ATSAML21E16B-ANT - 32-bit Cortex-M0+ MCU 64KB Flash | Microchip
MPN: ATSAML21E16B-ANT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.95 | $2.95 |
| 10 | $2.66 | $26.60 |
| 100 | $2.36 | $236.00 |
| 500 | $2.13 | $1,065.00 |
| 1,000 | $1.9 | $1,900.00 |
| 3,000 | $1.65 | $4,950.00 |
ATSAML21E16B-ANT Overview
What is a Cortex-M0+ MCU? An ARM Cortex-M0+ microcontroller is a 32-bit reduced instruction set computing (RISC) processor core optimized for the smallest die area and lowest active power among the Cortex-M family. Cortex-M0+ MCUs sit in the hierarchy: microcontroller -> embedded MCU -> 32-bit MCU -> ARM Cortex-M family -> ultra-low-power class. They typically integrate Flash, SRAM, peripherals (ADC, timers, SERCOM), and clock generation onto a single die, serving as the central controller in battery-powered and sensor-driven embedded products.
Key features of the ATSAML21E16B-ANT include active-mode current under 35 uA/MHz and a deep Sleep mode drawing as low as 200 nA, enabled by sophisticated power-management technology including multiple low-power modes, on-demand peripheral activation, and an event system that allows peripherals to communicate without waking the CPU. The integrated 12-bit ADC and 12-bit DAC, multiple SERCOM modules (configurable as UART/SPI/I2C), and a 32-pin TQFP footprint delivering up to 26 GPIO pins make it well suited for space-constrained low-power designs.
Architecturally, the SAM L21E combines the Cortex-M0+ core with Microchip's proprietary SleepWalking peripheral controllers and an event system that enables I/O-driven state changes without CPU intervention, dramatically reducing average power in sensor-edge applications. The FuSa (Functional Safety) variant adds diagnostic libraries and documentation packages to support IEC 60730 Class B compliance for home appliances and similar regulated products.
Typical applications include battery-powered IoT sensor nodes, wearable health monitors, smart-home edge controllers, industrial wireless sensor transmitters, energy-harvesting devices, and home-appliance control boards. The wide 1.62V-3.63V supply range and 200 nA Sleep current make it particularly attractive for designs that spend most of their life in standby and wake briefly to take measurements.
When designing with this part, evaluate peripheral activation patterns and SleepWalking configuration early - average power is dominated by how often peripherals wake the CPU rather than by active-mode current alone. Decoupling should follow Microchip's SAM L21 hardware design guidelines with a 100 nF close to each supply pair and a 4.7 uF bulk capacitor on VDDIN.
This page synthesizes distributor pricing across 9+ sources, drop-in alternatives from Microchip's SAM L21 family, and practical design notes not consolidated in the manufacturer datasheet, giving engineers a single point of reference for BOM decisions.
Drop-in alternatives for ATSAML21E16B-ANT — 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-ANT (same form factor and footprint) — differing in Package, RoHS Status, SRAM, ADC, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAML21E17B-ANT
✅ Drop-In📋 Reference alternative (not in catalog)
ATSAML21E18B-ANT
✅ Drop-In📋 Reference alternative (not in catalog)
ATSAML21E16B-AUT
✅ Drop-In✓ In Stock
$2.65 / Unit
View Datasheet →ATSAML21E15B-ANT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.72 / Unit
View Datasheet →ATSAML21E16B-MUT
✅ Drop-In✓ In Stock
$2.3 / Unit
View Datasheet →ATSAML21E16B-ANT Maximum Ratings & Electrical Characteristics
| Core Architecture | ARM Cortex-M0+ (32-bit) |
| Series | SAM L21E, Functional Safety (FuSa) |
| Maximum CPU Frequency | 48 MHz |
| Program Memory (Flash) | 64 KB (64K x 8) |
| SRAM | 8 KB |
| Supply Voltage (VDDIN) | 1.62 V to 3.63 V |
| Active Current | <35 uA/MHz |
| Sleep Mode Current | 200 nA |
| Package | 32-pin TQFP (7x7 mm) |
| ADC | 12-bit |
| DAC | 12-bit |
| Communication Interfaces | SERCOM (UART/SPI/I2C configurable) |
| Operating Temperature | -40C to +85C (industrial) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (per Mouser listing) |
| Functional Safety | IEC 60730 Class B (FuSa) |
| Evaluation Platform | MPLAB X IDE, MPLAB Harmony, ASF |
ATSAML21E16B-ANT Pin Configuration
| Pin 1 | PA03 — GPIO / ADC AIN[1] / VREFA |
| Pin 2 | PA04 — GPIO / ADC AIN[2] / VREFB |
| Pin 3 | PA05 — GPIO / ADC AIN[3] |
| Pin 4 | PA06 — GPIO / ADC AIN[4] |
| Pin 5 | PA07 — GPIO / ADC AIN[5] |
| Pin 6 | PA08 — GPIO / NMI |
| Pin 7 | PA09 — GPIO |
| Pin 8 | PA10 — GPIO |
| Pin 9 | PA11 — GPIO / SERCOM0 PAD[3] |
| Pin 10 | VDDIO — Digital I/O supply |
| Pin 11 | GND — Ground |
| Pin 12 | PA14 — GPIO / SERCOM2 PAD[2] |
| Pin 13 | PA15 — GPIO / SERCOM2 PAD[3] |
| Pin 14 | PA16 — GPIO / SERCOM1 PAD[0] / I2S SD[0] |
| Pin 15 | PA17 — GPIO / SERCOM1 PAD[1] / I2S MCK[0] |
| Pin 16 | PA18 — GPIO / SERCOM1 PAD[2] / I2S SCK[0] |
| Pin 17 | PA19 — GPIO / SERCOM1 PAD[3] / I2S FS[0] |
| Pin 18 | PA20 — GPIO / SERCOM3 PAD[2] |
| Pin 19 | PA21 — GPIO / SERCOM3 PAD[3] |
| Pin 20 | PA22 — GPIO / SERCOM3 PAD[0] / I2C SDA[0] |
| Pin 21 | PA23 — GPIO / SERCOM3 PAD[1] / I2C SCL[0] |
| Pin 22 | PA24 — GPIO / USB D- |
| Pin 23 | PA25 — GPIO / USB D+ |
| Pin 24 | RESETn — Reset input (active low) |
| Pin 25 | VDDCORE — Core voltage output (LDO bypass cap) |
| Pin 26 | GND — Ground |
| Pin 27 | VDDIN — Main supply input 1.62-3.63V |
| Pin 28 | PA30 — GPIO / SWCLK |
| Pin 29 | PA31 — GPIO / SWDIO |
| Pin 30 | PB02 — GPIO / ADC AIN[10] |
| Pin 31 | PB03 — GPIO / ADC AIN[11] |
| Pin 32 | GND — Ground (thermal pad area) |
Typical Applications
ATSAML21E16B-ANT is suitable for 7 applications: Battery-Powered IoT Sensor Nodes, Wearable Health Monitors, Smart Home Edge Controllers, Industrial Wireless Sensor Transmitters, Home Appliance Control Boards, Energy-Harvesting Devices, HID and Consumer Input Devices.
Battery-Powered IoT Sensor Nodes
The ATSAML21E16B-ANT is well matched to battery-powered IoT sensor nodes that spend most of their life in deep Sleep. Its 200 nA Sleep current and Cortex-M0+ efficiency keep idle drain negligible, while the 64 KB Flash and 8 KB SRAM accommodate sensor drivers, BLE stack fragments, and over-the-air update staging buffers. SleepWalking peripherals wake the CPU only when threshold-crossing events occur on ADC or GPIO, holding average current in the low microamp range. The 32-TQFP footprint allows reflow-compatible manufacturing and supports up to 26 GPIO for sensor and antenna interfaces.
Recommended
Wearable Health Monitors
For wearable health monitors, the ATSAML21E16B-ANT's combination of sub-35 uA/MHz active current, 200 nA Sleep, and 12-bit ADC is ideal for continuous biometric sampling. The Cortex-M0+ core drives heart-rate, SpO2, and motion-processing algorithms within tight power budgets. The integrated 12-bit DAC supports audio cue generation for hearing-aid accessories. The 32-TQFP package enables compact PCB layouts for wrist-form-factor designs, and Functional Safety (FuSa) documentation supports IEC 60601 medical device certification paths.
Recommended
Smart Home Edge Controllers
Smart-home edge controllers benefit from the ATSAML21E16B-ANT's on-chip SERCOM modules (configurable as UART/SPI/I2C), event system for I/O-driven state changes, and 48 MHz Cortex-M0+ throughput. The device aggregates inputs from multiple sensors and bridges to gateways via UART or SPI. Its 1.62V-3.63V supply tolerance supports direct operation from a single 3V coin cell or two AA cells, while FuSa compliance (IEC 60730 Class B) accelerates certification of connected appliances.
Recommended
Industrial Wireless Sensor Transmitters
Industrial wireless sensor transmitters leverage the ATSAML21E16B-ANT's extended -40C to +85C industrial temperature range, robust SERCOM interfaces, and SleepWalking to wake the CPU only on sensor threshold events. The 12-bit ADC samples process variables with 1 LSB typical DNL, and the event system routes interrupts without software polling, reducing power and latency. The 32-TQFP package withstands high-vibration industrial environments and the FuSa documentation supports IEC 61508 SIL 2 designs.
Recommended
Home Appliance Control Boards
Home-appliance control boards are a primary target for the ATSAML21E16B-ANT thanks to its FuSa (Functional Safety) certification for IEC 60730 Class B, which is mandatory for washing machines, dishwashers, refrigerators, and ovens. The 64 KB Flash accommodates motor-control state machines plus safety diagnostic libraries; 8 KB SRAM buffers sensor samples and communication stacks. The 32-TQFP package drops onto existing Class B board footprints; the SERCOM modules drive UART displays, I2C sensors, and SPI motor drivers.
Recommended
Energy-Harvesting Devices
Energy-harvesting devices such as solar-powered BLE beacons and kinetic switches demand the absolute lowest Sleep current, where the ATSAML21E16B-ANT's 200 nA Sleep with full SRAM retention is competitive. The Cortex-M0+ core executes measurement and transmit tasks in milliseconds, then returns to Sleep before harvested energy reserves drain. The wide 1.62V-3.63V supply tolerance operates directly from supercapacitor or lithium-thionyl-chloride chemistries without additional regulation. The 32-TQFP is hand-solderable for low-volume energy-harvesting prototyping.
Recommended
HID and Consumer Input Devices
The ATSAML21E16B-ANT is a strong fit for wireless HID devices such as keyboard, mouse, and presenter remotes, where its 48 MHz Cortex-M0+ handles USB HID or BLE HID report generation with margin. Sleep current of 200 nA extends coin-cell life to 6-12 months in typical usage, and the 12-bit ADC supports capacitive touch or potentiometer analog inputs directly. The 32-TQFP package reflows cleanly and gives access to the full SERCOM set for SPI displays and I2C sensors. FuSa documentation is overkill for HID but provides diagnostic confidence.
Recommended
Recommended Products Summary
Engineering reference data for ATSAML21E16B-ANT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAML21E17B-ANT | ATSAML21E18B-ANT | ATSAML21E16B-AUT | ATSAML21E15B-ANT |
|---|---|---|---|---|---|
| Package | 32-TQFP (7x7 mm) | 32-TQFP (7x7) - same | 32-TQFP (7x7) - same | 32-TQFP (7x7) - same | 32-TQFP (7x7) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ |
| Maximum Clock | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| Flash Memory | 64 KB | 128 KB | 256 KB | 64 KB | 32 KB |
| SRAM | 8 KB | 16 KB | 32 KB | 8 KB | 4 KB |
| Supply Voltage | 1.62V to 3.63V | 1.62V to 3.63V | 1.62V to 3.63V | 1.62V to 3.63V | 1.62V to 3.63V |
| Sleep Current | 200 nA | 200 nA | 200 nA | 200 nA | 200 nA |
| Functional Safety | IEC 60730 Class B (FuSa) | IEC 60730 Class B (FuSa) | IEC 60730 Class B (FuSa) | IEC 60730 Class B (FuSa) | IEC 60730 Class B (FuSa) |
Key Differentiators
- Lowest Sleep current in the SAM L21 family at 200 nA (vs ATSAMD20E15A-ANT)
- Functional Safety (IEC 60730 Class B) certification included (vs ATSAMD20E15A-ANT)
- Event system for CPU-less peripheral-to-peripheral signaling (vs ATSAMD20E15A-ANT)
Design Notes
Estimated: For a typical sensor-node duty cycle of 0.1% (10 ms active, 9990 ms Sleep per second), average current = (10/1000 * 35 uA/MHz * 48 MHz * 0.5 typical utilization) + (9990/1000 * 200 nA) = ~10.4 uA average. To minimize this, configure peripherals for SleepWalking so SERCOM and ADC wake the CPU only on threshold events; verify in MPLAB X Power Analysis that the SERCOM idle current does not exceed 1 uA. Place a 100 nF decoupling capacitor within 3 mm of every VDD pin pair.
Route the SWD signals (SWDIO, SWCLK, RESETn) with ground reference and avoid crossing high-current traces. Keep the 32.768 kHz crystal traces within 5 mm of the XIN32/XOUT32 pins and surround them with a ground pour to minimize noise coupling into the DFLL. The exposed thermal pad on the TQFP package should be soldered to a continuous ground pour to meet the 31.5 C/W theta_JA rating. Per Microchip SAM L21 hardware design guide, place a 4.7 uF bulk capacitor on VDDIN and a 100 nF cap on each VDDIO pin.
Do not exceed 3.63V on VDDIN - the SAM L21E is NOT 5V tolerant on any pin. Avoid leaving unused GPIO floating; configure them as output driven low or input with internal pull enabled to minimize Sleep current leakage. When migrating from SAM D20E to SAM L21E, verify that your application does not depend on the D20's full-speed USB controller - the L21E retains USB but with reduced endpoint count. Always read the SAM L21 family errata document (DS80000769) before finalizing firmware; known silicon revisions affect ADC gain error and DFLL closed-loop stability at temperatures below -20C.
Separate analog and digital ground planes if the design uses the ADC for precision measurements. Connect AGND and DGND at a single point near the device's GND pins. The VDDCORE pin requires a 1 uF low-ESR ceramic capacitor placed within 2 mm of the pin; do not substitute a tantalum or electrolytic capacitor at this location as the internal LDO cannot compensate for high-ESR loads. For USB applications, the D+/D- traces must be 90-ohm differential with length matching within 2 mm.
Compliance Information
RoHS and REACH compliance per Mouser product listing. Not AEC-Q100 qualified (use SAM V71/SAM S70 for automotive). Halogen-free status not explicitly stated in provided data.
