ATSAMD21G18A-UUT - 48MHz Cortex-M0+ MCU, 256KB Flash, 45-WLCSP
N.º da peça: ATSAMD21G18A-UUT ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $5.42 | $5,42 |
| 10 | $4.88 | $48,80 |
| 100 | $4.35 | $435,00 |
| 500 | $3.91 | $1.955,00 |
| 1.000 | $3.48 | $3.480,00 |
ATSAMD21G18A-UUT Visão geral
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.
Alternativas drop-in para ATSAMD21G18A-UUT — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Variantes desta série
Modelos da mesma série compatíveis como drop-in com ATSAMD21G18A-UUT (mesmo formato e footprint) — diferindo em Package, USB, ADC, DAC, Operating Temperature.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
ATSAMD21G18A-UUT
✅ Drop-In✓ Em estoque
$3.48 / unidade
Ver ficha técnica →ATSAMD21G18A-MU
✅ Drop-In✓ Em estoque
$3.15 / unidade
Ver ficha técnica →ATSAMD21G18A-MUT
✅ Drop-In✓ Em estoque
$3.37 / unidade
Ver ficha técnica →ATSAMD21E18A-MF
✅ Drop-In✓ Em estoque
$6.95 / unidade
Ver ficha técnica →ATSAMD21G18A-MF
✅ Drop-In✓ Em estoque
$2.61 / unidade
Ver ficha técnica →STM32G031K8T6
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
ATSAMD21G17A-MU
✅ Drop-In✓ Em estoque
$2.89 / unidade
Ver ficha técnica →ATSAMD21G18A-UUT Classificações máximas e características elétricas
| Core | ARM Cortex-M0+ (32-bit) |
| Maximum CPU Frequency | 48 MHz |
| CoreMark/MHz | 2.46 |
| Flash Memory | 256 KB |
| SRAM | 32 KB |
| Encapsulamento | 45-ball WLCSP |
| Supply Voltage (VDD) | 1.6 V to 3.6 V |
| Temperatura de operação | -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 |
| Status RoHS | Compliant (Green) |
| Lead-Free | Yes |
Configuração de pinos do ATSAMD21G18A-UUT
| Pino A1 | VDDIO — Digital I/O supply |
| Pino A2 | GND — Ground |
| Pino A3 | PA03 — GPIO / ADC AIN1 |
| Pino A4 | PA04 — GPIO / ADC AIN2 / VREFP |
| Pino A5 | PA05 — GPIO / ADC AIN3 |
| Pino B1 | PA06 — GPIO / ADC AIN4 |
| Pino B2 | PA07 — GPIO / ADC AIN5 |
| Pino B3 | PA08 — GPIO / SERCOM0 I2C SDA |
| Pino B4 | PA09 — GPIO / SERCOM0 I2C SCL |
| Pino B5 | PA10 — GPIO / SERCOM2 SPI MOSI |
| Pino C1 | PA11 — GPIO / SERCOM2 SPI SCK |
| Pino C2 | PA14 — GPIO / SERCOM2 SPI CS |
| Pino C3 | PA15 — GPIO / SERCOM3 SPI MISO |
| Pino C4 | PA16 — GPIO / SERCOM1 I2C SDA |
| Pino C5 | PA17 — GPIO / SERCOM1 I2C SCL |
| Pino D1 | PA18 — GPIO / USB DM |
| Pino D2 | PA19 — GPIO / USB DP |
| Pino D3 | PA20 — GPIO |
| Pino D4 | PA21 — GPIO |
| Pino D5 | PA22 — GPIO / SERCOM3 SPI MOSI |
| Pino E1 | PA23 — GPIO / SERCOM3 SPI SCK |
| Pino E2 | PA24 — GPIO / USB SOF |
| Pino E3 | PA25 — GPIO |
| Pino E4 | PB02 — GPIO / ADC AIN10 |
| Pino E5 | PB03 — GPIO / ADC AIN11 |
| Pino F1 | PB08 — GPIO / ADC AIN2 (alt) |
| Pino F2 | PB09 — GPIO / ADC AIN3 (alt) |
| Pino F3 | PB10 — GPIO |
| Pino F4 | PB11 — GPIO |
| Pino F5 | PB22 — GPIO / SERCOM5 SPI MISO |
| Pino G1 | PB23 — GPIO / SERCOM5 SPI SCK |
| Pino G2 | PA27 — GPIO |
| Pino G3 | PA28 — GPIO / Reset (alt) |
| Pino G4 | PA30 — GPIO / SWCLK |
| Pino G5 | PA31 — GPIO / SWDIO |
| Pino H1 | VDDIN — Main voltage regulator input |
| Pino H2 | VDD — Internal regulator output - decouple with 1uF |
| Pino H3 | GND — Ground |
| Pino H4 | XIN32 — 32.768 kHz crystal input |
| Pino H5 | XOUT32 — 32.768 kHz crystal output |
| Pino J1 | RESETn — Active-low reset input |
| Pino J2 | VBUS — USB VBUS detect |
| Pino J3 | GND — Ground |
| Pino J4 | DAC0 — 10-bit DAC output |
| Pino J5 | AREF — ADC reference voltage |
Aplicações típicas
ATSAMD21G18A-UUT é adequado para 6 aplicaçãos: 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.
Recomendado
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.
Recomendado
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.
Recomendado
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.
Recomendado
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.
Recomendado
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.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para ATSAMD21G18A-UUT — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | 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 |
Principais diferenciais
- Ultra-compact 45-WLCSP package for smallest possible PCB footprint (vs ATSAMD21G18A-MU (QFN-48))
- Larger Flash (256 KB) and SRAM (32 KB) than entry-level competitors (vs STM32G031K8T6)
- Integrated USB 2.0 Full-Speed controller without external PHY (vs STM32G031K8T6)
Notas de projeto
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.
Informações de conformidade
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.
