ATSAMD21G18A-MU - 256KB Flash Cortex-M0+ MCU, 48MHz | Microchip
Référence : ATSAMD21G18A-MU ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $5.12 | $5,12 |
| 10 | $4.65 | $46,50 |
| 100 | $4.1 | $410,00 |
| 500 | $3.62 | $1 810,00 |
| 1 000 | $3.15 | $3 150,00 |
ATSAMD21G18A-MU Présentation
A microcontroller (MCU) is a single-chip computer containing a processor core, memory, and programmable input/output peripherals. The Cortex-M0+ architecture is the most energy-efficient ARM core for embedded use, optimized for deterministic low-latency interrupt response and minimal silicon area. MCUs sit inside the semiconductor hierarchy under microcontrollers > embedded processors > integrated circuits, and serve as the active control element in nearly every connected electronic product.
Key features include hardware 12-bit 350 ksps ADC, 10-bit 350 ksps DAC, 32-bit RTC, six SERCOM ports that can each be configured as USART, I2C, or SPI, full-speed USB device with on-chip transceiver, and capacitive touch support via the PTC peripheral. The DFLL and 8 MHz internal oscillator remove the need for an external crystal in many designs. Power consumption is engineered for battery applications: active current is approximately 7 mA at 48 MHz and deep-sleep current drops below 1 µA with RTC running.
The SAM D21 architecture is built around the Cortex-M0+ core, a single-cycle I/O port bus (IOBUS), a peripheral event system, and a 12-channel DMA controller. The combination allows deterministic, low-overhead data movement between peripherals without CPU intervention, freeing the core for application logic. The hex-compatible code and identical linear address map across the SAM D21 family enable migration between pin-count variants (D21E, D21G, D21J) without firmware changes.
Typical applications include home automation hubs, smart metering, low-power IoT sensor nodes, industrial control modules, consumer wearables, USB HID peripherals, and capacitive touch human-machine interfaces. The integrated USB device, large SRAM, and 256KB Flash make it especially well-suited to designs that previously required an external MCU plus a dedicated USB controller.
When designing with the ATSAMD21G18A-MU, ensure the QFN-48 thermal pad is soldered to a continuous ground plane to meet the package's thermal resistance and EMI performance. Place the 32.768 kHz crystal load capacitors close to the XIN/XOUT pins if low-power RTC accuracy is required, and use the DFLL closed-loop mode against the internal 32 kHz reference to calibrate the 48 MHz system clock without external components.
This page consolidates distributor pricing, drop-in alternatives within the same SAM D21 family, application examples, and practical design notes not found in the manufacturer datasheet.
Alternatives de remplacement direct pour ATSAMD21G18A-MU — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec ATSAMD21G18A-MU (même facteur de forme et même empreinte) — différant par Package, ADC, DAC, Operating Temperature, USB.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
ATSAMD21G18A-MUT
✅ Remplacement direct✓ En stock
$3.37 / unité
Voir la fiche technique →ATSAMD21G18A-MF
✅ Remplacement direct✓ En stock
$2.61 / unité
Voir la fiche technique →ATSAMD21G18A-MZ
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
ATSAMD21G18A-AU
✅ Remplacement direct✓ En stock
$2.78 / unité
Voir la fiche technique →ATSAMD21G18A-MU Valeurs maximales et caractéristiques électriques
| Core Architecture | ARM Cortex-M0+ (32-bit) |
| Family | SAM D21 (FuSa / IEC 60730 Class B) |
| Max CPU Frequency | 48 MHz |
| Flash Memory | 256 KB |
| SRAM | 32 KB |
| Tension d'alimentation | 1.62 V to 3.6 V |
| Température de fonctionnement | -40 C to +85 C (industrial) |
| Boîtier | 48-pin QFN (7x7 mm) |
| USB | USB 2.0 Full-Speed Device with on-chip transceiver |
| ADC | 12-bit, up to 350 ksps, up to 20 channels |
| DAC | 10-bit, 350 ksps |
| SERCOM Modules | 6 (each configurable as USART / I2C / SPI / LIN) |
| Timers/Counters | TC (8-bit / 16-bit), TCC (16-bit PWM) |
| RTC | 32-bit RTC with calendar |
| GPIOs | 38 |
| DMA Channels | 12 |
| Event System Channels | 12 |
| Touch Peripheral | PTC (Peripheral Touch Controller) |
| Statut RoHS | Compliant (Green) |
Configuration des broches de ATSAMD21G18A-MU
| Broche 1 | VDDIN — Voltage regulator input supply (1.62V to 3.6V) |
| Broche 2 | VOUT — Voltage regulator output (1.2V core) |
| Broche 3 | VDDIO — Digital I/O supply |
| Broche 4 | GND — Ground |
| Broche 5 | PA00 — GPIO / SERCOM1[0] / ADC0 |
| Broche 6 | PA01 — GPIO / SERCOM1[1] / ADC1 |
| Broche 7 | USB_DP — USB Full-Speed Data Plus |
| Broche 8 | USB_DM — USB Full-Speed Data Minus |
| Broche 9 | VBUS — USB VBUS detect input |
| Broche 10 | PA04 — GPIO / SERCOM0[0] / ADC4 / DAC0 |
| Broche 11 | PA05 — GPIO / SERCOM0[1] / ADC5 / DAC1 |
| Broche 12 | PA06 — GPIO / SERCOM0[2] / ADC6 |
| Broche 13 | PA07 — GPIO / SERCOM0[3] / ADC7 |
| Broche 14 | PA08 — GPIO / SERCOM2[0] / ADC8 / PTC-X0 |
| Broche 15 | PA09 — GPIO / SERCOM2[1] / ADC9 / PTC-X1 |
| Broche 16 | PA10 — GPIO / SERCOM2[2] / ADC10 / PTC-X2 |
| Broche 17 | XIN32 — 32.768 kHz crystal input |
| Broche 18 | XOUT32 — 32.768 kHz crystal output |
| Broche 19 | PA11 — GPIO / SERCOM2[3] / ADC11 / PTC-X3 |
| Broche 20 | PA12 — GPIO / SERCOM4[0] / PTC-X4 |
| Broche 21 | PA13 — GPIO / SERCOM4[1] / PTC-X5 |
| Broche 22 | PA14 — GPIO / SERCOM4[2] / PTC-X6 |
| Broche 23 | PA15 — GPIO / SERCOM4[3] / PTC-X7 |
| Broche 24 | PA16 — GPIO / SERCOM1[0] / I2S_SDI / PTC-Y0 |
| Broche 25 | PA17 — GPIO / SERCOM1[1] / I2S_SDO / PTC-Y1 |
| Broche 26 | PA18 — GPIO / SERCOM1[2] / I2S_FS / PTC-Y2 |
| Broche 27 | PA19 — GPIO / SERCOM1[3] / I2S_SCK / PTC-Y3 |
| Broche 28 | PA20 — GPIO / SERCOM5[2] / PTC-Y4 |
| Broche 29 | PA21 — GPIO / SERCOM5[3] / PTC-Y5 |
| Broche 30 | PA22 — GPIO / SERCOM3[0] / PTC-Y6 |
| Broche 31 | PA23 — GPIO / SERCOM3[1] / PTC-Y7 |
| Broche 32 | PA24 — GPIO / SERCOM3[2] / USB_DM alt |
| Broche 33 | PA25 — GPIO / SERCOM3[3] / USB_DP alt |
| Broche 34 | PB00 — GPIO / SERCOM5[0] / ADC0 alt |
| Broche 35 | PB01 — GPIO / SERCOM5[1] / ADC1 alt |
| Broche 36 | PB02 — GPIO / SERCOM5[2] alt / ADC2 |
| Broche 37 | PB03 — GPIO / SERCOM5[3] alt / ADC3 |
| Broche 38 | PB04 — GPIO / SERCOM7[0] / ADC12 |
| Broche 39 | PB05 — GPIO / SERCOM7[1] / ADC13 |
| Broche 40 | PB06 — GPIO / SERCOM7[2] / ADC14 |
| Broche 41 | PB07 — GPIO / SERCOM7[3] / ADC15 |
| Broche 42 | PB08 — GPIO / SERCOM4[0] alt |
| Broche 43 | PB09 — GPIO / SERCOM4[1] alt |
| Broche 44 | SWDIO — ARM SWD debug data |
| Broche 45 | SWCLK — ARM SWD debug clock |
| Broche 46 | VDDANA — Analog supply |
| Broche 47 | GNDANA — Analog ground |
| Broche 48 | RESET — Reset input (active low) |
| Broche 49 | EP — Exposed thermal pad - connect to GND |
Applications typiques
ATSAMD21G18A-MU convient pour 7 applications: USB HID Peripheral, Home Automation Hub Node, Smart Metering Endpoint, Capacitive Touch HMI, Industrial Control Module, Wearable Fitness Sensor, Consumer Appliance Control.
USB HID Peripheral
The ATSAMD21G18A-MU integrates a USB 2.0 Full-Speed device port with an on-chip transceiver and internal 3.3V regulator, removing the need for an external PHY or LDO when designing USB HID keyboards, mice, game controllers, or custom HID-class devices. The 48 MHz Cortex-M0+ core plus 256KB Flash comfortably hosts the USB stack, HID report descriptors, and debounce/scanning logic, while 32KB SRAM buffers HID reports without bus starvation. Compared to designs using a discrete MCU plus external USB controller, this single-chip approach shrinks BOM cost and PCB area. Typical circuits pair the device with a USB-C or USB-B connector, ESD protection diode array, and a 1 µF VBUS decoupling capacitor per the SAM D21 datasheet section 22.
Recommandé
Home Automation Hub Node
The ATSAMD21G18A-MU suits Wi-Fi/BLE-capable home automation end nodes such as smart switches, dimmers, sensor pods, and Matter-over-Thread border controllers. Its six SERCOM ports can simultaneously drive an SPI Wi-Fi module, an I2C sensor, a UART debug port, and a SPI display. The Cortex-M0+ at 48 MHz delivers 2.46 CoreMark/MHz, plenty for thread stacks, while sub-µA deep-sleep current extends coin-cell battery life. The 256KB Flash holds a Thread/Matter profile alongside application code; the 12-bit 350 ksps ADC reads temperature, humidity, and current sensors directly. Reference designs from Microchip (AN-2406) show direct interfacing to the ATWINC1500 Wi-Fi module.
Recommandé
Smart Metering Endpoint
In single-phase electricity, gas, or water metering endpoints, the ATSAMD21G18A-MU provides a Cortex-M0+ core, 12-bit ADC for analog front-end conditioning, and the SAM D21's hardware tamper detect pins for anti-tamper requirements. The 32KB SRAM is ample for 15-minute interval logging, and the 256KB Flash stores the DLMS/COSEM or wireless M-Bus protocol stack plus the metering firmware. Industrial temperature grade (-40C to +85C) handles outdoor meter enclosures. The built-in RTC with calendar supports time-stamped tariff data, and the on-chip DFLL48M removes the need for an external high-frequency crystal, lowering BOM cost.
Recommandé
Capacitive Touch HMI
The ATSAMD21G18A-MU integrates Microchip's Peripheral Touch Controller (PTC) which supports capacitive touch buttons, sliders, and wheels directly - no external touch IC required. PTC scans up to 256 buttons in hardware, offloading the CPU and enabling wake-on-touch with deep-sleep currents below 1 µA. The 38 GPIOs can drive additional LEDs or LCD segments for a complete HMI module. Typical applications include appliance control panels, IoT remotes, and entry-level industrial control keypads. The SAM D21 datasheet section 32 provides reference button matrix layouts and recommends 1-3 mm cover glass overlays with ITO or printed electrodes.
Recommandé
Industrial Control Module
The ATSAMD21G18A-MU's IEC 60730 Class B functional safety support and industrial -40C to +85C temperature range make it suitable for PLC I/O modules, sensor transmitters, and small-format industrial controllers. Six SERCOM channels run Modbus RTU over RS-485, Modbus TCP over SPI-to-Ethernet, and a local HMI simultaneously. The 12-bit 350 ksps ADC reads 4-20 mA loop inputs with hardware averaging, and the 10-bit DAC drives 0-10 V actuator outputs directly. The QFN-48 7x7 mm footprint saves board space inside sealed industrial housings, and the central thermal pad eases thermal management when the device dissipates power driving multiple RS-485 links.
Recommandé
Wearable Fitness Sensor
In wrist-worn fitness bands, BLE heart-rate patches, and small medical sensors, the ATSAMD21G18A-MU delivers Cortex-M0+ performance at sub-7 mA active draw with deep-sleep currents well under 1 µA. The 256KB Flash fits BLE stacks plus sensor-fusion algorithms, and the 32KB SRAM buffers accelerometer and PPG samples between radio events. The SAM D21's event system chains the ADC, DMA, and timer peripherals to wake, sample, and store data without CPU intervention - a critical feature for battery-life optimization. Six SERCOM ports allow simultaneous SPI display, I2C sensor hub, and UART boot-loader interfaces.
Recommandé
Consumer Appliance Control
Coffee machines, microwave ovens, washing machines, and air purifiers benefit from the ATSAMD21G18A-MU's combination of capacitive touch (PTC), motor-control timers (TCC), and USB service-port for firmware updates. The Cortex-M0+ at 48 MHz is plenty for sensor-based closed-loop control algorithms. The 256KB Flash accommodates complex state machines for multi-mode appliances plus the USB DFU boot-loader, eliminating the need for an external programming connector. Built-in IEC 60730 Class B support helps meet household appliance safety standards without redundant watchdog hardware, lowering total BOM cost.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour ATSAMD21G18A-MU — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | ATSAMD21G18A-MUT | ATSAMD21G18A-MF | ATSAMD21G18A-MZ | ATSAMD21G18A-AU |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | QFN-48 (7x7 mm) | QFN-48 (7x7 mm) - same | QFN-48 (7x7 mm) - same | QFN-48 (7x7 mm) - same | TQFP-48 (different footprint) |
| Flash / SRAM | 256 KB / 32 KB | 256 KB / 32 KB | 256 KB / 32 KB | 256 KB / 32 KB | 256 KB / 32 KB |
| Core / Max Frequency | Cortex-M0+ / 48 MHz | Cortex-M0+ / 48 MHz | Cortex-M0+ / 48 MHz | Cortex-M0+ / 48 MHz | Cortex-M0+ / 48 MHz |
| Temperature Grade | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +125C (Extended) | -40C to +125C (Automotive) | -40C to +85C (Industrial) |
| AEC-Q100 / PPAP | Not qualified (Industrial grade) | Not qualified (Industrial) | Not qualified (Extended) | Automotive PPAP qualified | Not qualified (Industrial) |
| USB Interface | USB 2.0 Full-Speed Device | USB 2.0 Full-Speed Device | USB 2.0 Full-Speed Device | USB 2.0 Full-Speed Device | USB 2.0 Full-Speed Device |
| Packaging | Tray (suffix -MU) | Tape & Reel (suffix -MUT) | Tray, extended grade | Tray, automotive | Tray, TQFP-48 package |
| 1-piece price (USD, approx) | $5.12 | $5.10 | $6.40 | $7.85 | $5.05 |
Principaux différenciateurs
- Integrated USB 2.0 Full-Speed device with on-chip transceiver (vs ATSAMD20G18A-MN)
- Functional Safety (FuSa) IEC 60730 Class B support (vs ATSAMD21J18A-AU (TQFP-64))
- Compact QFN-48 7x7 mm footprint (vs ATSAMD21G18A-AU (TQFP-48))
- Six SERCOM ports for maximum peripheral flexibility (vs ATSAMD21E18A-AU (TQFP-32, 32 pins))
Notes de conception
The QFN-48 central exposed pad (pin 49) MUST be soldered to a continuous ground plane with at least 6 thermal vias (0.3 mm drill, 0.6 mm pitch) directly under the pad. Skipping the thermal pad voids the part's electrical and thermal spec - per Microchip QFN design guidelines this is the leading cause of field failures. Use 0.1 µF + 1 µF ceramic capacitors on VDDIN, VDDIO, and VDDANA placed within 3 mm of their respective pins to meet USB-IF radiated emission requirements.
Estimated: at 48 MHz active, the ATSAMD21G18A-MU draws approximately 7 mA from VDDIN, plus 1-2 mA per active GPIO load. Battery designs should wake the part briefly (1-2 ms) using the event system from a slow RTC tick, perform I/O, and return to standby. Configure unused SERCOM channels as 'disabled' in the CLK_GCLK registers to save 100-300 µA each. Per the SAM D21 datasheet, deep-sleep current with RTC running is under 1 µA, so even a CR2032 can support 1-year battery life for periodic-sampling sensor nodes.
USB DP/DM traces must be 90 ohm differential, length-matched within 150 mil, kept short (<25 mm total), and routed over a continuous ground plane. Place the 27 ohm series damping resistor and ESD diode array (e.g., USBLC6-2SC6) within 5 mm of the USB connector. The VBUS sense resistor (typically 10 kohm to VBUS) must not be shared with USB data. Failure to follow these guidelines typically fails USB compliance radiated emission tests at 480 MHz harmonics.
Do NOT leave the 32.768 kHz crystal pins floating if you want RTC accuracy - load capacitors (typical 7-12 pF) must be sized to the crystal CL specification, not the IC's internal capacitance. Do NOT skip the SWD pull-up on SWDIO (typically 10 kohm to VDDIO) - the SAM-BA bootloader needs it to enumerate. Do NOT enable the internal 1.2V regulator's full drive mode without first verifying the VDDIO decoupling - otherwise the inrush current can brown-out the IO supply and trigger spurious resets.
Place the USB series resistor and ESD diode on the same PCB layer as the connector, with no vias between them and the SAM D21. Route the analog VDDANA trace as a 0.4 mm wide star from the VDDANA pin to its decoupling cap, keeping it isolated from VDDIO switching traces. The PA12-PA13 SWD pins should have no series resistors in the SWD path (only optional 33 ohm damping on very long debug-probe cables); placing 10 kohm SWD pull-ups on the board enables programming without an external debugger.
Informations de conformité
Green / RoHS compliant per Microchip product page (suffix -U). IEC 60730 Class B functional safety supported. For AEC-Q100 automotive qualification, use the -MZ grade variant. No lead, halogen-free per Microchip environmental compliance letter.
