ATSAML21-XPRO-B - SAM L21 Xplained Pro Evaluation Kit | Microchip
MPN: ATSAML21-XPRO-B ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $124.65 | $124.65 |
| 5 | $119.5 | $597.50 |
| 10 | $115.2 | $1,152.00 |
| 25 | $109.8 | $2,745.00 |
| 100 | $101.92 | $10,192.00 |
ATSAML21-XPRO-B Overview
A development board (also called an evaluation board or starter kit) is a printed-circuit assembly that combines a target microcontroller or processor with the minimum circuitry needed to demonstrate and program the part, including voltage regulators, clock sources, programming/debug interfaces, and standardised expansion headers. Development boards sit within the broader hierarchy of evaluation platforms -> prototyping platforms -> embedded design tools, allowing engineers to validate firmware, measure power consumption, and prototype interfaces before committing to a custom PCB layout. The Xplained Pro form factor standardises extension-board compatibility across the entire SAM and PIC32 family, simplifying peripheral expansion through MikroElektronika Click boards, weather sensors, and other Xplained Pro extensions.
Key features of the ATSAML21-XPRO-B include the ATSAML21J18B MCU with 256 KB Flash, 32 KB SRAM, and a Cortex-M0+ core running up to 48 MHz reaching 2.46 CoreMark/MHz. The board exposes the SAM L21 ultra-low-power peripherals through the standard Xplained Pro headers, supports SleepWalking peripherals and event system, and integrates an on-board 32.768 kHz crystal for RTC operation. The integrated EDBG provides full programming and debug via USB, eliminating the need for an external programmer.
The ATSAML21-X18B silicon itself is built on a low-power process and offers 6 SERCOM (serial communication) interfaces configurable as UART/SPI/I2C, a 12-bit ADC, 10-bit DAC, and a segmented LCD controller. Power analysis is supported through Atmel Data Visualizer or Microchip Data Visualizer, allowing real-time current profiling of the target MCU down to nanoamp resolution when paired with a Power Debugger accessory.
Typical applications for this evaluation kit include low-power IoT sensor nodes, battery-powered wearable devices, energy-harvesting designs, home automation endpoints, and industrial wireless sensor networks. Engineers typically use this platform to validate SleepWalking-based firmware, benchmark ultra-low-power RTC wake cycles, and prototype LoRa or BLE sensor nodes that depend on the SAM L21's sub-microamp sleep current.
When developing with the ATSAML21-XPRO-B, ensure that the target MCU is powered from the on-board 3.3 V regulator when the USB cable is connected. For accurate power measurements, disconnect the EDBG power rail using the relevant current-measurement jumper so the on-board debugger does not skew nanoamp-level consumption readings.
This page synthesises distributor pricing, drop-in Xplained Pro alternatives from the same product family, and practical development notes not found in the manufacturer user guide.
Drop-in alternatives for ATSAML21-XPRO-B — 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 ATSAML21-XPRO-B (same form factor and footprint) — differing in Product Type, Target MCU, RoHS Status, Debug Interface, Form Factor.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAML22-XPRO-B
✅ Drop-In✓ In Stock
$75.5 / Unit
View Datasheet →ATSAML21-XPRO
✅ Drop-In✓ In Stock
$66.75 / Unit
View Datasheet →ATSAMHA1G16A-XPRO
✅ Drop-In✓ In Stock
$73.4 / Unit
View Datasheet →ATSAMHA1E16A-XPRO
✅ Drop-In✓ In Stock
$79 / Unit
View Datasheet →ATSAMG55-XPRO
✅ Drop-In✓ In Stock
$40.25 / Unit
View Datasheet →ATSAML21-XPRO-B Specifications (manufacturer-published)
| Product Type | Evaluation / Development Board |
| Series | SAM L Xplained Pro |
| Target MCU | ATSAML21J18B |
| MCU Core | ARM Cortex-M0+ 32-bit |
| Maximum Clock Frequency | 48 MHz |
| CoreMark/MHz | 2.46 |
| Flash Memory (on-board MCU) | 256 KB |
| SRAM (on-board MCU) | 32 KB |
| Operating Voltage | 3.3 V |
| Debug Interface | Embedded Debugger (EDBG) over USB |
| Expansion Interface | 3x Xplained Pro extension headers |
| Crystal | 32.768 kHz RTC crystal (on-board) |
| Connectivity | USB Micro-B, 3 Xplained Pro headers |
| Form Factor | Xplained Pro |
| Supported IDE | MPLAB X IDE, Microchip Studio, MPLAB Harmony 3 |
| Compliance | RoHS |
ATSAML21-XPRO-B Interfaces & Connectors
No manufacturer-published interface list is available for ATSAML21-XPRO-B. Refer to the manufacturer documentation for connector and header details.
Refer to the manufacturer documentation for the full expansion header pinout and connector pin numbering.
Typical Applications
ATSAML21-XPRO-B is suitable for 6 applications: Ultra-Low-Power IoT Sensor Node Prototyping, Battery-Powered Wearable Device Evaluation, Home Automation Endpoint Development, Industrial Wireless Sensor Networks, Energy-Harvesting Proof-of-Concept Designs, Medical and Health Monitoring Device Prototyping.
Ultra-Low-Power IoT Sensor Node Prototyping
The ATSAML21-XPRO-B evaluation kit provides an ideal starting point for ultra-low-power IoT sensor node prototypes because the on-board ATSAML21J18B integrates SleepWalking peripherals, an event system, and a segmented LCD controller. Engineers can profile SleepWalking wake cycles, measure nanoamp-level RTC sleep current with the Power Debugger accessory, and validate firmware that minimises active duty cycle. The kit's three Xplained Pro headers accept Click boards and wireless extensions, making it well-suited for prototyping LoRaWAN, BLE, or sub-GHz sensor nodes where months-to-years of battery life depend on the SAM L21's sub-microamp deep-sleep modes.
Recommended
Battery-Powered Wearable Device Evaluation
Wearables demand sub-100 µA average current draw while still supporting Bluetooth, display updates, and sensor fusion. The ATSAML21-XPRO-B exposes the SAM L21's full peripheral set (six SERCOM, 12-bit ADC, 10-bit DAC, segmented LCD controller) through Xplained Pro headers, allowing engineers to prototype wearables that pair the SAM L21 with an external BLE module. Real-time power visualisation through Atmel/Microchip Data Visualizer helps quantify wake/sleep current budgets and verify that firmware achieves the multi-week battery life required by fitness bands and smart watches.
Recommended
Home Automation Endpoint Development
The ATSAML21-XPRO-B serves as a development platform for home automation endpoints such as smart thermostats, occupancy sensors, and battery-powered door/window contacts. Its Cortex-M0+ core delivers 2.46 CoreMark/MHz at 48 MHz, sufficient for Zigbee or BLE stack execution while leaving the MCU in deep sleep between events. The kit's on-board EDBG eliminates the need for external programmers, accelerating firmware iteration during the proof-of-concept phase, and the standard Xplained Pro headers accept MikroElektronika Click boards for HVAC sensors, relays, and displays.
Recommended
Industrial Wireless Sensor Networks
Industrial WSN nodes require long battery life, robust peripherals, and the ability to communicate over sub-GHz radios or LoRa. The ATSAML21-XPRO-B provides a representative platform for benchmarking SAM L21 firmware against the real industrial protocol stack, including time-synchronised wake cycles, event-driven sensor reads, and over-the-air firmware updates. The board's Cortex-M0+ core and 256 KB Flash can host lightweight LoRaWAN or Wireless M-Bus stacks while the SAM L21's RTC and SleepWalking reduce idle consumption to nanoamp levels.
Recommended
Energy-Harvesting Proof-of-Concept Designs
Energy-harvesting designs require the MCU to start from microvolt-level reservoir voltages and operate at sub-microamp currents. The ATSAML21-XPRO-B integrates the SAM L21, which is specifically designed for energy-harvesting applications thanks to its ultra-low-power RTC, event system, and SleepWalking peripherals. Engineers can prototype self-powered wireless switches, solar-powered environmental sensors, and vibration-energy nodes using the kit's accessible power rails and the optional Power Debugger for current profiling down to nanoamp resolution.
Recommended
Medical and Health Monitoring Device Prototyping
Portable medical and health monitoring devices such as pulse oximeters, continuous glucose monitors, and wearable ECG patches require ultra-low power consumption, precision analog peripherals, and reliable RTC wake behaviour. The ATSAML21-XPRO-B exposes the SAM L21's 12-bit ADC, 10-bit DAC, and 6 SERCOM channels through Xplained Pro headers, allowing engineers to prototype medical sensor front-ends that demand years of battery life. The kit's on-board 32.768 kHz crystal provides an accurate RTC timebase for medical data timestamping and event logging.
Recommended
Recommended Products Summary
Engineering reference data for ATSAML21-XPRO-B — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAML22-XPRO-B | ATSAML21-XPRO | ATSAMHA1G16A-XPRO | ATSAMHA1E16A-XPRO | ATSAMG55-XPRO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package / Form Factor | Xplained Pro board | Xplained Pro board - same | Xplained Pro board - same | Xplained Pro board - same | Xplained Pro board - same | Xplained Pro board - same |
| Target MCU | ATSAML21J18B | ATSAML22J18B | ATSAML21J18B | SAM HA1G16A (automotive) | SAM HA1E16A (automotive) | ATSAMG55J19A (Cortex-M4) |
| Core | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M4 |
| Maximum Clock Frequency | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 120 MHz |
| On-board Flash | 256 KB | 256 KB | 256 KB | 64 KB | 64 KB | 512 KB |
| On-board SRAM | 32 KB | 32 KB | 32 KB | 8 KB | 8 KB | 128 KB |
| Debug Interface | On-board EDBG (USB) | On-board EDBG (USB) | On-board EDBG (USB) | On-board EDBG (USB) | On-board EDBG (USB) | On-board EDBG (USB) |
| Ultra-Low-Power Focus | Yes (SleepWalking, sub-uA sleep) | Yes (SleepWalking) | Yes (SleepWalking) | Yes (automotive, low-power) | Yes (automotive, low-power) | No (performance Cortex-M4) |
Key Differentiators
- Lowest-power Cortex-M0+ Xplained Pro board in the SAM L family (vs ATSAMG55-XPRO)
- Production-ready -B revision with long-term supply (vs ATSAML21-XPRO)
- Standardised Xplained Pro form factor for cross-family compatibility (vs ATSAML22-XPRO-B)
Design Notes
For accurate current profiling, disconnect the EDBG power rail from the target MCU using the on-board current-measurement jumper. Without this isolation, the on-board debugger contributes leakage current that masks the SAM L21's true nanoamp-level deep-sleep consumption. Microchip's Power Debugger accessory (sold separately) supports sub-microamp resolution when paired with the Data Visualizer tool.
When migrating from the ATSAML21-XPRO-B evaluation board to a custom PCB, retain the SAM L21's decoupling scheme of one 100 nF X7R per VDD pin plus a single 4.7 µF bulk capacitor. Place the 32.768 kHz crystal within 5 mm of the XIN32/XOUT32 pins with a grounded guard ring to minimise RTC drift from stray switching noise on adjacent traces.
Do not assume the SAM L21 and SAM L22 share identical firmware binaries: the SAM L22 adds hardware AES, a true-rail-to-rail 12-bit DAC, and different peripheral revision IDs, requiring linker-script adjustments when migrating projects between ATSAML21-XPRO-B and ATSAML22-XPRO-B. Always re-validate SleepWalking configurations on the target MCU, because event-system channel mappings differ between the two silicon revisions.
When using the ATSAML21-XPRO-B's Xplained Pro extension headers for high-speed SERCOM (SPI > 10 MHz) or I2S peripherals, keep cable lengths under 100 mm and add series damping resistors near the source pin to suppress ringing. The kit's headers are not impedance-controlled, so production designs should use matched-length, impedance-controlled traces for any interface exceeding 10 MHz.
Compliance Information
RoHS compliant per Microchip product page. The on-board ATSAML21J18B MCU is available in an automotive-grade variant (ATSAML21J18B-AUT) for AEC-Q100 designs, but the evaluation board itself is not AEC-Q100 qualified.