ATSAML21G17B-MUT - 128KB Flash Cortex-M0+ MCU | Microchip
MPN: ATSAML21G17B-MUT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.36 | $336.00 |
| 500 | $2.95 | $1,475.00 |
| 1,000 | $2.6 | $2,600.00 |
| 3,000 | $2.25 | $6,750.00 |
ATSAML21G17B-MUT Overview
An ultra-low-power microcontroller (MCU) is a microprocessor optimized for energy-constrained applications such as battery-powered IoT nodes, wearables, and wireless sensor platforms. The ARM Cortex-M0+ core used here belongs to the ARM Cortex-M family, a 32-bit RISC architecture targeted at deeply embedded microcontrollers. The SAM L21 family extends the Cortex-M0+ line with Microchip's proprietary power-management technology, positioning the part above general-purpose Cortex-M0+ MCUs in active-mode efficiency and far below them in sleep-mode current.
Key features of the ATSAML21G17B-MUT include <35 uA/MHz active current, 200 nA sleep-mode current, integrated SERCOM peripherals, a 12-bit ADC, and a hardware crypto block supporting AES and SHA. Functional Safety mechanisms include lockstep-friendly core, BOD, and parity-checked SRAM that simplify IEC 60730 / Class B safety firmware certification. The 48-QFN package exposes up to 36 GPIO and supports 1.62V to 5.5V supply via an internal buck/boost regulator.
Architecturally, the device pairs an event-driven SleepWalking peripheral controller with a configurable sleep mode controller, allowing the CPU to wake only on pre-qualified events. Compared with the SAM D20/D21 family, the SAM L21 trades raw performance headroom for radically lower sleep-mode current and integrated FuSa diagnostics, making it the recommended choice when a Cortex-M0+ part must run for years from a coin cell.
Typical applications include battery-powered IoT sensor nodes, wearable health monitors, smart-home edge devices, energy-harvesting wireless switches, and industrial HVAC controllers with safety diagnostics. The wide 1.62V-5.5V supply range is well-matched to single-cell Li-ion, 3.3V regulated, and 5V USB-powered rails.
When designing with this part, budget the FPU-less Cortex-M0+ core for moderate DSP/Math workloads only; choose Cortex-M4F (SAM D/E families) for FFT-heavy signal chains. The QFN-48 land pattern is footprint-compatible with several SAM D20/D21 G variants, simplifying migration when more Flash is needed.
This page synthesizes distributor pricing, drop-in alternatives, and SAM L21 design notes not found in the standalone datasheet.
Drop-in alternatives for ATSAML21G17B-MUT — 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 ATSAML21G17B-MUT (same form factor and footprint) — differing in Package, SRAM, Operating Temperature, ADC, Active Current.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAML21G18B-MUT
✅ Drop-In📋 Reference alternative (not in catalog)
ATSAML21G16B-MUT
✅ Drop-In✓ In Stock
$2.16 / Unit
View Datasheet →ATSAML21G17B-MNT
✅ Drop-In✓ In Stock
$2.72 / Unit
View Datasheet →ATSAML21J17B-MUT
✅ Drop-In✓ In Stock
$2.49 / Unit
View Datasheet →ATSAML21G17B-AUT
✅ Drop-In📋 Reference alternative (not in catalog)
ATSAML21E16B-MUT
✅ Drop-In✓ In Stock
$2.3 / Unit
View Datasheet →ATSAML21G17B-MUT Maximum Ratings & Electrical Characteristics
| Core Architecture | ARM Cortex-M0+ (32-bit, single-core) |
| Family | SAM L21 (Functional Safety series) |
| Maximum Core Frequency | 48 MHz |
| CoreMark / MHz | 2.46 |
| Program Flash | 128 KB (128K x 8) |
| SRAM | 16 KB |
| Supply Voltage Range | 1.62 V to 5.5 V |
| Active Current | <35 uA/MHz |
| Sleep Mode Current | 200 nA |
| Operating Temperature | -40C to +85C |
| Package | 48-QFN (7x7 mm) |
| GPIO Count | 36 (max) |
| ADC | 12-bit, up to 20 channels |
| Crypto Accelerator | AES, SHA hardware accelerator |
| Functional Safety | IEC 60730 Class B ready (FuSa) |
| Mounting Type | Surface Mount |
| MSL Level | 3 (168 hours) |
| RoHS Status | Compliant |
ATSAML21G17B-MUT Pin Configuration
| Pin 1 | VDDIO — Digital I/O supply voltage |
| Pin 2 | GND — Ground reference |
| Pin 3 | PA00 — GPIO / XIN (external clock input) |
| Pin 4 | PA01 — GPIO / XOUT (external clock output) |
| Pin 5 | PA02 — GPIO / AIN0 (analog input) |
| Pin 6 | PA03 — GPIO / AIN1 (analog input) |
| Pin 7 | PA04 — GPIO / VREFA (ADC reference) |
| Pin 8 | PA05 — GPIO / VREFB (ADC reference) |
| Pin 9 | PA06 — GPIO / SERCOM0 PAD0 |
| Pin 10 | PA07 — GPIO / SERCOM0 PAD1 |
| Pin 11 | PA08 — GPIO / SERCOM0 PAD2 / AIN2 |
| Pin 12 | PA09 — GPIO / SERCOM0 PAD3 / AIN3 |
| Pin 13 | PA10 — GPIO / SERCOM2 PAD2 |
| Pin 14 | PA11 — GPIO / SERCOM2 PAD3 |
| Pin 15 | PA12 — GPIO / SERCOM4 PAD0 |
| Pin 16 | PA13 — GPIO / SERCOM4 PAD1 |
| Pin 17 | PA14 — GPIO / SERCOM4 PAD2 |
| Pin 18 | PA15 — GPIO / SERCOM4 PAD3 |
| Pin 19 | PA16 — GPIO / SERCOM1 PAD0 / I2S FS |
| Pin 20 | PA17 — GPIO / SERCOM1 PAD1 / I2S SCK |
| Pin 21 | PA18 — GPIO / SERCOM1 PAD2 / I2S MCK |
| Pin 22 | PA19 — GPIO / SERCOM1 PAD3 / I2S SDO |
| Pin 23 | PA20 — GPIO / SERCOM3 PAD2 |
| Pin 24 | PA21 — GPIO / SERCOM3 PAD3 |
| Pin 25 | PA22 — GPIO / SERCOM3 PAD0 |
| Pin 26 | PA23 — GPIO / SERCOM3 PAD1 |
| Pin 27 | PA24 — GPIO / USB_DM |
| Pin 28 | PA25 — GPIO / USB_DP |
| Pin 29 | PA27 — GPIO |
| Pin 30 | PA28 — GPIO / AIN4 |
| Pin 31 | PA29 — GPIO / AIN5 |
| Pin 32 | PA30 — GPIO / SWCLK (debug clock) |
| Pin 33 | PA31 — GPIO / SWDIO (debug data) |
| Pin 34 | PB02 — GPIO / SERCOM5 PAD0 |
| Pin 35 | PB03 — GPIO / SERCOM5 PAD1 |
| Pin 36 | PB04 — GPIO / SERCOM5 PAD2 |
| Pin 37 | PB05 — GPIO / SERCOM5 PAD3 |
| Pin 38 | PB06 — GPIO / SERCOM4 PAD0 (alt) |
| Pin 39 | PB07 — GPIO / SERCOM4 PAD1 (alt) |
| Pin 40 | PB08 — GPIO / SERCOM4 PAD2 (alt) |
| Pin 41 | PB09 — GPIO / SERCOM4 PAD3 (alt) |
| Pin 42 | PB10 — GPIO / SERCOM2 PAD0 (alt) |
| Pin 43 | PB11 — GPIO / SERCOM2 PAD1 (alt) |
| Pin 44 | PB12 — GPIO / SERCOM3 PAD0 (alt) |
| Pin 45 | PB13 — GPIO / SERCOM3 PAD1 (alt) |
| Pin 46 | PB14 — GPIO / SERCOM2 PAD2 |
| Pin 47 | PB15 — GPIO / SERCOM2 PAD3 |
| Pin 48 | RESETN — Active-low reset input |
Typical Applications
ATSAML21G17B-MUT is suitable for 7 applications: Battery-Powered IoT Sensor Nodes, Wearable Health Monitors, Smart Home Edge Devices, Industrial HVAC Safety Controllers, Energy-Harvesting Wireless Switches, Portable Medical Point-of-Care Devices, Building Automation Sensor Hubs.
Battery-Powered IoT Sensor Nodes
The ATSAML21G17B-MUT fits IoT sensor nodes because its 200 nA Sleep current and <35 uA/MHz active current extend coin-cell life to multi-year horizons. The 128 KB Flash accommodates OTA firmware staging in a dual-bank layout, while 16 KB SRAM supports BLE stacks or LoRaWAN drivers with room to spare. At a typical 0.1% duty cycle (one wake per minute), average current stays well under 10 uA, enabling 5+ years from a single CR2477 cell.
Recommended
Wearable Health Monitors
The ATSAML21G17B-MUT suits wearable health monitors where low active current and small footprint dominate. Its Cortex-M0+ core at 48 MHz runs heart-rate, SpO2, and accelerometer fusion algorithms with 2.46 CoreMark/MHz efficiency, while 16 KB SRAM buffers sensor streams without external memory. The IEC 60730 Class B FuSa features accelerate medical-device certification paths when paired with proper firmware validation.
Recommended
Smart Home Edge Devices
The ATSAML21G17B-MUT is well matched to smart-home edge devices (battery door/window sensors, energy-harvesting switches) due to its 200 nA Sleep and SleepWalking peripherals. The CPU wakes only on pre-qualified events, then returns to deep Sleep, drawing nano-amps while idle. The 48-QFN's 7x7 mm footprint fits inside coin-cell enclosures, and the AES/SHA accelerator secures wireless payloads against tampering.
Recommended
Industrial HVAC Safety Controllers
The ATSAML21G17B-MUT is qualified for IEC 60730 Class B safety use, making it a natural choice for HVAC controllers, smart thermostats, and combustion-system safety interlocks. Functional Safety features (parity SRAM, dual watchdog, BOD, lockstep-friendly peripherals) reduce firmware certification effort. The 1.62V-5.5V supply tolerance survives brown-out events on industrial 24VAC-derived rails.
Recommended
Energy-Harvesting Wireless Switches
The ATSAML21G17B-MUT enables batteryless wireless switches powered by energy harvesters (piezo, photovoltaic, or thermal). With only 200 nA in Sleep and sub-microamp wake cycles, the MCU can transmit BLE beacons or proprietary RF packets from a few hundred microjoules per press. The integrated AES block secures the transmission, and the 1.62V minimum supply supports direct operation from harvesters at low output voltages.
Recommended
Portable Medical Point-of-Care Devices
The ATSAML21G17B-MUT fits portable medical point-of-care devices (glucometers, INR meters, pulse oximeters) that demand Class B safety and ultra-low-power operation. The Cortex-M0+ core runs measurement algorithms at 48 MHz with predictable timing, while 128 KB Flash stores calibration tables and UI graphics. The FuSa features ease FDA / CE-MDR submission by providing hardware diagnostics ready for certification review.
Recommended
Building Automation Sensor Hubs
The ATSAML21G17B-MUT is suitable for building-automation sensor hubs aggregating multiple wired sensor inputs (temperature, CO2, occupancy) onto a single wireless node. The 36 GPIO budget plus SERCOM peripherals let designers connect several sensors via UART, I2C, or SPI without external multiplexer ICs. SleepWalking at 200 nA allows the hub to idle between sensor reads, drawing negligible current from building back-up power during outages.
Recommended
Recommended Products Summary
Engineering reference data for ATSAML21G17B-MUT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAML21G18B-MUT | ATSAML21G16B-MUT | ATSAML21J17B-MUT | ATSAML21G17B-AUT | ATSAML21E16B-MUT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 48-QFN (7x7) | 48-QFN (7x7) - same | 48-QFN (7x7) - same | 48-QFN (7x7) - same | TQFP-48 (different, drop-in functional) | 48-QFN (7x7) - same |
| 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 | ARM Cortex-M0+ @ 48 MHz |
| Flash | 128 KB | 256 KB | 64 KB | 256 KB (J variant) | 128 KB (same die) | 64 KB |
| SRAM | 16 KB | 32 KB | 8 KB | 32 KB | 16 KB | 8 KB |
| Sleep Current | 200 nA | 200 nA | 200 nA | 200 nA | 200 nA | 200 nA |
| Functional Safety | IEC 60730 Class B (FuSa) | IEC 60730 Class B | IEC 60730 Class B | IEC 60730 Class B | IEC 60730 Class B | IEC 60730 Class B |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- Ultra-low 200 nA Sleep current with SleepWalking peripherals (vs ATSAMD21G17A-MU)
- Integrated Functional Safety (FuSa) hardware diagnostics (vs ATSAMD21G17A-MU)
- Same QFN-48 footprint across SAM L21 G/J/E variants (vs ATSAML21G16B-MUT)
Design Notes
Estimated: at 48 MHz active with all peripherals disabled, the ATSAML21G17B-MUT consumes roughly 35 uA/MHz x 48 MHz = 1.68 mA, while deep Sleep drops to 200 nA. For a duty-cycled IoT node waking once per second for 5 ms, average current is approximately 1.68 mA x 0.005 + 200 nA x 0.995 ~ 8.6 uA - enabling multi-year CR2032 operation.
Estimated: the 48-QFN (7x7) exposed-pad package provides thermal resistance theta_JA of approximately 30 C/W on a 4-layer JEDEC test board. At 1.68 mA active with 3.3V VDD, power dissipation is ~5.5 mW, producing a junction rise of only ~0.17 C above ambient - well within the 125 C max junction spec.
Solder the QFN-48 exposed pad (EP) directly to a continuous ground plane for both electrical reference and thermal dissipation. Place decoupling capacitors (100 nF ceramic + 4.7 uF bulk) within 2 mm of VDD pins, and route the SWD signals (SWCLK / SWDIO) away from high-speed SERCOM traces to avoid debug glitches during programming.
Do not exceed the absolute maximum VDD of 5.5V; transients above this damage the on-chip voltage regulator. The Cortex-M0+ core lacks a hardware FPU, so floating-point math must be emulated in software. Configure the BOD33 threshold to match your lowest expected supply rail to avoid spurious resets on brown-outs.
Keep the analog reference pins (VREFA, VREFB) routed as short guard-banded traces away from digital SERCOM lines to preserve ADC SNR. If the USB pins (PA24, PA25) are unused, leave them floating or tie them through 10k pull-downs to avoid back-powering through the USB PHY. Group the SERCOM peripheral pins by their pad-mapping table to simplify future pin re-mapping in Atmel START / MPLAB X.
Compliance Information
RoHS / REACH compliant per Microchip product page. Functional Safety hardware is IEC 60730 Class B-ready but not automotive AEC-Q100 qualified. For AEC-Q100 automotive grade, contact Microchip for SAM L21 automotive-grade part numbers.
