ATSAMD21E17A-AF - 48MHz Cortex-M0+ MCU, 128KB Flash | Microchip
MPN: ATSAMD21E17A-AF β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.85 | $3.85 |
| 10 | $3.47 | $34.70 |
| 100 | $2.95 | $295.00 |
| 500 | $2.62 | $1,310.00 |
| 1,000 | $2.34 | $2,340.00 |
ATSAMD21E17A-AF Overview
A 32-bit ARM Cortex-M0+ microcontroller is an entry-level 32-bit MCU that combines the energy efficiency of a simple instruction set with the performance of a 32-bit datapath. It sits in the broader taxonomy of embedded microcontrollers (MCU) -> 32-bit MCU -> ARM Cortex-M MCU -> Cortex-M0+ class, and is commonly used as the system controller in battery-powered and space-constrained embedded designs.
Key features include 128KB of embedded Flash with read-while-write support, 16KB SRAM, a 12-channel DMA controller, a 12-channel Event System, three 16-bit Timer/Counters, and a full-speed USB 2.0 device interface. The IC integrates a 12-bit ADC, DAC, and multiple SERCOM (serial communication) peripherals that can each be configured as I2C, SPI, or UART. Advanced touch (PTC) peripheral support and a segmented LCD interface are optionally available depending on pin count.
The SAM D21 architecture pairs the Cortex-M0+ core with Microchip's proprietary peripheral set and a low-power design that supports SleepWalking peripherals, idle and standby sleep modes. Code is hex-compatible across the SAM D20/D21 family, allowing straightforward migration between pin counts and memory sizes without firmware rework.
Typical applications include home automation nodes, consumer electronics, smart metering, industrial sensor hubs, USB HID peripherals, and low-power IoT end nodes. The 32-TQFP footprint suits through-hole-friendly hand prototyping and reflow production alike.
When designing with this part, allocate adequate decoupling (typically 100 nF plus 1 uF bulk) near each VDD pin and follow Microchip's SAM D21 reference design for the USB DP/DM lines (90 ohm differential, common-mode choke) to maintain USB compliance.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATSAMD21E17A-AF 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 ATSAMD21E17A-AF (same form factor and footprint) β differing in ADC, Package, Operating Temperature Range, RoHS Status, MSL Level.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAMD21E17A-AU
β Drop-Inβ In Stock
$2.3 / Unit
View Datasheet βATSAMD21E18A-AF
β Drop-Inπ Reference alternative (not in catalog)
ATSAMD21E16B-AF
β Drop-Inβ In Stock
$2.19 / Unit
View Datasheet βATSAMD21E15B-AFT
β Drop-Inβ In Stock
$1.96 / Unit
View Datasheet βATSAMD20E17A-AU
β Drop-Inβ In Stock
$2.5 / Unit
View Datasheet βATSAMD21E17A-AF Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M0+ (32-bit) |
| Family | SAM D21 / SAM D21E sub-family |
| Maximum CPU Clock | 48 MHz |
| Flash Program Memory | 128 KB |
| SRAM | 16 KB |
| RWW (Read-While-Write) Partition | 4 KB auxiliary flash |
| Supply Voltage (VDD) | 1.62 V to 3.63 V |
| Operating Temperature Range | -40 C to +125 C (125C GREEN) |
| Package | 32-pin TQFP (7x7 mm) |
| Mounting Type | Surface Mount |
| USB | USB 2.0 Full-Speed Device |
| DMA Channels | 12 |
| Timer/Counters | Three 16-bit TC |
| SERCOM Modules | Up to 6 (configurable as I2C/SPI/UART) |
| ADC / DAC | 12-bit ADC, 10-bit DAC |
| RoHS Status | Compliant (GREEN) |
| Debug Interface | Two-pin Serial Wire Debug (SWD) |
| Functional Safety (FuSa) | FuSa-capable family |
ATSAMD21E17A-AF Pin Configuration
| Pin 1 | PA00 β GPIO / XIN (32 kHz crystal input) |
| Pin 2 | PA01 β GPIO / XOUT (32 kHz crystal output) |
| Pin 3 | PA02 β GPIO / AIN0 (ADC input) |
| Pin 4 | PA03 β GPIO / AREF (ADC reference) |
| Pin 5 | GND β Ground |
| Pin 6 | VDD β Digital supply (1.62-3.63 V) |
| Pin 7 | PA04 β GPIO / AIN4 |
| Pin 8 | PA05 β GPIO / AIN5 |
| Pin 9 | PA06 β GPIO / AIN6 |
| Pin 10 | PA07 β GPIO / AIN7 |
| Pin 11 | PA08 β GPIO / AIN8 / SERCOM0 PAD |
| Pin 12 | PA09 β GPIO / AIN9 / SERCOM0 PAD |
| Pin 13 | PA10 β GPIO / AIN10 / SERCOM2 PAD |
| Pin 14 | PA11 β GPIO / AIN11 / SERCOM2 PAD |
| Pin 15 | PA14 β GPIO / SERCOM2 PAD |
| Pin 16 | PA15 β GPIO / SERCOM3 PAD |
| Pin 17 | PA16 β GPIO / SERCOM3 PAD |
| Pin 18 | PA17 β GPIO / SERCOM1 PAD |
| Pin 19 | PA18 β GPIO / SERCOM1 PAD |
| Pin 20 | PA19 β GPIO / SERCOM3 PAD |
| Pin 21 | PA20 β GPIO / SERCOM5 PAD |
| Pin 22 | PA21 β GPIO / SERCOM5 PAD |
| Pin 23 | PA22 β GPIO / SERCOM3 PAD |
| Pin 24 | PA23 β GPIO / SERCOM5 PAD |
| Pin 25 | PA24 β GPIO / USB_DM |
| Pin 26 | PA25 β GPIO / USB_DP |
| Pin 27 | PA27 β GPIO |
| Pin 28 | PA28 β GPIO / RESET pin (alternate) |
| Pin 29 | GND β Ground |
| Pin 30 | VDD β Digital supply (1.62-3.63 V) |
| Pin 31 | PA30 β GPIO / SWCLK (debug) |
| Pin 32 | PA31 β GPIO / SWDIO (debug) |
Typical Applications
ATSAMD21E17A-AF is suitable for 7 applications: USB HID Peripherals, Home Automation Sensor Hubs, Smart Metering Endpoints, Industrial Sensor Transmitters, Wearable Fitness Bands, Consumer Audio Remote Controls, IoT Edge Sensor Nodes.
USB HID Peripherals
The ATSAMD21E17A-AF's integrated USB 2.0 Full-Speed device controller makes it a strong fit for USB HID peripherals such as keyboards, mice, custom HID input devices, and USB-to-UART bridges. With 128 KB Flash the part can hold full HID descriptors, multiple endpoint definitions, and a USB bootloader without an external flash. The on-chip 90 ohm differential DP/DM pins and integrated pull-up on DP simplify hardware to a few passive components and a USB connector. Unlike discrete USB-to-UART bridges, the on-chip USB removes BOM cost and frees the SERCOM peripherals for sensor I/O. Power consumption in suspend mode meets the USB suspend requirement of less than 2.5 mA.
Recommended
Home Automation Sensor Hubs
The SAM D21E sub-family, including the ATSAMD21E17A-AF, was designed for home automation gateways with multiple low-speed wireless or wired sensor interfaces. The six SERCOM modules allow simultaneous I2C sensor arrays, SPI radios, and UART peripherals, all coordinated by the 12-channel DMA controller without CPU load. The SleepWalking peripherals wake the Cortex-M0+ core only when an event matches a hardware threshold, drawing standby currents that keep the average power well under 100 uA for a typical battery sensor hub. Compared to a discrete 8-bit MCU plus external ADC, the integrated 12-bit ADC and 10-bit DAC cut the BOM substantially. The 125 C temperature grade is adequate for outdoor or attic sensor housings.
Recommended
Smart Metering Endpoints
For smart electricity, water, or gas meters, the ATSAMD21E17A-AF offers 128 KB Flash for metering firmware stacks (DLMS/COSEM, ANSI C12.18, or vendor-specific) plus tamper detection logic. The 12-bit ADC, with oversampling in firmware, achieves better than 16 effective bits for energy measurement when paired with a precision shunt or current transformer. The RTC with calendar mode, low-power sleep modes, and battery backup support multi-year battery life on a single lithium cell. Code is hex-compatible across the SAM D21 family, allowing the same firmware to be used on higher-pin-count meter gateways without rework.
Recommended
Industrial Sensor Transmitters
The ATSAMD21E17A-AF suits 4-20 mA loop-powered sensor transmitters, RTD/thermocouple signal conditioners, and process-control field instruments. The 1.62-3.63 V supply range is compatible with low-drop regulators or directly with 3.3 V industrial backplanes, and the 32-TQFP package supports a small footprint needed for in-head transmitters. Three 16-bit Timer/Counters support PWM excitation for sensor bridges and quadrature decoding for rotary encoders. The integrated SERCOM peripherals provide multiple HART or Modbus interfaces for legacy industrial networks.
Recommended
Wearable Fitness Bands
The ATSAMD21E17A-AF works in wearable fitness band applications where small size, low power, and integrated peripherals matter. The Cortex-M0+ core at 48 MHz is powerful enough to drive BLE control via a companion radio, run pedometer and heart-rate sensor fusion, and refresh an I2C OLED display simultaneously. The 12-bit ADC reads battery voltage, optical heart-rate sensors, and motion sensors without external parts, while the SERCOM peripherals handle I2C/SPI for the display, radio, and sensor. Sleep currents in the microamp range allow coin-cell operation for one to two weeks of typical use.
Recommended
Consumer Audio Remote Controls
For consumer AV remote controls with voice wake, IR, and BLE, the ATSAMD21E17A-AF provides the right balance of Flash (128 KB) for audio front-end processing and small package (32-TQFP 7x7 mm) for slim enclosures. The DAC can drive a small beeper or amplifier for key-click feedback, and the SERCOM peripherals can interface to IR LEDs, capacitive touch, and a BLE module over UART. Standby currents below 10 uA allow months of battery life from a pair of AAA cells. The Cortex-M0+ code is portable across the SAM D21 family for higher- or lower-tier variants.
Recommended
IoT Edge Sensor Nodes
For low-power IoT edge sensor nodes transmitting via LoRa, BLE, or Sub-GHz radios, the ATSAMD21E17A-AF offers Cortex-M0+ performance plus sufficient Flash for sensor fusion and secure over-the-air firmware updates. The SAM D21's hex-compatible code across the family allows a single image to support different pin-count boards. Integrated touch (PTC) peripheral can replace discrete capacitive touch ICs for HMI buttons. The on-chip 12-channel DMA offloads sensor sampling from the CPU, leaving 48 MHz headroom for radio stack management.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD21E17A-AF β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD21E17A-AU | ATSAMD21E18A-AF | ATSAMD21E16B-AF | ATSAMD21E15B-AF | ATSAMD20E17A-AU |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 32-pin TQFP (7x7 mm) | 32-pin TQFP (7x7 mm) - same | 32-pin TQFP (7x7 mm) - same | 32-pin TQFP (7x7 mm) - same | 32-pin TQFP (7x7 mm) - same | 32-pin TQFP (7x7 mm) - same |
| Core | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ |
| Max CPU Clock | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| Flash Memory | 128 KB | 128 KB | 256 KB | 64 KB | 32 KB | 128 KB |
| SRAM | 16 KB | 16 KB | 32 KB | 8 KB | 4 KB | 16 KB |
| USB | USB 2.0 Full-Speed Device | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed | No USB (SAM D20 family) |
| 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 |
| Temperature Grade (suffix) | 125C GREEN (AF) | 85C GREEN (AU) | 125C GREEN (AF) | 125C GREEN (AF) | 125C GREEN (AF) | 85C GREEN (AU) |
Key Differentiators
- Combines 128 KB Flash with integrated USB 2.0 FS in 32-pin TQFP (vs ATSAMD20E17A-AU)
- Doubles Flash and SRAM versus the cost-down E15/E16 siblings (vs ATSAMD21E16B-AF)
- Functional Safety (FuSa) capable family (vs Generic Cortex-M0+ MCUs)
- Wide 125 C industrial temperature grade (vs ATSAMD21E17A-AU)
- Higher CIV (CoreMark/MHz) than legacy 8-bit MCUs (vs PIC16F720-I/SS)
Design Notes
Place a 100 nF ceramic decoupling capacitor within 2 mm of each VDD pin, plus a single 1 uF to 4.7 uF bulk capacitor near the package, per the SAM D21 datasheet power supply design guidelines. This decoupling layout stabilizes the internal 1.2 V regulator output and prevents load-step noise on the ADC reference. Estimated: assuming a 48 MHz CPU and active peripherals, peak transient current can reach 30 mA, so the bulk capacitor must be sized accordingly. The 32-TQFP package has 2 VDD pins (6 and 30) and 2 GND pins (5 and 29); both must be bonded.
Route the USB DP and DM pair as a 90 ohm differential microstrip with matched length and continuous ground reference, per Microchip SAM D21 hardware design guide. Place the optional common-mode choke close to the USB connector and provide ESD protection diodes rated for IEC 61000-4-2 air-discharge at the connector. Avoid routing DP/DM near switching regulators or RF traces to keep USB compliance margin. Add a 50 kohm pull-up on DP if bus-powered device mode is needed.
For the 12-bit ADC, keep analog traces short and isolated from digital switching traces. Place a ferrite bead or small resistor between the digital supply and AVDD if available, and use a clean ground plane for the analog section. Reference the SAM D21 datasheet section on Analog Inputs for grounding and bypass guidance. Estimated: a 5 mm analog trace next to a noisy digital trace can couple >10 mV of switching noise, exceeding 1 LSB of the 12-bit ADC at 3.3 V reference.
Common pitfalls: (1) configuring PA24/PA25 for GPIO when USB is required; (2) leaving the 32 kHz crystal load capacitors unpopulated, which causes RTC drift; (3) using 5 V logic on the GPIO, which damages the part since the absolute maximum is 3.8 V; (4) forgetting to enable the on-chip pull-up on DP for USB bus-powered mode; (5) using the wrong DFLL configuration when crystal-less USB operation is intended.
For SERCOM SPI operation above 10 MHz, source-terminate the SCK trace with a small resistor (22-33 ohm) to dampen reflections on longer PCB traces. Use a series resistor on the MISO line if multiple devices share the bus to avoid bus contention during slave transitions. Reference Microchip application note AN2461 for SERCOM SPI master mode configuration details.
Compliance Information
GREEN (RoHS-compliant) per Microchip ordering code. AEC-Q100 automotive grade NOT available for this family; for AEC-Q100 use the SAM C20/C21 family or PIC32 family.
