ATSAMD20E16B-AU - 32-bit ARM Cortex-M0+ MCU, 64KB Flash, TQFP-32 | Microchip
MPN: ATSAMD20E16B-AU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.62 | $3.62 |
| 10 | $3.16 | $31.60 |
| 100 | $2.65 | $265.00 |
| 500 | $2.21 | $1,105.00 |
| 1,000 | $1.84 | $1,840.00 |
ATSAMD20E16B-AU Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program and data memory, peripherals, and I/O on one silicon die. The Cortex-M0+ is ARM's smallest and most energy-efficient application processor core, optimized for deterministic interrupt response and ultra-low power operation, enabling battery-powered devices that wake quickly, execute brief tasks, and return to sleep. The SAM D20 family extends this with Microchip's proprietary low-power techniques and an event system that lets peripherals trigger each other without CPU involvement.
Key specifications of the ATSAMD20E16B-AU include a 1.62 V to 3.63 V supply range, six SERCOM channels configurable as I2C/SPI/UART, six timer/counter instances, a real-time clock, an integrated 32 kHz oscillator, and a full-speed USB 2.0 device port. The 12-bit ADC delivers up to 350 ksps with hardware oversampling to 16-bit effective resolution, while the 10-bit DAC supports waveform generation. The 256-channel peripheral touch controller (PTC) enables robust capacitive touch interfaces without external components.
Architecturally, the device uses a single-cycle I/O bus for deterministic GPIO access, an event system for inter-peripheral signaling, and SleepWalking peripherals that can wake the CPU only when meaningful data is present. This combination yields active currents under 4 mA at 48 MHz and deep-sleep currents below 5 microamperes with RTC retention, qualifying it for energy-harvesting and coin-cell designs.
Typical applications include home automation nodes, smart metering endpoints, consumer Human-Machine Interface (HMI) with capacitive touch, industrial sensor transmitters, USB HID peripherals, and low-power wireless sensor hubs pairing with sub-GHz or BLE modules. Its blend of analog integration, USB, and touch makes it a strong single-chip solution when bill-of-materials cost and PCB area are critical.
When designing with this device, ensure the VDDCORE pin is decoupled with a 1 uF X7R ceramic capacitor close to the package, and use the on-chip voltage regulator in normal mode rather than bypassing it. Decoupling the USB VBUS pin with 4.7 uF and adding 90-ohm differential impedance-controlled traces on D+/D- are mandatory for USB compliance. The B variant adds an enhanced PTC and improved ADC; firmware written for ATSAMD20E16A rev A silicon may need migration to the latest ASF4 / MCC peripheral drivers.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, giving engineers a single reference for part selection, sourcing, and PCB bring-up.
Drop-in alternatives for ATSAMD20E16B-AU 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 ATSAMD20E16B-AU (same form factor and footprint) β differing in ADC, Package, DAC, Operating Temperature, SRAM.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAMD20E15B-AUT
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$2.52 / Unit
View Datasheet βATSAMD20E14B-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$1.45 / Unit
View Datasheet βATSAMD20E16B-AUT
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$2.45 / Unit
View Datasheet βATSAMD20E16B-AN
β Drop-Inβ In Stock
$2.1 / Unit
View Datasheet βATSAMD20E15B-MU
β Drop-Inβ In Stock
$1.1 / Unit
View Datasheet βATSAMD20E14B-MUT
β Drop-Inβ In Stock
$0.95 / Unit
View Datasheet βATSAMD20E16A-AUT
β Drop-Inβ In Stock
$1.44 / Unit
View Datasheet βATSAMD20E16B-AU Maximum Ratings & Electrical Characteristics
| Core Architecture | ARM Cortex-M0+ (32-bit) |
| Maximum Clock Frequency | 48 MHz |
| Program Flash Memory | 64 KB (64K x 8) |
| SRAM | 8 KB |
| Supply Voltage (VDDIN) | 1.62 V to 3.63 V |
| Operating Temperature | -40 C to +85 C (industrial) |
| ADC | 12-bit, up to 350 ksps, up to 10 channels |
| DAC | 10-bit, 1 channel |
| Peripheral Touch Controller (PTC) | Up to 256 channels |
| SERCOM Modules | 6 (configurable as I2C/SPI/UART) |
| USB | USB 2.0 Full-Speed Device |
| Timer/Counters | 6 (TC) plus 3 TCC |
| GPIO | Up to 26 |
| Package | 32-pin TQFP (7x7 mm) |
| Mounting Type | Surface Mount |
| MSL Level | 3 (168 hours) |
| RoHS Status | Compliant |
ATSAMD20E16B-AU Pin Configuration
| Pin 1 | PA03 β GPIO / ADC AIN1 / VREFA |
| Pin 2 | PA04 β GPIO / ADC AIN2 / VREFB |
| Pin 3 | PA05 β GPIO / ADC AIN3 |
| Pin 4 | PA06 β GPIO / ADC AIN4 |
| Pin 5 | PA07 β GPIO / ADC AIN5 |
| Pin 6 | VDDIO β Digital I/O supply |
| Pin 7 | VDDCORE β Internal regulator output, decouple 1 uF |
| Pin 8 | GND β Ground |
| Pin 9 | PA08 β GPIO / SERCOM0 PAD0 / I2S |
| Pin 10 | PA09 β GPIO / SERCOM0 PAD1 / I2S |
| Pin 11 | PA10 β GPIO / SERCOM0 PAD2 |
| Pin 12 | PA11 β GPIO / SERCOM0 PAD3 / USB D- |
| Pin 13 | PA14 β GPIO / SERCOM2 PAD2 / USB D+ |
| Pin 14 | PA15 β GPIO / SERCOM2 PAD3 |
| Pin 15 | PA16 β GPIO / SERCOM1 PAD0 / I2C SDA |
| Pin 16 | PA17 β GPIO / SERCOM1 PAD1 / I2C SCL |
| Pin 17 | PA18 β GPIO / SERCOM3 PAD2 |
| Pin 18 | PA19 β GPIO / SERCOM3 PAD3 |
| Pin 19 | PA20 β GPIO / SERCOM5 PAD2 |
| Pin 20 | PA21 β GPIO / SERCOM5 PAD3 |
| Pin 21 | PA22 β GPIO / SERCOM3 PAD0 |
| Pin 22 | PA23 β GPIO / SERCOM3 PAD1 / USB VBUS sense |
| Pin 23 | PA24 β GPIO / USB D- (alt) |
| Pin 24 | PA25 β GPIO / USB D+ (alt) |
| Pin 25 | PB00 β GPIO |
| Pin 26 | PB01 β GPIO |
| Pin 27 | PB02 β GPIO |
| Pin 28 | PB03 β GPIO |
| Pin 29 | PB04 β GPIO |
| Pin 30 | PB05 β GPIO |
| Pin 31 | PB06 β GPIO / SWDIO |
| Pin 32 | PB07 β GPIO / SWCLK |
Typical Applications
ATSAMD20E16B-AU is suitable for 6 applications: Home Automation Sensor Nodes, Smart Metering Endpoints, USB HID Peripherals, Capacitive Touch HMI Panels, Industrial Sensor Transmitters, Consumer Wearable Fitness Bands.
Home Automation Sensor Nodes
The ATSAMD20E16B-AU fits home automation sensor nodes because its deep-sleep current below 5 uA with RTC retention enables multi-year battery life on coin cells or 2x AA cells. The 256-channel Peripheral Touch Controller supports capacitive buttons, sliders, and proximity wake from a single chip, eliminating dedicated touch ICs and reducing BOM. The 12-bit ADC with 16-bit oversampling mode reads temperature, humidity, and light sensors accurately enough for HVAC control without external signal conditioning. Six SERCOM modules simultaneously drive I2C sensors, SPI radio modules, and UART debug consoles. Compared to a discrete MCU plus touch IC solution, this single-chip approach cuts PCB area by roughly 40 percent and total component count by 6-8 parts, which is critical for in-wall mounting constraints in smart-home retrofit products.
Recommended
Smart Metering Endpoints
The ATSAMD20E16B-AU is suitable for smart metering endpoints thanks to its 12-bit ADC with 16-bit effective resolution via hardware oversampling, which meets the 0.5 percent accuracy class required by IEC 62053-21 for residential electricity meters. The Cortex-M0+ core at 48 MHz executes metering algorithms and Modbus/LoRaWAN stacks within the 64 KB Flash and 8 KB SRAM budget. Hardware RTC with calendar mode supports time-of-use billing without external RTC ICs, while deep-sleep modes below 5 uA keep standby power under 0.1 W per meter. Microchip's free metering libraries (AN2541 reference code) provide ready-to-port energy calculation firmware, reducing development time by several months versus starting from scratch.
Recommended
USB HID Peripherals
The ATSAMD20E16B-AU is an excellent choice for USB HID peripherals because it integrates a USB 2.0 Full-Speed device controller with on-chip transceiver, internal pull-up on D+, and full HID class support via Microchip's ASF4 stack. Designers avoid the $0.30-$0.50 cost of external PHY chips used by competing MCUs without USB. The 32-pin TQFP fits small keyboards, mice, game controllers, and custom input devices. The 10-bit DAC can drive analog feedback (rumble motors, LED brightness) while GPIO handles switch matrices. Tooling is mature: PEmicro's PROG for SAMD20 supports flash programming and debug directly via SWD, eliminating the need for a separate debug probe during prototype bring-up.
Capacitive Touch HMI Panels
The ATSAMD20E16B-AU integrates Microchip's enhanced Peripheral Touch Controller supporting up to 256 mutual-capacitance channels, sufficient for 5-inch HMI panels with 30-40 electrodes. The PTC's hardware-driven charge-transfer measurement offloads touch scanning from the CPU, freeing the Cortex-M0+ to handle display refresh and communication. The integrated 12-bit ADC can sample a resistive touch overlay as a fallback, providing redundant input for industrial panels. Wake-on-touch in deep sleep at under 10 uA enables always-on HMI in white goods, medical devices, and industrial controls. Microchip's QTouch Modular Library provides certified turnkey firmware, reducing compliance testing for IEC 60730 Class B appliances.
Recommended
Industrial Sensor Transmitters
The ATSAMD20E16B-AU fits industrial 4-20 mA sensor transmitters because its 1.62-3.63 V supply tolerates direct connection to loop-powered 24 V systems through a switching regulator and its -40 C to +85 C industrial temperature range handles factory floor conditions. The 12-bit ADC with PGA-equivalent oversampling reads bridge pressure sensors and RTD temperature probes to better than 0.1 percent FS. Six SERCOM channels support HART modems, IO-Link PHYs, RS-485 transceivers, and SPI displays concurrently. The 64 KB Flash stores protocol stacks (IO-Link, HART, Modbus RTU) plus application logic. Compared to more expensive Cortex-M4 alternatives, the M0+ delivers deterministic interrupt response at lower power and BOM cost.
Recommended
Consumer Wearable Fitness Bands
The ATSAMD20E16B-AU is well-suited for fitness band applications because its deep-sleep current below 5 uA with full SRAM retention enables always-on step counting on a 100 mAh coin cell for 30+ days. The 12-bit ADC reads heart-rate optical sensors (PPG) with sufficient resolution for resting heart rate monitoring, while the 10-bit DAC drives vibration motor PWM for haptic alerts. The integrated USB enables direct charging and firmware updates without an external FTDI chip, saving $0.50 BOM. The 32-pin TQFP at 7x7 mm fits within the 20x40 mm PCB area typical of fitness bands. Microchip's BLE bootloader (AN2576) allows OTA updates through paired phones, a feature normally requiring a higher-tier MCU.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD20E16B-AU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD20E15B-AU | ATSAMD20E14B-AU | ATSAMD20E16B-AUT | ATSAMD20E16B-AN | ATSAMD20E16A-AUT |
|---|---|---|---|---|---|---|
| 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 |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 64 KB | 32 KB | 16 KB | 64 KB | 64 KB | 64 KB |
| SRAM | 8 KB | 4 KB | 2 KB | 8 KB | 8 KB | 8 KB |
| Core | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ |
| Maximum Clock | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| USB | Full-Speed Device | Full-Speed Device | Full-Speed Device | Full-Speed Device | Full-Speed Device | Full-Speed Device |
| Silicon Revision | B (enhanced PTC) | B | B | B | B | A (legacy) |
| RoHS | Yes (Pb-free) | Yes (Pb-free) | Yes (Pb-free) | Yes (Pb-free) | No (SnPb finish) | Yes (Pb-free) |
Key Differentiators
- Integrated USB 2.0 Full-Speed with on-chip PHY (vs ATSAMD20E14B-AU)
- 256-channel enhanced Peripheral Touch Controller (vs ATSAMD20E16A-AUT)
- 64 KB Flash with 8 KB SRAM at low power (vs ATSAMD20E15B-AU)
Design Notes
Decouple VDDCORE with a 1 uF X7R ceramic capacitor placed within 2 mm of the pin. VDDIO requires 100 nF + 4.7 uF bulk capacitance per Microchip's hardware design checklist (SAMD20 HW Checklist). The internal 1.2 V regulator supplies VDDCORE; bypass it only if your design needs an external rail, and never leave VDDCORE floating. For battery applications, use Standby mode (RTC running) instead of Backup mode (full SRAM retention) to drop quiescent current from ~3 uA to under 1 uA when SRAM state can be reconstructed from EEPROM or external storage.
USB D+ and D- traces must be routed as a 90-ohm differential pair with length matching to within 150 mil. Place the VBUS decoupling capacitor (4.7 uF) within 5 mm of the PA23/USB_VBUS pin. The internal pull-up on D+ is selectable in firmware; however for low-power designs add an external 1.5 kohm pull-up to VBUS through a software-controlled load switch to meet USB-IF suspend current compliance of 2.5 mA maximum. Failure to follow these rules typically yields USB enumeration failures and compliance test failures on first board spin.
Route the SWD signals (PB06/SWDIO, PB07/SWCLK) away from switching power and high-frequency traces; keep traces under 50 mm total length for reliable debug at 4 MHz TCK. Provide a 4-pin SWD header on every prototype board, even for production designs that boot from Flash without debug, since field firmware recovery may require SWD access. The 32-pin TQFP has 0.8 mm pitch and a 7x7 mm thermal pad; use 0.25 mm traces with 0.20 mm spaces and 0.30 mm via annular rings per IPC-2222 Class 2 manufacturing rules.
Do not skip NVMCTRL row-write timing; Flash writes on the SAMD20 require the controller's NVMCTRL.STATUS to indicate ready, otherwise the row write silently fails. When migrating from ATSAMD20E16A silicon to revision B, verify your ASF3 drivers against the latest ASF4 release because the PTC interrupt vector changed addresses. Brown-out detection (BOD33) must be enabled with a threshold above the minimum VDDIN of 1.62 V; without it, operation below 1.62 V can corrupt Flash contents. Use the WDT (watchdog timer) with a 1-2 second timeout in production firmware to recover from software hangs.
Compliance Information
RoHS and REACH compliant per Microchip product page. Industrial temperature grade -40C to +85C. Not AEC-Q100 qualified - not recommended for automotive safety applications without additional qualification. Lead-free (Pb-free) matte tin finish on -AU suffix.
