ATSAML21G16B-ANT - 32-bit Cortex-M0+ MCU, 64KB Flash, 48MHz | Microchip
MPN: ATSAML21G16B-ANT β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.18 | $4.18 |
| 10 | $3.76 | $37.60 |
| 100 | $3.42 | $342.00 |
| 500 | $3.05 | $1,525.00 |
| 1,000 | $2.78 | $2,780.00 |
ATSAML21G16B-ANT Overview
What is a low-power microcontroller? A microcontroller (MCU) is a single-chip computer containing a CPU core, Flash program memory, SRAM data memory, and a rich set of peripherals. An ultra-low-power MCU like the SAM L21 family adds sophisticated power management that minimizes active and sleep-mode current draw, making it the preferred choice for battery-powered and energy-harvesting products where every microamp matters. Within the broader taxonomy, the SAM L21 belongs to: microcontroller -> embedded processor -> ARM Cortex-M -> power management IC ecosystem -> semiconductor IC.
Key features of the ATSAML21G16B-ANT include under 35 uA/MHz active current consumption and 200 nA in Sleep mode, an integrated Cortex-M0+ core delivering 1.48 CoreMark/MHz, a 12-bit ADC, multiple serial interfaces (SERCOM), and a hardware touch controller supporting Peripheral Touch Controller (PTC) buttons, sliders, and wheels. The device also integrates a full-speed USB 2.0 interface, an Event System for inter-peripheral signaling without CPU intervention, and SleepWalking peripherals that wake the CPU only when needed.
The SAM L21 architecture uses a pipelined Cortex-M0+ core with single-cycle I/O access, deterministic interrupt latency, and a Memory Protection Unit. The 64KB Flash supports in-application programming and is paired with an 8-channel DMA controller for low-overhead data movement. Power is managed by a Sleep Modes Controller with Idle, Standby, Off, Backup, and Retention modes, enabling the <35 uA/MHz active and 200 nA Sleep power budget claimed in Microchip's family datasheet.
Typical applications include IoT sensor nodes, wearable fitness bands, home automation devices, low-power wireless sensor hubs, and Human-Machine Interface (HMI) products using capacitive touch. The wide 1.6V-3.6V supply range simplifies designs powered directly from single-cell Li-Ion or two AA cells. The integrated USB 2.0 full-speed transceiver also supports PC peripherals and tethered accessories.
When designing with the ATSAML21G16B-ANT, use Microchip's MPLAB X IDE with MPLAB Harmony 3 or ASF frameworks, and program/debug via the integrated Serial Wire Debug (SWD) interface. For optimal sleep-mode performance, route all wake-up sources through the Event System and avoid polling loops. Decouple VDDCORE and VDDIO close to the IC with 100 nF ceramic capacitors.
This page synthesizes distributor pricing across 8+ sources, same-package drop-in alternatives, and engineering design notes beyond the manufacturer datasheet, giving procurement and design teams a single reference for the ATSAML21G16B-ANT.
Drop-in alternatives for ATSAML21G16B-ANT 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 ATSAML21G16B-ANT (same form factor and footprint) β differing in ADC, Active Current, Operating Temperature, Package, RoHS Status.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAML21G17B-ANT
β Drop-Inβ In Stock
$2.71 / Unit
View Datasheet βATSAML21G18B-ANT
β Drop-Inβ In Stock
$3.78 / Unit
View Datasheet βATSAML21E16B-ANT
β Drop-Inπ Reference alternative (not in catalog)
ATSAML21G16B-ANT Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M0+ (32-bit) |
| Maximum Clock Frequency | 48 MHz |
| Flash Program Memory | 64 KB (64K x 8) |
| SRAM | 8 KB |
| Supply Voltage (VDD) | 1.6 V to 3.6 V |
| Operating Temperature | -40 C to +105 C (industrial) |
| Active Current | <35 uA/MHz |
| Sleep Mode Current | 200 nA (typical, Sleep mode) |
| Package | 48-pin TQFP, 7x7x1 mm |
| Mounting Type | Surface Mount |
| Carrier Type | Tape & Reel |
| ADC | 12-bit (SAR) |
| USB | USB 2.0 Full-Speed device |
| Touch Controller | Peripheral Touch Controller (PTC) |
| Debug Interface | Serial Wire Debug (SWD) |
| RoHS Status | Compliant (Green) |
| DMA Channels | 12 |
| CoreMark/MHz | 1.48 |
ATSAML21G16B-ANT Pin Configuration
| Pin 1 | PA00 β GPIO/SERCOM/I2C/SPI/UART |
| Pin 2 | PA01 β GPIO/SERCOM/I2C/SPI/UART |
| Pin 3 | PA02 β GPIO/AIN0/PTC |
| Pin 4 | PA03 β GPIO/AIN1/PTC |
| Pin 5 | VDDIO β I/O supply voltage |
| Pin 6 | GND β Ground |
| Pin 7 | VDDCORE β Internal core LDO output (decouple 1uF+100nF) |
| Pin 8 | PA04 β GPIO/AIN2/PTC |
| Pin 9 | PA05 β GPIO/AIN3/PTC |
| Pin 10 | PA06 β GPIO/AIN4/PTC |
| Pin 11 | PA07 β GPIO/AIN5/PTC |
| Pin 12 | PA08 β GPIO/AIN6/PTC/SERCOM |
| Pin 13 | PA09 β GPIO/AIN7/PTC/SERCOM |
| Pin 14 | PA10 β GPIO/AIN8/PTC/SERCOM |
| Pin 15 | PA11 β GPIO/AIN9/PTC/SERCOM |
| Pin 16 | PA12 β GPIO/AIN10/PTC |
| Pin 17 | PA13 β GPIO/AIN11/PTC |
| Pin 18 | PA14 β GPIO/AIN12/PTC |
| Pin 19 | PA15 β GPIO/AIN13/PTC |
| Pin 20 | PA16 β GPIO/AIN14/PTC/SERCOM |
| Pin 21 | PA17 β GPIO/AIN15/PTC/SERCOM |
| Pin 22 | PA18 β GPIO/SERCOM |
| Pin 23 | PA19 β GPIO/SERCOM |
| Pin 24 | PA20 β GPIO/SERCOM |
| Pin 25 | PA21 β GPIO/SERCOM |
| Pin 26 | PA22 β GPIO/SERCOM/I2C |
| Pin 27 | GND β Ground |
| Pin 28 | VDDIO β I/O supply voltage |
| Pin 29 | PA23 β GPIO/SERCOM/USB |
| Pin 30 | PA24 β GPIO/SERCOM/USB |
| Pin 31 | PA25 β GPIO/SERCOM/USB |
| Pin 32 | PA27 β GPIO/SERCOM |
| Pin 33 | RESETn β Reset input (active low) |
| Pin 34 | SWDIO β Serial Wire Debug data |
| Pin 35 | SWCLK β Serial Wire Debug clock |
| Pin 36 | PA30 β GPIO/SERCOM |
| Pin 37 | PA31 β GPIO/SERCOM |
| Pin 38 | PB00 β GPIO/SERCOM |
| Pin 39 | PB01 β GPIO/SERCOM |
| Pin 40 | PB02 β GPIO/SERCOM |
| Pin 41 | GND β Ground |
| Pin 42 | VDDCORE β Internal core LDO output (decouple 1uF+100nF) |
| Pin 43 | GND β Ground |
| Pin 44 | VDDIO β I/O supply voltage |
| Pin 45 | PB03 β GPIO/SERCOM |
| Pin 46 | PB04 β GPIO/SERCOM |
| Pin 47 | PB05 β GPIO/SERCOM |
| Pin 48 | PB06 β GPIO/SERCOM |
Typical Applications
ATSAML21G16B-ANT is suitable for 6 applications: Battery-Powered IoT Sensor Nodes, Wearable Fitness Bands, Home Automation HMI Panels, Smart Home Sensor Hubs, USB PC Peripherals and Accessories, Industrial Remote Control Transmitters.
Battery-Powered IoT Sensor Nodes
The ATSAML21G16B-ANT fits battery-powered IoT sensor nodes because its 200 nA Sleep mode current and under 35 uA/MHz active consumption enable years of operation on a CR2032 coin cell or 2x AA cells. SleepWalking peripherals let the MCU stay in deep sleep until the ADC, SERCOM, or external interrupt wakes it, so the CPU only runs when data is actually available. The 64 KB Flash holds a typical LoRaWAN or BLE sensor stack with OTA update partition, while the 1.6V-3.6V supply range accepts the Li-Ion discharge curve directly. Engineers typically pair it with an SPI-connected sensor and a sub-GHz or BLE transceiver.
Recommended
Wearable Fitness Bands
The ATSAML21G16B-ANT's integrated Peripheral Touch Controller (PTC) makes it ideal for wearable fitness bands that need capacitive touch buttons on a small enclosure without external touch ICs. The 48 MHz Cortex-M0+ core handles step-counting, accelerometer sampling over I2C SERCOM, and BLE radio control in active mode while dropping to 200 nA Sleep between samples. The TQFP48 7x7 mm package fits wrist-sized PCBs and the -40C to +105C rating survives body heat and cold-weather use. Power is typically a 100 mAh Li-Po cell charged via USB, with the SAM L21's USB 2.0 Full-Speed device handling data sync and charging.
Recommended
Home Automation HMI Panels
The ATSAML21G16B-ANT is a strong fit for low-cost home-automation HMI panels where capacitive touch sliders and buttons replace mechanical switches. The PTC peripheral supports up to 32 self-capacitance or 144 mutual-capacitance touch channels, sufficient for full room-control panels with light dimmers and blind sliders. The 12-bit ADC reads rotary encoders, temperature sensors, and ambient-light sensors through the same SERCOM/I2C buses. Active current under 35 uA/MHz keeps wall-powered idle consumption low, while the Sleep mode is reached automatically when the panel is untouched for several seconds. Engineers typically use MPLAB Harmony 3's QTouch library for touch tuning.
Recommended
Smart Home Sensor Hubs
Smart-home sensor hubs benefit from the ATSAML21G16B-ANT's combination of low active current, full-speed USB, and Cortex-M0+ processing headroom. The MCU acts as a ZigBee/BLE bridge, processing RF commands and forwarding them to a host SoC over USB. The 64 KB Flash stores bridge firmware and security keys; 8 KB SRAM holds routing tables for active devices. SleepWalking wakes the hub on GPIO from a PIR sensor without CPU wake-up, then the event system triggers USB notification only when motion is detected. The 1.6V-3.6V supply simplifies 3.3V-only power designs from a USB or wall adapter.
Recommended
USB PC Peripherals and Accessories
The ATSAML21G16B-ANT's integrated USB 2.0 Full-Speed device port makes it ideal for low-cost USB PC peripherals such as keyboards, mice, presenters, and HID-class accessories. The Cortex-M0+ handles HID reports, debouncing, and battery charging logic on a single chip. The TQFP48 package and industrial -40C to +105C rating suit retail and industrial peripherals. Active current under 35 uA/MHz at 48 MHz keeps bus-powered devices within USB suspend current limits, while Sleep mode drops to 200 nA when the host suspends the bus. Firmware updates use the SAM-BA bootloader over USB without an external programmer.
Recommended
Industrial Remote Control Transmitters
Industrial remote-control transmitters benefit from the ATSAML21G16B-ANT's wide -40C to +105C operating range, low Sleep current, and Event System for deterministic GPIO-to-radio signaling. The 48 MHz Cortex-M0+ scans button matrices via the PTC and triggers sub-GHz RF transmissions on SERCOM SPI. Idle current of 200 nA keeps handheld remotes on a single 9V battery for years; only the Event System wakes the MCU on button press. Engineers can leverage the same SAM L21 family across the receiver side, sharing firmware drivers and reducing BOM cost across product variants.
Recommended
Recommended Products Summary
Engineering reference data for ATSAML21G16B-ANT β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAML21G17B-ANT | ATSAML21G18B-ANT | ATSAML21E16B-ANT |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 48-TQFP (7x7 mm) | 48-TQFP (7x7 mm) - same | 48-TQFP (7x7 mm) - same | 32-TQFP (different pin count) |
| Flash Memory | 64 KB | 128 KB | 256 KB | 64 KB |
| SRAM | 8 KB | 16 KB | 32 KB | 8 KB |
| Maximum Clock | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| 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 |
| Operating Temperature | -40 C to +105 C | -40 C to +105 C | -40 C to +105 C | -40 C to +105 C |
| Sleep Mode Current | 200 nA | 200 nA | 200 nA | 200 nA |
| Pin Count | 48 | 48 | 48 | 32 (smaller package) |
Key Differentiators
- Memory scalability within identical TQFP48 footprint (vs ATSAML21G17B-ANT and ATSAML21G18B-ANT)
- Ultra-low Sleep current with SleepWalking peripherals (vs ATSAMD21G16)
- Integrated Peripheral Touch Controller (PTC) on-chip (vs STM32L031F4Px)
Design Notes
Estimated: at VDD=3.3V, CPU active at 48 MHz, the ATSAML21G16B-ANT draws roughly 1.7 mA from the VDDIO rail (35 uA/MHz x 48 MHz). In Sleep mode the same rail sees ~200 nA. Use a low-Iq LDO (e.g., MCP1700) with at least 1 uF input/output capacitance to keep quiescent current below 2 uA so total sleep current is dominated by the MCU. Tie all unused I/O pins to GND through the internal pulldown to prevent floating-pin leakage above 1 uA.
Place 100 nF + 1 uF ceramic decoupling capacitors within 2 mm of the VDDCORE pins (7 and 42) and the VDDIO pins (5, 28, 44). Use a 4-layer PCB with a dedicated ground plane to keep the 48 MHz core and 12-bit ADC noise isolated. Route the SWD signals (SWDIO/SWCLK) away from switching DC/DC nodes, and add a 100 nF cap on the RESETn pin if it is exposed on a programming header.
Do not exceed 3.6V on any VDD pin - the SAM L21 core is not 5V tolerant and back-powering through I/O can latch-up. Always configure the PTC peripheral via QTouch Composer before relying on touch readings; the default GPIO settings do not enable the touch sense lines. When using SleepWalking, route events through the Event System channels 0-11, not through polled GPIO, to actually achieve the 200 nA Sleep figure. Finally, lock the GCLK_MAIN source before changing it, or the MCU can hang.
Keep the USB DP/DM traces (PA24/PA25) at 90 ohm differential impedance and route them over a continuous ground plane with no splits. Match trace length within 2 mm to avoid signal-integrity violations on USB Full-Speed. If the design uses the integrated PTC, surround the touch sensors with a hatched ground guard ring driven by the same PTC channel set to a shielding mode to suppress moisture and ESD events. Do not route digital signals under the touch sensors.
Compliance Information
RoHS compliant and Pb-free per Microchip product page; 'Green' marking confirms halogen-free status per Microchip datasheet conventions (verify against current material declaration). AEC-Q100 qualification not claimed - choose SAM C20/SAM V71 or other automotive-grade families for AEC-Q100 needs.
