ATSAMD20J16A-MN - 48MHz Cortex-M0+ MCU 64KB Flash | Microchip
MPN: ATSAMD20J16A-MN β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.1 | $4.10 |
| 10 | $3.62 | $36.20 |
| 100 | $3.05 | $305.00 |
| 500 | $2.65 | $1,325.00 |
| 1,000 | $2.4 | $2,400.00 |
ATSAMD20J16A-MN Overview
Background: a microcontroller (MCU) is a single-chip computer that integrates a CPU core, non-volatile program memory (Flash), volatile working memory (SRAM), and programmable peripherals on one die. ARM Cortex-M0+ is the smallest and most energy-efficient member of the ARM Cortex-M family, using the Thumb-2 instruction set and designed for deterministic interrupt response in low-power embedded systems. The Cortex-M0+ class sits within the broader hierarchy: microcontroller -> embedded processor -> SoC -> semiconductor. Compared to 8-bit AVR MCUs that Microchip also sells, the SAM D20 offers higher code density, faster arithmetic, and modern serial peripherals such as SERCOM and USB.
Key features of the ATSAMD20J16A-MN include 64 KB Flash, 8 KB SRAM, up to 48 MHz CPU clock, 1.62 V to 3.63 V wide VDD range, low-power Sleep and Idle modes drawing a few microamps, a 12-channel 12-bit 350 ksps ADC, two I2C ports, three SPI, six UART, full-speed USB 2.0 device, and a Peripheral Touch Controller supporting capacitive buttons and sliders. The integrated 6-channel DMA engine offloads memory-move and peripheral-streaming work from the Cortex-M0+ core, freeing cycles for application logic.
On the architecture side, the SAM D20 uses a two-layer AHB-Lite bus matrix with bridges to APB for peripherals, single-cycle 32x32 hardware multiplier, and a SysTick timer. The 64-pin QFN package exposes 52 GPIO plus dedicated USB D+/D- and XIN/XOUT pins. Programming is supported by Microchip Studio (formerly Atmel Studio), MPLAB X IDE, and the on-board SAM-BA bootloader over USB or UART.
Typical applications include IoT sensor nodes, smart-home appliances (thermostats, white-goods HMIs), portable medical devices, industrial control boards, USB HID peripherals (keyboards, mice, custom input devices), and LoRaWAN/Zigbee sensor endpoints. The wide 1.62-3.63 V supply range allows direct Li-ion battery operation with a low-dropout regulator.
When designing with this part, budget for a 32.768 kHz crystal if accurate RTC timing is required, and add a 1uF plus 100 nF decoupling pair near each VDD pin. Use the SERCOM multiplexer rather than fixed-position UART/SPI/I2C pins to remap peripherals when PCB routing forces pin swaps.
This page synthesizes distributor pricing, same-brand and cross-brand drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATSAMD20J16A-MN 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 ATSAMD20J16A-MN (same form factor and footprint) β differing in ADC, Package, USB, SRAM, MSL Level.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATSAMD20J16A-AUT
β Drop-Inπ Reference alternative (not in catalog)
ATSAMD20J15A-AUT
β Drop-Inβ In Stock
$1.85 / Unit
View Datasheet βATSAMD20J16B-MU
β Drop-Inπ Reference alternative (not in catalog)
ATSAMD20J14B-MU
β Drop-Inβ In Stock
$2.05 / Unit
View Datasheet βATSAMD20J18A-MU
β Drop-Inβ In Stock
$2.69 / Unit
View Datasheet βATSAMR21G18A-MU
β Drop-Inπ Reference alternative (not in catalog)
ATSAMD20J16A-MN Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M0+ (32-bit) |
| Maximum CPU Clock | 48 MHz |
| Flash Memory | 64 KB (64K x 8) |
| SRAM | 8 KB |
| Operating Voltage (VDD) | 1.62 V to 3.63 V |
| Package | 64-pin QFN (9x9 mm), industrial temp grade |
| GPIO Count | 52 |
| ADC | 12-bit SAR, up to 12 channels, 350 ksps |
| DAC | 10-bit, 1 channel |
| USB | USB 2.0 Full-Speed Device |
| Serial Interfaces (SERCOM) | 6 (configurable as UART/SPI/I2C) |
| Timers | Six 16-bit TC, three 24-bit TCC |
| DMA Channels | 6 |
| RTC | Yes, with 32.768 kHz crystal support |
| Peripheral Touch Controller (PTC) | Yes, capacitive touch support |
| Operating Temperature | -40C to +105C (industrial) |
| Mounting Type | Surface Mount |
| MSL Level | 3 (168 hours) |
| RoHS Status | Compliant |
ATSAMD20J16A-MN Pin Configuration
| Pin 1 | PA00 β GPIO / XIN32 (RTC crystal input) |
| Pin 2 | PA01 β GPIO / XOUT32 (RTC crystal output) |
| Pin 3 | PA02 β GPIO / ADC AIN0 |
| Pin 4 | PA03 β GPIO / ADC AIN1 / VREFA |
| Pin 5 | GND β Ground |
| Pin 6 | VDDIO β I/O supply voltage |
| Pin 7 | PA04 β GPIO / ADC AIN2 |
| Pin 8 | PA05 β GPIO / ADC AIN3 |
| Pin 9 | PA06 β GPIO / ADC AIN4 |
| Pin 10 | PA07 β GPIO / ADC AIN5 |
| Pin 11 | PA08 β GPIO / ADC AIN6 |
| Pin 12 | PA09 β GPIO / ADC AIN7 |
| Pin 13 | PA10 β GPIO / ADC AIN8 |
| Pin 14 | PA11 β GPIO / ADC AIN9 |
| Pin 15 | VDDANA β Analog supply voltage |
| Pin 16 | GND β Ground |
| Pin 17 | PA12 β GPIO / I2S SDO / SERCOM |
| Pin 18 | PA13 β GPIO / I2S SDI / SERCOM |
| Pin 19 | PA14 β GPIO / I2S FS / SERCOM |
| Pin 20 | PA15 β GPIO / I2S SCK / SERCOM |
| Pin 21 | PA16 β GPIO / SERCOM1 PAD0 (I2C SDA) |
| Pin 22 | PA17 β GPIO / SERCOM1 PAD1 (I2C SCL) |
| Pin 23 | PA18 β GPIO / SERCOM1 PAD2 |
| Pin 24 | PA19 β GPIO / SERCOM1 PAD3 |
| Pin 25 | PA20 β GPIO / SERCOM5 PAD2 |
| Pin 26 | PA21 β GPIO / SERCOM5 PAD3 |
| Pin 27 | PA22 β GPIO / SERCOM3 PAD0 |
| Pin 28 | PA23 β GPIO / SERCOM3 PAD1 / USB SOF |
| Pin 29 | PA24 β GPIO / USB D- |
| Pin 30 | PA25 β GPIO / USB D+ |
| Pin 31 | GND β Ground |
| Pin 32 | PA26 β GPIO |
| Pin 33 | PA27 β GPIO |
| Pin 34 | PA28 β GPIO / Reset (default) |
| Pin 35 | PA29 β GPIO / SWDIO |
| Pin 36 | PA30 β GPIO / SWCLK |
| Pin 37 | PA31 β GPIO / Bootloader entry (default) |
| Pin 38 | PB00 β GPIO / SERCOM5 PAD0 |
| Pin 39 | PB01 β GPIO / SERCOM5 PAD1 |
| Pin 40 | PB02 β GPIO / SERCOM5 PAD2 / ADC AIN14 |
| Pin 41 | PB03 β GPIO / SERCOM5 PAD3 / ADC AIN15 |
| Pin 42 | PB04 β GPIO / ADC AIN6 alt |
| Pin 43 | PB05 β GPIO / ADC AIN7 alt |
| Pin 44 | PB06 β GPIO / ADC AIN8 alt |
| Pin 45 | PB07 β GPIO / ADC AIN9 alt |
| Pin 46 | PB08 β GPIO / ADC AIN2 alt |
| Pin 47 | PB09 β GPIO / ADC AIN3 alt |
| Pin 48 | PB10 β GPIO / SERCOM4 PAD0 |
| Pin 49 | PB11 β GPIO / SERCOM4 PAD1 |
| Pin 50 | PB12 β GPIO / SERCOM4 PAD2 |
| Pin 51 | PB13 β GPIO / SERCOM4 PAD3 |
| Pin 52 | PB14 β GPIO / SERCOM2 PAD2 |
| Pin 53 | PB15 β GPIO / SERCOM2 PAD3 |
| Pin 54 | PB16 β GPIO / SERCOM2 PAD0 / TC0 WO0 |
| Pin 55 | PB17 β GPIO / SERCOM2 PAD1 / TC0 WO1 |
| Pin 56 | PB18 β GPIO / TC4 WO0 |
| Pin 57 | PB19 β GPIO / TC4 WO1 |
| Pin 58 | PB20 β GPIO / TC5 WO0 |
| Pin 59 | PB21 β GPIO / TC5 WO1 |
| Pin 60 | PB22 β GPIO / TC6 WO0 |
| Pin 61 | PB23 β GPIO / TC6 WO1 |
| Pin 62 | PB24 β GPIO / TC7 WO0 |
| Pin 63 | PB25 β GPIO / TC7 WO1 |
| Pin 64 | VDD β Digital supply voltage (core) |
Typical Applications
ATSAMD20J16A-MN is suitable for 7 applications: IoT Sensor Node, USB HID Peripheral, Home Automation HMI, Industrial Sensor Board, Portable Medical Device, Smart Metering Endpoint, Wearable Fitness Tracker.
IoT Sensor Node
The ATSAMD20J16A-MN fits IoT sensor nodes because it combines a 48 MHz Cortex-M0+ core with deep Sleep modes drawing a few microamps, plus a 12-bit SAR ADC accurate enough for environmental sensors. With 64 KB Flash it holds a LoRaWAN or Zigbee stack plus application logic without external memory. The wide 1.62-3.63 V supply supports direct Li-ion or 2xAA battery operation, eliminating an external LDO.
Recommended
USB HID Peripheral
The ATSAMD20J16A-MN is ideal for USB keyboards, mice, custom input devices, and data loggers because it integrates a USB 2.0 Full-Speed device controller with on-chip transceiver, requiring only a single 1.5 kohm pull-up on D+ and external ESD protection. The 6-channel DMA engine offloads endpoint-buffer moves, freeing Cortex-M0+ cycles for HID report assembly. The 64-pin QFN exposes USB D+/D- on dedicated pins, simplifying PCB layout.
Recommended
Home Automation HMI
The ATSAMD20J16A-MN drives capacitive-touch home-automation HMIs (thermostats, white-goods panels) thanks to the integrated Peripheral Touch Controller, which supports up to 12 self-capacitance buttons and sliders without an external touch IC. The 52 GPIO drive LED matrices, character LCDs, or segment displays. The wide 1.62-3.63 V supply allows operation from rectified 3.3 V rails, and 8 KB SRAM is sufficient for a small graphics buffer.
Recommended
Industrial Sensor Board
The ATSAMD20J16A-MN suits industrial sensor boards operating up to 105C with RS-485, 4-20 mA loops, and isolated digital I/O. Six SERCOM peripherals map onto UART, SPI, or I2C interfaces as needed for sensor and transceiver links, while the 12-bit ADC handles analog inputs with 350 ksps throughput. The 64-pin QFN footprint is mechanically rugged and the -40C to +105C industrial grade supports factory-floor deployment.
Recommended
Portable Medical Device
The ATSAMD20J16A-MN powers portable medical peripherals such as pulse-oximeter probes, single-parameter patient monitors, and home-care diagnostic accessories. Its 12-bit ADC captures photodiode and bio-impedance signals with sufficient resolution for SpO2 trending, while the Cortex-M0+ core runs a deterministic control loop. Low Sleep current extends battery life, and the wide supply range accepts 2xAAA alkaline or Li-ion packs directly.
Recommended
Smart Metering Endpoint
The ATSAMD20J16A-MN fits electricity, water, and gas metering endpoints because it integrates a high-accuracy RTC with 32.768 kHz crystal, a 12-bit ADC for analog sensor inputs, and 8 KB SRAM enough for hourly profile buffering. The SERCOM multiplexer supports M-Bus, UART, or wireless module links. Low Sleep current below 5 uA (RTC + RAM retention) lets the meter run for years on a single battery.
Recommended
Wearable Fitness Tracker
The ATSAMD20J16A-MN drives entry-level wearable fitness bands because the 52 GPIO support I2C sensor hubs (accelerometer, gyroscope, heart rate), SPI OLED displays, and battery gauge links via SERCOM. The compact 9x9 mm QFN leaves room for a small PCB, while the 1.62 V minimum supply allows direct coin-cell operation. The integrated Peripheral Touch Controller handles tap and swipe gestures on a single-button interface.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD20J16A-MN β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD20J16A-AUT | ATSAMD20J15A-AUT | ATSAMD20J16B-MU | ATSAMD20J14B-MU | ATSAMD20J18A-MU | ATSAMR21G18A-MU |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 64-QFN (9x9 mm) | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same | 64-QFN (9x9 mm) - same |
| Core | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ with 2.4 GHz radio |
| Max CPU Clock | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| Flash | 64 KB | 64 KB | 32 KB | 64 KB | 16 KB | 256 KB | 256 KB |
| SRAM | 8 KB | 8 KB | 8 KB | 8 KB | 4 KB | 32 KB | 32 KB |
| 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 | 1.62 V to 3.63 V | 1.62 V to 3.63 V |
| 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 | USB 2.0 FS Device + 2.4 GHz radio |
| Touch (PTC) | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Operating Temperature | -40C to +105C | -40C to +85C | -40C to +105C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- Full-speed USB 2.0 device integrated with on-chip transceiver (vs ATSAMD20J14B-MU)
- Balanced Flash/SRAM budget at lowest cost (vs ATSAMD20J18A-MU)
- Industrial -40C to +105C operating range as standard (vs ATSAMD20J16B-MU)
Design Notes
Place a 1 uF X7R ceramic plus a 100 nF X7R decoupling capacitor on each VDD, VDDIO, and VDDANA pin, located within 2 mm of the pin with short, wide traces. According to Microchip's SAM D20 hardware design guidelines, the analog supply VDDANA should be filtered with a ferrite bead to keep ADC noise below 1 LSB. Estimated: at 48 MHz active current of roughly 9 mA, the 1 uF cap supplies peak transient bursts during DMA bursts without drooping VDDANA below 1.62 V.
The SERCOM multiplexer must be configured before peripheral drivers can use UART/SPI/I2C - many first-time users forget this and see 'no response' on the bus. According to Microchip, PA22/PA23 and PA24/PA25 (USB D+/D-) must be configured for their alternate-function pads before enabling USB clocks. Also, NVMCTRL.NVMLOCK must be cleared before the row-writes to user signature row succeed.
Use a 4-layer PCB with a continuous ground plane under the QFN package's exposed pad; stitch vias around the pad perimeter at 0.5 mm pitch for thermal relief. According to Microchip AN00099, the SAM D20's exposed pad is the primary ground return and must be soldered with at least 16 thermal vias. For USB designs, keep D+/D- traces at 90 ohm differential with length matching to within 150 mil.
Route the 32.768 kHz crystal traces symmetrically within 5 mm of XIN32/XOUT32 (PA00/PA01) and guard them with a ground pour to avoid capacitive loading that pulls the RTC frequency. According to Microchip's SAM D20 datasheet, the internal load capacitor trim must be configured in the RTC MODE1 register for crystals with 7 pF or 12.5 pF load.
Compliance Information
RoHS and REACH compliant per Microchip product page. Not AEC-Q100 qualified - choose ATSAMx20x-xNUT variants or other automotive-grade parts for AEC-Q100.
