ATSAMD21E17A-MU - 48MHz Cortex-M0+ MCU 128KB Flash | Microchip
MPN: ATSAMD21E17A-MU ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.62 | $3.62 |
| 10 | $3.18 | $31.80 |
| 100 | $2.74 | $274.00 |
| 500 | $2.45 | $1,225.00 |
| 1,000 | $2.18 | $2,180.00 |
ATSAMD21E17A-MU Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (flash), working memory (SRAM), and a wide range of peripherals such as timers, communication interfaces, and analog blocks. The ATSAMD21E17A-MU is a Cortex-M0+ MCU, the most energy-efficient variant of the Arm Cortex-M family, providing deterministic interrupt handling and Thumb-2 instruction set compatibility at a low gate count. Within the broader semiconductor hierarchy, this part belongs to: ARM Cortex-M0+ -> 32-bit microcontroller -> microcontroller -> embedded processor -> integrated circuit -> semiconductor.
Key features include 128 KB flash with 4 KB read-while-write area, 16 KB SRAM, full-speed USB 2.0 with embedded transceiver, up to 26 GPIO, SERCOM peripherals (configurable as I2C/SPI/UART), a 12-bit ADC, a 10-bit DAC, and SleepWalking peripherals that allow the device to wake from sleep on peripheral activity without full CPU wake. The 2.46 CoreMark/MHz performance rating translates to roughly 118 CoreMark at 48 MHz, suitable for deterministic sensor and protocol handling.
The SAM D21E family is a drop-in compatible evolution of the SAM D20 family, adding the full-speed USB controller and richer analog peripherals. Process technology is a low-power CMOS flash process with on-chip voltage regulator and brown-out detector. Operating voltage spans 1.62 V to 3.63 V, supporting single-cell Li-ion, 2xAA, and 3.3 V regulated rails.
Typical applications include low-power IoT sensor nodes, USB HID peripherals, home automation control panels, consumer electronics with touch or display LED indicators, industrial metering, and wearable devices. The integrated USB and SERCOM channels make it a strong fit for any product needing both USB connectivity and flexible serial communication. Pair with a SAMD21-compatible debugger such as the ATSAM-ICE for SWD programming.
Design tip: when laying out the VQFN-32 PCB, connect the exposed pad to a clean ground pour; inadequate thermal/ground bonding is the most common source of noise-induced ADC inaccuracy and USB signal-integrity issues. Decouple VDDIN and VDDANA with separate 100 nF capacitors placed within 2 mm of their respective pins.
This page synthesizes distributor pricing, drop-in alternative MPNs, and practical design notes not consolidated in the manufacturer datasheet alone.
Drop-in alternatives for ATSAMD21E17A-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 ATSAMD21E17A-MU (same form factor and footprint) — differing in ADC, Core, DAC, Package, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAMD21E18A-MU
✅ Drop-In✓ In Stock
$2.27 / Unit
View Datasheet →ATSAMD21E16B-MU
✅ Drop-In✓ In Stock
$2.65 / Unit
View Datasheet →ATSAMD21E17A-MFT
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →ATSAMD20E17A-MU
✅ Drop-In📋 Reference alternative (not in catalog)
LPC11U35FHI33/501
✅ Drop-In📋 Reference alternative (not in catalog)
ATSAMD21E17A-MU Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M0+ (32-bit) |
| Series | SAM D21E (Functional Safety) |
| Maximum CPU Frequency | 48 MHz |
| CoreMark/MHz | 2.46 |
| Flash Memory | 128 KB (128K x 8) |
| SRAM | 16 KB |
| Read-While-Write Flash Area | 4 KB |
| Operating Voltage Range | 1.62 V to 3.63 V |
| GPIO Count | Up to 26 |
| USB Interface | USB 2.0 Full-Speed Device with embedded transceiver |
| ADC | 12-bit, up to 20 channels |
| DAC | 10-bit, 1 channel |
| Timer/Counters | Three 16-bit TC |
| SERCOM | Up to 6 configurable (I2C/SPI/UART) |
| DMAC Channels | 12 |
| Event System Channels | 12 |
| Package | 32-VQFN (5x5) with exposed pad |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free | Yes |
| Debug Interface | 2-pin Serial Wire Debug (SWD) |
ATSAMD21E17A-MU Pin Configuration
| Pin 1 | PA00 — GPIO PA00, XIN |
| Pin 2 | PA01 — GPIO PA01, XOUT |
| Pin 3 | PA02 — GPIO PA02, AIN0 |
| Pin 4 | PA03 — GPIO PA03, AIN1, VREFA |
| Pin 5 | GND — Ground |
| Pin 6 | VDDANA — Analog supply voltage |
| Pin 7 | PA04 — GPIO PA04, AIN2 |
| Pin 8 | PA05 — GPIO PA05, AIN3 |
| Pin 9 | PA06 — GPIO PA06, AIN4 |
| Pin 10 | PA07 — GPIO PA07, AIN5 |
| Pin 11 | PA08 — GPIO PA08, AIN5 |
| Pin 12 | PA09 — GPIO PA09, AIN6 |
| Pin 13 | PA10 — GPIO PA10, AIN7 |
| Pin 14 | PA11 — GPIO PA11 |
| Pin 15 | VDDIN — Digital supply voltage |
| Pin 16 | GND — Ground |
| Pin 17 | PA12 — GPIO PA12, I2S_FS0 |
| Pin 18 | PA13 — GPIO PA13, I2S_SCK0 |
| Pin 19 | PA14 — GPIO PA14, I2S_MCK0 |
| Pin 20 | PA15 — GPIO PA15, I2S_SD0 |
| Pin 21 | PA16 — GPIO PA16, I2S_SD1 |
| Pin 22 | PA17 — GPIO PA17 |
| Pin 23 | PA18 — GPIO PA18 |
| Pin 24 | PA19 — GPIO PA19 |
| Pin 25 | PA20 — GPIO PA20 |
| Pin 26 | PA21 — GPIO PA21 |
| Pin 27 | PA22 — GPIO PA22, USB_DM |
| Pin 28 | PA23 — GPIO PA23, USB_DP |
| Pin 29 | PA24 — GPIO PA24, USB_SOF |
| Pin 30 | PA25 — GPIO PA25, SWDIO |
| Pin 31 | RESET — Reset (active low) |
| Pin 32 | PA27 — GPIO PA27, SWDCLK |
Typical Applications
ATSAMD21E17A-MU is suitable for 6 applications: Low-Power IoT Sensor Node, USB HID Peripheral Device, Home Automation Control Panel, Consumer Wearable Device, Industrial Metering and Monitoring, Touch / LED User Interface Controller.
Low-Power IoT Sensor Node
The ATSAMD21E17A-MU's Cortex-M0+ core, 1.62 V to 3.63 V operating range, and SleepWalking peripherals make it ideal for battery-powered IoT sensor nodes that wake on peripheral events without full CPU wake. With 128 KB flash and 16 KB SRAM it can hold Zigbee, BLE-through-SPI-host, LoRa driver, or proprietary RF protocol stacks alongside sensor-fusion algorithms. The 12-bit ADC with up to 20 channels supports direct connection to multiple analog sensors (temperature, light, gas) with 4 KB RWW flash enabling OTA firmware updates while the node continues to sense. Pair with an SPI-92 LR4450 or ATSAM R34 SAMD21 wireless co-processor module for complete wireless node design.
Recommended
USB HID Peripheral Device
The ATSAMD21E17A-MU's integrated USB 2.0 Full-Speed device with on-chip transceiver makes it a natural choice for USB HID peripherals such as keyboards, mice, custom input devices, and HID-class game controllers, eliminating the need for an external USB PHY. The Cortex-M0+ core running at 48 MHz is sufficient to handle HID report generation, debouncing, and macro processing, while the 128 KB flash accommodates rich HID descriptor tables and custom firmware features. Up to six SERCOM channels provide flexible UART/SPI/I2C expansion for additional sensors or wireless links. Place a 1.5 kohm pull-up on D+ and a USBLC6-2SC6 ESD array on the connector for robust USB operation.
Recommended
Home Automation Control Panel
The ATSAMD21E17A-MU's combination of USB connectivity for commissioning, multiple SERCOM channels for UART/SPI/I2C peripherals, and 26 GPIO for keypad, LED, and relay control fits the home-automation control-panel use case well. With 128 KB flash it can run Z-Wave/Zigbee host stacks or proprietary RF protocol bridges, while the 10-bit DAC drives analog setpoint outputs for HVAC dimming. The 12-bit ADC reads thermistor inputs for room-temperature regulation with adequate resolution for ±0.5 C accuracy after calibration. The 1.62 V minimum supply enables single-cell Li-ion or 2xAA battery backup for power-loss ride-through in smart-thermostat applications.
Recommended
Consumer Wearable Device
The ATSAMD21E17A-MU targets consumer wearables with its sub-microamp sleep modes, Cortex-M0+ efficiency, and integrated USB for charging-data cradle communication, allowing a single-chip design for fitness bands or simple smartwatches. The 16 KB SRAM buffers sensor-fusion data from on-board accelerometers and PPG sensors, while the 128 KB flash holds firmware, BLE GATT tables (when paired with an external BT module), and asset-tracking code. Operating down to 1.62 V supports direct connection to a single Li-ion or Li-poly cell without boost converters, reducing BOM cost and PCB area. Pair with the LIS2DH accelerometer and an OPT3001 ambient-light sensor over SERCOM-I2C.
Recommended
Industrial Metering and Monitoring
The ATSAMD21E17A-MU's 12-bit ADC with up to 20 channels, 1.62 V to 3.63 V supply range, and -40 C to +85 C industrial temperature rating make it a strong fit for industrial metering front ends (electricity, water, gas) and remote-monitoring endpoints. The Cortex-M0+ core computes metering algorithms and pushes results over UART, RS-485, or an external wireless M-Bus/NB-IoT modem, while 4 KB of read-while-write flash allows field firmware upgrades without service downtime. The SERCOM channels can be reconfigured in firmware to support RS-485, SPI displays, or I2C sensor hubs. The 32-VQFN footprint and exposed pad support conformal-coated industrial PCB designs.
Recommended
Touch / LED User Interface Controller
The ATSAMD21E17A-MU's 10-bit DAC, PWM-driven LED control via timer/counters, and QTouch peripheral library support make it well suited for capacitive-touch and LED-based user interface panels in appliances and audio products. The 26 GPIO can directly drive 7-segment or Charlieplexed LED arrays, while SERCOM channels interface to I2C-controlled LED drivers for higher-density RGB lighting. With 16 KB SRAM the MCU can buffer LED animation tables and respond to touch events with sub-10 ms latency. The 32-VQFN 5x5 mm footprint fits small-appliance control boards with tight space constraints.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD21E17A-MU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD21E18A-MU | ATSAMD21E16B-MU | ATSAMD20E17A-MU | ATSAMD21E17A-MFT | LPC11U35FHI33/501 |
|---|---|---|---|---|---|---|
| Package | 32-VQFN (5x5) | 32-VQFN (5x5) | 32-VQFN (5x5) | 32-VQFN (5x5) | 32-VQFN (5x5) | QFN-32 (HVQFN) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | NXP Semiconductors |
| Core | Cortex-M0+ @48 MHz | Cortex-M0+ @48 MHz | Cortex-M0+ @48 MHz | Cortex-M0+ @48 MHz | Cortex-M0+ @48 MHz | Cortex-M0+ @50 MHz |
| Flash | 128 KB | 256 KB | 64 KB | 128 KB | 128 KB | 64 KB |
| SRAM | 16 KB | 32 KB | 8 KB | 16 KB | 16 KB | 12 KB |
| USB | USB 2.0 FS device | USB 2.0 FS device | USB 2.0 FS device | No USB | USB 2.0 FS device | USB 2.0 FS device |
| GPIO | 26 | 26 | 26 | 26 | 26 | 26 |
| Operating 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 | 1.8 V to 3.6 V |
Key Differentiators
- Integrated USB 2.0 Full-Speed with on-chip transceiver (vs ATSAMD20E17A-MU)
- Optimal flash/SRAM balance for IoT firmware (vs ATSAMD21E16B-MU)
- Drop-in upgrade path to 256 KB flash on same footprint (vs ATSAMD21E18A-MU)
Design Notes
The 32-VQFN package has an exposed thermal pad on the underside that MUST be soldered to a ground-pour PCB pad for both thermal dissipation and electrical reference. With a theta_JA of approximately 39 C/W on a 4-layer JEDEC test board, the device dissipates up to ~2.5 W before additional copper or airflow is required. Inadequate thermal/ground bonding is the most common source of ADC inaccuracy and USB signal-integrity issues in customer boards.
Place a 100 nF decoupling capacitor within 2 mm of each VDDIN pin and a separate 100 nF on VDDANA. Add a 4.7 uF bulk capacitor at the regulator output to handle USB suspend current transients. Use the on-chip voltage regulator to generate the internal 1.2 V core from a single 1.62 V to 3.63 V external supply; do not attempt to drive an external 1.2 V rail, as the internal LDO controls power sequencing.
Keep the USB D+/D- traces matched within 150 mil length differential and routed over a continuous ground plane to maintain 90 ohm differential impedance for USB 2.0 Full-Speed compliance. Place the USBLC6-2SC6 ESD array as close to the USB connector as possible, with its ground paddle directly to the chassis/shield ground. Avoid routing noisy switching signals across the analog VDDANA area to minimize ADC crosstalk.
Do not exceed 3.63 V on any VDD pin; ESD latchup risk is high on the Cortex-M0+ process. When using SleepWalking peripherals, ensure the event system is correctly configured to wake the CPU only on selected peripheral events - misconfigured event routing is a frequent cause of unexpected current consumption in battery-powered designs. Verify the 32 kHz crystal load capacitor values against the crystal CL specification rather than copying reference designs blindly.
Compliance Information
RoHS and REACH compliant per Microchip product page. Not AEC-Q100 qualified; for automotive applications use SAM HA/EHA grade parts. Lead-free and halogen-free per Microchip material declaration.
