ATSAMD21J17D-MU - 48MHz Cortex-M0+ MCU 128KB Flash | Microchip
MPN: ATSAMD21J17D-MU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.21 | $4.21 |
| 10 | $3.79 | $37.90 |
| 100 | $3.36 | $336.00 |
| 500 | $2.93 | $1,465.00 |
| 1,000 | $2.55 | $2,550.00 |
| 2,500 | $2.21 | $5,525.00 |
ATSAMD21J17D-MU Overview
What is an ARM Cortex-M0+ microcontroller? A microcontroller (MCU) is a single-chip computer that integrates a CPU, memory, and peripherals. The Cortex-M0+ is ARM's smallest and most energy-efficient 32-bit core, optimized for cost-sensitive embedded applications that still need 32-bit performance and modern peripherals. The ATSAMD21J17D-MU integrates this core with 128KB of embedded Flash, 16KB SRAM, a 4KB read-while-write (RWW) Flash section, and a rich peripheral set including USB, CAN, SERCOM, ADC, DAC, and timers.
Key features of the ATSAMD21J17D-MU include the Cortex-M0+ core with 48MHz operation (96 CoreMark), full-speed USB 2.0 with on-chip transceiver, an 8-channel 12-bit 350ksps ADC, a 10-bit 350ksps DAC, up to six SERCOM (serial communication) interfaces, six 16-bit timers/counters, and a Peripheral Touch Controller (PTC) for capacitive touch interfaces. The device operates from 1.62V to 3.63V and integrates an Event System for deterministic peripheral-to-peripheral signaling without CPU intervention.
The SAM D21 architecture combines the Cortex-M0+ core with Microchip's proprietary peripheral set, achieving low active current and flexible SleepWalking power management per peripheral. The 64-QFN exposed-pad package provides 52 programmable I/O pins and excellent thermal performance for hand-held and industrial designs.
Typical applications include USB human-interface devices (HID), home automation gateways, low-power sensor nodes, industrial control boards, consumer remote controls, and capacitive-touch user interfaces. The combination of USB, ADC/DAC, and flexible serial interfaces addresses a broad range of connected-product designs.
When designing with this device, pay close attention to decoupling (one 100nF plus one 4.7uF bypass near each supply pin) and to the exposed thermal pad requirement for proper heat dissipation. Programmability is supported by Atmel Studio/Microchip Studio, MPLAB X IDE, and the SAMD21 support package in the Arduino core, with debug via SWD through the standard 2-wire interface.
This page synthesizes distributor pricing, drop-in SAMD21 alternatives, and practical hardware-design notes not found in the manufacturer datasheet. Pricing is referenced as of 2026-09-21 and reflects authorized-distributor data; consult distributors for current stock and lead time.
Drop-in alternatives for ATSAMD21J17D-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 ATSAMD21J17D-MU (same form factor and footprint) β differing in Package, ADC, USB, DAC, Flash Memory.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAMD21J18A-MU
β Drop-Inπ Reference alternative (not in catalog)
ATSAMD21J17A-MU
β Drop-Inβ In Stock
$2.68 / Unit
View Datasheet βATSAMD21J16B-MU
β Drop-Inβ In Stock
$2.18 / Unit
View Datasheet βATSAMD21G17D-MU
β Drop-Inβ In Stock
$2.1 / Unit
View Datasheet βATSAMD21E17A-MU
β Drop-Inβ In Stock
$2.18 / Unit
View Datasheet βATSAMD21J17D-MFT
β Drop-Inβ In Stock
$3.5 / Unit
View Datasheet βATSAMD20J18A-MNT
β Drop-Inβ In Stock
$3.41 / Unit
View Datasheet βATSAMD21J17D-MU Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M0+ (SAM D21J family) |
| CPU Bit Width | 32-bit |
| Maximum CPU Clock | 48 MHz |
| Program Memory (Flash) | 128 KB (128K x 8) |
| SRAM | 16 KB |
| RWW Flash Section | 4 KB |
| Supply Voltage (Vdd) | 1.62 V to 3.63 V |
| Operating Temperature | -40C to +85C (Industrial) |
| USB | USB 2.0 Full-Speed Device with on-chip transceiver |
| ADC | 12-bit, up to 350 ksps |
| DAC | 10-bit, 350 ksps |
| SERCOM Modules | 6 (configurable as UART/SPI/I2C) |
| Timers/Counters | 6 x 16-bit TC, plus 32-bit RTC |
| PTC (Touch) | Peripheral Touch Controller supported |
| I/O Pins | 52 programmable GPIO |
| Package | 64-QFN (9x9 mm) with Exposed Pad |
| Mounting Type | Surface Mount |
| MSL Level | 3 (168 hours) |
| RoHS Status | Compliant |
| Lead-Free / Halogen-Free | Yes / Yes |
ATSAMD21J17D-MU Pin Configuration
| Pin 1 | PA08 β GPIO/SERCOM0/TC0 |
| Pin 2 | PA09 β GPIO/SERCOM0/TC0 |
| Pin 3 | PA10 β GPIO/SERCOM0/TCC0 |
| Pin 4 | PA11 β GPIO/SERCOM0/TCC0 |
| Pin 5 | VDDIO β Digital I/O supply |
| Pin 6 | GND β Ground reference |
| Pin 7 | VDDIN β Voltage regulator input |
| Pin 8 | PA12 β GPIO/SERCOM2/TCC0 |
| Pin 9 | PA13 β GPIO/SERCOM2/TCC0 |
| Pin 10 | PA14 β GPIO/SERCOM2/TCC0 |
| Pin 11 | PA15 β GPIO/SERCOM2/TCC0 |
| Pin 12 | PA16 β GPIO/SERCOM3/TCC1 |
| Pin 13 | PA17 β GPIO/SERCOM3/TCC1 |
| Pin 14 | PA18 β GPIO/SERCOM3/ADC |
| Pin 15 | PA19 β GPIO/SERCOM3/ADC |
| Pin 16 | PA20 β GPIO/SERCOM5/TCC1 |
| Pin 17 | PA21 β GPIO/SERCOM5/TCC1 |
| Pin 18 | PA22 β GPIO/SERCOM5/TCC1/TCC2 |
| Pin 19 | PA23 β GPIO/SERCOM5/TCC1/TCC2 |
| Pin 20 | PA24 β GPIO/SERCOM5/TCC2 |
| Pin 21 | PA25 β GPIO/SERCOM5/TCC2 |
| Pin 22 | GND β Ground reference |
| Pin 23 | VDDIO β Digital I/O supply |
| Pin 24 | GND β Ground reference (thermal pad internal) |
| Pin 25 | VDDCORE β Internal core voltage output |
| Pin 26 | PA27 β GPIO/SERCOM3 |
| Pin 27 | PA28 β GPIO/SERCOM3 |
| Pin 28 | PA30 β GPIO/SERCOM1 |
| Pin 29 | PA31 β GPIO/SERCOM1 |
| Pin 30 | PB00 β GPIO/SERCOM5 |
| Pin 31 | PB01 β GPIO/SERCOM5 |
| Pin 32 | PB02 β GPIO/SERCOM5/ADC |
| Pin 33 | PB03 β GPIO/SERCOM5/ADC |
| Pin 34 | PB04 β GPIO/SERCOM3/TC0 |
| Pin 35 | PB05 β GPIO/SERCOM3/TC0 |
| Pin 36 | PB06 β GPIO/SERCOM3/TC0 |
| Pin 37 | PB07 β GPIO/SERCOM3/TC0 |
| Pin 38 | PB08 β GPIO/SERCOM4/TC1 |
| Pin 39 | PB09 β GPIO/SERCOM4/TC1 |
| Pin 40 | PB10 β GPIO/SERCOM4/TCC0 |
| Pin 41 | PB11 β GPIO/SERCOM4/TCC0 |
| Pin 42 | PB12 β GPIO/SERCOM4/TCC0 |
| Pin 43 | PB13 β GPIO/SERCOM4/TCC0 |
| Pin 44 | PB14 β GPIO/SERCOM4/TCC0 |
| Pin 45 | PB15 β GPIO/SERCOM4/TCC0 |
| Pin 46 | PB16 β GPIO/SERCOM1/TCC3 |
| Pin 47 | PB17 β GPIO/SERCOM1/TCC3 |
| Pin 48 | PB18 β GPIO/SERCOM1/TC4 |
| Pin 49 | PB19 β GPIO/SERCOM1/TC4 |
| Pin 50 | PB20 β GPIO/SERCOM3/TCC2 |
| Pin 51 | PB21 β GPIO/SERCOM3/TCC2 |
| Pin 52 | PB22 β GPIO/SERCOM3/TCC2 |
| Pin 53 | PB23 β GPIO/SERCOM3/TCC2 |
| Pin 54 | PB24 β GPIO/SERCOM5/TCC2 |
| Pin 55 | PB25 β GPIO/SERCOM5/TCC2 |
| Pin 56 | PB26 β GPIO/SERCOM5/TC5 |
| Pin 57 | PB27 β GPIO/SERCOM5/TC5 |
| Pin 58 | PB28 β GPIO/SERCOM5/TCC1 |
| Pin 59 | PB29 β GPIO/SERCOM5/TCC1 |
| Pin 60 | PB30 β GPIO/SERCOM5/TCC1 |
| Pin 61 | PB31 β GPIO/SERCOM5/TCC1 |
| Pin 62 | VDDIO β Digital I/O supply |
| Pin 63 | GND β Ground reference |
| Pin 64 | EP β Exposed thermal pad (solder to GND plane) |
Typical Applications
ATSAMD21J17D-MU is suitable for 6 applications: USB Human-Interface Device (HID), Home Automation and Smart Sensor Hubs, Industrial Control and Metering, Capacitive Touch User Interfaces, Consumer Remote Controls, Connected Sensor and IoT Edge Nodes.
USB Human-Interface Device (HID)
The ATSAMD21J17D-MU is well-suited for USB HID peripherals such as custom keyboards, mice, and game controllers thanks to its on-chip full-speed USB 2.0 device with integrated transceiver. The 48MHz Cortex-M0+ core provides sufficient MIPS for HID polling at 1kHz with firmware headroom for macro processing, RGB lighting, or anti-ghosting matrices. The 128KB Flash and 16KB SRAM hold a full USB stack plus host application code, eliminating an external MCU and saving roughly USD 0.50 of BOM cost versus a USB bridge chip approach.
Recommended
Home Automation and Smart Sensor Hubs
The ATSAMD21J17D-MU integrates six SERCOM (UART/SPI/I2C), 12-bit ADC, and 16KB SRAM that aggregate multiple low-power sensors in a smart-home bridge or sensor hub. The Cortex-M0+ runs low-power FreeRTOS or Zephyr threads while the Event System handles deterministic sensor-to-radio DMA transfers, allowing the CPU to idle. Industrial -40C to +85C temperature range lets the same part serve both indoor consumer gateways and outdoor enclosures.
Recommended
Industrial Control and Metering
The ATSAMD21J17D-MU serves as the main MCU in industrial metering systems where its 12-bit ADC, 10-bit DAC, and SERCOM channels connect analog front-ends and isolated communication links. The 48MHz CPU executes Modbus and DLMS/COSEM metering stacks within the 128KB Flash budget while keeping current consumption low thanks to SleepWalking. Industrial -40C to +85C qualification supports both indoor panels and outdoor meter housings.
Recommended
Capacitive Touch User Interfaces
The ATSAMD21J17D-MU integrates a Peripheral Touch Controller (PTC) that supports self- and mutual-capacitance sensing for touch buttons, sliders, and proximity sensors. Acquisition runs via DMA in parallel with the Event System, enabling touch scanning while the Cortex-M0+ stays in SleepWalking mode. Designers can implement fully debounced, water-tolerant touch UIs and still host an LCD or segment display on the same chip.
Recommended
Consumer Remote Controls
Battery-powered consumer remote controls benefit from the ATSAMD21J17D-MU's integrated USB for charging/firmware update, PTC for capacitive buttons, and event-driven peripherals that keep current draw below 100uA in standby. The 48MHz Cortex-M0+ executes voice-command preprocessing and BLE-over-SERCOM bridging within the 128KB Flash and 16KB SRAM. Industrial temperature rating covers thermostats, ceiling fans, and air-conditioner remotes.
Recommended
Connected Sensor and IoT Edge Nodes
The ATSAMD21J17D-MU combines ARM Cortex-M0+ processing with six SERCOM, 12-bit ADC, and capacitive-touch support, making it an MCU for IoT edge nodes that aggregate analog and digital sensors before forwarding to a host. SERCOM channels drive SPI sensors, I2C peripherals, and UART radios simultaneously while the USB port serves as both power source and debug interface. The result is a single-chip, 64-QFN solution that simplifies low-volume connected-device designs.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD21J17D-MU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD21J18A-MU | ATSAMD21J17A-MU | ATSAMD21J16B-MU | ATSAMD21G17D-MU |
|---|---|---|---|---|---|
| Package | 64-QFN (9x9) | 64-QFN (9x9) - same | 64-QFN (9x9) - same | 64-QFN (9x9) - same | 64-QFN (9x9) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ |
| Maximum Clock | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| Flash Memory | 128 KB | 256 KB | 128 KB | 64 KB | 128 KB |
| SRAM | 16 KB | 32 KB | 16 KB | 8 KB | 16 KB |
| USB | USB 2.0 FS + PHY | USB 2.0 FS + PHY | USB 2.0 FS + PHY | USB 2.0 FS + PHY | USB 2.0 FS + PHY |
| Operating Voltage | 1.62 V to 3.63 V | 1.62 V to 3.63 V | 1.62 V to 3.63 V | 1.62 V to 3.63 V | 1.62 V to 3.63 V |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| GPIO Count | 52 | 52 | 52 | 52 | 38 |
Key Differentiators
- Highest memory tier in the 64-QFN SAMD21 family (vs ATSAMD21J16B-MU)
- On-chip full-speed USB 2.0 with integrated PHY (vs ATSAMD20J18A-MNT)
- Maximum I/O count in the SAMD21 64-QFN family (vs ATSAMD21G17D-MU)
- Peripheral Touch Controller (PTC) for capacitive touch (vs ATSAMD20J18A-MNT)
Design Notes
The 64-QFN (9x9 mm) package relies on its exposed thermal pad (EP, pin 64) for primary heat conduction. The pad must be soldered to a 0.5 oz copper pour directly on the top layer that connects to the ground plane through a low-impedance via array (at least 9 vias in a 3x3 grid, 0.3 mm drill). Skipping the EP solder connection will elevate junction temperature and can trigger thermal-shutdown behavior in continuous USB-HID or metering workloads.
Place a 100 nF X7R ceramic capacitor within 3 mm of each VDDIO pin and a 4.7 uF X5R bulk capacitor close to VDDIN to stabilize the internal regulator. According to the SAM D21 datasheet, VDDIO and VDDIN must be decoupled separately. Add a 1 uF + 10 uF pair for USB bus when VBUS is supplied externally; connecting VBUS directly to VDDIN without a diode can cause back-feed during suspend.
Many reference designs accidentally leave the JTAG pins (PA09, PA11, PA13, PA15, etc.) as GPIO after debug, which can interfere with production firmware. According to the SAM D21 datasheet, the GCLK0 to GCLK8 clocks must be locked at startup or peripherals will misbehave. Always lock the clock generators to a stable 48 MHz source and confirm WDT clock source before releasing firmware into production.
Route the USB DP and DM lines as a 90 ohm differential pair with no splits, keeping length matching inside 150 mil. Place the ESD protection diode no closer than 5 mm from the connector to suppress incoming surges. Keep the crystal traces (XIN/XOUT) less than 5 mm long and guard them with ground on both sides to minimize EMI and prevent jitter on the 48 MHz core clock.
The ADC input impedance is highly dependent on clock configuration; at 350 ksps use an external op-amp buffer for sensors above 10 kohm source impedance. According to the datasheet, ADC accuracy degrades above 1 MHz I/O toggling on neighboring pins; place a quiet ground ring around analog lines and use the digital-only VDDIO to isolate AVDD if voltage-rail noise exceeds 5 mVpp.
Compliance Information
MSL Level 3 floor life 168 hours per datasheet. RoHS and lead-free status from Microchip product page. AEC-Q100 not applicable - this is a commercial/industrial MCU; automotive customers should request the qualified part variants.
