ATSAMD21G16B-MFT - 48MHz ARM Cortex-M0+ MCU 64KB Flash | Microchip
MPN: ATSAMD21G16B-MFT β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.42 | $3.42 |
| 10 | $3.07 | $30.70 |
| 100 | $2.61 | $261.00 |
| 500 | $2.18 | $1,090.00 |
| 1,000 | $1.96 | $1,960.00 |
ATSAMD21G16B-MFT Overview
A microcontroller (MCU) is a compact system-on-chip that combines a CPU core, program and data memory, and a rich set of peripherals on a single die. The Cortex-M0+ is ARM's smallest and most energy-efficient application processor core, designed for deterministic embedded control in cost- and power-sensitive applications. Within Microchip's portfolio the SAM D21 sits below the SAM D51 (Cortex-M4F) and above the SAM D11 (Cortex-M0+) families, occupying the low-power general-purpose MCU tier with USB, SERCOM, and event system integration.
Key features include six SERCOM communication interfaces (each configurable as UART, SPI, or I2C), a USB 2.0 Full-Speed device with on-chip transceiver, a 12-bit 350ksps ADC, two analog comparators, a 10-bit DAC, up to 38 GPIO pins, and the Event System for inter-peripheral triggers. The peripheral touch controller (PTC) supports capacitive touch sensing, and the device includes a real-time clock, multiple timer/counters, and a DMA controller for offloading CPU data movement.
The SAM D21 architecture combines a single-cycle hardware multiplier, a Micro Trace Buffer for lightweight instruction tracing, and a SleepWalking interrupt scheme that lets peripherals wake the CPU on events without full domain wake-up. Brown-out detection, power-on reset, and a DFLL48M closed-loop oscillator with FDPLL96K 96MHz fractional digital PLL deliver robust analog performance. The complete brown-out and POR chain, hardware-managed with multiple threshold choices, enhances robustness in noisy environments.
Drop-in alternatives for ATSAMD21G16B-MFT 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 ATSAMD21G16B-MFT (same form factor and footprint) β differing in Operating Temperature, ADC, DAC, RoHS Status, Debug Interface.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAMD21G16B-MF
β Drop-Inπ Reference alternative (not in catalog)
ATSAMD21G15B-MFT
β Drop-Inπ Reference alternative (not in catalog)
ATSAMD20G16B-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$1.92 / Unit
View Datasheet βATSAMD21G16B-MFT Maximum Ratings & Electrical Characteristics
| Core Architecture | ARM Cortex-M0+ (32-bit) |
| Maximum CPU Frequency | 48 MHz |
| CoreMark Performance | 2.46 CoreMark/MHz |
| Program Flash | 64 KB (in-system self-programmable) |
| SRAM | 8 KB |
| Supply Voltage (VDDIN) | 1.62 V to 3.63 V |
| Operating Temperature | -40 C to +125 C (industrial) |
| Package | 48-QFN (7x7 mm) |
| Mounting Type | Surface Mount |
| Packaging Type | Tape & Reel (MFT suffix) |
| GPIO Count | Up to 38 pins |
| ADC | 12-bit, up to 350 ksps |
| DAC | 10-bit |
| Analog Comparators | 2 |
| SERCOM Modules | 6 (configurable UART/SPI/I2C) |
| USB | USB 2.0 Full-Speed Device, on-chip transceiver |
| DMA Channels | 12 |
| Peripheral Touch Controller (PTC) | Yes (capacitive touch sensing) |
| Debug Interface | 2-pin Serial Wire Debug (SWD) |
| Functional Safety (FuSa) | IEC 60730 class B capable |
| Hardware Multiplier | Single-cycle |
| RoHS Status | Green, RoHS compliant |
ATSAMD21G16B-MFT Pin Configuration
| Pin 1 | VDD β Digital supply voltage |
| Pin 2 | PA00 β GPIO / SERCOM1 PAD0 |
| Pin 3 | PA01 β GPIO / SERCOM1 PAD1 |
| Pin 4 | PA02 β GPIO / Analog input |
| Pin 5 | PA03 β GPIO / Analog input / reference |
| Pin 6 | GND β Ground |
| Pin 7 | PA04 β GPIO / SERCOM0 PAD0 |
| Pin 8 | PA05 β GPIO / SERCOM0 PAD1 |
| Pin 9 | PA06 β GPIO / SERCOM0 PAD2 |
| Pin 10 | PA07 β GPIO / SERCOM0 PAD3 |
| Pin 11 | PA08 β GPIO / SERCOM2 PAD0 / I2S |
| Pin 12 | PA09 β GPIO / SERCOM2 PAD1 / I2S |
| Pin 13 | PA10 β GPIO / SERCOM2 PAD2 / I2S |
| Pin 14 | PA11 β GPIO / SERCOM2 PAD3 / I2S |
| Pin 15 | VDD β Digital supply voltage |
| Pin 16 | PA12 β GPIO / SERCOM4 PAD0 |
| Pin 17 | PA13 β GPIO / SERCOM4 PAD1 |
| Pin 18 | PA14 β GPIO / SERCOM4 PAD2 |
| Pin 19 | PA15 β GPIO / SERCOM4 PAD3 |
| Pin 20 | PA16 β GPIO / SERCOM1 PAD0 / I2C |
| Pin 21 | PA17 β GPIO / SERCOM1 PAD1 / I2C |
| Pin 22 | PA18 β GPIO / SERCOM3 PAD0 |
| Pin 23 | PA19 β GPIO / SERCOM3 PAD1 |
| Pin 24 | PA20 β GPIO / SERCOM5 PAD2 |
| Pin 25 | PA21 β GPIO / SERCOM5 PAD3 |
| Pin 26 | PA22 β GPIO / SERCOM3 PAD0 |
| Pin 27 | PA23 β GPIO / SERCOM3 PAD1 |
| Pin 28 | PA24 β GPIO / USB D- |
| Pin 29 | PA25 β GPIO / USB D+ |
| Pin 30 | GND β Ground |
| Pin 31 | PA27 β GPIO / boot loader entry |
| Pin 32 | RESET β Active-low reset input |
| Pin 33 | PA28 β GPIO / SERCOM5 PAD2 |
| Pin 34 | PA29 β GPIO / SERCOM5 PAD3 |
| Pin 35 | PA30 β GPIO / SWDIO |
| Pin 36 | PA31 β GPIO / SWCLK |
| Pin 37 | PB00 β GPIO / SERCOM5 PAD0 |
| Pin 38 | PB01 β GPIO / SERCOM5 PAD1 |
| Pin 39 | PB02 β GPIO / SERCOM5 PAD2 / ADC |
| Pin 40 | PB03 β GPIO / SERCOM5 PAD3 / ADC |
| Pin 41 | PB04 β GPIO / SERCOM3 PAD0 / ADC |
| Pin 42 | PB05 β GPIO / SERCOM3 PAD1 / ADC |
| Pin 43 | PB06 β GPIO / SERCOM3 PAD2 / ADC |
| Pin 44 | PB07 β GPIO / SERCOM3 PAD3 / ADC |
| Pin 45 | PB08 β GPIO / SERCOM4 PAD0 / I2C |
| Pin 46 | PB09 β GPIO / SERCOM4 PAD1 / I2C |
| Pin 47 | VSW β Voltage regulator switching output |
| Pin 48 | GND β Ground / Exposed pad (EP) |
Typical Applications
ATSAMD21G16B-MFT is suitable for 6 applications: USB HID Human-Interface Devices, IoT Sensor Edge Nodes, Capacitive Touch User Interfaces, Industrial Control & Monitoring, Wearable Fitness & Health Devices, Battery-Powered Data Loggers.
USB HID Human-Interface Devices
The ATSAMD21G16B-MFT is well-suited to USB HID peripherals such as keyboards, mice, game controllers, and custom input devices. Its integrated USB 2.0 Full-Speed device controller with on-chip transceiver and internal 3.3V regulator eliminates the need for an external PHY or LDO, reducing BOM cost and PCB area for bus-powered designs. The six SERCOM interfaces provide ample UART/SPI/I2C channels for connecting to sensors, displays, or wireless modules, while the 64KB Flash accommodates USB-HID report descriptors and HID-class middleware. Typical designs pair the MCU with a USB-C connector, ESD protection array, and 10uF bulk capacitor, and the -40C to +125C industrial temperature range supports use in outdoor or automotive cabin environments.
Recommended
IoT Sensor Edge Nodes
For IoT edge sensor nodes the ATSAMD21G16B-MFT provides the right combination of low power, peripherals, and code space. The Cortex-M0+ core at 48 MHz with SleepWalking peripherals wakes on sensor events without full-domain wake, while the 12-bit 350 ksps ADC and 10-bit DAC enable analog sensor interfaces and excitation. The six SERCOM channels drive I2C sensors, SPI flash for data logging, and UART for NB-IoT or LoRa modem modules. With 64KB Flash and 8KB SRAM, the device hosts TLS stacks, sensor drivers, and over-the-air firmware update (OTA) bootloaders. The -40C to +125C operating range and the 1.62V-3.63V supply window support battery-powered deployments on 2xAA, coin cell, or rechargeable Li-Ion chemistries.
Recommended
Capacitive Touch User Interfaces
The ATSAMD21G16B-MFT's integrated Peripheral Touch Controller (PTC) makes it a strong fit for capacitive touch user interfaces such as appliance control panels, IoT switches, and smart-home dimmers. The PTC supports up to 256 touch channels via hardware-driven charge-transfer measurement, offloading the touch-sensing algorithm from the Cortex-M0+ core and freeing CPU cycles for communication stacks. Combined with the 12-bit ADC, 10-bit DAC for buzzer feedback, and 38 GPIO for LED indication, the device implements a complete HMI in a single chip. The 64KB Flash is sufficient for QTouch library firmware, gesture recognition, and a Wi-Fi/BLE host interface via SPI or UART to a wireless coprocessor.
Recommended
Industrial Control & Monitoring
In industrial control and monitoring applications the ATSAMD21G16B-MFT operates reliably across the -40C to +125C industrial temperature range while providing the analog and digital peripherals required for sensor aggregation and actuator control. The 12-bit 350 ksps ADC multiplexes up to 14 channels for voltage, current, and temperature sensing, while the two analog comparators handle overcurrent/undervoltage protection with hardware response. The six SERCOM channels drive RS-485 transceivers via UART, Modbus or PROFIBUS links, and SPI-based isolation barriers for high-voltage interfaces. Functional Safety (FuSa) capability targeting IEC 60730 class B appliances and brown-out detection support safety-critical industrial designs.
Recommended
Wearable Fitness & Health Devices
Wearable fitness and health devices benefit from the ATSAMD21G16B-MFT's low-power Cortex-M0+ core, integrated USB for charging and data sync, and 12-bit ADC for biometric sensing. The device's SleepWalking mode keeps the heart-rate sensor, accelerometer SPI interface, and BLE SoC connection alive while the CPU sleeps, drawing only a few microamps in idle states. The USB 2.0 device interface eliminates the need for a separate charging IC in many designs, supporting direct Li-Ion battery charging and PC-side data synchronization. The 64KB Flash and 8KB SRAM accommodate BLE host stacks, sensor-fusion algorithms, and OTA firmware bootloaders. The 48-QFN 7x7 mm package fits wrist-worn form factors with limited PCB real estate.
Recommended
Battery-Powered Data Loggers
Battery-powered data loggers leverage the ATSAMD21G16B-MFT's low-power standby modes, multiple SERCOM interfaces, and 64KB Flash for sensor buffering. The Micro Trace Buffer supports lightweight instruction tracing during firmware debug without external debuggers, while the DMA controller offloads data movement from SPI flash or I2S microphones without CPU intervention. The 12-bit ADC captures temperature, voltage, and current data at 350 ksps, with the DMA storing samples into SRAM and batching writes to external SPI flash. Operating from 1.62V to 3.63V, the MCU supports direct connection to 2xAA alkaline, 1x Li-Ion, or 1x Li-SOCl2 primary cells with no additional LDO. The 8KB SRAM buffers 4 kHz audio logging or vibration signatures between flash writes.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD21G16B-MFT β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD21G16B-MF | ATSAMD21G15B-MFT | ATSAMD21E16B-AU |
|---|---|---|---|---|
| Package | 48-QFN (7x7 mm) | 48-QFN (7x7 mm) - same | 48-QFN (7x7 mm) - same | TQFP-48 - different footprint |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core | ARM Cortex-M0+ 32-bit | ARM Cortex-M0+ 32-bit | ARM Cortex-M0+ 32-bit | ARM Cortex-M0+ 32-bit |
| Max CPU Frequency | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| Flash Memory | 64 KB | 64 KB | 32 KB (-50%) | 64 KB |
| SRAM | 8 KB | 8 KB | 4 KB (-50%) | 8 KB |
| USB | USB 2.0 Full-Speed Device | USB 2.0 Full-Speed Device | USB 2.0 Full-Speed Device | USB 2.0 Full-Speed Device |
| Operating Temperature | -40C to +125C | -40C to +125C | -40C to +125C | -40C to +125C |
| Packaging | Tape & Reel | Tray | Tape & Reel | Tray |
Key Differentiators
- Integrated USB 2.0 Full-Speed with on-chip transceiver (vs ATSAMD20G16B-MU)
- Same QFN-48 footprint with full 64KB Flash (vs ATSAMD21G15B-MFT)
- Functional Safety (FuSa) capability for IEC 60730 class B (vs PIC16F722-E/SP)
Design Notes
The ATSAMD21G16B-MFT integrates an on-chip 1.2V core regulator fed by VDDIN. Decouple VDDIN with a 1uF X7R ceramic capacitor as close as possible to the VDDIN pin (pin 1 or 15), and place a 0.1uF X7R bypass within 2mm of each VDD pin pair. The VSW pin (pin 47) requires a 1uH power inductor and 1uF X5R capacitor to complete the switching regulator output filter; keep the VSW loop area under 25 mm^2 to minimize radiated EMI. For USB bus-powered designs, VDDIN accepts the 5V-to-3.3V drop directly; ensure the 5V input respects the VDDIN max of 3.63V via external regulation or LDO.
Route the USB D- (PA24, pin 28) and USB D+ (PA25, pin 29) as a 90-ohm differential pair with 7.5 mil trace width and ground reference on an adjacent layer. Keep total length under 25 mm and match lengths within 150 mil. Place the ESD protection array within 5 mm of the USB receptacle. For SERCOM SPI interfaces clocked above 25 MHz, route SCK and MOSI as a length-matched pair (within 200 mil). The exposed thermal pad (GND, pin 48) must be soldered to a continuous ground plane with at least 8 thermal vias (0.3 mm drill) to a bottom-side copper pour for thermal dissipation.
Do not enable the Peripheral Touch Controller (PTC) without first configuring the Y-lines as inputs in the PORT group; misconfigured PTC pins can source continuous current and damage the device. The SAM D21 errata sheet documents multiple GPIO and ADC errata - review errata documents 40001882A-SAMD21-Errata before layout finalization. The RESET pin (pin 32) requires a 10 kohm pull-up to VDDIN and a 100 nF capacitor to ground for proper power-on-reset timing. Avoid using PB04-PB07 (pins 41-44) for high-speed SERCOM signals in designs that also need ADC on those pins, as channel switching causes 2-3 ADC LSB of cross-talk.
Place the 32.768 kHz crystal (XOSC32K) within 5 mm of pins PA00 (XIN32) and PA01 (XOUT32), surrounded by a ground ring connected to GND. The crystal load capacitors (typically 12-22 pF) should connect from each crystal pin to GND with traces under 2 mm. For the 48 MHz DFLL48M closed-loop operation with USB, ensure VDDIN has less than 50 mV peak-to-peak ripple; otherwise USB eye-pattern compliance fails. Maintain 4 mm clearance between the analog traces (ADC inputs) and the digital switching traces (SWD, SERCOM clocks) to preserve ADC SNR above 60 dB.
Compliance Information
Per Microchip product page and DigiKey listing, ATSAMD21G16B-MFT is RoHS compliant (Green), lead-free, and supplied in industrial -40C to +125C temperature grade. AEC-Q100 is not applicable (consumer/industrial MCU, not automotive qualified).
