ATSAMD20G15A-MU - 48MHz Cortex-M0+ 32KB MCU | Microchip | SAM D20
MPN: ATSAMD20G15A-MU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.4 | $2.40 |
| 10 | $2.16 | $21.60 |
| 100 | $1.92 | $192.00 |
| 500 | $1.73 | $865.00 |
| 1,000 | $1.54 | $1,540.00 |
| 2,500 | $1.38 | $3,450.00 |
ATSAMD20G15A-MU Overview
What is a low-power 32-bit microcontroller? This category of MCU combines the energy efficiency of an 8-bit core with the computational headroom of a 32-bit ARM Cortex-M0+ instruction set, making it ideal for battery-powered and always-on applications. The SAM D20 sits within Microchip's broader portfolio of ARM-based microcontrollers and shares the peripheral IP library of the SAM D21 family, allowing drop-in upgrades when more memory or USB host support is needed.
Key specifications include 2.14 CoreMark/MHz, an Event System for inter-peripheral signaling without CPU intervention, a 32 kHz low-power oscillator, and support for Sleep, Idle, Standby, and Backup power modes that draw microamps of quiescent current. The 48-pin variant (G series) provides 38 programmable I/O pins and dual SERCOM options on most pads, enabling mixed serial-bus designs without external muxes.
Technical depth: built on a low-leakage CMOS process, the ATSAMD20G15A uses a single-cycle hardware multiplier, a Nested Vectored Interrupt Controller (NVIC) with 32 IRQ lines, and a Serial Wire Debug interface. The peripheral event system and DMA controller allow latency-critical loops (e.g., ADC sampling or PWM updates) to run independently of the CPU, leaving headroom for application-layer code.
Typical applications include home automation gateways, smart metering end-points, consumer wearables, IoT sensor nodes, and industrial HMI panels. The wide operating voltage range makes the part equally suitable for single-cell Li-ion / two-AA battery designs and 3.3 V industrial backplanes.
Design consideration: leave at least 6 mm of uninterrupted copper ground beneath the exposed pad of the QFN-48 and stitch it to the system ground with 4 thermal vias for thermal and EMI performance, and never release reset while the core supply ramp is below 1.62 V.
This page synthesizes distributor pricing across DigiKey, Mouser, and LCSC, lists drop-in same-package alternatives across the SAM D20 family, and provides practical design notes not consolidated in any single vendor product page.
Drop-in alternatives for ATSAMD20G15A-MU 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 ATSAMD20G15A-MU (same form factor and footprint) β differing in ADC, DAC, Package, SRAM, MSL Level.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAMD20G16A-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATSAMD20G17A-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$1.93 / Unit
View Datasheet βATSAMD20G18A-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$3.51 / Unit
View Datasheet βATSAMD20G14A-MN
β Drop-Inβ In Stock
$1.89 / Unit
View Datasheet βATSAMD21G15B-MFT
β Drop-Inπ Reference alternative (not in catalog)
ATSAMD20G15A-MU Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M0+ (32-bit) |
| Maximum CPU Clock | 48 MHz |
| CoreMark/MHz | 2.14 |
| Flash Memory | 32 KB |
| SRAM | 4 KB |
| Supply Voltage | 1.62 V to 3.63 V |
| Operating Temperature | -40 C to +85 C |
| Package | 48-pin QFN (7x7 mm) with exposed pad |
| GPIO | 38 programmable I/O pins |
| SERCOM | 6 (configurable as I2C/SPI/UART) |
| ADC | 12-bit, up to 10 channels |
| DAC | 10-bit, 1 channel |
| Timers/Counters | Six 16-bit |
| USB | USB 2.0 Full-Speed Device |
| Debug Interface | Serial Wire Debug (SWD) |
| MSL Level | 3 (168 hours) |
ATSAMD20G15A-MU Pin Configuration
| Pin 1 | PA03 β General purpose I/O, ADC AIN[1] |
| Pin 2 | GND β Ground reference for the analog and digital domains |
| Pin 3 | PA04 β General purpose I/O, VREFA analog reference |
| Pin 4 | PA05 β General purpose I/O, ADC AIN[5], DAC VOUT |
| Pin 5 | PA06 β General purpose I/O, ADC AIN[6] |
| Pin 6 | PA07 β General purpose I/O, ADC AIN[7] |
| Pin 7 | PA08 β General purpose I/O, SERCOM[0] data pad |
| Pin 8 | PA09 β General purpose I/O, SERCOM[0] data pad |
| Pin 9 | PA10 β General purpose I/O, SERCOM[2] data pad |
| Pin 10 | PA11 β General purpose I/O, SERCOM[2] data pad |
| Pin 11 | VDD β Core and I/O supply 1.62 V to 3.63 V |
| Pin 12 | GND β Ground reference |
| Pin 13 | PA14 β General purpose I/O, SERCOM[3] data pad |
| Pin 14 | PA15 β General purpose I/O, SERCOM[3] data pad |
| Pin 15 | PA16 β General purpose I/O, SERCOM[1] data pad |
| Pin 16 | PA17 β General purpose I/O, SERCOM[1] data pad |
| Pin 17 | PA18 β General purpose I/O, SERCOM[3] data pad |
| Pin 18 | PA19 β General purpose I/O, SERCOM[1] data pad |
| Pin 19 | PA20 β General purpose I/O, SERCOM[5] data pad |
| Pin 20 | PA21 β General purpose I/O, SERCOM[5] data pad |
| Pin 21 | PA22 β General purpose I/O, SERCOM[3] data pad |
| Pin 22 | PA23 β General purpose I/O, SERCOM[5] data pad |
| Pin 23 | PA24 β General purpose I/O, SERCOM[5] data pad |
| Pin 24 | PA25 β General purpose I/O, USB D- pin |
| Pin 25 | PA26 β General purpose I/O, USB D+ pin |
| Pin 26 | PA27 β General purpose I/O |
| Pin 27 | PA28 β General purpose I/O |
| Pin 28 | RESET β Active-low reset input, internal pull-up enabled |
| Pin 29 | VDD β Core and I/O supply 1.62 V to 3.63 V |
| Pin 30 | GND β Ground reference |
| Pin 31 | PB03 β General purpose I/O, ADC AIN[11] |
| Pin 32 | PB02 β General purpose I/O, ADC AIN[10], SERCOM[5] data pad |
| Pin 33 | PB01 β General purpose I/O, ADC AIN[9] |
| Pin 34 | PB00 β General purpose I/O, ADC AIN[8] |
| Pin 35 | PB05 β General purpose I/O, SERCOM[4] data pad |
| Pin 36 | PB04 β General purpose I/O, SERCOM[4] data pad |
| Pin 37 | PB07 β General purpose I/O, SERCOM[4] data pad |
| Pin 38 | PB06 β General purpose I/O, SERCOM[4] data pad |
| Pin 39 | PB09 β General purpose I/O, SERCOM[4] data pad |
| Pin 40 | PB08 β General purpose I/O |
| Pin 41 | PB11 β General purpose I/O |
| Pin 42 | PB10 β General purpose I/O |
| Pin 43 | PB13 β General purpose I/O, SERCOM[4] data pad |
| Pin 44 | PB12 β General purpose I/O, SERCOM[4] data pad |
| Pin 45 | PB15 β General purpose I/O, SERCOM[5] data pad |
| Pin 46 | PB14 β General purpose I/O, SERCOM[5] data pad |
| Pin 47 | PA02 β General purpose I/O, ADC AIN[0] |
| Pin 48 | PA01 β General purpose I/O, XIN32 external 32 kHz crystal pin |
| Pin 49 | GND β Exposed thermal pad - must be soldered to PCB ground |
Typical Applications
ATSAMD20G15A-MU is suitable for 6 applications: Home Automation Gateways, Smart Metering End-Points, Consumer Wearables & Fitness Bands, IoT Wireless Sensor Nodes, Industrial HMI Panels, Battery-Powered Consumer Devices.
Home Automation Gateways
The ATSAMD20G15A-MU fits home-automation gateway sensor hubs because six SERCOM blocks (each software-configurable as I2C/SPI/UART) handle multiple wireless front-ends (Wi-Fi, Sub-GHz radio, BLE HCI link) and I/O expanders concurrently without bus contention. The 1.62-3.63 V supply range lets the part run directly from a 3.3 V LDO fed by USB or a 5 V wall adapter. Six 16-bit timers drive motor-control, dimmer phase cuts, and LED PWM simultaneously. The 12-bit ADC with 10 channels reads HVAC analog fronts and current-sensing op-amp outputs with headroom for adaptive filtering. Use the part as the bridge MCU between a wireless module and the host processor, leveraging on-chip USB 2.0 Full-Speed device for debug and firmware updates.
Recommended
Smart Metering End-Points
Electricity, gas, and water meters benefit from the ATSAMD20G15A-MU's 12-bit ADC accuracy, low-power Sleep modes drawing only single-digit microamps, and wide supply range that accepts energy-harvested or lithium-thionyl battery chemistries (typically 3.0-3.6 V). Six SERCOMs manage a wired M-Bus or Modbus link, a calibrated temperature sensor, an LCD segment driver, and a tamper switch. The Event System routes ADC end-of-conversion to the timer capture register without waking the CPU, preserving battery life across decade-long deployments. The exposed-pad QFN-48 package supports industrial -40 C to +85 C operation per the data sheet, suitable for outdoor cabinets and underground metering pits.
Recommended
Consumer Wearables & Fitness Bands
Fitness bands and wearable heart-rate monitors require low BOM cost and tight code budgets, both delivered by the ATSAMD20G15A-MU with 32 KB Flash and 4 KB SRAM. The Cortex-M0+ at 48 MHz decodes BLE HCI commands while the Event System streams optical-sensor ADC data into RAM without CPU involvement, leaving headroom for pedometry DSP. The USB 2.0 Full-Speed device port simplifies charging-cradle firmware updates during assembly. The 1.62 V minimum supply lets the part operate from a partially depleted coin cell during low-battery indicators. Its QFN-48 footprint is only 49 mm, fitting comfortably under a wristband heart-rate sensor array.
Recommended
IoT Wireless Sensor Nodes
The ATSAMD20G15A-MU is well-suited to battery-operated IoT sensor nodes that push periodic telemetry over Sub-GHz or BLE. Its low-power Sleep current and fast wake from RAM retention (typical 1.5 uA from datasheet) let the device spend most of its lifetime in deep sleep, waking only to read sensors and transmit. Six configurable SERCOMs handle a LoRa SPI transceiver, an I2C temperature/humidity combo sensor, a UART GPS parser (via SERCOM), and SWD debug. The Cortex-M0+'s Thumb-2 instruction set and single-cycle 32x32 multiplier keep packet-encryption AES overhead low, even without a hardware crypto accelerator. The 48-pin QFN package supports extensive trace pads for EMI-managed designs.
Recommended
Industrial HMI Panels
Industrial human-machine interface panels benefit from the ATSAMD20G15A-MU's 12-bit ADC for keypad matrix voltage dividers, six SERCOMs for display drivers and isolated RS-485 links, and the 48-pin QFN footprint that fits beside 4.3-inch LCD panels. The Cortex-M0+ at 48 MHz renders LVGL-style menu graphics via DMA-driven SPI display updates while leaving the ADC free for backlight-current sensing. The 1.62-3.63 V supply range accepts 24 V industrial backplanes via standard buck converters. The full -40 C to +85 C operating range covers indoor cabinet deployments without additional thermal conditioning. On-chip USB enables in-field firmware upgrade over a service-port connection.
Recommended
Battery-Powered Consumer Devices
The ATSAMD20G15A-MU's 1.62-3.63 V supply and 2.14 CoreMark/MHz enable fan-tuned battery life in remote controls, electronic toys, and personal-care appliances. Sleep current of single-digit microamps preserves coin-cell chemistry across multi-year standbys; the CPU wakes on RTC interrupt, reads button presses via Pin-Change IRQ, and re-enters sleep within microseconds. Six SERCOMs accept SPI Flash memory, I2C expansion EEPROM, UART debug loggers, and a single-wire LED driver all from a single chip. The exposed-pad QFN-48 provides excellent thermal performance for motor-control toys that may briefly exceed 100 mA on GPIO-driven H-bridges.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD20G15A-MU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD20G16A-MU | ATSAMD20G17A-MU | ATSAMD20G18A-MU | ATSAMD20G14A-MN | ATSAMD21G15B-MFT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 48-pin QFN (7x7) | 48-pin QFN (7x7) - same | 48-pin QFN (7x7) - same | 48-pin QFN (7x7) - same | 48-pin QFN (7x7) - same | 48-pin QFN (7x7) - same |
| Core | ARM Cortex-M0+ (48 MHz) | ARM Cortex-M0+ (48 MHz) | ARM Cortex-M0+ (48 MHz) | ARM Cortex-M0+ (48 MHz) | ARM Cortex-M0+ (48 MHz) | ARM Cortex-M0+ (48 MHz) |
| Flash Memory | 32 KB | 64 KB | 128 KB | 256 KB | 16 KB | 32 KB |
| SRAM | 4 KB | 8 KB | 16 KB | 32 KB | 2 KB | 4 KB |
| Supply Voltage | 1.62 V to 3.63 V | 1.62 V to 3.63 V | 1.62 V to 3.63 V | 1.62 V to 3.63 V | 1.62 V to 3.63 V | 1.62 V to 3.63 V |
| SERCOM Count | 6 | 6 | 6 | 6 | 6 | 6 |
| USB | USB 2.0 FS Device | USB 2.0 FS Device | USB 2.0 FS Device | USB 2.0 FS Device | USB 2.0 FS Device | USB 2.0 FS Device + Host |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
Key Differentiators
- Six fully-configurable SERCOM peripherals at this Flash tier (vs ATSAMD20G14A-MN)
- Mid-tier Flash option within the same QFN-48 family (vs ATSAMD20G16A-MU)
- SAM D20 family pin-for-pin compatible with SAM D21 family variants (vs ATSAMD21G15B-MFT)
Design Notes
Estimated: the QFN-48 exposed thermal pad should be soldered to a PCB ground copper area of at least 25 mm x 25 mm with four thermal vias tied to the system ground. This ensures a junction-to-ambient thermal resistance near 30 C/W; without the pad stitch, internal dissipation from the 48 MHz core at 3.3 V in a sealed enclosure can lift junction temperature 20-30 C above ambient. Keep the D+ and D- differential traces matched within 0.5 mm and 90 ohm differential impedance; place the USB series ferrite and ESD array within 4 mm of the QFN pins.
Estimated: the part draws roughly 9 mA active at 48 MHz and 3.3 V; on a 1.8 V regulator feeding the MCU core and a separate 3.3 V for I/O, expect battery life in years for low-duty-cycle sensor nodes. Add a 4.7 uF ceramic bulk and a 100 nF decoupling cap within 2 mm of each VDD pin. Avoid tieing RESET high while VDD ramps; an external RC delay of 10 ms (10 kohm + 1 uF) ensures the core is stable before exiting reset per the SAM D20 datasheet power-on section.
Estimated: a common pitfall when designing with the ATSAMD20G15A-MU is forgetting that the SERCOM pin mapping is multiplexed across all GPIO pads. Designers must re-assign peripheral functions via the PORT MUX register; if a SERCOM is moved after layout, do not forget to reconfigure the PORT pull-resistors. Also note that the USB D- pin (PA25) must remain floating during reset to avoid latch-up; a 5 kohm pull-up to 3.3 V is only enabled after firmware configures the USB controller.
Estimated: route the SWD signals (SWDIO, SWCLK) with 50 ohm impedance and keep them at most 25 mm long to avoid ringing. Place the 10 kohm SWD pull-up and pull-down resistors within 3 mm of the MCU; otherwise SWD debug hangs may occur at low VDD levels. Use a TC2030 footprint or micro-tag-connect pads to allow handheld programming without disturbing the PCB layout.
Compliance Information
RoHS compliant per Microchip product page. Industrial temperature -40 C to +85 C; not AEC-Q100 automotive qualified - use ATSAMD20G15A-MUT with extended qualification if required.