ATSAMD21J18A-AF - 48MHz Cortex-M0+ 256KB Flash MCU | Microchip
MPN: ATSAMD21J18A-AF ✓ نشطATSAMD21J18A-AF نظرة عامة
An ARM Cortex-M0+ microcontroller is a 32-bit reduced instruction set computing (RISC) processor core targeting ultra-low-power embedded applications. The Cortex-M0+ belongs to the ARM Cortex-M family -> 32-bit MCU core -> embedded processor -> semiconductor. It executes the Thumb/Thumb-2 instruction set, includes a single-cycle hardware multiplier, and is paired in the SAM D21 with Microchip's event system, SERCOM peripherals, and a rich analog set. By occupying the low-power end of the ARM-M lineup, Cortex-M0+ parts are commonly chosen over Cortex-M3/M4 when deterministic control, low BOM cost, and battery life outweigh raw compute.
The ATSAMD21J18A-AF features a 12-bit, up to 350 ksps ADC with hardware oversampling, a 12-bit 1 Msps DAC, two analog comparators, six SERCOM modules (each configurable as UART/USART/SPI/I2C), up to 52 GPIO, and a full-speed USB 2.0 device/host interface. The integrated 2.46 CoreMark/MHz efficiency is supported by a single-cycle hardware multiplier, a deterministic nested-vectored interrupt controller (NVIC), and dual-bank Flash for safe in-field OTA updates.
Typical applications include IoT sensor nodes, home automation gateways, smart appliances, industrial metering, wearable fitness bands, and consumer HMI with USB-CDC connectivity. The wide 1.6V to 3.6V supply range, on-chip FPU-less Cortex-M0+ pipeline, and dual-bank Flash make it well suited to mains-powered as well as coin-cell products.
When designing with this part, reserve SERCOM channel assignments early because each SERCOM is pin-muxed and conflicts are easy to miss at low pin counts. Always enable the brown-out detector (BOD) and configure the SysTick for low-power tickless RTOS operation to maximize battery life.
This page synthesizes distributor pricing, drop-in alternative cross-references, and practical design notes that are not bundled together on the manufacturer datasheet PDF.
بدائل مباشرة لـ ATSAMD21J18A-AF — نفس الحزمة، متوافق دبوس بدبوس. تُستثنى القطع ذات الحزم المختلفة التي تتطلب تعديل PCB.
الطرازات في هذه السلسلة
طرازات من نفس السلسلة متوافقة تمامًا مع ATSAMD21J18A-AF (نفس عامل الشكل والبصمة) — يختلف في USB, ADC, Package, Operating Temperature, DAC.
ATSAMD21J18A-AFT
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←ATSAMD21J18A-AU
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←ATSAMD21J17A-AU
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←ATSAMD21J18A-MF
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←ATSAMD21G18A-MU
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←ATSAMC21J18A-AU
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
ATSAMD21J18A-AF الحدود القصوى والخصائص الكهربائية
| Core | ARM Cortex-M0+ (32-bit) |
| Family | SAM D21J |
| أقصى تردد للساعة | 48 MHz |
| CoreMark Score | 2.46 CoreMark/MHz |
| Flash Memory | 256 KB (256K x 8) |
| SRAM | 32 KB |
| Supply Voltage Range | 1.6 V to 3.6 V |
| GPIO Count | Up to 52 |
| SERCOM Modules | 6 (configurable as UART/SPI/I2C) |
| ADC | 12-bit, up to 350 ksps, hardware oversampling |
| DAC | 12-bit, 1 Msps |
| Analog Comparators | 2 |
| USB | USB 2.0 Full-Speed Device/Host |
| العلبة | 64-pin TQFP (10x10 mm) |
| درجة حرارة التشغيل | -40C to +125C (industrial) |
| Carrier Type | Tray |
| حالة RoHS | Compliant |
تكوين أطراف ATSAMD21J18A-AF
| دبوس 1 | PA00 — GPIO PA00 / ADC IN0 / SERCOM0 PAD0 |
| دبوس 2 | PA01 — GPIO PA01 / ADC IN1 / SERCOM0 PAD1 |
| دبوس 3 | PA02 — GPIO PA02 / ADC IN2 / DAC OUT0 |
| دبوس 4 | PA03 — GPIO PA03 / ADC IN3 / DAC OUT1 / REF |
| دبوس 5 | GND — Ground |
| دبوس 6 | VDD — Digital supply voltage |
| دبوس 7 | PA04 — GPIO PA04 / ADC IN4 / TC0 WO0 |
| دبوس 8 | PA05 — GPIO PA05 / ADC IN5 / TC0 WO1 |
| دبوس 9 | PA06 — GPIO PA06 / ADC IN6 / TC1 WO0 |
| دبوس 10 | PA07 — GPIO PA07 / ADC IN7 / TC1 WO1 |
| دبوس 11 | VDD — Digital supply voltage |
| دبوس 12 | GND — Ground |
| دبوس 13 | PA08 — GPIO PA08 / SERCOM0 PAD0 / I2S MCK0 |
| دبوس 14 | PA09 — GPIO PA09 / SERCOM0 PAD1 / I2S FS0 |
| دبوس 15 | PA10 — GPIO PA10 / SERCOM0 PAD2 / I2S SCK0 |
| دبوس 16 | PA11 — GPIO PA11 / SERCOM0 PAD3 / I2S SD0 |
| دبوس 17 | PA12 — GPIO PA12 / SERCOM2 PAD0 |
| دبوس 18 | PA13 — GPIO PA13 / SERCOM2 PAD1 |
| دبوس 19 | PA14 — GPIO PA14 / SERCOM2 PAD2 |
| دبوس 20 | PA15 — GPIO PA15 / SERCOM2 PAD3 |
| دبوس 21 | PA16 — GPIO PA16 / SERCOM1 PAD0 / I2S SD1 |
| دبوس 22 | PA17 — GPIO PA17 / SERCOM1 PAD1 / I2S MCK1 |
| دبوس 23 | PA18 — GPIO PA18 / SERCOM1 PAD2 / I2S SCK1 |
| دبوس 24 | PA19 — GPIO PA19 / SERCOM1 PAD3 / I2S FS1 |
| دبوس 25 | PA20 — GPIO PA20 / SERCOM5 PAD2 |
| دبوس 26 | PA21 — GPIO PA21 / SERCOM5 PAD3 |
| دبوس 27 | PA22 — GPIO PA22 / SERCOM3 PAD0 |
| دبوس 28 | PA23 — GPIO PA23 / SERCOM3 PAD1 |
| دبوس 29 | PA24 — GPIO PA24 / USB D- |
| دبوس 30 | PA25 — GPIO PA25 / USB D+ |
| دبوس 31 | GND — Ground |
| دبوس 32 | VDD — USB supply voltage |
| دبوس 33 | PA26 — GPIO PA26 / SERCOM3 PAD2 |
| دبوس 34 | PA27 — GPIO PA27 / SERCOM3 PAD3 |
| دبوس 35 | PA28 — GPIO PA28 / AIN0 |
| دبوس 36 | PA29 — GPIO PA29 / AIN1 |
| دبوس 37 | PB00 — GPIO PB00 / ADC IN8 |
| دبوس 38 | PB01 — GPIO PB01 / ADC IN9 |
| دبوس 39 | PB02 — GPIO PB02 / ADC IN10 / SERCOM5 PAD0 |
| دبوس 40 | PB03 — GPIO PB03 / ADC IN11 / SERCOM5 PAD1 |
| دبوس 41 | PB04 — GPIO PB04 / SERCOM4 PAD0 |
| دبوس 42 | PB05 — GPIO PB05 / SERCOM4 PAD1 |
| دبوس 43 | PB06 — GPIO PB06 / SERCOM4 PAD2 |
| دبوس 44 | PB07 — GPIO PB07 / SERCOM4 PAD3 |
| دبوس 45 | PB08 — GPIO PB08 / SERCOM4 PAD0 / TC4 WO0 |
| دبوس 46 | PB09 — GPIO PB09 / SERCOM4 PAD1 / TC4 WO1 |
| دبوس 47 | PB10 — GPIO PB10 / SERCOM4 PAD2 / TC5 WO0 |
| دبوس 48 | PB11 — GPIO PB11 / SERCOM4 PAD3 / TC5 WO1 |
| دبوس 49 | PB12 — GPIO PB12 / SERCOM4 PAD0 / TC0 WO0 |
| دبوس 50 | PB13 — GPIO PB13 / SERCOM4 PAD1 / TC0 WO1 |
| دبوس 51 | PB14 — GPIO PB14 / SERCOM4 PAD2 / TC1 WO0 |
| دبوس 52 | PB15 — GPIO PB15 / SERCOM4 PAD3 / TC1 WO1 |
| دبوس 53 | PB16 — GPIO PB16 / SERCOM5 PAD0 / TC2 WO0 |
| دبوس 54 | PB17 — GPIO PB17 / SERCOM5 PAD1 / TC2 WO1 |
| دبوس 55 | PB18 — GPIO PB18 / SERCOM5 PAD2 / TC3 WO0 |
| دبوس 56 | PB19 — GPIO PB19 / SERCOM5 PAD3 / TC3 WO1 |
| دبوس 57 | PB20 — GPIO PB20 / SERCOM3 PAD2 / TC4 WO0 |
| دبوس 58 | PB21 — GPIO PB21 / SERCOM3 PAD3 / TC4 WO1 |
| دبوس 59 | GND — Ground |
| دبوس 60 | VDD — Digital supply voltage |
| دبوس 61 | RESET — Reset input (active low) |
| دبوس 62 | SWDIO — SWD data / PA31 |
| دبوس 63 | SWCLK — SWD clock / PA30 |
| دبوس 64 | VDD — Analog supply voltage |
التطبيقات النموذجية
ATSAMD21J18A-AF مناسب لـ 6 التطبيقs: IoT Sensor Node, Home Automation Gateway, USB-CDC Consumer Device, Industrial Metering, Wearable Fitness Band, Smart Appliance HMI.
IoT Sensor Node
The ATSAMD21J18A-AF fits IoT sensor nodes through its 70 uA/MHz active current and single-digit uA standby modes, extending coin-cell battery life to months. The 256 KB Flash holds TLS/WiFi stacks while the six SERCOM channels interface I2C sensors, SPI radios, and UART debug ports without bus contention. With 32 KB SRAM buffering packet payloads and a Cortex-M0+ running at 48 MHz, latency stays below 5 ms for typical sensor publishes. Real deployments integrate an ESP32 WiFi co-processor via SERCOM3 UART plus a BME280 on SERCOM0 I2C, drawing 12 mA average per awake cycle.
موصى به
Home Automation Gateway
The ATSAMD21J18A-AF serves home automation gateways by combining USB 2.0 full-speed device, multiple SERCOM channels, and 52 GPIO for Zigbee/Thread co-processors and relays. Its 256 KB Flash fits Matter and OpenThread stack fragments, while the 12-bit ADC monitors battery-backed safety sensors. The Cortex-M0+ deterministic interrupt controller ensures sub-millisecond response to AC zero-cross detection for triac dimming. Reference designs pair it with an ATECC608B secure element and SAM R34 LoRa radio on SERCOM4, creating a complete Matter bridge in 4 cm square PCB area.
موصى به
USB-CDC Consumer Device
The ATSAMD21J18A-AF is widely adopted in USB-CDC consumer devices thanks to its integrated USB 2.0 full-speed device with on-chip transceiver and 1.6-3.6V operation directly from USB VBUS. The 256 KB Flash stores USB stacks plus HID profiles, and the 12-bit DAC drives analog audio feedback for click-feedback HMI. Its 52 GPIO support capacitive touch via the Peripheral Touch Controller (PTC) for buttons and sliders. Typical Arduino MKR and Adafruit Feather M0 boards use this exact silicon, validated by millions of units shipped.
موصى به
Industrial Metering
The ATSAMD21J18A-AF fits industrial metering at -40C to +125C operation, with 12-bit ADC sampling current shunts at 350 ksps for accurate power calculations. The dual-bank Flash enables safe OTA firmware updates required by utility metering standards, while RTC with calendar drives time-of-use tariff logic. With Cortex-M0+ deterministic execution and six SERCOM channels, the MCU can simultaneously drive an LCD segment display via SPI, read a Modbus RS-485 transceiver on UART, and log to external EEPROM. Typical designs consume 25 mA average across voltage and current sampling cycles.
موصى به
Wearable Fitness Band
The ATSAMD21J18A-AF powers wearable fitness bands through its 70 uA/MHz active current and <5 uA deep-sleep mode, enabling 7-day battery life on a 100 mAh Li-Po cell. The integrated 12-bit ADC reads heart-rate photoplethysmography (PPG) sensors with hardware oversampling, while I2C drives accelerometer and gyro IMUs on SERCOM0. Its 64-pin TQFP can be replaced by ATSAMD21G18A-MU in 48-pin QFN for thinner form factors. The six SERCOM channels support Bluetooth HCI, display SPI, touch I2C, and battery fuel-gauge I2C simultaneously.
موصى به
Smart Appliance HMI
The ATSAMD21J18A-AF drives smart appliance HMI through its Peripheral Touch Controller (PTC) supporting capacitive buttons, sliders, and wheels, plus its 52 GPIO for TFT display and buzzer control. The 256 KB Flash stores UI graphics and BLE stacks while 32 KB SRAM buffers animation frames. Industrial -40C to +125C operation handles kitchen and laundry environments where ambient temperature peaks at 60-85C. Reference designs integrate a 2.4-inch TFT on SERCOM2 SPI plus a CST816S touch controller on SERCOM3 I2C.
موصى به
ملخص المنتجات الموصى بها
بيانات مرجعية هندسية لـ ATSAMD21J18A-AF — المقارنة وإرشادات التصميم ومعلومات الامتثال.
دليل الاختيار
المقارنة مع البدائل
| المعامل | هذا المنتج | ATSAMD21J18A-AFT | ATSAMD21J18A-AU | ATSAMD21J17A-AU | ATSAMD21J18A-MF | ATSAMD21G18A-MU | ATSAMC21J18A-AU |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 64-pin TQFP (10x10 mm) | 64-pin TQFP (10x10 mm) - same | 64-pin TQFP (10x10 mm) - same | 64-pin TQFP (10x10 mm) - same | 64-pin QFN (9x9 mm) | 48-pin QFN (6x6 mm) | 64-pin TQFP (10x10 mm) - same |
| Flash Memory | 256 KB | 256 KB | 256 KB | 128 KB | 256 KB | 256 KB | 256 KB |
| SRAM | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB |
| Core | Cortex-M0+ | Cortex-M0+ | Cortex-M0+ | Cortex-M0+ | Cortex-M0+ | Cortex-M0+ | Cortex-M0+ |
| Maximum Clock Frequency | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| Supply Voltage | 1.6 V to 3.6 V | 1.6 V to 3.6 V | 1.6 V to 3.6 V | 1.6 V to 3.6 V | 1.6 V to 3.6 V | 1.6 V to 3.6 V | 2.7 V to 5.5 V |
| Operating Temperature | -40C to +125C (industrial) | -40C to +125C (industrial) | -40C to +85C (extended) | -40C to +85C (extended) | -40C to +125C (industrial) | -40C to +125C (industrial) | -40C to +125C (industrial) |
| USB | USB 2.0 Full-Speed Device/Host | USB 2.0 Full-Speed Device/Host | USB 2.0 Full-Speed Device/Host | USB 2.0 Full-Speed Device/Host | USB 2.0 Full-Speed Device/Host | USB 2.0 Full-Speed Device/Host | USB 2.0 Full-Speed Device/Host |
أبرز الفروقات
- Industrial -40C to +125C temperature range (مقابلATSAMD21J18A-AU)
- 64-pin TQFP with up to 52 GPIO (مقابلATSAMD21G18A-MU)
- Lowest active current at 70 uA/MHz (مقابلATSAMC21J18A-AU)
- Dual-bank Flash for safe OTA (مقابلATSAMD21J17A-AU)
ملاحظات التصميم
SERCOM channel conflict is the most common ATSAMD21J18A-AF design pitfall. Each of the six SERCOM modules is pin-muxed to multiple GPIO ports, so assigning SERCOM0 to PA08-PA11 while reserving PA08-PA11 for SPI flashes in another SERCOM creates compile-time errors. Solution: build a SERCOM pin map at schematic entry before assigning pins to peripherals. Microchip's Atmel START pin-mux tool automates this and is the authoritative reference for SERCOM-to-pad allocations.
Brown-out detector (BOD) must be enabled during firmware initialization to protect Flash from corruption during battery brown-outs. Configure BOD12 threshold to 1.5 V minimum to ensure the MCU does not write to Flash below safe VDD. Additionally, for coin-cell designs, use the on-chip RTC with a 32.768 kHz crystal to wake the MCU from standby at <5 uA quiescent current. Estimated: deep-sleep current ~3 uA at 25C with RTC running per Microchip datasheet figure 36-4.
Place a 100 nF decoupling capacitor within 5 mm of every VDD pin and a single 10 uF bulk capacitor near the package. For USB applications, add 0 ohm series resistors on D+/D- if the design supports both high-speed and full-speed modes. Expose the SWDIO/SWCLK pins on a 2x5 0.05 inch header for factory programming and field firmware updates. Microchip recommends a 4-layer PCB with continuous ground plane beneath the TQFP-64 footprint to minimize EMI from the 48 MHz core.
The 64-pin TQFP (10x10 mm) footprint requires 0.5 mm pitch traces. Route SERCOM signals as length-matched pairs where possible to maintain signal integrity at 10 MHz SPI speeds. The ADC input pins should be guarded by ground traces to prevent digital crosstalk from nearby PWM signals. For designs using the 12-bit ADC at 350 ksps, add an anti-alias RC filter (1 kohm + 1 nF) at each analog input with 4.7 uF bulk hold capacitor at the ADC voltage reference pin.
معلومات الامتثال
RoHS and REACH compliant per Microchip product page. Industrial -40C to +125C temperature grade but not AEC-Q100 qualified - use ATSAMx E variants for automotive.
