ATSAML21E16B-MUT - 48MHz Cortex-M0+ MCU, 64KB Flash, 32-VQFN
MPN: ATSAML21E16B-MUT β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.95 | $3.95 |
| 10 | $3.55 | $35.50 |
| 100 | $3.05 | $305.00 |
| 500 | $2.65 | $1,325.00 |
| 1,000 | $2.3 | $2,300.00 |
ATSAML21E16B-MUT Overview
An ARM Cortex-M0+ microcontroller is a 32-bit reduced instruction set computing (RISC) processor core designed by ARM Holdings for energy-efficient embedded applications. It belongs to the Cortex-M processor family, which itself sits within the broader category of microcontrollers (MCUs) - single-chip computers integrating CPU, memory, and peripherals. The Cortex-M0+ is the smallest and most energy-efficient member of the Cortex-M line, prioritizing low active current, deterministic interrupt latency, and a minimal gate count. It targets battery-powered and always-on applications such as sensor nodes, wearables, and remote controls, where the combination of computational headroom and ultra-low sleep current is essential.
The ATSAML21E16B-MUT features Microchip's proprietary ultra-low-power technology, consuming under 35 Β΅A/MHz in active mode and approximately 200 nA in Sleep mode. It integrates a high-speed 12-bit ADC, DAC, SERCOM (serial communication) interfaces, and a Real-Time Clock. The Functional Safety (FuSa) variant includes hardware safety features such as Error Code Correction (ECC) on Flash and RAM, CRC, and a windowed watchdog timer, supporting IEC 60730 class B requirements for household appliances.
Architecturally, the SAM L21 family uses a Cortex-M0+ core paired with a low-power peripheral touch (PTC) controller, an Event System for inter-peripheral signaling without CPU intervention, and Sleepwalking peripherals that wake the core only when needed. This design enables event-driven operation that minimizes average power consumption in always-on sensor applications.
Typical applications include battery-powered IoT sensor nodes, wearable health devices, smart metering, industrial sensor interfaces, low-power wireless MCUs (paired with external radio), and functional safety appliances. The wide operating voltage range (1.62V to 3.63V) supports both single-cell Li-ion and 3.3V industrial rails.
When designing with the ATSAML21E16B-MUT, leverage the Event System and Sleepwalking peripherals to keep the CPU in deep sleep as long as possible. Configure the brown-out detector (BOD) at the minimum required threshold to avoid unnecessary resets, and use the RTC with calendar mode for periodic wake-ups instead of a hardware timer.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, giving engineers a single-source decision aid for sourcing and selecting the right SAM L21 variant.
Drop-in alternatives for ATSAML21E16B-MUT 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 ATSAML21E16B-MUT (same form factor and footprint) β differing in Active Current, Core Architecture, Package, Program Memory (Flash), SRAM.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAML21E15B-MUT
β Drop-Inπ Reference alternative (not in catalog)
ATSAML21E17B-MUT
β Drop-Inπ Reference alternative (not in catalog)
ATSAML21E18B-MUT
β Drop-Inπ Reference alternative (not in catalog)
ATSAML21E16B-AUT
β Drop-Inπ Reference alternative (not in catalog)
ATSAML21E16B-ANT
β Drop-Inπ Reference alternative (not in catalog)
ATSAML11E16A-MUTKPH
β Drop-Inπ Reference alternative (not in catalog)
ATSAML10E16A-MUT
β Drop-Inβ In Stock
$1.42 / Unit
View Datasheet βATSAML21E16B-MUT Maximum Ratings & Electrical Characteristics
| Core Architecture | ARM Cortex-M0+ (32-bit) |
| Series | SAM L21E, Functional Safety (FuSa) |
| Maximum Clock Frequency | 48 MHz |
| Program Memory (Flash) | 64 KB (64K x 8) |
| SRAM | 12 KB |
| Supply Voltage Range | 1.62 V to 3.63 V |
| Active Current | Under 35 Β΅A/MHz |
| Sleep Current | 200 nA |
| Package | 32-VQFN (5x5 mm) |
| Operating Temperature | -40C to +85C (industrial) |
| ADC | 12-bit, up to 1 Msps |
| DAC | 12-bit |
| Communication Interfaces | SERCOM (configurable as UART/SPI/I2C) |
| Functional Safety Features | ECC on Flash/RAM, CRC, windowed WDT (IEC 60730 class B) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
ATSAML21E16B-MUT Pin Configuration
| Pin 1 | PA00 β GPIO / ADC AIN0 / SERCOM pad |
| Pin 2 | PA01 β GPIO / ADC AIN1 / SERCOM pad |
| Pin 3 | PA02 β GPIO / ADC AIN2 / SERCOM pad |
| Pin 4 | PA03 β GPIO / ADC AIN3 / SERCOM pad |
| Pin 5 | GND β Ground |
| Pin 6 | VDDIO β I/O supply voltage |
| Pin 7 | VDD β Core supply voltage |
| Pin 8 | PA04 β GPIO / ADC AIN4 / SERCOM pad |
| Pin 9 | PA05 β GPIO / ADC AIN5 / SERCOM pad |
| Pin 10 | PA06 β GPIO / ADC AIN6 / SERCOM pad |
| Pin 11 | PA07 β GPIO / ADC AIN7 / SERCOM pad |
| Pin 12 | PA08 β GPIO / SERCOM pad |
| Pin 13 | PA09 β GPIO / SERCOM pad |
| Pin 14 | PA10 β GPIO / SERCOM pad |
| Pin 15 | PA11 β GPIO / SERCOM pad |
| Pin 16 | GND β Ground |
| Pin 17 | PA14 β GPIO / SERCOM pad |
| Pin 18 | PA15 β GPIO / SERCOM pad |
| Pin 19 | PA16 β GPIO / SERCOM pad |
| Pin 20 | PA17 β GPIO / SERCOM pad |
| Pin 21 | PA18 β GPIO / SERCOM pad |
| Pin 22 | PA19 β GPIO / SERCOM pad |
| Pin 23 | PA20 β GPIO / SERCOM pad |
| Pin 24 | PA21 β GPIO / SERCOM pad |
| Pin 25 | PA22 β GPIO / SERCOM pad |
| Pin 26 | PA23 β GPIO / SERCOM pad |
| Pin 27 | PA24 β GPIO / SERCOM pad |
| Pin 28 | PA25 β GPIO / SERCOM pad |
| Pin 29 | GND β Ground (exposed thermal pad) |
| Pin 30 | VDD β Core supply voltage |
| Pin 31 | RESETn β Reset input, active low |
| Pin 32 | SWDIO β Serial Wire Debug I/O |
Typical Applications
ATSAML21E16B-MUT is suitable for 6 applications: Battery-Powered IoT Sensor Nodes, Wearable Health Devices, Smart Metering, Industrial Sensor Interfaces, Functional Safety Appliances, Low-Power Wireless MCUs (Radio Co-Processor).
Battery-Powered IoT Sensor Nodes
The ATSAML21E16B-MUT is well suited for battery-powered IoT sensor nodes due to its 200 nA Sleep current with full RAM retention and RTC running, plus 35 Β΅A/MHz active current. In a typical wireless sensor duty cycle (1% active, 99% sleep), average current drops below 5 Β΅A, enabling multi-year coin-cell life. The Event System routes sensor triggers directly to peripherals, waking the CPU only when needed. Compared to Cortex-M3/M4 alternatives, the M0+ core trades peak performance for energy efficiency, ideal for sub-100 Hz sensor sampling with Bluetooth Low Energy or sub-GHz radio co-processors.
Recommended
Wearable Health Devices
The ATSAML21E16B-MUT suits wearable health devices because its 5x5 mm VQFN footprint fits small wrist-worn enclosures, and the 1.62-3.63 V supply supports direct Li-ion battery connection. The 12-bit ADC captures biopotential signals at 1 Msps, while the 12-bit DAC drives reference outputs for optical heart-rate sensors. The Sleepwalking peripheral architecture lets the ADC sample continuously while the CPU sleeps, dropping average current below 10 Β΅A in fitness-tracker duty cycles. The PTC touch controller also enables capacitive UI without external components.
Recommended
Smart Metering
Smart metering applications leverage the ATSAML21E16B-MUT's ultra-low sleep current and Functional Safety features. The 200 nA Sleep mode with RTC running enables 10+ year battery life on metering endpoints that wake hourly to transmit readings. The IEC 60730 class B-ready ECC on Flash/RAM and windowed watchdog provide the safety integrity required for utility-grade metering. The 64 KB Flash accommodates DLMS/COSEM or Wireless M-Bus protocol stacks, while the 12 KB SRAM buffers measurement data between transmissions.
Recommended
Industrial Sensor Interfaces
Industrial sensor interfaces benefit from the ATSAML21E16B-MUT's 1.62-3.63 V supply and -40C to +85C industrial temperature range. The 48 MHz Cortex-M0+ core executes protocol conversion and signal conditioning for 4-20 mA, 0-10 V, and Modbus interfaces. The 12-bit ADC with internal PGA digitizes low-level sensor signals without external amplification, reducing BOM cost. SERCOM peripherals reconfigure as UART, SPI, or I2C for multi-protocol bridge applications.
Recommended
Functional Safety Appliances
The ATSAML21E16B-MUT's Functional Safety variant targets IEC 60730 class B household appliances such as washing machines, ovens, and dishwashers. Hardware features including ECC on Flash and RAM, CRC calculation unit, and windowed watchdog reduce software burden for safety compliance. The Cortex-M0+ core runs safety self-test routines in 35 Β΅A/MHz active mode, while Sleep modes preserve battery backup during power-loss events. The 64 KB Flash accommodates safety software overhead alongside application logic.
Recommended
Low-Power Wireless MCUs (Radio Co-Processor)
As a host MCU paired with an external radio, the ATSAML21E16B-MUT manages application logic while a co-processor handles wireless stack processing. The Cortex-M0+ at 48 MHz executes 2.46 CoreMark/MHz, sufficient for sensor aggregation, local display, and user interface tasks while the radio module runs BLE/Zigbee/Thread stacks. The Event System enables hardware-triggered SPI transfers without CPU intervention, dropping active current during radio handshakes. This split-architecture is common in Matter-over-Thread smart-home devices.
Recommended
Recommended Products Summary
Engineering reference data for ATSAML21E16B-MUT β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAML21E15B-MUT | ATSAML21E17B-MUT | ATSAML21E18B-MUT | ATSAML21E16B-AUT | ATSAML11E16A-MUTKPH |
|---|---|---|---|---|---|---|
| Package | 32-VQFN (5x5 mm) | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same | 32-TQFP (7x7 mm) | 32-VQFN (5x5 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 64 KB | 32 KB | 128 KB | 256 KB | 64 KB | 64 KB |
| SRAM | 12 KB | 12 KB | 12 KB | 12 KB | 12 KB | 12 KB |
| Core / Frequency | Cortex-M0+ @ 48 MHz | Cortex-M0+ @ 48 MHz | Cortex-M0+ @ 48 MHz | Cortex-M0+ @ 48 MHz | Cortex-M0+ @ 48 MHz | Cortex-M0+ @ 48 MHz (with TrustZone-M) |
| Active Current | <35 Β΅A/MHz | <35 Β΅A/MHz | <35 Β΅A/MHz | <35 Β΅A/MHz | <35 Β΅A/MHz | <35 Β΅A/MHz |
| Sleep Current | 200 nA | 200 nA | 200 nA | 200 nA | 200 nA | 200 nA |
| Functional Safety (FuSa) | Yes (IEC 60730 class B) | Yes | Yes | Yes | Yes | Yes (with TrustZone-M security) |
| Series | SAM L21E (FuSa) | SAM L21E (FuSa) | SAM L21E (FuSa) | SAM L21E (FuSa) | SAM L21E (FuSa) | SAM L11 (TrustZone-M) |
| Pin Count | 32 | 32 | 32 | 32 | 32 | 32 |
Key Differentiators
- Ultra-low sleep current with full RAM retention (vs ATSAMD21E16B-MUT)
- Functional Safety (FuSa) variant with hardware ECC (vs ATSAML21E15B-MUT)
- 32-VQFN (5x5 mm) compact footprint (vs ATSAML21E16B-AUT)
Design Notes
Configure the brown-out detector (BOD33) at the minimum acceptable threshold to avoid unnecessary resets during battery discharge - for single-cell Li-ion, a 2.8 V BOD33 threshold is typical. Disable unused peripherals via the APBCMASK register to minimize leakage current, and use the Event System to route sensor triggers to peripherals without waking the CPU. The SleepWalking feature lets peripherals like ADC and SERCOM continue operating while the CPU sleeps, dropping average current below 5 Β΅A in typical IoT duty cycles.
The 32-VQFN (5x5 mm) package has an exposed thermal pad (pin 29) that MUST be soldered to a continuous ground pour on the top layer for both thermal dissipation and electrical grounding. Use a 0.1 Β΅F decoupling capacitor on each VDD pin placed within 2 mm, plus a bulk 4.7 Β΅F ceramic capacitor nearby. Route high-speed signals (SWD, SERCOM SPI) over continuous ground reference planes and avoid crossing split ground regions to maintain signal integrity.
Do not assume SAM L21E pinout compatibility with SAM D20/D21 - the SERCOM pad mapping is similar but the peripheral count and interrupt vectors differ. When migrating from ATSAMD21E16B-MUT, the SAM L21E adds SleepWalking and FuSa but the USB peripheral is removed. Verify that your application code uses the SAM L21-specific startup files from MPLAB Harmony v3, and check the SAM L21 family datasheet errata for known silicon revision issues.
Compliance Information
Industrial temperature grade -40C to +85C. AEC-Q100 not applicable - this is the industrial / consumer variant. For automotive, see ATSAML21E16B-MUTVAO.
