 mm of the SAME51 SCK/MOSI pins to dampen the rising-edge overshoot from the capacitive display connector. For CAN-FD nodes above 2 Mbit/s, keep the CANH/CANL differential pair length-matched to within 0.25 mm and place a 100 nF Y-cap on the isolated side of the isolated CAN transceiver to bypass common-mode noise. Always terminate CAN with 120 Ω at each end of the bus, NOT at every node.
Compliance Information
RoHS and REACH compliant per Microchip product page; JEDEC J-STD-020 MSL3 floor life applies. The ATSAME51J18A-AFT is NOT AEC-Q100 qualified; for AEC-Q100 designs consult Microchip's SAME51 automotive variants.
