ATSAMD20J18A-MN - ARM Cortex-M0+ MCU 256KB Flash | Microchip
MPN: ATSAMD20J18A-MN ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.84 | $5.84 |
| 10 | $5.26 | $52.60 |
| 100 | $4.67 | $467.00 |
| 500 | $4.21 | $2,105.00 |
| 1,000 | $3.75 | $3,750.00 |
ATSAMD20J18A-MN 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 such as ADC, timers, communication interfaces, and GPIOs. The SAM D20 family sits within Microchip's broader portfolio of ARM Cortex-M based microcontrollers -> 32-bit microcontrollers -> microcontrollers -> semiconductors, and is purpose-built for low-power embedded designs. The Cortex-M0+ core delivers 2.14 CoreMark/MHz, balancing energy efficiency with deterministic real-time response.
Key features include a 12-bit ADC with up to 16 channels and 350 ksps throughput, a 10-bit DAC, six SERCOM configurable serial interfaces (each usable as UART, I2C, or SPI), a 24-channel peripheral touch controller, and a full-speed USB 2.0 device port. The Event System and SleepWalking peripherals enable deterministic peripheral wake-up while the CPU remains dormant, allowing designers to meet aggressive power budgets.
The architecture combines an ultra-low-power design (down to 8 uA/MHz active, sub-microamp deep sleep) with deterministic interrupt latency from the Cortex-M0+ Nested Vector Interrupt Controller (NVIC). Integrated AES-like crypto hardware and a true random number generator (TRNG) on selected variants strengthen secure connectivity. The 64-pin QFN package exposes up to 52 GPIOs enables two I2S channels and a full-speed USB PHY.
Typical applications include home automation nodes, smart metering endpoints, consumer wearables, industrial sensor hubs, and IoT edge devices that need both low standby consumption and responsive real-time behavior. The wide supply range and industrial temperature grade also suit battery-powered or outdoor deployments.
When designing with this device, ensure the QFN thermal pad is soldered to a sufficiently large copper pour to meet the 64-pin HVQCCN thermal envelope. The SAM D20's SERCOM multiplexing requires careful pin mapping via the PORT controller; refer to the device pinout table before committing PCB layout.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATSAMD20J18A-MN — 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 ATSAMD20J18A-MN (same form factor and footprint) — differing in ADC, Package, SRAM, Operating Temperature Range, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAMD20J18A-MU
✅ Drop-In✓ In Stock
$2.69 / Unit
View Datasheet →ATSAMD20J18A-AU
✅ Drop-In✓ In Stock
$2.15 / Unit
View Datasheet →ATSAMD20J17A-MNT
✅ Drop-In✓ In Stock
$2.18 / Unit
View Datasheet →ATSAMD20J16B-MN
✅ Drop-In✓ In Stock
$1.73 / Unit
View Datasheet →ATSAMD20J15A-CNT
✅ Drop-In✓ In Stock
$2.54 / Unit
View Datasheet →ATSAMC21J18A-MUT64
✅ Drop-In✓ In Stock
$2.85 / Unit
View Datasheet →ATSAMD20J18A-MN Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M0+ (32-bit) |
| Maximum CPU Frequency | 48 MHz |
| CoreMark/MHz | 2.14 |
| Flash Program Memory | 256 KB |
| SRAM | 32 KB |
| Supply Voltage Range | 1.62 V to 3.63 V |
| Package | 64-pin QFN (HVQCCN) |
| Mounting Type | Surface Mount |
| ADC | 12-bit, up to 16 channels, 350 ksps |
| DAC | 10-bit |
| SERCOM Interfaces | 6 (configurable as UART/SPI/I2C) |
| USB | Full-Speed USB 2.0 Device |
| Peripheral Touch Controller | Up to 256 channels (24 enabled) |
| GPIOs | Up to 52 |
| MSL Level | 3 |
| RoHS Status | Compliant (per Mouser listing) |
ATSAMD20J18A-MN Pin Configuration
| Pin 1 | VDD — Digital supply voltage input |
| Pin 2 | GND — Ground reference |
| Pin 3 | PA00 — PORT A GPIO 0 / SERCOM1 PAD0 / ADC0 AIN0 |
| Pin 4 | PA01 — PORT A GPIO 1 / SERCOM1 PAD1 / ADC0 AIN1 |
| Pin 5 | PA02 — PORT A GPIO 2 / SERCOM1 PAD2 / ADC0 AIN2 |
| Pin 6 | PA03 — PORT A GPIO 3 / SERCOM1 PAD3 / ADC0 AIN3 |
| Pin 7 | PA04 — PORT A GPIO 4 / SERCOM0 PAD0 / ADC0 AIN4 |
| Pin 8 | PA05 — PORT A GPIO 5 / SERCOM0 PAD1 / ADC0 AIN5 |
| Pin 9 | PA06 — PORT A GPIO 6 / SERCOM0 PAD2 / ADC0 AIN6 |
| Pin 10 | PA07 — PORT A GPIO 7 / SERCOM0 PAD3 / ADC0 AIN7 |
| Pin 11 | PA08 — PORT A GPIO 8 / SERCOM2 PAD0 / ADC0 AIN8 |
| Pin 12 | PA09 — PORT A GPIO 9 / SERCOM2 PAD1 / ADC0 AIN9 |
| Pin 13 | PA10 — PORT A GPIO 10 / SERCOM2 PAD2 / ADC0 AIN10 |
| Pin 14 | PA11 — PORT A GPIO 11 / SERCOM2 PAD3 / ADC0 AIN11 |
| Pin 15 | PA12 — PORT A GPIO 12 / SERCOM3 PAD0 / ADC0 AIN12 |
| Pin 16 | PA13 — PORT A GPIO 13 / SERCOM3 PAD1 / ADC0 AIN13 |
| Pin 17 | PA14 — PORT A GPIO 14 / SERCOM3 PAD2 / ADC0 AIN14 |
| Pin 18 | PA15 — PORT A GPIO 15 / SERCOM3 PAD3 / ADC0 AIN15 |
| Pin 19 | PA16 — PORT A GPIO 16 / SERCOM1 PAD0 / I2S SD0 |
| Pin 20 | PA17 — PORT A GPIO 17 / SERCOM1 PAD1 / I2S MCK0 |
| Pin 21 | PA18 — PORT A GPIO 18 / SERCOM1 PAD2 / I2S FS0 |
| Pin 22 | PA19 — PORT A GPIO 19 / SERCOM1 PAD3 / I2S SCK0 |
| Pin 23 | PA20 — PORT A GPIO 20 / SERCOM5 PAD2 |
| Pin 24 | PA21 — PORT A GPIO 21 / SERCOM5 PAD3 |
| Pin 25 | PA22 — PORT A GPIO 22 / SERCOM3 PAD0 / I2S SD1 |
| Pin 26 | PA23 — PORT A GPIO 23 / SERCOM3 PAD1 / I2S MCK1 |
| Pin 27 | PA24 — PORT A GPIO 24 / SERCOM3 PAD2 / USB D- |
| Pin 28 | PA25 — PORT A GPIO 25 / SERCOM3 PAD3 / USB D+ |
| Pin 29 | RESET — System reset (active low) |
| Pin 30 | PA27 — PORT A GPIO 27 |
| Pin 31 | PA28 — PORT A GPIO 28 |
| Pin 32 | GND — Ground reference |
| Pin 33 | PA30 — PORT A GPIO 30 / SWCLK |
| Pin 34 | PA31 — PORT A GPIO 31 / SWDIO |
| Pin 35 | PB00 — PORT B GPIO 0 / SERCOM4 PAD0 / ADC0 AIN8 alt |
| Pin 36 | PB01 — PORT B GPIO 1 / SERCOM4 PAD1 |
| Pin 37 | PB02 — PORT B GPIO 2 / SERCOM4 PAD2 / ADC0 AIN10 alt |
| Pin 38 | PB03 — PORT B GPIO 3 / SERCOM4 PAD3 |
| Pin 39 | PB04 — PORT B GPIO 4 / SERCOM4 PAD0 alt |
| Pin 40 | PB05 — PORT B GPIO 5 / SERCOM4 PAD1 alt |
| Pin 41 | PB06 — PORT B GPIO 6 / SERCOM4 PAD2 alt |
| Pin 42 | PB07 — PORT B GPIO 7 / SERCOM4 PAD3 alt |
| Pin 43 | PB08 — PORT B GPIO 8 / SERCOM4 PAD0 / I2S MCK1 alt |
| Pin 44 | PB09 — PORT B GPIO 9 / SERCOM4 PAD1 / I2S MCK0 alt |
| Pin 45 | PB10 — PORT B GPIO 10 / SERCOM4 PAD2 / I2S FS0 alt |
| Pin 46 | PB11 — PORT B GPIO 11 / SERCOM4 PAD3 / I2S SCK0 alt |
| Pin 47 | PB12 — PORT B GPIO 12 / SERCOM4 PAD0 alt / DAC0 VOUT |
| Pin 48 | PB13 — PORT B GPIO 13 / SERCOM4 PAD1 alt |
| Pin 49 | PB14 — PORT B GPIO 14 / SERCOM4 PAD2 alt |
| Pin 50 | PB15 — PORT B GPIO 15 / SERCOM4 PAD3 alt |
| Pin 51 | PB17 — PORT B GPIO 17 |
| Pin 52 | PB18 — PORT B GPIO 18 |
| Pin 53 | PB19 — PORT B GPIO 19 |
| Pin 54 | PB20 — PORT B GPIO 20 |
| Pin 55 | PB21 — PORT B GPIO 21 |
| Pin 56 | PB22 — PORT B GPIO 22 |
| Pin 57 | PB23 — PORT B GPIO 23 |
| Pin 58 | VDD — Digital supply voltage input |
| Pin 59 | GND — Ground reference |
| Pin 60 | VDDIO — I/O supply voltage reference |
| Pin 61 | VDDANA — Analog supply voltage reference |
| Pin 62 | GND — Ground reference |
| Pin 63 | PA06 — PORT A GPIO 6 alternate mapping |
| Pin 64 | NC — Not connected (per datasheet) |
Typical Applications
ATSAMD20J18A-MN is suitable for 6 applications: Home Automation Sensor Hub, Smart Metering Endpoints, Wearable Fitness Devices, Industrial Sensor Transmitters, IoT Edge Connectivity Nodes, Consumer Appliance Control Boards.
Home Automation Sensor Hub
The ATSAMD20J18A-MN's 256 KB Flash accommodates Zigbee or BLE host-stack firmware while 32 KB SRAM supports RTOS-based task scheduling. Its 6 SERCOM interfaces map directly to UART/I2C/SPI sensor buses for HVAC, lighting, and occupancy sensors. SleepWalking peripherals plus sub-uA deep-sleep current enable multi-year coin-cell operation in wireless door/window sensors.
Recommended
Smart Metering Endpoints
The ATSAMD20J18A-MN's 12-bit ADC with 16 channels at 350 ksps captures voltage and current waveforms in single-phase electricity, gas, and water meters. Its RTC with calendar mode plus tamper-detection GPIOs meets metering accuracy and security requirements. The wide 1.62 V to 3.63 V supply supports direct connection to lithium battery backup.
Recommended
Wearable Fitness Devices
The ATSAMD20J18A-MN integrates a 12-bit ADC for heart-rate/SPO2 sensors, 10-bit DAC for haptic feedback, and a 24-channel peripheral touch controller for capacitive button/slider inputs. Its 8 uA/MHz active current plus deep-sleep current below 1 uA delivers all-day battery life. The Cortex-M0+ core provides deterministic interrupt response for low-latency sensor reads.
Recommended
Industrial Sensor Transmitters
The ATSAMD20J18A-MN operates across the industrial -40 C to +105 C range and runs 4-20 mA loop-powered or IO-Link sensor transmitters. Its 12-bit ADC plus DAC and 6 SERCOM interfaces support HART or IO-Link communication stacks. Hardware AES plus 256 KB Flash accommodates secure firmware update procedures required by IEC 62443.
Recommended
IoT Edge Connectivity Nodes
The ATSAMD20J18A-MN's full-speed USB 2.0 device port and 6 SERCOMs route LTE-M, NB-IoT, or LoRa modules in a portable design. Its 32 KB RAM holds the TLS record layer. ATP conditional timing plus a real-time OS keeps the firmware updated over the air.
Recommended
Consumer Appliance Control Boards
The ATSAMD20J18A-MN drives brushed DC or stepper motors in coffee machines, vacuum robots, and small kitchen appliances through its PWM timers and Event System. Its 12-bit ADC monitors temperature and current sensors, while SERCOM interfaces connect to displays and BLE modules. The wide supply range tolerates rectified 5 V to 24 V mains after regulation.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD20J18A-MN — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD20J18A-MU | ATSAMD20J17A-MNT | ATSAMD20J16B-MN | ATSAMD20J15A-CNT | ATSAMC21J18A-MUT64 |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 64-pin QFN (HVQCCN) | 64-pin QFN - same | 64-pin QFN - same | 64-pin QFN - same | 64-pin QFN - same | 64-pin QFN - same |
| Flash Memory | 256 KB | 256 KB | 128 KB | 64 KB | 32 KB | 256 KB |
| SRAM | 32 KB | 32 KB | 16 KB | 8 KB | 4 KB | 32 KB |
| CPU Frequency | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| Core | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ with FPU |
| USB | Full-Speed USB 2.0 Device | Full-Speed USB 2.0 Device | Full-Speed USB 2.0 Device | Full-Speed USB 2.0 Device | Full-Speed USB 2.0 Device | Full-Speed USB 2.0 Device + Host |
| ADC | 12-bit, 16 channels | 12-bit, 16 channels | 12-bit, 16 channels | 12-bit, 16 channels | 12-bit, 16 channels | 12-bit, 16 channels |
Key Differentiators
- Largest Flash + SRAM in SAM D20J QFN package (vs ATSAMD20J15A-CNT)
- Identical silicon footprint for layout reuse (vs ATSAMD20J18A-AU)
- Cortex-M0+ with full SAM D20 peripheral set vs SAM C21 CAN-FD upgrade (vs ATSAMC21J18A-MUT64)
Design Notes
The 64-pin QFN (HVQCCN) package requires soldering the central exposed thermal pad to a sufficiently large ground copper pour with at least 16 thermal vias to the inner ground plane. Without this, junction temperature rises beyond the 105 C industrial limit at moderate loads. Keep the QFN GND pad solid copper with no signal traces routed underneath to maximize thermal dissipation.
The SAM D20 SERCOM peripherals require pin multiplexing via the PORT controller; not every GPIO supports every peripheral function. Before committing PCB layout, verify each pin's peripheral mapping against the SAM D20 datasheet pinout table. Mis-mapping SERCOM pads is the most common reason for first-spin firmware failures.
Place a 1 uF X7R ceramic bypass capacitor as close as possible to every VDD pin and a 10 uF bulk capacitor on VDDANA to keep ADC readings clean. The SAM D20 ADC is sensitive to digital supply noise; route analog VDD/VDDANA traces separately from switching regulator outputs. Estimated noise contribution improves by 6 dB with proper analog/digital power separation.
Compliance Information
RoHS compliant per Mouser listing. Not AEC-Q100 qualified; choose ATSAMD20J18A-MU-Y or SAM D21 automotive variants for vehicle applications.
