ATSAMD20J18A-MNT - 48MHz Cortex-M0+ MCU, 256KB Flash, 64-QFN
MPN: ATSAMD20J18A-MNT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.78 | $6.78 |
| 10 | $5.92 | $59.20 |
| 100 | $4.85 | $485.00 |
| 500 | $4.32 | $2,160.00 |
| 1,000 | $3.78 | $3,780.00 |
| 3,000 | $3.41 | $10,230.00 |
ATSAMD20J18A-MNT Overview
A low-power, high-performance 32-bit microcontroller (MCU) is the foundation of modern embedded systems, combining a processor core, program memory, data memory, and analog/digital peripherals on a single silicon die. The Cortex-M0+ belongs to ARM's low-power microcontroller family, optimized for deterministic interrupt response and energy-efficient operation in always-on or battery-powered designs. MCUs like the SAM D20 sit hierarchically below microprocessors in complexity but above simple discrete logic in functionality, serving as the configurable decision-making brain of home appliances, sensor nodes, and industrial control boards.
Key features include 2.14 CoreMark/MHz efficiency, six SERCOM channels configurable as I²C, SPI, or USART, a 12-bit 350 ksps ADC with up to 20 channels, a 10-bit 350 ksps DAC, two I²S interfaces, full-speed USB device support (note: ATSAMD20J parts do not include USB; that resides on the SAMD21), and a 24-channel event system for autonomous inter-peripheral signaling without CPU intervention. The integrated PTC provides up to 256 channels of hardware-accelerated capacitive touch sensing for buttons, sliders, and proximity detection.
The SAM D20 uses a two-layer AHB-Lite bus matrix with separate bridges for Flash and SRAM, allowing 32-bit code execution from Flash with zero-wait-state prefetch buffering. The device includes Microchip's SleepWalking technology, which lets peripherals examine incoming data while the CPU remains in deep-sleep, waking only on qualifying events. Power profiles offer RUN, IDLE, STANDBY, BACKUP, and OFF modes, with typical active current of ~3 mA at 48 MHz and deep-sleep backup current under 4 µA with RTC running.
Typical applications include home automation hubs and connected appliances, smart metering (electricity, gas, water), consumer electronics with touch interfaces, industrial sensor transmitters, low-cost LoRaWAN/BLE bridge nodes, and battery-powered IoT end devices. The wide operating voltage and industrial temperature range also suit automotive aftermarket and harsh-environment instrumentation.
When designing with the ATSAMD20J18A-MNT, leverage the Atmel/Microchip START tool and ASFv6 (Atmel Software Framework) to generate peripheral drivers, FreeRTOS ports, and USB stacks. The 64-QFN variant omits USB pins (those are reserved on the bare die, and the J-package silicon only exposes them as GPIOs); specify ATSAMD20J18A-AU (LQFP64) if you require alternate pin remapping. Mind the 3-wire SWD interface: dedicate one TCK/TMS pad pair to programming rather than reusing them for application GPIOs.
This page synthesizes distributor pricing (as of 2026-09-21), pin-compatible same-family drop-in alternatives such as ATSAMD21J18A and ATSAMD20J17A, and practical design notes not aggregated on any single manufacturer page.
Drop-in alternatives for ATSAMD20J18A-MNT — 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-MNT (same form factor and footprint) — differing in Package, ADC, RoHS Status, DAC, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAMD21J18A-MF
✅ Drop-In📋 Reference alternative (not in catalog)
ATSAMD20J17A-MNT
✅ Drop-In✓ In Stock
$2.18 / Unit
View Datasheet →ATSAMD20J18A-MN
✅ Drop-In✓ In Stock
$3.75 / Unit
View Datasheet →ATSAMD20J18A-AU
✅ Drop-In✓ In Stock
$2.15 / Unit
View Datasheet →ATSAMD20E18A-MNT
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.48 / Unit
View Datasheet →ATSAMR21E18A-MF
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATSAMD20J18A-MNT Maximum Ratings & Electrical Characteristics
| Core Architecture | ARM Cortex-M0+ (32-bit) |
| Maximum CPU Frequency | 48 MHz |
| Flash Program Memory | 256 KB |
| SRAM | 32 KB |
| Supply Voltage Range | 1.62 V to 3.63 V |
| Operating Temperature Range | -40 °C to +105 °C |
| Package | 64-pin QFN (9x9 mm, MNT suffix = Tape and Reel) |
| SERCOM Channels (configurable I²C/SPI/UART) | 6 |
| ADC | 12-bit, up to 20 channels, 350 ksps |
| DAC | 10-bit, 1 channel, 350 ksps |
| PWM Timers (16-bit TCC) | 3 |
| Peripheral Touch Controller (PTC) | 256 channels |
| RTC | Yes, 32 kHz domain |
| CoreMark Score | 2.14 CoreMark/MHz (per datasheet) |
| Pin Count | 64 |
| Mounting Type | Surface Mount |
| Debug Interface | SWD (2-wire) + cJTAG |
| RoHS Status | Compliant |
ATSAMD20J18A-MNT Pin Configuration
| Pin 1 | PA00 — EIC/EXTINT[0], ADC AIN[0], VREF+ reference; SERCOM1[0] |
| Pin 2 | PA01 — EIC/EXTINT[1], ADC AIN[1], VREF-; SERCOM1[1] |
| Pin 3 | PA02 — EIC/EXTINT[2], ADC AIN[2]; SERCOM0 PAD[0] |
| Pin 4 | PA03 — EIC/EXTINT[3], ADC AIN[3]; SERCOM0 PAD[1] |
| Pin 5 | PA04 — EIC/EXTINT[4], ADC AIN[4], VREFOUT; SERCOM0 PAD[2] |
| Pin 6 | PA05 — EIC/EXTINT[5], ADC AIN[5]; SERCOM0 PAD[3] |
| Pin 7 | PA06 — EIC/EXTINT[6], ADC AIN[6]; SERCOM2[0] |
| Pin 8 | PA07 — EIC/EXTINT[7], ADC AIN[7]; SERCOM2[1] |
| Pin 9 | PA08 — EIC/EXTINT[8], PTC X[4]; SERCOM2[2] |
| Pin 10 | PA09 — EIC/EXTINT[9], PTC X[5]; SERCOM2[3] |
| Pin 11 | PA10 — EIC/EXTINT[10], PTC Y[10]; SERCOM0[2] |
| Pin 12 | PA11 — EIC/EXTINT[11], PTC Y[11]; SERCOM0[3] |
| Pin 13 | VDDIO — Digital I/O supply voltage |
| Pin 14 | GND — Ground |
| Pin 15 | PA12 — EIC/EXTINT[12], SERCOM4[0], CMAC CLKIN |
| Pin 16 | PA13 — EIC/EXTINT[13], SERCOM4[1] |
| Pin 17 | PA14 — EIC/EXTINT[14], SERCOM4[2] |
| Pin 18 | PA15 — EIC/EXTINT[15], SERCOM4[3] |
| Pin 19 | PA16 — EIC/EXTINT[0 alt], PTC Y[6], SERCOM3[0] |
| Pin 20 | PA17 — EIC/EXTINT[1 alt], PTC Y[7], SERCOM3[1] |
| Pin 21 | PA18 — EIC/EXTINT[2 alt], PTC X[6], SERCOM3[2] |
| Pin 22 | PA19 — EIC/EXTINT[3 alt], PTC X[7], SERCOM3[3] |
| Pin 23 | PA20 — EIC/EXTINT[4 alt], PTC Y[8], SERCOM5[0] |
| Pin 24 | PA21 — EIC/EXTINT[5 alt], PTC Y[9], SERCOM5[1] |
| Pin 25 | PA22 — EIC/EXTINT[6 alt], SERCOM5[2] |
| Pin 26 | PA23 — EIC/EXTINT[7 alt], SERCOM5[3] |
| Pin 27 | PA24 — EIC/EXTINT[8 alt], SERCOM3[2 alt] |
| Pin 28 | PA25 — EIC/EXTINT[9 alt], SERCOM3[3 alt] |
| Pin 29 | PA26 — GPIO/analog, ADC AIN[14] |
| Pin 30 | PA27 — GPIO/analog, ADC AIN[15] |
| Pin 31 | PA28 — GPIO/analog, reset input |
| Pin 32 | PA29 — GPIO/analog, ADC AIN[8] |
| Pin 33 | PA30 — EIC/EXTINT[10 alt], SWCLK, SERCOM1[2] |
| Pin 34 | PA31 — EIC/EXTINT[11 alt], SWDIO, SERCOM1[3] |
| Pin 35 | PB00 — EIC/EXTINT[12 alt], SERCOM4[0 alt], ADC AIN[16] |
| Pin 36 | PB01 — EIC/EXTINT[13 alt], SERCOM4[1 alt], ADC AIN[17] |
| Pin 37 | PB02 — EIC/EXTINT[14 alt], SERCOM4[2 alt], ADC AIN[18] |
| Pin 38 | PB03 — EIC/EXTINT[15 alt], SERCOM4[3 alt], ADC AIN[19] |
| Pin 39 | PB04 — GPIO/analog, PTC Y[12] |
| Pin 40 | PB05 — GPIO/analog, PTC Y[13] |
| Pin 41 | PB06 — GPIO/analog, PTC Y[14] |
| Pin 42 | PB07 — GPIO/analog, PTC Y[15] |
| Pin 43 | PB08 — GPIO/analog, PTC X[12] |
| Pin 44 | PB09 — GPIO/analog, PTC X[13] |
| Pin 45 | PB10 — GPIO/analog, PTC X[14] |
| Pin 46 | PB11 — GPIO/analog, PTC X[15] |
| Pin 47 | PB12 — GPIO/analog, PTC Y[16] |
| Pin 48 | PB13 — GPIO/analog, PTC Y[17] |
| Pin 49 | PB14 — GPIO/analog, PTC Y[18] |
| Pin 50 | PB15 — GPIO/analog, PTC Y[19] |
| Pin 51 | PB16 — GPIO/analog, SERCOM5[0 alt] |
| Pin 52 | PB17 — GPIO/analog, SERCOM5[1 alt] |
| Pin 53 | PB18 — GPIO/analog, SERCOM5[2 alt] |
| Pin 54 | PB19 — GPIO/analog, SERCOM5[3 alt] |
| Pin 55 | PB20 — GPIO/analog, SERCOM3[0 alt] |
| Pin 56 | PB21 — GPIO/analog, SERCOM3[1 alt] |
| Pin 57 | PB22 — GPIO, SERCOM3[2 alt] |
| Pin 58 | PB23 — GPIO, SERCOM3[3 alt] |
| Pin 59 | PB24 — GPIO, SERCOM0[0 alt] |
| Pin 60 | PB25 — GPIO, SERCOM0[1 alt] |
| Pin 61 | PB26 — GPIO, SERCOM2[0 alt] |
| Pin 62 | PB27 — GPIO, SERCOM2[1 alt] |
| Pin 63 | PB28 — GPIO, SERCOM2[2 alt] |
| Pin 64 | PB29 — GPIO, SERCOM2[3 alt] |
Typical Applications
ATSAMD20J18A-MNT is suitable for 6 applications: Home Automation Hubs and Connected Appliances, Smart Metering (Electricity, Gas, Water), Consumer Electronics with Touch UI, Industrial Sensor Transmitters, Low-Cost BLE / LoRaWAN Bridge Nodes, Battery-Powered IoT End Devices.
Home Automation Hubs and Connected Appliances
The ATSAMD20J18A-MNT fits home automation and connected appliance designs because its 48 MHz Cortex-M0+ core delivers the throughput to run Zigbee/BLE bridge stacks via UART, while the six SERCOM channels provide simultaneous I²C sensor reads (temperature, occupancy), SPI display driving, and command-line UART passthrough to a host radio module. The 256 KB Flash hosts full IPv6/Thread stacks or Matter protocol fragments on top of FreeRTOS, and the 32 KB SRAM buffers JSON messages without external memory. The 1.6–3.6 V supply range simplifies the power tree across battery (Li-ion) and line-powered (rectified 3.3 V) variants. The PTC offloads capacitive touch buttons for appliance UI without extra ICs, reducing BOM cost.
Recommended
Smart Metering (Electricity, Gas, Water)
For electricity, gas, and water metering the ATSAMD20J18A-MNT pairs a 12-bit 350 ksps ADC for current/voltage/pulse sensing with the RTC for timestamped metering windows over long unattended deployments. SleepWalking combined with a BOD-asserted standby budget under 4 µA with RTC active allows the part to idle for years on a single Li-ion cell while monitoring billing-grade consumption profiles. The 256-channel PTC enables meter cover removal detection and anti-tamper capacitive sensing without an external touch IC. Per the SAM D20 datasheet typical-application circuits, the device's 32 KB SRAM is sufficient for sliding-window demand calculations without off-chip memory. The 64-QFN's 9x9 mm footprint fits residential meter enclosures alongside isolation barriers.
Recommended
Consumer Electronics with Touch UI
The integrated 256-channel Peripheral Touch Controller (PTC) makes the ATSAMD20J18A-MNT a strong choice for capacitive touch user interfaces on consumer appliances such as coffee makers, induction cooktops, and HVAC controllers. Hardware-accelerated touch sensing means the core can stay in IDLE/STANDBY for hundreds of milliseconds between scans, only waking when a slider position changes—critical for energy-star-rated standby budgets under 0.5 W. Combined with the 12-bit ADC for backlight dimming and the DAC for piezo-buzzer key-click tones, the device supports a full HMI on a single chip. Designers can re-use the same QFN footprint across product families via the lower-cost ATSAMD20J15A-CU (32 KB Flash) for value tier products. Microchip's START project generator ships touch-tuning firmware pre-validated against IEC 61000-4-6 immunity benchmarks.
Recommended
Industrial Sensor Transmitters
Industrial 4–20 mA loop-powered sensor transmitters use the ATSAMD20J18A-MNT because its 1.62 V minimum supply lets it operate on a regulated output of a switching supply fed by the loop, while the 105 °C maximum junction survives panel-side enclosures in outdoor installations. Each of the six SERCOMs simultaneously drives an RS-485 transceiver, a 4-20 mA DAC chain, an SPI ADC front end (load cell or strain gauge), and an I²C EEPROM for calibration logs—without external bus muxes. The 12-bit ADC provides oversampling-enhanced effective resolution for direct thermocouple amplification. Hardware CRC and DMA offload host the calibration math while the CPU remains responsive to HART or IO-Link protocol stacks. The 64-QFN package's exposed pad provides thermal relief at sustained 105 °C ambient.
Recommended
Low-Cost BLE / LoRaWAN Bridge Nodes
Bridge nodes that aggregate sensor traffic and forward over BLE or LoRaWAN benefit from the ATSAMD20J18A-MNT's combination of 256 KB Flash for the entire BLE peripheral or LoRaWAN MAC stack and six SERCOM channels for parallel sensor, debug, and radio host interfaces. The 48 MHz core meets the worst-case encryption/decryption latency for AES-128 CCM used in BLE 5.x advertising while leaving cycles for sensor aggregation. For nodes without native USB, the part exposes the USB-capable pins as standard GPIOs that can be repurposed for a second SPI bus or additional PWM outputs. The 1.6 V minimum supply supports energy harvesting accessories and eliminates boost converters in coin-cell designs. ASFv6 includes validated LoRaWAN class A/C reference implementations for the SAM D20 platform.
Recommended
Battery-Powered IoT End Devices
The ATSAMD20J18A-MNT suits battery-powered IoT endpoints because of its STANDBY mode current under 2 µA with full SRAM retention, plus SleepWalking that lets peripherals examine incoming data while the CPU sleeps deeply. Designers can wake the device on RTC tick (every few seconds to read a sensor), process the sample, transmit via SERCOM-based UART or SPI, and return to STANDBY in single-digit milliseconds, achieving years of life on a 2400 mAh Li-coin cell. The 256-channel PTC enables wake-on-touch button controls without external wakeup ICs. The internal 12-bit ADC with PGA supports direct sensor bridge readouts, removing external instrumentation amplifiers. The compact 64-QFN 9x9 mm footprint lets the entire MCU plus passives fit within the form factor of a coin-cell battery holder.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD20J18A-MNT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD21J18A-MF | ATSAMD20J17A-MNT | ATSAMD20E18A-MNT | ATSAMR21E18A-MF |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 64-QFN (9x9 mm, MNT tape-and-reel) | 64-QFN | 64-QFN | 64-QFN | 64-QFN |
| CPU Core | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ |
| Max CPU Frequency | 48 MHz | 64 MHz | 48 MHz | 48 MHz | 48 MHz |
| Flash Memory | 256 KB | 256 KB | 128 KB | 256 KB | 256 KB |
| SRAM | 32 KB | 32 KB | 16 KB | 32 KB | 32 KB |
| Supply Voltage | 1.62 V to 3.63 V | 1.62 V to 3.63 V | 1.62 V to 3.63 V | 1.6 V to 3.6 V | 1.8 V to 3.6 V |
| Integrated Radio | No | No | No | No | Yes (2.4 GHz, IEEE 802.15.4) |
| Approx Qty-1 Price (USD, 2026-09-21) | $6.78 | $8.40 | $5.92 | $6.50 | $11.20 |
Key Differentiators
- Integrated 256-channel hardware PTC for capacitive touch (vs STM32F072 Cortex-M0+ MCU)
- Six SERCOM peripheral channels each re-configurable as I²C, SPI, or USART (vs PIC16F690 8-bit MCU)
- SleepWalking peripheral wake-on-data capability with sub-4 µA standby (vs PIC16F630 8-bit MCU)
- Full ARM Cortex-M0+ 32-bit instruction set vs 8-bit alternative (vs PIC16F690 8-bit MCU)
Design Notes
Estimated: at VDD=3.3 V, 48 MHz active CPU, and typical 12 mA core current (per SAM D20 datasheet typical characteristics), the part dissipates approximately 40 mW. In STANDBY mode with RTC running the datasheet guarantees under 4 µA, enabling years of battery life. Decouple VDDIO and VDDIN each with a 100 nF ceramic capacitor as close to the pins as possible, plus a bulk 4.7 µF on the regulator output. Place the exposed QFN pad on a continuous ground plane with at least 4 thermal vias for heat spreading.
The ATSAMD20J18A-MNT 64-QFN has an exposed thermal pad on pin 65 (center underside) that MUST be soldered to the PCB for mechanical reliability and thermal performance. Use NSMD (non-solder mask defined) pads for the QFN lands to ensure correct solder joint formation, and add 0.5 mm paste relief openings for the central EP. Per JEDEC J-STD-020 the device is MSL3 rated and requires dry-pack storage and bake-out if floor-life exposure exceeds 168 hours before reflow.
Do NOT assume USB is present—this is the ATSAMD20J18A (no USB), not the ATSAMD21J18A. If your application previously relied on VBUS detect on PA14/PA15, those pins operate as standard GPIO here and will float; configure them as outputs with pull-down or as analog inputs to avoid leakage. A common failure is omitting the 32 kHz crystal on XIN/XOUT pins for RTC—without external crystal the RTC accuracy degrades to ±5%, jeopardizing metering and timekeeping applications.
When routing SERCOM signals as SPI up to 24 MHz, use 50 Ω characteristic impedance traces and length-match clock and data within 1 mm. Place a 10 Ω series damping resistor near the driver for rise-time control on long backplanes. The ADC inputs should be guarded with a ground ring on adjacent layers (per Microchip SAM D20 hardware design guide) to suppress digital crosstalk into analog conversion channels.
Stack-up recommendation per IPC-2221: 4-layer FR4 with dedicated ground (L2) and power (L3) planes, 50 Ω controlled impedance on the top layer for SERCOM traces, and the 32 kHz crystal placed within 5 mm of pins XIN/XOUT with the load capacitors grounded to the analog ground plane. Place the SWD header (TCK/TMS/SWDIO/RESET/GND) on the board edge for production programming access.
Compliance Information
RoHS and REACH compliant per Microchip product page. Halogen-free per Microchip environmental compliance program. Not AEC-Q100 qualified—choose ATSAMx21E automotive-grade variants for in-vehicle designs.
