ATSAML21G16B-MNT - 48MHz ARM Cortex-M0+ MCU, 64KB Flash | Microchip
MPN: ATSAML21G16B-MNT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.4374 | $4.44 |
| 10 | $3.95 | $39.50 |
| 100 | $3.42 | $342.00 |
| 500 | $2.98 | $1,490.00 |
| 1,000 | $2.65 | $2,650.00 |
ATSAML21G16B-MNT Overview
What is an ARM Cortex-M0+ microcontroller? An ARM Cortex-M0+ microcontroller is a 32-bit RISC processor core designed for embedded systems that need deterministic real-time performance at very low power consumption. The Cortex-M0+ sits at the low-power end of the ARM Cortex-M family, using the Armv6-M architecture and the Thumb-2 instruction set, and integrates a Nested Vectored Interrupt Controller (NVIC) and Wake-up Interrupt Controller (WIC). MCUs based on this core (microcontroller -> RISC processor -> embedded processor -> semiconductor) are widely used in IoT, sensor hubs, wearables, and battery-powered industrial nodes.
Key features of the ATSAML21G16B-MNT include the Cortex-M0+ core at 48 MHz, 64 KB Flash, 8 KB SRAM, multiple low-power modes (Sleep at 200 nA, Standby, Backup, and Off), 14 SERCOM channels (which can be configured as I2C, SPI, or UART), a 12-bit ADC with up to 20 channels, and built-in touch-support peripherals. The 48-pin QFN (7x7 mm) package provides a compact footprint with an exposed thermal pad for improved thermal dissipation in space-constrained designs.
Technically, the SAM L21 family is built on an ultra-low-power process and integrates a sophisticated power management unit (PMU) that selects among active, idle, sleep, standby, backup, and off modes on a per-peripheral basis. The on-chip voltage regulator supports operation from 1.6 V to 3.6 V, and the device includes up to 5 SERCOM, 1 TC, 1 TCC, and various analog peripherals depending on pin count. The -MNT suffix denotes the 48-QFN package operating from -40°C to 85°C industrial range.
Typical applications include IoT sensor nodes, wearable health and fitness devices, smart home sensors, low-power wireless modules, industrial battery-powered meters, and Human-Machine Interface (HMI) control with touch. The combination of 200 nA Sleep current and fast wake-up makes it ideal for systems that spend most of their time in deep sleep and only wake briefly to take measurements.
When designing with the ATSAML21G16B-MNT, ensure that firmware implements proper Sleep mode entry via the ARM Wait-For-Interrupt (WFI) or Wait-For-Event (WFE) instructions, and that unused peripherals are clock-gated. The 48-QFN exposed pad must be soldered to the PCB ground plane for electrical and thermal performance.
This page synthesizes distributor pricing, same-family alternatives, cross-references, and design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for ATSAML21G16B-MNT — 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 ATSAML21G16B-MNT (same form factor and footprint) — differing in Package, SRAM, ADC, Operating Temperature, Sleep Mode Current.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAML21G17B-MUT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.25 / Unit
View Datasheet →ATSAML21G16B-AUT
✅ Drop-In📋 Reference alternative (not in catalog)
ATSAML21E16B-MUT
✅ Drop-In✓ In Stock
$2.3 / Unit
View Datasheet →ATSAML21G15B-MUT
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ATSAML21J16B-MUT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.18 / Unit
View Datasheet →STM32L031G8U6
✅ Drop-In📋 Reference alternative (not in catalog)
ATSAML21G16B-MNT Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M0+ (32-bit) |
| Maximum CPU Frequency | 48 MHz |
| Flash Memory | 64 KB (64K x 8) |
| SRAM | 8 KB |
| Operating Voltage Range | 1.6 V to 3.6 V |
| Active Mode Current | <35 µA/MHz |
| Sleep Mode Current | 200 nA |
| Operating Temperature Range | -40°C to +85°C |
| Package | 48-QFN (7x7 mm) with exposed pad |
| Mounting Type | Surface Mount |
| Number of SERCOM Channels | 14 |
| ADC | 12-bit, up to 20 channels |
| RoHS Status | Compliant |
| Lead-Free | Yes |
| Family | SAM L21 |
| Carrier Type | Tape & Reel (per ordering code) |
ATSAML21G16B-MNT Pin Configuration
| Pin 1 | VDDIO — Digital I/O supply voltage |
| Pin 2 | PA00 — GPIO / SERCOM / ADC |
| Pin 3 | PA01 — GPIO / SERCOM / ADC |
| Pin 4 | PA02 — GPIO / SERCOM / ADC |
| Pin 5 | PA03 — GPIO / SERCOM / ADC |
| Pin 6 | GND — Ground |
| Pin 7 | PA04 — GPIO / SERCOM / ADC |
| Pin 8 | PA05 — GPIO / SERCOM / ADC |
| Pin 9 | PA06 — GPIO / SERCOM / ADC |
| Pin 10 | PA07 — GPIO / SERCOM / ADC |
| Pin 11 | PA08 — GPIO / SERCOM / ADC |
| Pin 12 | PA09 — GPIO / SERCOM / ADC |
| Pin 13 | PA10 — GPIO / SERCOM / ADC |
| Pin 14 | PA11 — GPIO / SERCOM / ADC |
| Pin 15 | VDD — Core supply voltage |
| Pin 16 | GND — Ground |
| Pin 17 | PA12 — GPIO / SERCOM / ADC |
| Pin 18 | PA13 — GPIO / SERCOM / ADC |
| Pin 19 | PA14 — GPIO / SERCOM |
| Pin 20 | PA15 — GPIO / SERCOM |
| Pin 21 | PA16 — GPIO / SERCOM |
| Pin 22 | PA17 — GPIO / SERCOM |
| Pin 23 | PA18 — GPIO / SERCOM |
| Pin 24 | PA19 — GPIO / SERCOM |
| Pin 25 | PA20 — GPIO / SERCOM |
| Pin 26 | PA21 — GPIO / SERCOM |
| Pin 27 | PA22 — GPIO / SERCOM |
| Pin 28 | PA23 — GPIO / SERCOM |
| Pin 29 | PA24 — GPIO / SERCOM |
| Pin 30 | PA25 — GPIO / SERCOM |
| Pin 31 | PA27 — GPIO |
| Pin 32 | RESET — Reset input (active low) |
| Pin 33 | PA28 — GPIO |
| Pin 34 | PA30 — GPIO |
| Pin 35 | PA31 — GPIO |
| Pin 36 | PB00 — GPIO / SERCOM |
| Pin 37 | PB01 — GPIO / SERCOM |
| Pin 38 | PB02 — GPIO / SERCOM |
| Pin 39 | PB03 — GPIO / SERCOM |
| Pin 40 | PB04 — GPIO / SERCOM |
| Pin 41 | PB05 — GPIO / SERCOM |
| Pin 42 | PB06 — GPIO / SERCOM |
| Pin 43 | PB07 — GPIO / SERCOM |
| Pin 44 | PB08 — GPIO / SERCOM |
| Pin 45 | PB09 — GPIO / SERCOM |
| Pin 46 | PB10 — GPIO / SERCOM |
| Pin 47 | PB11 — GPIO / SERCOM |
| Pin 48 | GND — Ground / exposed pad |
Typical Applications
ATSAML21G16B-MNT is suitable for 6 applications: Battery-Powered IoT Sensor Nodes, Wearable Health and Fitness Devices, Smart Home Sensor Hubs, Industrial Battery-Powered Meters, Low-Power Wireless Sensor Modules, Touch-Enabled HMI Controls.
Battery-Powered IoT Sensor Nodes
The ATSAML21G16B-MNT's 200 nA Sleep current and <35 µA/MHz Active current make it ideal for IoT sensor nodes that spend most of their life in deep sleep and wake briefly to take measurements. With 64 KB of Flash, designers can run a full LoRaWAN or BLE beacon stack plus application code, while 8 KB of SRAM accommodates modest buffers. The Cortex-M0+ core at 48 MHz executes sensor fusion or edge inference quickly enough to keep wake windows short, preserving battery life. The 1.6-3.6 V supply range allows direct connection to a single Li-ion cell or two AA batteries, and the small 48-QFN (7x7 mm) footprint fits into coin-cell powered PCB designs.
Recommended
Wearable Health and Fitness Devices
Wearable health monitors demand sub-mA average current consumption to survive on coin cells, and the ATSAML21G16B-MNT delivers with 200 nA Sleep current. The integrated 12-bit ADC with up to 20 channels captures heart-rate, SpO2, and motion sensor data, while 14 SERCOM channels support I2C sensors and SPI displays. The Cortex-M0+ runs at 48 MHz, sufficient for real-time step counting, heart-rate algorithms, and BLE radio coordination. The 7x7 mm QFN enables slim, lightweight wearable form factors.
Recommended
Smart Home Sensor Hubs
The ATSAML21G16B-MNT powers smart-home sensors for temperature, occupancy, leak detection, and air quality with its low-power Cortex-M0+ core. The 14 SERCOM channels let designers connect multiple I2C/SPI sensors without an external multiplexer, while the 48 MHz performance handles on-device thresholding before reporting to a central hub. The 1.6-3.6 V supply range suits battery, energy-harvesting, or USB-powered installations. The industrial -40 to +85°C operating range handles attics, basements, and outdoor enclosures.
Recommended
Industrial Battery-Powered Meters
For utility meters and remote industrial sensors, the ATSAML21G16B-MNT provides the long-term reliability and low-power operation required for 10+ year battery life. Sleep current at 200 nA dominates total energy budget, while the Cortex-M0+ executes measurement cycles quickly. The 64 KB Flash supports meter calibration tables, encryption keys, and communication stacks; 8 KB SRAM handles measurement buffers. The industrial temperature grade (-40 to +85°C) and wide supply range (1.6-3.6 V) tolerate harsh meter environments.
Recommended
Low-Power Wireless Sensor Modules
The ATSAML21G16B-MNT serves as the host MCU in low-power wireless sensor modules pairing with sub-GHz or BLE transceivers. Its 48 MHz core handles radio stack tasks, sensor I/O, and edge processing while the SERCOM channels provide UART/SPI interfaces to popular transceivers. The 200 nA Sleep current keeps quiescent draw negligible when the radio is idle, and the 48-QFN's exposed pad provides thermal margin for higher transmit-duty-cycle applications. The same firmware image scales across the SAM L21 family for SKU consolidation.
Recommended
Touch-Enabled HMI Controls
The ATSAML21G16B-MNT integrates Microchip's Peripheral Touch Controller (PTC) supporting capacitive touch buttons, sliders, and wheels, making it well suited for white-good, appliance, and industrial HMI panels. The 12-bit ADC supports up to 20 channels for additional sensor inputs, and 14 SERCOM channels handle display drivers or external peripherals. The 64 KB Flash accommodates touch firmware plus graphical UI logic, while the 48-QFN package is compact enough for appliance front panels.
Recommended
Recommended Products Summary
Engineering reference data for ATSAML21G16B-MNT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAML21G17B-MUT | ATSAML21E16B-MUT | ATSAML21G15B-MUT | STM32L031G8U6 |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | STMicroelectronics |
| Package | 48-QFN (7x7) | 48-QFN (7x7) - same | 48-QFN - same | 48-QFN - same | 48-QFN - same |
| Core | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ |
| Maximum Frequency | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 32 MHz |
| Flash Memory | 64 KB | 128 KB | 64 KB | 32 KB | 64 KB |
| SRAM | 8 KB | 16 KB | 8 KB | 4 KB | 8 KB |
| Operating Voltage | 1.6 V to 3.6 V | 1.6 V to 3.6 V | 1.6 V to 3.6 V | 1.6 V to 3.6 V | 1.65 V to 3.6 V |
| Operating Temperature | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C | -40°C to +125°C |
Key Differentiators
- Ultra-low-power Sleep current at 200 nA (vs STM32L031G8U6)
- Higher core frequency than competing Cortex-M0+ parts (vs STM32L031G8U6)
- 14 SERCOM channels for flexible peripheral mapping (vs ATSAML10E16A-MUT)
Design Notes
Use the ARM Wait-For-Event (WFE) or Wait-For-Interrupt (WFI) instructions to enter Sleep mode; the SAM L21 PMU will then drop to ~200 nA while retaining SRAM and register state. Gate the clocks of all unused peripherals via the PMU's SLEEPCFG register before sleep, and prefer the on-chip RTC (running from a 32.768 kHz crystal) to wake the core on a periodic schedule. Estimated: at 0.1% active duty cycle and 35 µA/MHz active current, average system current is approximately 17 µA on a 3 V supply - well within coin-cell capabilities.
The 48-QFN (7x7 mm) exposed pad must be soldered to a ground plane that is at least 25 mm² of 1 oz copper for thermal and electrical performance. Place decoupling capacitors (100 nF X7R + 4.7 µF X5R) within 3 mm of the VDD and VDDIO pins. Route the 32.768 kHz crystal traces short, guard them with a ground ring, and keep them away from switching signal lines to minimize jitter on the RTC and low-power timer.
Do not leave unused SERCOM pins floating; configure them as outputs driven low or enable the internal pull-downs to avoid parasitic current paths. The brown-out detector (BOD) should be enabled to prevent undefined behavior below 1.6 V. When migrating from SAM L21E to L21G, double-check the SERCOM instance count and PTC channel availability - the E variant trims some peripherals.
Compliance Information
RoHS and lead-free compliance confirmed per Microchip product page; AEC-Q100 not applicable for industrial-grade -40°C to +85°C parts.
