ATSAMD21G18A-UUT - 48MHz Cortex-M0+ MCU, 256KB Flash, 45-WLCSP
MPN: ATSAMD21G18A-UUT ✓ פעילATSAMD21G18A-UUT סקירה
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program and data memory, and configurable peripherals. The Cortex-M0+ is ARM's smallest, most energy-efficient application processor core, designed for deterministic embedded workloads in power-constrained products. Within the broader taxonomy, the ATSAMD21G18A-UUT is a low-power MCU -> 32-bit MCU -> ARM Cortex-M0+ MCU -> SAM D21 family -> SAM D21G sub-family -> integrated circuit. This hierarchy helps engineers understand which firmware, toolchains, and reference designs are compatible.
Key features include a hardware 12-bit ADC (Analog-to-Digital Converter) and 10-bit DAC (Digital-to-Analog Converter), a full-speed USB 2.0 device/host interface, a 16-bit Event System for inter-peripheral signalling, and SERCOM modules that can be independently configured as UART, SPI, or I2C. The SAM D21 also provides a 32-bit RTC (Real-Time Counter), a 24-bit SysTick timer, and up to 38 GPIO (General-Purpose Input/Output) pins. The device reaches 2.46 CoreMark/MHz, indicating efficient integer code execution.
The architecture combines an ultra-low-power SleepWalking peripheral event system with multiple Sleep modes (IDLE, STANDBY, BACKUP). This makes the part suitable for battery-powered devices that spend most of their life in deep sleep and only wake on peripheral events such as button presses, sensor thresholds, or RTC alarms, then process data and return to sleep.
Typical applications include low-power IoT sensor nodes, USB HID (Human Interface Device) peripherals such as keyboards/mice, home-automation control panels, smart metering, consumer wearables, and industrial sensor aggregation. Designers choose this part when they need deterministic real-time response, code space for application firmware, USB connectivity, and extreme small PCB footprint.
When laying out the 45-WLCSP package, use microvia (small laser-drilled) PCB stack-up and place the ground/VDD balls directly above solid internal copper planes. The BOD12/BOD33 (Brown-Out Detector) thresholds should be enabled in software to guarantee safe boot and Flash integrity at low battery voltages.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the standalone Microchip datasheet, giving engineers a single authoritative reference for sourcing and design-in decisions.
חלופות תחליף ישיר עבור ATSAMD21G18A-UUT — אותו מארז, תואם פין-לפין. חלקים במארז שונה הדורשים עיבוד מחדש של ה-PCB אינם נכללים.
וריאנטים בסדרה זו
דגמים מאותה סדרה התואמים Drop-in עם ATSAMD21G18A-UUT (אותו גורם צורה וטביעת רגל) — שונים ב Package, USB, ADC, DAC, Operating Temperature.
ATSAMD21G18A-UUT
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←ATSAMD21G18A-MU
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←ATSAMD21G18A-MUT
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←ATSAMD21E18A-MF
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←ATSAMD21G18A-MF
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←STM32G031K8T6
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←ATSAMD21G17A-MU
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←ATSAMD21G18A-UUT דירוגים מרביים ומאפיינים חשמליים
| Core | ARM Cortex-M0+ (32-bit) |
| Maximum CPU Frequency | 48 MHz |
| CoreMark/MHz | 2.46 |
| Flash Memory | 256 KB |
| SRAM | 32 KB |
| מארז | 45-ball WLCSP |
| Supply Voltage (VDD) | 1.6 V to 3.6 V |
| טמפרטורת פעולה | -40 C to +85 C |
| ADC | 12-bit, up to 20 channels |
| DAC | 10-bit, 1 channel |
| USB | USB 2.0 Full-Speed Device/Host |
| SERCOM Modules | 6 (each configurable as UART/SPI/I2C) |
| RTC | 32-bit, with calendar mode |
| Timers (TC) | 5 x 16-bit Timer/Counter |
| Event System Channels | 12 |
| סטטוס RoHS | Compliant (Green) |
| Lead-Free | Yes |
תצורת פינים של ATSAMD21G18A-UUT
| פין A1 | VDDIO — Digital I/O supply |
| פין A2 | GND — Ground |
| פין A3 | PA03 — GPIO / ADC AIN1 |
| פין A4 | PA04 — GPIO / ADC AIN2 / VREFP |
| פין A5 | PA05 — GPIO / ADC AIN3 |
| פין B1 | PA06 — GPIO / ADC AIN4 |
| פין B2 | PA07 — GPIO / ADC AIN5 |
| פין B3 | PA08 — GPIO / SERCOM0 I2C SDA |
| פין B4 | PA09 — GPIO / SERCOM0 I2C SCL |
| פין B5 | PA10 — GPIO / SERCOM2 SPI MOSI |
| פין C1 | PA11 — GPIO / SERCOM2 SPI SCK |
| פין C2 | PA14 — GPIO / SERCOM2 SPI CS |
| פין C3 | PA15 — GPIO / SERCOM3 SPI MISO |
| פין C4 | PA16 — GPIO / SERCOM1 I2C SDA |
| פין C5 | PA17 — GPIO / SERCOM1 I2C SCL |
| פין D1 | PA18 — GPIO / USB DM |
| פין D2 | PA19 — GPIO / USB DP |
| פין D3 | PA20 — GPIO |
| פין D4 | PA21 — GPIO |
| פין D5 | PA22 — GPIO / SERCOM3 SPI MOSI |
| פין E1 | PA23 — GPIO / SERCOM3 SPI SCK |
| פין E2 | PA24 — GPIO / USB SOF |
| פין E3 | PA25 — GPIO |
| פין E4 | PB02 — GPIO / ADC AIN10 |
| פין E5 | PB03 — GPIO / ADC AIN11 |
| פין F1 | PB08 — GPIO / ADC AIN2 (alt) |
| פין F2 | PB09 — GPIO / ADC AIN3 (alt) |
| פין F3 | PB10 — GPIO |
| פין F4 | PB11 — GPIO |
| פין F5 | PB22 — GPIO / SERCOM5 SPI MISO |
| פין G1 | PB23 — GPIO / SERCOM5 SPI SCK |
| פין G2 | PA27 — GPIO |
| פין G3 | PA28 — GPIO / Reset (alt) |
| פין G4 | PA30 — GPIO / SWCLK |
| פין G5 | PA31 — GPIO / SWDIO |
| פין H1 | VDDIN — Main voltage regulator input |
| פין H2 | VDD — Internal regulator output - decouple with 1uF |
| פין H3 | GND — Ground |
| פין H4 | XIN32 — 32.768 kHz crystal input |
| פין H5 | XOUT32 — 32.768 kHz crystal output |
| פין J1 | RESETn — Active-low reset input |
| פין J2 | VBUS — USB VBUS detect |
| פין J3 | GND — Ground |
| פין J4 | DAC0 — 10-bit DAC output |
| פין J5 | AREF — ADC reference voltage |
יישומים טיפוסיים
ATSAMD21G18A-UUT מתאים עבור 6 יישוםs: USB HID Wearable Peripherals, Battery-Powered IoT Sensor Nodes, Smart Home Control Panels, Industrial Sensor Aggregation Hubs, Consumer Wearable Fitness Trackers, Smart Metering Endpoints.
USB HID Wearable Peripherals
The ATSAMD21G18A-UUT's integrated USB 2.0 Full-Speed device/host controller, 48 MHz Cortex-M0+ core, and tiny 45-WLCSP footprint make it ideal for USB HID wearables such as custom mechanical-keyboard controllers, MIDI surfaces, and AI-pen HID interfaces. With 256 KB Flash it can host a USB HID stack plus macro/firmware logic, while 32 KB SRAM is more than enough for HID report buffers. Compared to using an external USB PHY plus a discrete MCU, this single-chip integration cuts BOM cost and PCB area by roughly 30% - critical for wearable form factors. Place a 4.7uF VDD decoupling capacitor within 2 mm of the WLCSP balls and route D+/D- as a 90 ohm differential pair per USB 2.0 spec.
מומלץ
Battery-Powered IoT Sensor Nodes
With its 1.6 V to 3.6 V wide supply range and the SAM D21 SleepWalking peripheral event system, the ATSAMD21G18A-UUT is well suited to coin-cell or 2x AA battery sensor nodes that wake on RTC, GPIO, or ADC threshold events and return to deep sleep. Active current around 4 mA at 48 MHz drops to single-digit microamps in standby, which lets a typical environmental sensor node run for years on two AA cells. The 6 SERCOM interfaces support concurrent I2C sensor, SPI radio, and UART debug links. Use BOD33 (Brown-Out Detector at 3.3 V) to guarantee safe Flash retention across battery end-of-life, and enable the 32 kHz crystal oscillator for RTC accuracy.
מומלץ
Smart Home Control Panels
The ATSAMD21G18A-UUT fits compact smart-home control panels that need to drive a small TFT (Thin-Film Transistor display) LCD, read capacitive touch keys, and talk to a host gateway over UART, SPI, or Wi-Fi co-processor. The 12-bit ADC supports accurate light/temperature sensing, and the 10-bit DAC can drive a piezo buzzer for audible feedback without extra components. With 256 KB Flash and 32 KB SRAM, it can host a local UI state machine plus a Modbus or BLE HCI (Host-Controller Interface) stack. Designers typically pair it with an ESP32 Wi-Fi co-processor and route the SERCOM UART at 3.3 V between the two.
מומלץ
Industrial Sensor Aggregation Hubs
For industrial sensor aggregation - collecting data from 4-20 mA loops, RS-485 Modbus nodes, and digital I/O - the ATSAMD21G18A-UUT provides the right mix of 6 SERCOM channels, a 12-bit ADC with 20 channels, and the Event System for low-latency inter-peripheral signalling. Its industrial temperature range -40 C to +85 C supports cabinet-mounted deployments. The Cortex-M0+ at 48 MHz executes deterministic control loops in under 21 ns per instruction, sufficient for 1 kHz PID loops on 4 axes. Use isolated RS-485 transceivers on the SERCOM UART and isolated 4-20 mA front-ends on the ADC channels for robust industrial connectivity.
מומלץ
Consumer Wearable Fitness Trackers
The 45-WLCSP ATSAMD21G18A-UUT enables fitness-tracker form factors under 15 mm x 15 mm while still providing USB charging, BLE HCI pass-through, and on-board heart-rate sensor support. The 256 KB Flash accommodates an algorithm library for step counting and sleep detection, while 32 KB SRAM holds minute-level activity buffers before BLE upload. Its 1.6 V to 3.6 V supply range supports direct LiPo battery operation without a boost converter, saving roughly 5 mm x 5 mm of PCB area. Use a low-quiescent LDO such as TPS7A02 to power the analog domain and keep total system sleep current under 10 uA.
מומלץ
Smart Metering Endpoints
Electricity, water, and gas metering endpoints benefit from the ATSAMD21G18A-UUT's wide 1.6 V to 3.6 V supply tolerance (supports direct battery operation) and its tamper-detection GPIO plus RTC calendar for time-stamped consumption logs. The 12-bit ADC is accurate enough for direct shunt-based current sensing, and the 10-bit DAC can generate the calibration excitation signal. With 256 KB Flash, it can run a complete metering protocol stack (DLMS/COSEM or wM-Bus) locally. The -40 C to +85 C industrial temperature range supports outdoor meter cabinet installations in most climates.
מומלץ
סיכום מוצרים מומלצים
נתוני עזר הנדסיים עבור ATSAMD21G18A-UUT — השוואה, הנחיות תכנון ומידע על תאימות.
מדריך בחירה
השוואה עם חלופות
| פרמטר | מוצר זה | ATSAMD21G18A-MU | ATSAMD21E18A-MF | STM32G031K8T6 |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | STMicroelectronics |
| Package | 45-WLCSP | QFN-48 | QFN-48 | LQFP-32 |
| Core | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ |
| Maximum Frequency | 48 MHz | 48 MHz | 48 MHz | 64 MHz |
| Flash Memory | 256 KB | 256 KB | 256 KB | 64 KB |
| SRAM | 32 KB | 32 KB | 32 KB | 8 KB |
| Supply Voltage | 1.6 V to 3.6 V | 1.6 V to 3.6 V | 1.6 V to 3.6 V | 2.0 V to 3.6 V |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +125 C | -40 C to +85 C |
| USB | USB 2.0 FS Device/Host | USB 2.0 FS Device/Host | USB 2.0 FS Device/Host | No USB |
מבדילים עיקריים
- Ultra-compact 45-WLCSP package for smallest possible PCB footprint (לעומתATSAMD21G18A-MU (QFN-48))
- Larger Flash (256 KB) and SRAM (32 KB) than entry-level competitors (לעומתSTM32G031K8T6)
- Integrated USB 2.0 Full-Speed controller without external PHY (לעומתSTM32G031K8T6)
הערות תכנון
The 45-WLCSP package has a 0.4 mm ball pitch and requires microvia PCB technology (laser-drilled vias at 0.1 mm pad). For prototypes, fab houses such as OSHPark or JLCPCB support 4-layer microvia stack-ups; do NOT attempt to use 6/6 mil rules with through-vias only - yield will be near zero. Place a continuous GND plane directly under the WLCSP footprint and stitch the perimeter with 0.3 mm via fence for thermal relief.
Estimated: with VDDIN = 3.3 V, active current is approximately 4 mA at 48 MHz with all peripherals off; standby current with RTC running is roughly 1.5 uA. For coin-cell designs, enable the SAM D21 SleepWalking event system so that only the wake-up peripheral (RTC, GPIO, or ADC window comparator) stays powered. Disable the unused SERCOM modules and unused TC channels in the Clock Enable register to save additional 200-400 uA.
Common pitfalls with the ATSAMD21G18A-UUT include: (1) forgetting to enable the 32 kHz crystal startup time (typically 32,768 cycles) before relying on the RTC; (2) routing USB DP/DM as a 90 ohm differential pair through the entire board rather than only over the immediate WLCSP exit region; (3) configuring a SERCOM for SPI master without first setting its PAD0/PAD1 to alternate function 2 - the SERCOM peripheral will not toggle its output pins until this is set; (4) leaving the internal 8 MHz DFLL (Digital Frequency-Locked Loop) untrimmed - production code should run the DFLL closed-loop calibration routine at boot.
מידע על תאימות
Green/RoHS compliant per Microchip product page; 'GREEN' suffix in Mouser description. Not AEC-Q100 qualified - for automotive use, consider ATSAMx21E variant with -40 C to +125 C rating.
