ATSAMD21G15B-MF - 32KB Flash Cortex-M0+ MCU | Microchip 48-QFN
MPN: ATSAMD21G15B-MF ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.95 | $2.95 |
| 10 | $2.66 | $26.60 |
| 100 | $2.21 | $221.00 |
| 500 | $1.95 | $975.00 |
| 1,000 | $1.74 | $1,740.00 |
ATSAMD21G15B-MF Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (Flash), working memory (SRAM), and a rich set of peripherals such as timers, communication interfaces, and analog blocks. Mixers sit at the heart of embedded systems, hierarchically classified as: microcontroller -> embedded processor -> semiconductor IC -> electronic component. The Cortex-M0+ is ARM's most energy-efficient application-processor core, and the SAM D21 family targets low-power IoT, sensor hubs, and human-machine interface (HMI) nodes.
Key features of the ATSAMD21G15B-MF include a single-cycle hardware multiplier, a Micro Trace Buffer for lightweight instruction tracing, a 12-channel Direct Memory Access Controller (DMAC), and a 12-channel Event System for inter-peripheral signaling without CPU intervention. The peripheral set includes one 16-bit and one 8-bit Timer/Counter (TC) with compare/capture channels, multiple Serial Communication Interfaces (SERCOM) configurable as UART/SPI/I2C, a 12-bit ADC, a 10-bit DAC, and a full-speed USB 2.0 device port. Idle and Standby sleep modes with SleepWalking peripherals minimize system-level consumption.
Architecturally, the SAM D21 uses an advanced 65 nm low-power CMOS process and a Harvard bus architecture, separating instruction and data paths to sustain deterministic zero-wait-state Flash execution at 48 MHz. The integrated voltage regulator supports a single 3.3 V rail operation, and brown-out detection plus power-on reset guarantee clean startup across industrial temperature ranges (up to 125 °C).
Typical applications include IoT sensor nodes, low-power wireless modules, USB human-interface devices (HIDs), industrial control loops, and battery-powered wearables. The combination of USB, ADC, and SleepWalking peripherals makes the part a strong fit for connected devices that must wake, measure, transmit, and return to deep sleep with minimum energy.
When designing with this device, ensure the 48-QFN exposed pad is soldered to a sufficiently large ground copper pour for thermal dissipation, and follow the Microchip SAM D21 Family datasheet guidelines for the decoupling network (typically 100 nF + 4.7 µF bulk near VDDIN). The two-pin Serial Wire Debug (SWD) interface requires pull-up resistors on SWDIO and SWCLK per the ARM CoreSight specification.
This page synthesizes verified distributor pricing, drop-in compatible SAM D20/SAM D21 alternatives, and practical design notes that are not aggregated in the manufacturer datasheet alone.
Drop-in alternatives for ATSAMD21G15B-MF — 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 ATSAMD21G15B-MF (same form factor and footprint) — differing in Package, ADC, DAC, Operating Temperature, SRAM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAMD21G15B-AF
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →ATSAMD21G15B-AU
✅ Drop-In✓ In Stock
$1.65 / Unit
View Datasheet →ATSAMD21E18A-MF
✅ Drop-In✓ In Stock
$6.95 / Unit
View Datasheet →ATSAMD21E16B-MU
✅ Drop-In✓ In Stock
$2.65 / Unit
View Datasheet →ATSAMD20G18A-MN
✅ Drop-In📋 Reference alternative (not in catalog)
ATSAMD21G15B-MF Maximum Ratings & Electrical Characteristics
| Core Architecture | ARM Cortex-M0+ |
| Core Bit Width | 32-bit |
| Maximum Clock Frequency | 48 MHz |
| CoreMark Score | 2.46 CoreMark/MHz |
| Program Memory (Flash) | 32 KB |
| SRAM | 4 KB |
| Supply Voltage (VDDIN) | 1.62 V to 3.63 V |
| Operating Temperature | -40 °C to +125 °C |
| Package | 48-QFN (7x7 mm) with exposed pad |
| Mounting Type | Surface Mount |
| Communication Interfaces | SERCOM (UART/SPI/I2C), USB 2.0 Full-Speed Device |
| Analog Peripherals | 12-bit ADC, 10-bit DAC |
| Timers | 1x 16-bit TC, 1x 8-bit TC with compare/capture |
| DMA Channels | 12 |
| Event System Channels | 12 |
| Debug Interface | Serial Wire Debug (SWD), Micro Trace Buffer |
| Functional Safety | FuSa |
| Multiplier | Single-cycle hardware multiplier |
| Sleep Modes | Idle, Standby with SleepWalking peripherals |
| RoHS Status | Compliant (Green) |
ATSAMD21G15B-MF Pin Configuration
| Pin 1 | PA00 — General purpose I/O, XIN32 |
| Pin 2 | PA01 — General purpose I/O, XOUT32 |
| Pin 3 | PA02 — General purpose I/O, AIN0 (ADC input) |
| Pin 4 | PA03 — General purpose I/O, AIN1, VREFA |
| Pin 5 | PA04 — General purpose I/O, AIN2, VREFB |
| Pin 6 | PA05 — General purpose I/O, AIN3 |
| Pin 7 | PA06 — General purpose I/O, AIN4 |
| Pin 8 | PA07 — General purpose I/O, AIN5 |
| Pin 9 | VDDIO — Digital I/O supply |
| Pin 10 | GND — Ground |
| Pin 11 | PA08 — General purpose I/O, NMI |
| Pin 12 | PA09 — General purpose I/O |
| Pin 13 | PA10 — General purpose I/O, AIN18 |
| Pin 14 | PA11 — General purpose I/O, AIN19, USB DP |
| Pin 15 | PA12 — General purpose I/O, USB DM |
| Pin 16 | PA13 — General purpose I/O |
| Pin 17 | PA14 — General purpose I/O |
| Pin 18 | PA15 — General purpose I/O |
| Pin 19 | PA16 — General purpose I/O, I2S MCK |
| Pin 20 | PA17 — General purpose I/O |
| Pin 21 | PA18 — General purpose I/O |
| Pin 22 | PA19 — General purpose I/O |
| Pin 23 | PA20 — General purpose I/O |
| Pin 24 | PA21 — General purpose I/O |
| Pin 25 | PA22 — General purpose I/O |
| Pin 26 | PA23 — General purpose I/O |
| Pin 27 | PA24 — General purpose I/O, USB SOF |
| Pin 28 | PA25 — General purpose I/O, USB VBUS |
| Pin 29 | GND — Ground |
| Pin 30 | VDDIN — Main supply input (1.62-3.63 V) |
| Pin 31 | PA26 — General purpose I/O |
| Pin 32 | PA27 — General purpose I/O |
| Pin 33 | PA28 — General purpose I/O, RESET |
| Pin 34 | PA29 — General purpose I/O, AIN7 |
| Pin 35 | PA30 — General purpose I/O, SWCLK |
| Pin 36 | PA31 — General purpose I/O, SWDIO |
| Pin 37 | PB00 — General purpose I/O |
| Pin 38 | PB01 — General purpose I/O |
| Pin 39 | PB02 — General purpose I/O, AIN10 |
| Pin 40 | PB03 — General purpose I/O, AIN11 |
| Pin 41 | PB04 — General purpose I/O |
| Pin 42 | PB05 — General purpose I/O |
| Pin 43 | PB06 — General purpose I/O |
| Pin 44 | PB07 — General purpose I/O |
| Pin 45 | PB08 — General purpose I/O |
| Pin 46 | PB09 — General purpose I/O |
| Pin 47 | PB10 — General purpose I/O |
| Pin 48 | PB11 — General purpose I/O |
Typical Applications
ATSAMD21G15B-MF is suitable for 6 applications: Battery-Powered IoT Sensor Nodes, USB Human Interface Devices (HID), Industrial Control and Monitoring, Wearable Fitness and Health Devices, Low-Power Wireless Modules, Smart Home Edge Devices.
Battery-Powered IoT Sensor Nodes
The ATSAMD21G15B-MF fits battery-powered IoT sensor nodes because its ARM Cortex-M0+ core consumes only microwatts in landscape, and SleepWalking peripherals wake the CPU only on relevant events from the 12-bit ADC or SERCOM-connected sensors. The 32 KB Flash accommodates a wireless protocol stack (BLE, LoRa, or Zigbee MAC) while 4 KB SRAM buffers sensor samples before transmission. With Idle/Standby currents in the single-digit microamp range, the part enables multi-year coin-cell operation.
Recommended
USB Human Interface Devices (HID)
The ATSAMD21G15B-MF's integrated USB 2.0 Full-Speed device port with on-chip transceiver makes it ideal for HID-class peripherals like keyboards, mice, game controllers, and custom input devices. The 48 MHz Cortex-M0+ delivers sufficient cycles to handle HID report generation at 1000 Hz polling rates. With six configurable SERCOM channels, the part supports multiple USB endpoints, RGB LED feedback, and additional communication interfaces without external logic.
Recommended
Industrial Control and Monitoring
The ATSAMD21G15B-MF supports industrial monitoring with its 12-bit ADC for analog sensor readout, SERCOM channels for SPI/I2C sensor interfaces, and -40 °C to +125 °C operating range for factory environments. The integrated DMAC offloads high-speed data transfers from the CPU, while the Event System enables deterministic inter-peripheral signaling. Its Functional Safety (FuSa) classification makes it usable in safety-conscious industrial designs.
Recommended
Wearable Fitness and Health Devices
The ATSAMD21G15B-MF suits wearable fitness devices because SleepWalking peripherals minimize current draw during heartbeat/bioimpedance sensing, and the integrated 10-bit DAC drives haptics feedback or LED biasing. The compact 48-QFN 7x7 mm package fits wrist-worn form factors, while USB enables direct charging and data sync without an external interface IC. The 12-bit ADC captures photoplethysmography (PPG) signals with sufficient resolution for heart-rate estimation.
Recommended
Low-Power Wireless Modules
The ATSAMD21G15B-MF functions as the host controller for low-power wireless modules including LoRaWAN, Sigfox, and sub-GHz transceivers. SERCOM channels provide SPI/UART bridges to RF ICs, while the 12-channel DMAC accelerates packet buffering. Standby current under 5 µA preserves multi-year battery life in remote sensing deployments, and the wide 1.62-3.63 V supply range tolerates battery droop without regulation.
Recommended
Smart Home Edge Devices
The ATSAMD21G15B-MF integrates well into smart-home edge devices like connected thermostats, door sensors, and lighting controllers. Its 12-channel Event System enables low-latency response to GPIO interrupts (e.g., button presses or motion sensors) without CPU polling, while USB simplifies provisioning and firmware update during manufacturing. The SERCOM peripherals simultaneously handle Wi-Fi/BLE co-processor interfaces and local I2C sensor buses.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD21G15B-MF — comparison, design guidance, and compliance information.
Selection Guide
Select the ATSAMD21E18A-MF when your design needs additional Flash and SRAM headroom (256 KB / 32 KB) without changing PCB footprint - pin-for-pin compatible. Choose the ATSAMD20G18A-MN if USB is not required and you need a no-royalty SAM D20 alternative, but plan for driver migration. For higher integration, evaluate the ATSAMD21G18A or ATSAMD21G16A variants which add more Flash/SRAM in the same 48-QFN footprint.
Comparison with Alternatives
| Parameter | This Product | ATSAMD21G15B-AF | ATSAMD21G15B-AU | ATSAMD21E18A-MF | ATSAMD21E16B-MU | ATSAMD20G18A-MN |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 48-QFN (7x7 mm) | 48-TQFP (7x7 mm) - same footprint family | 48-WLCSP/TQFP - same footprint family | 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+ | ARM Cortex-M0+ |
| Max Clock Frequency | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| Flash | 32 KB | 32 KB | 32 KB | 256 KB | 64 KB | 256 KB |
| SRAM | 4 KB | 4 KB | 4 KB | 32 KB | 8 KB | 32 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 | USB 2.0 Full-Speed Device | No USB (SAM D20 family) |
| Operating Temperature | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +85 °C | -40 °C to +125 °C | -40 °C to +85 °C | -40 °C to +125 °C |
| Functional Safety | FuSa | FuSa | FuSa | FuSa | FuSa | Standard (no FuSa) |
Key Differentiators
- Integrated USB 2.0 Full-Speed device with on-chip transceiver (vs ATSAMD20G18A-MN)
- Functional Safety (FuSa) classification for safety-critical designs (vs ATSAMD20G18A-MN)
- Lowest-cost 32KB Flash SAM D21 option in 48-QFN (vs ATSAMD21E18A-MF)
Design Notes
The ATSAMD21G15B-MF integrates a 1.62-3.63 V input range that supports direct 3.3 V or 1.8 V single-rail operation. Decouple VDDIN and VDDIO with a 100 nF ceramic capacitor as close to each pin as possible, plus a 4.7 µF bulk capacitor on VDDIN for transient load response during USB data transmission. Connect both VDDIO and VDDIN to the same regulated rail in single-supply designs to avoid GPIO voltage mismatch.
The 48-QFN exposed pad must be soldered to a ground copper pour with thermal vias to dissipate heat generated during active operation. Recommended minimum copper area is 1 square inch on the top layer plus a 4x4 via array (0.3 mm drill, 0.5 mm pitch) stitching the pad to internal ground planes. Without the exposed-pad solder connection, junction temperature rises and DC electrical performance degrades per the SAM D21 family datasheet.
Route the SWD signals (SWCLK on PA30 and SWDIO on PA31) as a differential pair with a ground trace between them, and place 100 kΩ pull-ups on both lines per ARM CoreSight recommendations. Keep the SWD traces under 50 mm to avoid signal-integrity issues during high-speed programming. The USB DP/DM traces (PA11, PA12) require 90 Ω differential impedance and matched length within 150 mil.
Do not leave the RESET pin (PA28) floating; either tie it to VDDIO via a 10 kΩ pull-up or drive it from an external supervisor IC. The NMI pin (PA08) requires similar treatment if unused. The XIN32/XOUT32 pins (PA00/PA01) must be configured correctly even when using the internal 32 kHz oscillator, to avoid excess current draw in deep-sleep modes.
The SERCOM peripherals share I/O pins with default peripheral functions; configure the PMUX registers correctly before enabling SERCOM channels to avoid contention. For high-speed SPI interfaces above 10 MHz, add 22 Ω series resistors on the CLK and MOSI lines near the MCU to dampen reflections. The I2C lines require external 2.2 kΩ-10 kΩ pull-ups to VDDIO since the SAM D21 I/O pads do not include internal I2C pull-ups in all configurations.
Compliance Information
Green-compliant per Microchip product page ordering code 'GREEN'. Halogen-free per Microchip environmental compliance data. Not AEC-Q100 qualified; for automotive safety-critical designs choose SAM D21 AEC-Q100 variants.
