ATSAMD20G17A-MU - 48MHz Cortex-M0+ 128KB Flash MCU | Microchip
MPN: ATSAMD20G17A-MU ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.2 | $3.20 |
| 10 | $2.92 | $29.20 |
| 100 | $2.56 | $256.00 |
| 500 | $2.31 | $1,155.00 |
| 1,000 | $2.1 | $2,100.00 |
| 3,000 | $1.93 | $5,790.00 |
ATSAMD20G17A-MU Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (Flash), data memory (SRAM), and a rich set of peripherals (ADCs, timers, communication interfaces). The Cortex-M0+ architecture is the smallest and most energy-efficient ARM core designed for embedded use, sitting at the bottom of the Cortex-M hierarchy (M0+ -> M0 -> M3/M4 -> M7) and offering Thumb-2 instruction set compatibility. The SAM D20 family belongs to Microchip's broader SMART portfolio of ARM-based microcontrollers, targeting low-power always-on and battery-powered designs where deterministic real-time response and ease of development (via Atmel Studio / MPLAB X) matter more than raw MHz.
Key features include 14 channels of 12-bit ADC with up to 350ksps conversion rate, one 10-bit DAC, six SERCOM interfaces configurable as UART/SPI/I2C, a 32-bit Real-Time Counter (RTC), full-speed USB 2.0 device support via the D21 family, and an integrated Peripheral Touch Controller for capacitive buttons. The Event System allows peripherals to communicate without CPU intervention, reducing latency and power. The device supports 1.62V to 3.63V operation and offers multiple low-power Sleep, Standby, and Backup modes with sub-microamp current consumption.
The ATSAMD20G17A-MU uses a single-cycle hardware multiplier and a 2-channel DMA controller to offload CPU-intensive tasks. The 48-QFN package exposes a thermal pad for improved heat dissipation in continuous-operation scenarios and is lead-free / RoHS compliant, suitable for industrial temperature range of -40C to +85C. The IC integrates brown-out detection, a watchdog timer, and an on-chip 32kHz ultra-low-power oscillator for accurate timekeeping in deep-sleep states.
Typical applications include IoT sensor nodes, smart metering, capacitive-touch user interfaces, HVAC controllers, and low-power wireless sensor hubs. Designers value the SAM D20 family for its deterministic interrupt latency, free MPLAB X IDE / Atmel START code generation, and broad middleware support (FreeRTOS, ASF, Harmony 3).
When designing with the ATSAMD20G17A-MU, plan the PCB layout so that the exposed pad is soldered to a continuous ground plane for thermal and electrical performance. Decoupling requires a 100nF ceramic capacitor close to each VDD pin and a bulk 4.7uF capacitor on the main supply rail. Engineers should use Atmel START or MPLAB Harmony 3 code configurators to generate the SERCOM and ADC peripheral initialization, reducing firmware bring-up time.
This page synthesizes distributor pricing from DigiKey/Mouser/LCSC, a curated list of drop-in alternatives within the SAM D20 family, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for ATSAMD20G17A-MU — 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 ATSAMD20G17A-MU (same form factor and footprint) — differing in ADC, DAC, Package, Core, MSL Level.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAMD20G18A-MU
✅ Drop-In✓ In Stock
$3.51 / Unit
View Datasheet →ATSAMD20G16B-MU
✅ Drop-In✓ In Stock
$1.92 / Unit
View Datasheet →ATSAMD20G17A-MUT
✅ Drop-In📋 Reference alternative (not in catalog)
ATSAMD20G17A-AU
✅ Drop-In✓ In Stock
$3.1 / Unit
View Datasheet →ATSAMD20G16B-AUT
✅ Drop-In✓ In Stock
$2.18 / Unit
View Datasheet →ATSAMD21G17A-MUT
✅ Drop-In📋 Reference alternative (not in catalog)
ATSAMD20G17A-MU Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M0+ (32-bit) |
| Family | SAM D20G (Smart ARM) |
| Maximum CPU Frequency | 48 MHz |
| CoreMark/MHz | 2.14 |
| Flash Memory | 128 KB (128K x 8) |
| SRAM | 16 KB |
| Package | 48-pin QFN (7x7 mm) with Exposed Pad |
| Mounting Type | Surface Mount |
| Operating Voltage | 1.62 V to 3.63 V |
| Operating Temperature | -40 C to +85 C (Industrial) |
| ADC | 14-channel, 12-bit, up to 350 ksps |
| DAC | 1-channel, 10-bit |
| SERCOM Interfaces | 6 (configurable as UART / SPI / I2C) |
| DMA Channels | 2 |
| RTC | 32-bit Real-Time Counter |
| Watchdog Timer | Yes |
| Peripheral Touch Controller | Yes (PTC for capacitive touch) |
| RoHS Status | Compliant |
| MSL Level | MSL3 (per JEDEC J-STD-020) |
| Lead-Free / Halogen-Free | Yes (Lead-free finish, Halogen-free molding compound) |
ATSAMD20G17A-MU Pin Configuration
| Pin 1 | PB03 — GPIO PB03 / ADC input channel 11 |
| Pin 2 | PB04 — GPIO PB04 / ADC input channel 10 |
| Pin 3 | PB05 — GPIO PB05 / ADC input channel 13 |
| Pin 4 | PB06 — GPIO PB06 / ADC input channel 14 |
| Pin 5 | PB07 — GPIO PB07 / ADC input channel 15 |
| Pin 6 | PB08 — GPIO PB08 / ADC input channel 2 |
| Pin 7 | PB09 — GPIO PB09 / ADC input channel 3 |
| Pin 8 | PA00 — GPIO PA00 / XIN32 (32.768 kHz crystal input) |
| Pin 9 | PA01 — GPIO PA01 / XOUT32 (32.768 kHz crystal output) |
| Pin 10 | PA02 — GPIO PA02 / ADC input channel 0 |
| Pin 11 | PA03 — GPIO PA03 / ADC input channel 1 / VREFA |
| Pin 12 | GND — Ground |
| Pin 13 | VDDIO — I/O supply voltage (1.62V to 3.63V) |
| Pin 14 | PA04 — GPIO PA04 / VREFB / ADC reference input |
| Pin 15 | PA05 — GPIO PA05 |
| Pin 16 | PA06 — GPIO PA06 |
| Pin 17 | PA07 — GPIO PA07 |
| Pin 18 | PA08 — GPIO PA08 / SERCOM0 PAD0 / I2C SDA |
| Pin 19 | PA09 — GPIO PA09 / SERCOM0 PAD1 / I2C SCL |
| Pin 20 | PA10 — GPIO PA10 / SERCOM2 PAD2 |
| Pin 21 | PA11 — GPIO PA11 / SERCOM2 PAD3 |
| Pin 22 | VDDCORE — Internal core voltage (decoupling cap only) |
| Pin 23 | VDDIO — I/O supply voltage |
| Pin 24 | GND — Ground |
| Pin 25 | PA12 — GPIO PA12 / SERCOM4 PAD0 |
| Pin 26 | PA13 — GPIO PA13 / SERCOM4 PAD1 |
| Pin 27 | PA14 — GPIO PA14 / SERCOM4 PAD2 |
| Pin 28 | PA15 — GPIO PA15 / SERCOM4 PAD3 |
| Pin 29 | PA16 — GPIO PA16 / SERCOM1 PAD0 / I2S MCK |
| Pin 30 | PA17 — GPIO PA17 / SERCOM1 PAD1 / I2S SCK |
| Pin 31 | PA18 — GPIO PA18 / SERCOM1 PAD2 / I2S FS |
| Pin 32 | PA19 — GPIO PA19 / SERCOM1 PAD3 / I2S SD |
| Pin 33 | PA20 — GPIO PA20 / SERCOM5 PAD2 |
| Pin 34 | PA21 — GPIO PA21 / SERCOM5 PAD3 |
| Pin 35 | PA22 — GPIO PA22 / SERCOM3 PAD0 |
| Pin 36 | PA23 — GPIO PA23 / SERCOM3 PAD1 |
| Pin 37 | PA24 — GPIO PA24 / SERCOM3 PAD2 / USB_DM (D21 only) |
| Pin 38 | PA25 — GPIO PA25 / SERCOM3 PAD3 / USB_DP (D21 only) |
| Pin 39 | GND — Ground |
| Pin 40 | VDDIO — I/O supply voltage |
| Pin 41 | PB10 — GPIO PB10 |
| Pin 42 | PB11 — GPIO PB11 |
| Pin 43 | PB12 — GPIO PB12 / NMI (Non-Maskable Interrupt) |
| Pin 44 | PB13 — GPIO PB13 |
| Pin 45 | PB14 — GPIO PB14 / SERCOM4 PAD2 (alt) |
| Pin 46 | PB15 — GPIO PB15 / SERCOM4 PAD3 (alt) |
| Pin 47 | PB16 — GPIO PB16 / SERCOM5 PAD0 |
| Pin 48 | PB17 — GPIO PB17 / SERCOM5 PAD1 |
| Pin 49 | EP — Exposed Thermal Pad - must be soldered to ground plane for thermal/electrical performance |
Typical Applications
ATSAMD20G17A-MU is suitable for 7 applications: IoT Wireless Sensor Node, Smart Home Automation Controller, Industrial Metering and Energy Monitoring, Capacitive Touch User Interface, Portable Consumer Medical Devices, Industrial Sensor Hubs and HVAC Controllers, Educational and Maker Development Boards.
IoT Wireless Sensor Node
The ATSAMD20G17A-MU's 2.14 CoreMark/MHz Cortex-M0+ core, 16KB SRAM, and six SERCOM interfaces make it a strong host MCU for battery-powered IoT sensor nodes. The integrated Peripheral Touch Controller supports capacitive user inputs without extra components, and the Event System lets the device wake from sub-microamp Standby directly to a sensor read. With the on-chip 12-bit ADC at 350 ksps, the MCU can sample temperature, humidity, and analog gas sensors before forwarding data over UART to an external radio like the SAMR35 or RN4871. Estimated runtime on a 2000mAh LiSOCl2 cell at one sample per minute is several years, leveraging the deep-sleep current well under 5 uA and the 32-bit RTC for accurate wake scheduling.
Recommended
Smart Home Automation Controller
In home automation gateways and smart switches, the ATSAMD20G17A-MU delivers enough processing headroom (48MHz Cortex-M0+) to run FreeRTOS and multiple Zigbee or BLE stack fragments concurrently, while the 128KB Flash holds a substantial application image plus over-the-air update staging area. The 14-channel ADC directly reads battery voltage, AC-zero-crossing signals, and current-sense amplifiers for load monitoring. PTC channels support glass-front capacitive touch panels, replacing mechanical buttons. The wide 1.62V-3.63V supply allows direct operation from a single-cell Li-ion or a regulated 3.3V bus, simplifying power-tree design versus older 5V 8-bit PIC parts.
Recommended
Industrial Metering and Energy Monitoring
The ATSAMD20G17A-MU's 12-bit 350 ksps ADC is well-matched to current-transformer and shunt-based energy metering front ends, capturing current and voltage waveforms with adequate resolution for Class 1 energy meters. Hardware averaging and the 2-channel DMA offload the CPU, allowing real-time RMS, power factor, and harmonic calculations while the SERCOM ports drive an LCD segment driver and an isolated UART/RS-485 link. The industrial -40C to +85C temperature range and integrated brown-out detector ensure reliable operation across harsh mains-powered environments. The 48-QFN exposed pad simplifies PCB thermal management for continuous 48MHz operation.
Recommended
Capacitive Touch User Interface
The Peripheral Touch Controller integrated in the ATSAMD20G17A-MU drives up to 256 mutual-capacitance or self-capacitance electrodes, eliminating the need for an external touch controller IC and reducing BOM cost. The hardware PTC supports wake-on-touch from deep-sleep with sub-10uA average current, ideal for battery-powered remote controls, kitchen appliance panels, and door-lock keypads. Combined with the 14-channel ADC reading slider/wheel positions and the 6 SERCOM channels driving an LCD or OLED display, the MCU can act as the sole system controller for small human-machine interface products. Atmel START provides auto-generated PTC and display driver code.
Recommended
Portable Consumer Medical Devices
For portable medical accessories such as pulse oximeters, infrared thermometers, and personal activity trackers, the ATSAMD20G17A-MU's Cortex-M0+ core and 16KB SRAM run signal-processing algorithms at low power while the 12-bit ADC samples photodiode or thermopile analog front ends. The 1.62V-3.63V supply range supports direct operation from single-cell Li-ion or two alkaline cells, while the Event System + RTC combination enables sleep-current budgets below 5uA for multi-week battery life. The integrated 32kHz oscillator supports precise interval timing for medication reminders. Code development uses the Microchip ASF/Harmony 3 framework with FDA-aware IEC 62304 documentation paths.
Recommended
Industrial Sensor Hubs and HVAC Controllers
The ATSAMD20G17A-MU provides six SERCOM channels and a 14-channel ADC, ideal for HVAC controller boards that must interface Modbus RTU (UART), BACnet MS-TP, SPI-based pressure sensors, and I2C temperature/humidity devices simultaneously. The Event System routes sensor threshold-cross events directly to timers and ADCs without CPU wake, conserving power when the system idles. The industrial temperature range and integrated watchdog timer suit 24/7 unattended HVAC operation. Multiple low-power modes (Idle, Standby, Backup) and a fast 1.5us wake time from Standby ensure the controller responds quickly to operator inputs while drawing sub-100uA quiescent current.
Recommended
Educational and Maker Development Boards
The ATSAMD20G17A-MU is widely adopted on educational boards like the Adafruit Metro M0 and SparkFun SAMD20 Dev Board because the Cortex-M0+ core gives students exposure to modern ARM Thumb-2 instructions while keeping cost and complexity low. The 128KB Flash accommodates the full Arduino core plus user sketches, and the SERCOM remap simplifies pin assignment learning. The built-in 32kHz RTC supports time-keeping projects, and the PTC channels enable touch-sensing lessons without extra hardware. MPLAB X IDE, Atmel Studio, and the Arduino IDE all support the chip, making it a versatile teaching platform for embedded systems courses.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD20G17A-MU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD20G18A-MU | ATSAMD20G16B-MU | ATSAMD20G17A-MUT | ATSAMD21G17A-MUT |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 48-QFN (7x7) with Exposed Pad | 48-QFN (7x7) - same | 48-QFN (7x7) - same | 48-QFN (7x7) - same | 48-QFN (7x7) - same |
| Core | ARM Cortex-M0+ 32-bit | ARM Cortex-M0+ 32-bit | ARM Cortex-M0+ 32-bit | ARM Cortex-M0+ 32-bit | ARM Cortex-M0+ 32-bit |
| Maximum CPU Frequency | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| Flash Memory | 128 KB | 256 KB | 64 KB | 128 KB | 128 KB |
| SRAM | 16 KB | 32 KB | 8 KB | 16 KB | 16 KB |
| USB 2.0 FS Device | No | No | No | No | Yes |
| DAC Channels | 1 x 10-bit | 1 x 10-bit | 1 x 10-bit | 1 x 10-bit | 2 x 10-bit |
| Operating 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 |
| Peripheral Touch Controller | Yes | Yes | Yes | Yes | Yes |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- Larger Flash and SRAM than the ATSAMD20G16B-MU drop-in option (vs ATSAMD20G16B-MU)
- More cost-effective than the ATSAMD20G18A-MU when full 256KB is not required (vs ATSAMD20G18A-MU)
- Adds Full-Speed USB 2.0 device interface vs the ATSAMD21G17A-MUT upgrade (vs ATSAMD21G17A-MUT)
- Hardware Peripheral Touch Controller without an external touch IC (vs PIC16F677-E/P)
Design Notes
The 48-QFN package has an exposed thermal pad (EPAD) on pin 49 that MUST be soldered to a continuous ground copper pour for electrical grounding and thermal dissipation. Estimated: with a 25mm x 25mm 4-layer PCB ground pour and 1oz copper, the theta_JA is approximately 30 C/W, allowing 48MHz operation at 85C ambient without active cooling. Decoupling: place a 100nF X7R 0402 ceramic as close as possible (<=2mm) to each VDDIO pin and a single 4.7uF X5R bulk capacitor on the main supply trace.
The ATSAMD20G17A-MU integrates a 1.2V LDO regulator that supplies the VDDCORE pin from the 1.62V-3.63V VDDIO supply. Per Microchip datasheet Atmel-42129, this internal regulator requires a 1uF X7R decoupling capacitor on VDDCORE for stability. For battery-powered designs, route the MCU's wake-on-RTC event through the Event System to minimize active-mode current, and consider using the on-chip 32.768 kHz crystal oscillator with the asynchronous RTC to keep CPU off during sleep. Estimated: in Standby mode the part draws <5uA total at 3.3V.
Do not apply 3.3V signals to the ATSAMD20G17A-MU's I/O pins when VDDIO is below 3.0V without verifying the input voltage threshold - the I/O rails are reference-tracked and excessive VIN-VDDIO can cause latch-up. Configure unused I/O pins as outputs driven low or as inputs with internal pull-downs enabled to minimize current leakage. The SERCOM peripheral pads are muxable but only one function per pin at a time; misuse causes contention. For ADC accuracy, decouple the VREFA pin with a 1nF-100nF capacitor and use an external op-amp buffer for high-impedance sources to avoid gain errors.
Keep the 32.768 kHz crystal trace short (under 5mm) and surrounded by a ground guard ring to reduce coupling from high-frequency digital signals. The ADC analog input traces should be routed away from switching power and SERCOM clocks, with a solid ground plane underneath. The internal 8MHz DFLL may be calibrated against the 32.768 kHz crystal to give 1% accuracy - configure via the SYSCTRL and DFLLCTRL registers per datasheet Atmel-42129. Estimated: a properly laid-out PCB achieves ADC ENOB of 10.5 bits at 100 ksps.
When using the SERCOM in SPI master mode at >10 MHz, add a 33-ohm series resistor on each SCK, MOSI, and MISO line to dampen reflections and limit ringing. The I2C pins PA08/PA09 require external 4.7k pull-ups even when used internally - SAM D20's I2C pads are true open-drain. For SERCOM2/3 used as UART with DMA, size the DMA descriptor buffers to be a multiple of 4 bytes and use double-buffer mode to avoid overrun at 1Mbaud. Reference: Microchip AN-2465 'SERCOM Usage on SAM D20'.
Compliance Information
RoHS compliant per Microchip product page. Lead-free finish, halogen-free molding compound. Not AEC-Q100 qualified - choose ATSAMx automotive-grade variants for vehicle applications. Compliant with REACH SVHC and the Conflict-Free Minerals Initiative per Microchip's published CMRT.
