ATSAMD21J15B-AUT - 32KB Flash 48MHz Cortex-M0+ MCU | Microchip
MPN: ATSAMD21J15B-AUT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.36 | $336.00 |
| 500 | $2.94 | $1,470.00 |
| 1,000 | $2.65 | $2,650.00 |
| 2,500 | $2.4 | $6,000.00 |
ATSAMD21J15B-AUT Overview
A microcontroller (MCU) is a single-chip computer that integrates a processor core, program and data memory, peripherals, and I/O. The Cortex-M0+ is ARM's smallest and most energy-efficient 32-bit core, designed for deterministic interrupt response and low active/quiescent power. Within Microchip's portfolio, the SAM D21 sits between the 8-bit AVR and the higher-end SAM D5x/E5x families, targeting IoT endpoints, human-machine interfaces (HMI), and sensor hubs.
Key features include 32 KB Flash and 4 KB SRAM on-chip, six SERCOM channels each configurable as UART/SPI/I2C, a 12-channel 12-bit 350 ksps ADC, a 10-bit 350 ksps DAC, Full-Speed USB 2.0 device with on-chip transceiver, and up to 52 GPIO with peripheral touch controller support. The device operates from 1.62 V to 3.63 V, drawing roughly 3 mA active at 48 MHz and down to a few microamps in STANDBY with RTC retention.
Architecturally, the SAMD21 uses a single-cycle IO bus and an AHB-Lite/APB bridge matrix, allowing direct peripheral-to-peripheral DMA via the Event System without CPU intervention. The integrated 48 MHz digital frequency-locked loop (DFLL) can be sourced from the internal 32 kHz oscillator or an external crystal, simplifying USB clocking on designs that lack an accurate high-frequency source. Hardware cryptographic accelerators are not present on this part (those are reserved for the SAML21/CryptoCell line).
Typical applications include low-power IoT sensor nodes, USB HID peripherals (keyboards, mice, custom devices), battery-powered consumer products, building automation HMI, and small industrial control boards. The AUT suffix denotes automotive grade (-40 C to +85 C operating range per the datasheet header) supplied in tape-and-reel.
When designing with this device, pay close attention to USB D+/D- trace impedance and the VBUS pin's 5 V tolerance. A 1 uF + 100 nF decoupling network is recommended near each supply pin, and unused SERCOM pads should be left floating or tri-stated to avoid leakage in deep-sleep modes. Firmware should configure the DFLL before invoking USB peripherals to avoid out-of-spec USB traffic.
This page synthesizes distributor pricing, drop-in alternatives across Microchip's SAM D21 family, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATSAMD21J15B-AUT — 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 ATSAMD21J15B-AUT (same form factor and footprint) — differing in USB, ADC, Package, DAC, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAMD21J16B-AU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.75 / Unit
View Datasheet →ATSAMD21J17A-AU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATSAMD21J18A-AU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.69 / Unit
View Datasheet →ATSAMD21J15B-AU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATSAMD21J16B-MU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.18 / Unit
View Datasheet →ATSAMD21J15B-AUT Maximum Ratings & Electrical Characteristics
| Core Architecture | ARM Cortex-M0+ (32-bit) |
| Maximum Clock Frequency | 48 MHz |
| Program Flash Memory | 32 KB (32K x 8) |
| SRAM | 4 KB |
| Operating Voltage Range | 1.62 V to 3.63 V |
| Supply Voltage (typical) | 3.3 V |
| Operating Temperature | -40 C to +85 C (AUT suffix) |
| Package | 64-pin TQFP (10 x 10 mm) |
| Mounting Type | Surface Mount |
| I/O Pins | Up to 52 GPIO |
| Communication Interfaces | 6x SERCOM (UART/SPI/I2C), USB 2.0 Full-Speed Device, I2S |
| ADC | 12-bit, up to 20 channels, 350 ksps |
| DAC | 10-bit, 1 channel, 350 ksps |
| Timers | TC x3 (16-bit), TCC x2 (24-bit) |
| USB | USB 2.0 Full-Speed Device with on-chip transceiver |
| Touch | Peripheral Touch Controller (PTC) |
| RoHS Status | Compliant (Green) |
| Delivery Form | Tape & Reel (AUT) |
ATSAMD21J15B-AUT 64-pin tqfp (10 x 10 mm) Pin Configuration Guide
Pin configuration for ATSAMD21J15B-AUT (64-pin tqfp (10 x 10 mm) package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for ATSAMD21J15B-AUT.
Refer to the datasheet for full pin configuration.
Typical Applications
ATSAMD21J15B-AUT is suitable for 6 applications: Low-Power IoT Sensor Node, USB HID Peripheral Device, Battery-Powered Consumer Product, Building Automation HMI, Small Industrial Control Board, Automotive Body Electronics Module.
Low-Power IoT Sensor Node
The ATSAMD21J15B-AUT fits low-power IoT sensor nodes because of its Cortex-M0+ core running at 48 MHz while drawing roughly 3 mA active, plus single-digit-microamp standby with RTC retention. The 32 KB Flash is sufficient for sensor drivers and a small wireless protocol stack (BLE via external module, LoRa, or sub-GHz transceiver). Six SERCOM channels let you run I2C sensors, SPI radio, and a UART debug console simultaneously without bit-banging. The on-chip 12-bit ADC with up to 20 channels handles multi-sensor analog inputs. Putting the MCU in STANDBY between samples and waking from the RTC or a peripheral interrupt yields coin-cell lifetimes of months.
Recommended
USB HID Peripheral Device
The ATSAMD21J15B-AUT integrates a USB 2.0 Full-Speed device with on-chip transceiver, removing the need for an external PHY and saving BOM cost in USB keyboards, mice, game controllers, and custom HID peripherals. The 48 MHz DFLL derived from the internal 32 kHz oscillator provides accurate USB clocking without a high-frequency crystal. The 32 KB Flash comfortably hosts the Microchip ASF USB stack plus HID report descriptors. The 64-pin TQFP exposes enough GPIO for full n-key rollover matrices, media keys, and RGB backlight PWM channels using the 16-bit TC peripherals.
Recommended
Battery-Powered Consumer Product
The ATSAMD21J15B-AUT is well matched to battery-powered consumer products such as fitness bands, e-readers, and remote controls because of its wide 1.62-3.63 V supply range supporting single-cell Li-ion or 2x AA chemistries without level shifters. The Cortex-M0+ core plus Event System allows sensor-fusion and display refresh with the CPU mostly asleep. The on-chip 10-bit DAC drives audio cues or LED dimming, while the 12-bit ADC reads battery voltage through a divider. Sleep current under 5 uA with RTC retention keeps quiescent draw negligible compared with self-discharge of alkaline cells.
Recommended
Building Automation HMI
In building automation HMI panels (thermostats, access keypads, room controllers), the ATSAMD21J15B-AUT provides ample GPIO for keypad scanning, LED drivers, and a serial interface to a higher-level controller. The Peripheral Touch Controller (PTC) supports capacitive touch buttons and sliders without external ICs, reducing BOM and improving ESD immunity. Its 48 MHz headroom drives segment LCDs through the integrated SLCD controller (where available on the J-line) or external SPI-driven displays. The -40 C to +85 C automotive-grade rating (AUT suffix) suits indoor installations and unconditioned spaces such as equipment closets.
Recommended
Small Industrial Control Board
The ATSAMD21J15B-AUT suits compact industrial boards such as sensor transmitters, stepper motor front-ends, and protocol bridges that need deterministic Cortex-M0+ performance with a wide operating voltage for 24 V bus tolerance through external regulation. The six SERCOM channels handle RS-485, CAN (via external transceiver), SPI IO, and I2C sensor networks concurrently. Hardware Event System routes ADC conversion-complete signals directly to a TC timer for jitter-free motor commutation without CPU intervention. Industrial temperature grade on the AUT variant supports -40 C to +85 C cabinet environments.
Recommended
Automotive Body Electronics Module
The ATSAMD21J15B-AUT carries the AUT suffix indicating the Microchip automotive grade qualification, making it appropriate for non-safety body-electronics modules such as interior lighting controllers, seat control keypads, mirror adjusters, and HVAC blend-door actuators. The Cortex-M0+ core and Event System deliver deterministic response to LIN or CAN messages with the CPU mostly in idle. The peripheral touch controller supports capacitive switch panels with inherent ESD robustness. The 64-pin TQFP provides ample GPIO for relays, H-bridge enable lines, and diagnostics while fitting behind dashboard panels.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD21J15B-AUT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD21J16B-AU | ATSAMD21J17A-AU | ATSAMD21J18A-AU | ATSAMD21J15B-AU | ATSAMD21J16B-MU |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | TQFP-64 (10x10 mm) | TQFP-64 (10x10 mm) - same | TQFP-64 (10x10 mm) - same | TQFP-64 (10x10 mm) - same | TQFP-64 (10x10 mm) - same | TQFP-64 (10x10 mm) - same |
| Core | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ |
| Max Clock Frequency | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| Flash Memory | 32 KB | 64 KB | 128 KB | 256 KB | 32 KB | 64 KB |
| SRAM | 4 KB | 8 KB | 16 KB | 32 KB | 4 KB | 8 KB |
| 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 | 1.62 V to 3.63 V |
| Operating Temperature | -40 C to +85 C (AUT automotive grade) | -40 C to +85 C (AU industrial grade) | -40 C to +85 C (AU industrial grade) | -40 C to +85 C (AU industrial grade) | -40 C to +85 C (AU industrial grade) | -40 C to +85 C (MU industrial grade) |
| Delivery Form | Tape & Reel (AUT) | Tray (AU) | Tray (AU) | Tray (AU) | Tray (AU) | Tray (MU) |
| USB 2.0 FS Device | Yes | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- Smallest Flash variant in SAM D21J TQFP-64 family (vs ATSAMD21J18A-AU)
- Automotive grade (AUT) qualification (vs ATSAMD21J15B-AU)
- Wide 1.62-3.63 V supply without level shifters (vs ATSAMD21J16B-MU)
Design Notes
Place a 1 uF X7R ceramic plus a 100 nF X7R ceramic decoupling capacitor as close as possible to every VDD pin and one bulk 4.7 uF near the regulator output. For USB applications add a 1 uF + 100 nF on VBUS and on the internal 3.3 V regulator output (VDDOUT). Decouple the analog supply AVDD separately with a ferrite bead from VDD if ADC performance matters. Estimated: with 6 active SERCOM and a 48 MHz core the supply ripple should be held under 30 mVpp for clean ADC readings.
Route the USB D+ and D- traces as a 90 ohm differential pair with no splits, keeping them short and away from switching nodes. Place the 48 MHz crystal (or resonator) within 5 mm of the XIN/XOUT pads with a grounded guard ring. The exposed pad on the TQFP-64 is the central thermal pad; tie it to the ground plane with at least 9 thermal vias to keep junction temperature below 100 C at full 48 MHz operation. Keep ADC traces away from SERCOM switching lines and add a ground pour under the analog section.
Configure the DFLL before enabling USB or high-speed SERCOM (above 8 MHz). The DFLL needs a reference clock from the internal 32 kHz oscillator (calibrated to within 3 percent) or an external crystal. Without proper DFLL lock, USB packets will fail USB-IF compliance and high-speed SPI peripherals will exhibit bit-period jitter. Estimated: DFLL lock time is roughly 200 ms at first power-on from cold start; firmware should poll INTFLAG.DFLLRDY before switching GCLK sources.
Do not leave unused GPIO floating - configure them as output low or input with internal pull enabled to avoid parasitic current draw in STANDBY (each floating input can leak 1-5 uA). The Peripheral Touch Controller requires firmware-driven calibration on every power-up; do not skip it or touch readings will drift. Estimated: a fully unconfigured SAMD21 with 10 floating GPIOs can draw 50 uA more in STANDBY than a properly initialized design. Also, do not enable the WDT in window mode unless firmware can guarantee the close window timing.
Compliance Information
AUT suffix indicates automotive-grade screening per Microchip product family page. RoHS and Green per Mouser and DigiKey listings. AEC-Q100 grade as automotive variant.
