ATSAMD21J17D-MFT - 48MHz Cortex-M0+ MCU, 128KB Flash | Microchip
MPN: ATSAMD21J17D-MFT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.2 | $5.20 |
| 10 | $4.85 | $48.50 |
| 100 | $4.3 | $430.00 |
| 500 | $3.85 | $1,925.00 |
| 1,000 | $3.5 | $3,500.00 |
ATSAMD21J17D-MFT Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, memory, and programmable peripherals on one silicon die, forming the heart of nearly every embedded electronic product. Modern 32-bit MCUs based on the ARM Cortex-M architecture dominate the embedded market because they balance deterministic real-time performance, ultra-low power consumption, and a vast software ecosystem. The SAM D21 family specifically targets low-power applications through Microchip's proprietary SleepWalking peripheral operation, which lets timers, SERCOM, and ADC continue sampling while the CPU remains asleep.
Key features of the ATSAMD21J17D-MFT include 128KB flash with 4KB read-while-write (RWW) section, six SERCOM communication interfaces configurable as UART/SPI/I2C, a full-speed USB 2.0 device interface, two I2S interfaces, one 12-bit ADC with up to 20 channels, one 10-bit DAC, and up to 52 GPIO pins. It supports 1.62V to 3.63V supply voltage with on-chip DC-DC converter for low-power operation, and provides comprehensive clock management including 48 MHz Digital Frequency Locked Loop (DFLL48M) and 32.768 kHz oscillator.
The architecture combines an ARM Cortex-M0+ core (Thumb-2 instruction set, single-cycle I/O port access, hardware multiplier) with Microchip's Event System for zero-latency inter-peripheral signaling and a Peripheral Touch Controller (PTC) supporting capacitive touch sensing. The Memory Protection Unit (MPU) and on-chip FPU emulation library enable deterministic interrupt response and floating-point arithmetic in C.
Typical applications include home automation and smart lighting controllers, industrial sensor hubs and metering, USB HID peripherals such as keyboards and mice, wearable fitness devices, consumer toys with capacitive touch UIs, and IoT edge nodes. The Functional Safety (FuSa) build option also suits medical and safety-critical control loops.
When designing with this device, choose an external 32.768 kHz crystal for RTC accuracy and provide adequate decoupling on both VDD and VDDIO; the on-chip DC-DC requires an external inductor and capacitor network per the datasheet reference schematic. PCB layout should keep the QFN exposed pad soldered to a continuous ground copper pour for thermal dissipation.
Drop-in alternatives for ATSAMD21J17D-MFT — 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 ATSAMD21J17D-MFT (same form factor and footprint) — differing in Operating Temperature, Package, ADC, USB, DAC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAMD21J15B-MFT
✅ Drop-In✓ In Stock
$2.39 / Unit
View Datasheet →ATSAMD21J17A-MU
✅ Drop-In✓ In Stock
$2.68 / Unit
View Datasheet →ATSAMD21J17A-MFT
✅ Drop-In📋 Reference alternative (not in catalog)
ATSAMD21J17D-AUT
✅ Drop-In✓ In Stock
$2.05 / Unit
View Datasheet →ATSAMD21G18A-MF
✅ Drop-In✓ In Stock
$2.65 / Unit
View Datasheet →ATSAMD21E17A-MFT
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →ATSAMD21J17D-MFT Maximum Ratings & Electrical Characteristics
| Core Architecture | ARM Cortex-M0+ (32-bit) |
| Maximum CPU Frequency | 48 MHz |
| Flash Memory | 128 KB (with 4 KB RWW section) |
| SRAM | 16 KB |
| Package | 64-pin QFN (9x9 mm) |
| Supply Voltage Range | 1.62 V to 3.63 V |
| Operating Temperature | -40C to +125C (extended) |
| USB Interface | USB 2.0 Full-Speed Device |
| SERCOM Interfaces | 6 (configurable UART/SPI/I2C) |
| ADC | 12-bit, up to 350 ksps, up to 20 channels |
| DAC | 10-bit |
| GPIO Pins | Up to 52 |
| On-chip DC-DC Converter | Yes |
| Peripheral Touch Controller | Yes |
| Event System | Yes (inter-peripheral signaling) |
| MPU | Yes (Memory Protection Unit) |
| Functional Safety (FuSa) | Yes (per datasheet family designation) |
| RoHS Status | Compliant |
ATSAMD21J17D-MFT Pin Configuration
| Pin 1 | PA02 — General-purpose I/O, analog input |
| Pin 2 | PA03 — General-purpose I/O, analog input |
| Pin 3 | VSS — Ground |
| Pin 4 | VDD — Digital supply voltage |
| Pin 5 | PA04 — General-purpose I/O, SERCOM |
| Pin 6 | PA05 — General-purpose I/O, SERCOM |
| Pin 7 | PA06 — General-purpose I/O, SERCOM, USB |
| Pin 8 | PA07 — General-purpose I/O, SERCOM, USB |
| Pin 9 | PA08 — General-purpose I/O, SERCOM, I2S |
| Pin 10 | PA09 — General-purpose I/O, SERCOM, I2S |
| Pin 11 | PA10 — General-purpose I/O, SERCOM, I2S |
| Pin 12 | PA11 — General-purpose I/O, SERCOM, I2S |
| Pin 13 | VDDIO — I/O supply voltage |
| Pin 14 | VSS — Ground |
| Pin 15 | PA12 — General-purpose I/O |
| Pin 16 | PA13 — General-purpose I/O |
| Pin 17 | PA14 — General-purpose I/O |
| Pin 18 | PA15 — General-purpose I/O |
| Pin 19 | PA16 — General-purpose I/O, SERCOM |
| Pin 20 | PA17 — General-purpose I/O, SERCOM |
| Pin 21 | PA18 — General-purpose I/O, SERCOM |
| Pin 22 | PA19 — General-purpose I/O, SERCOM |
| Pin 23 | PA20 — General-purpose I/O, SERCOM |
| Pin 24 | PA21 — General-purpose I/O, SERCOM |
| Pin 25 | PA22 — General-purpose I/O, SERCOM |
| Pin 26 | PA23 — General-purpose I/O, SERCOM |
| Pin 27 | PA24 — General-purpose I/O, SERCOM |
| Pin 28 | PA25 — General-purpose I/O, SERCOM |
| Pin 29 | VSS — Ground |
| Pin 30 | VDDIO — I/O supply voltage |
| Pin 31 | PA26 — General-purpose I/O |
| Pin 32 | PA27 — General-purpose I/O |
| Pin 33 | PA28 — General-purpose I/O |
| Pin 34 | PA29 — General-purpose I/O |
| Pin 35 | PA30 — General-purpose I/O, SWCLK |
| Pin 36 | PA31 — General-purpose I/O, SWDIO |
| Pin 37 | PB00 — General-purpose I/O |
| Pin 38 | PB01 — General-purpose I/O |
| Pin 39 | PB02 — General-purpose I/O, analog |
| Pin 40 | PB03 — General-purpose I/O, analog |
| Pin 41 | PB04 — General-purpose I/O, analog |
| Pin 42 | PB05 — General-purpose I/O, analog |
| Pin 43 | PB06 — General-purpose I/O, SERCOM |
| Pin 44 | PB07 — General-purpose I/O, SERCOM |
| Pin 45 | PB08 — General-purpose I/O, SERCOM, I2S |
| Pin 46 | PB09 — General-purpose I/O, SERCOM, I2S |
| Pin 47 | PB10 — General-purpose I/O, SERCOM, I2S |
| Pin 48 | PB11 — General-purpose I/O, SERCOM, I2S |
| Pin 49 | VSS — Ground |
| Pin 50 | VDD — Digital supply voltage |
| Pin 51 | PB12 — General-purpose I/O, SERCOM |
| Pin 52 | PB13 — General-purpose I/O, SERCOM |
| Pin 53 | PB14 — General-purpose I/O, SERCOM |
| Pin 54 | PB15 — General-purpose I/O, SERCOM |
| Pin 55 | PB16 — General-purpose I/O, SERCOM |
| Pin 56 | PB17 — General-purpose I/O, SERCOM |
| Pin 58 | PB18 — General-purpose I/O |
| Pin 59 | PB19 — General-purpose I/O |
| Pin 60 | PB20 — General-purpose I/O |
| Pin 61 | PB21 — General-purpose I/O |
| Pin 62 | PB22 — General-purpose I/O |
| Pin 63 | PB23 — General-purpose I/O |
| Pin 64 | VSS — Ground (exposed pad) |
Typical Applications
ATSAMD21J17D-MFT is suitable for 6 applications: Home Automation Controllers, USB HID Peripherals, Industrial Sensor Hubs, Wearables and Fitness Bands, Smart Metering and Energy Monitoring, Consumer Electronics with Touch UI.
Home Automation Controllers
The ATSAMD21J17D-MFT's 48 MHz Cortex-M0+ core, six configurable SERCOM interfaces, and integrated USB 2.0 Full-Speed device make it a strong fit for home automation gateway nodes and smart-bridge controllers. Its 128 KB flash comfortably runs Z-Wave/Zigbee/BLE coexistence logic alongside an MQTT stack and OTA firmware updater, while the 4 KB RWW section lets designers swap application firmware in the field without bricking the device. The on-chip Peripheral Touch Controller enables capacitive touch wall-switch UIs without an external touch IC, reducing BOM cost and PCB area in mass-market white goods and connected-lighting products.
Recommended
USB HID Peripherals
The integrated USB 2.0 Full-Speed device port on the ATSAMD21J17D-MFT removes the need for an external USB controller, enabling compact keyboard, mouse, gaming peripheral, and custom HID designs. The 48 MHz core handles USB polling and HID report generation with substantial headroom for debounce, macro logic, and RGB lighting control via the Event System. Extended temperature range (-40C to +125C) and 128 KB flash accommodate large keymap firmware plus wireless receiver stacks when paired with an SPI-radio companion IC.
Recommended
Industrial Sensor Hubs
The ATSAMD21J17D-MFT's 12-bit ADC with 350 ksps sampling and 20 analog input channels supports multi-sensor aggregation in industrial environments - thermocouples, RTDs, 4-20 mA loops, and bridge pressure sensors can all be digitized through external signal conditioning into the on-chip ADC. The Cortex-M0+ deterministic interrupt latency plus Memory Protection Unit make it suitable for safety-related industrial control where predictable response to alarms and fault conditions is required. The Functional Safety (FuSa) family designation aids IEC 61508 SIL-rated designs.
Recommended
Wearables and Fitness Bands
The ATSAMD21J17D-MFT's on-chip DC-DC converter and SleepWalking peripherals enable the deep-sleep current performance required for wearables that must run days on small batteries. The 12-bit ADC captures heart-rate and SpO2 photodiode signals, while the integrated USB device interface simplifies charging-crate connectivity without an extra IC. Its 64-QFN package (9x9 mm) is well-suited to compact wrist-form-factor enclosures, and the PTC supports capacitive touch for swipe UIs on fitness bands.
Recommended
Smart Metering and Energy Monitoring
The ATSAMD21J17D-MFT combines 48 MHz processing, 128 KB flash for metering firmware stacks, and SERCOM-driven interfaces for communication with metering front-end ICs (AFE for CT/PT shunts). Its 12-bit ADC with hardware averaging is suitable for power-quality measurements including RMS voltage, current, and harmonic content. The wide 1.62V to 3.63V supply range supports battery-backed metering designs, while extended temperature range suits outdoor meter installations.
Recommended
Consumer Electronics with Touch UI
The ATSAMD21J17D-MFT integrates Microchip's Peripheral Touch Controller that supports up to 256 touch channels with hardware-driven scanning and water-tolerant firmware extensions. Designers can build capacitive slider, button, and proximity-sensor interfaces for kitchen appliances, audio equipment, and remote controls without an external touch IC. The Cortex-M0+ core plus Event System handles UI logic alongside audio processing, BLE control via SERCOM, and battery management on a single chip.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD21J17D-MFT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD21J15B-MFT | ATSAMD21J17A-MU | ATSAMD21J17A-MFT | ATSAMD21J17D-AUT |
|---|---|---|---|---|---|
| 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 |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core | ARM Cortex-M0+ @ 48 MHz | ARM Cortex-M0+ @ 48 MHz | ARM Cortex-M0+ @ 48 MHz | ARM Cortex-M0+ @ 48 MHz | ARM Cortex-M0+ @ 48 MHz |
| Flash Memory | 128 KB | 128 KB (same family) | 128 KB | 128 KB | 128 KB |
| SRAM | 16 KB | 16 KB | 16 KB | 16 KB | 16 KB |
| Operating Temperature | -40C to +125C | -40C to +125C | -40C to +85C | -40C to +125C | -40C to +125C (AEC-Q100) |
| USB Interface | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed |
| Automotive Grade (AEC-Q100) | No | No | No | No | Yes |
Key Differentiators
- Extended industrial temperature range -40C to +125C (vs ATSAMD21J17A-MU)
- Functional Safety (FuSa) family designation (vs ATSAMD21J15B-MFT)
- 128 KB flash with 4 KB RWW section enables live firmware updates (vs ATSAMD21G18A-MF)
Design Notes
The ATSAMD21J17D-MFT includes an on-chip DC-DC converter that supplies the core logic from the VDDIO rail, but it requires an external inductor (typically 4.7 uH) and a 1 uF decoupling capacitor on the DECOUPLING_OUT pin per the SAM D21 datasheet reference schematic. Omitting the inductor or using an undersized inductor causes core voltage droop under load and may trigger brown-out resets. Estimated: at 48 MHz active, the DC-DC saves roughly 30-40% versus an internal LDO topology.
Place VDD and VDDIO decoupling capacitors (100 nF + 1 uF) within 2 mm of their respective supply pins. The exposed thermal pad of the 64-QFN package must be soldered to a continuous ground copper pour with at least 16 thermal vias connecting to inner ground planes; this is required both for electrical grounding and for thermal dissipation. Estimated: thermal pad provides approximately 70% of the device's heat-dissipation path.
Keep the USB D+ and D- traces as a 90-ohm differential pair with matched length (within 150 mil) and routed over a continuous ground plane; place the 22-ohm series resistors within 4 mm of the MCU USB pins. Keep noisy switching traces (PWM, DC-DC) away from the 32.768 kHz crystal traces and route the crystal signals over a guarded ground pour to prevent jitter from disturbing the RTC.
Do not exceed the absolute maximum VDD of 3.63 V; transient spikes from external USB VBUS or inductive loads can destroy the part. Ensure the NVMCTRL is unlocked before attempting flash operations during debugging. When using the Event System, configure the channel mux after enabling the peripheral clock - otherwise events silently fail. The boot loader pin (BOOT) must be pulled high in normal operation to boot from flash; floating it may lock up the device.
Compliance Information
RoHS compliant per Microchip product page. Standard grade - not AEC-Q100 qualified; choose ATSAMD21J17D-AUT for AEC-Q100 automotive. Functional Safety (FuSa) family designation per datasheet family naming convention.
