ATSAMD20G18A-ANT - ARM Cortex-M0+ 48MHz 256KB Flash MCU | Microchip
MPN: ATSAMD20G18A-ANT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.95 | $3.95 |
| 10 | $3.56 | $35.60 |
| 100 | $3.18 | $318.00 |
| 500 | $2.84 | $1,420.00 |
| 1,000 | $2.55 | $2,550.00 |
ATSAMD20G18A-ANT Overview
What is a Cortex-M0+ microcontroller? The ARM Cortex-M0+ is the smallest and most energy-efficient member of the Cortex-M processor family, designed for deeply embedded applications that require deterministic real-time behaviour, low active and sleep power, and ease of programming in C. The Cortex-M0+ sits within the broader taxonomy of 32-bit microcontrollers -> ARM Cortex-M -> ARM microcontrollers -> embedded microcontrollers -> integrated circuits, and the SAM D20G family positions itself as an ultra-low-power general-purpose MCU line from Microchip. The single-cycle hardware multiplier and the Microchip SleepWalking peripheral event system are key architectural differentiators.
Key features of the ATSAMD20G18A-ANT include the 48MHz Cortex-M0+ core reaching 2.46 CoreMark/MHz, 256KB in-system programmable Flash, 32KB SRAM, full-speed USB 2.0 device with on-chip transceiver, 12-bit 1 MSPS ADC with up to 20 channels, two I2C interfaces, six SERCOM modules configurable as UART/SPI/I2C, six 16-bit timers/counters, RTC with calendar mode, and a wide operating voltage range of 1.62V to 3.63V. The 48-TQFP package provides ample GPIO for typical embedded designs while remaining hand-solderable for prototyping.
Architecturally, the SAM D20G uses the Cortex-M0+ with a 2-stage pipeline, a single-cycle 32x32 hardware multiplier (replacing the older 32-cycle software emulation), and a Nested Vectored Interrupt Controller (NVIC) with 32 interrupt sources. The Event System allows peripherals to communicate without CPU intervention, dramatically reducing active power consumption. The Power Manager supports multiple sleep modes (Idle, Standby, Backup) with fast wake-up, and the USB 2.0 Full-Speed controller includes an on-chip transceiver that eliminates the need for an external PHY.
Typical applications include USB HID devices, IoT sensor nodes, home automation controllers, consumer electronics, smart metering, industrial control, and human-machine interface (HMI) panels. The combination of USB, ADC, and SERCOM flexibility makes the ATSAMD20G18A-ANT especially well suited to designs where a small footprint MCU must bridge to legacy RS-485 buses, sensors, and USB hosts simultaneously.
When designing with this part, ensure that the decoupling network uses at least one 100nF X7R capacitor placed as close as possible to each VDD pin pair, plus a bulk 4.7uF capacitor for the USB 3.3V rail. The full-speed USB DP/DM traces must be routed as a 90-ohm differential pair with length matching within 150 mils. Developers should plan to use the Atmel/Microchip START toolchain or MPLAB X IDE with the DFP (Device Family Pack) and the ASF4 framework to accelerate firmware development.
This page synthesizes distributor stock and pricing snapshots, same-family drop-in alternatives, and practical design notes not aggregated on any single distributor or manufacturer page, giving engineers a one-stop reference for the ATSAMD20G18A-ANT.
Drop-in alternatives for ATSAMD20G18A-ANT — 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 ATSAMD20G18A-ANT (same form factor and footprint) — differing in ADC, DAC, Package, Peripheral Touch Controller (PTC), Communication Interfaces.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAMD20G18A-AU
✅ Drop-In✓ In Stock
$2.84 / Unit
View Datasheet →ATSAMD20E18A-AU
✅ Drop-In✓ In Stock
$2.18 / Unit
View Datasheet →ATSAMD20G17A-AUT
✅ Drop-In✓ In Stock
$1.42 / Unit
View Datasheet →ATSAMD20G17A-AU
✅ Drop-In✓ In Stock
$3.1 / Unit
View Datasheet →ATSAMD21G18A-AU
✅ Drop-In✓ In Stock
$2.2273 / Unit
View Datasheet →ATSAMD20G18A-ANT Maximum Ratings & Electrical Characteristics
| Core Architecture | ARM Cortex-M0+ (32-bit) |
| Maximum CPU Frequency | 48 MHz |
| CoreMark/MHz | 2.46 |
| Program Memory (Flash) | 256 KB (256K x 8) |
| Data Memory (SRAM) | 32 KB |
| Operating Voltage Range | 1.62 V to 3.63 V |
| Package | 48-pin TQFP (7 x 7 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature Range | -40 C to +105 C |
| ADC | 12-bit, up to 1 MSPS, up to 20 channels |
| USB Interface | USB 2.0 Full-Speed Device with on-chip transceiver |
| SERCOM Modules | 6 (configurable as UART / SPI / I2C) |
| I2C Interfaces | 2 |
| Timers/Counters | Six 16-bit TC channels |
| RTC | 16-bit RTC with calendar mode |
| RoHS Status | Compliant |
| Lead-Free / Halogen-Free | Yes (per Mouser GREEN marking) |
ATSAMD20G18A-ANT Pin Configuration
| Pin 1 | PA00 — GPIO / XIN32 (32.768 kHz crystal input) |
| Pin 2 | PA01 — GPIO / XOUT32 (32.768 kHz crystal output) |
| Pin 3 | PA02 — GPIO / AIN0 (ADC input) |
| Pin 4 | PA03 — GPIO / AIN1 / VREFA (ADC reference) |
| Pin 5 | GND — Ground |
| Pin 6 | VDDIO — Digital I/O supply (1.62-3.63V) |
| Pin 7 | VDDIN — Voltage regulator input |
| Pin 8 | PA04 — GPIO / AIN4 |
| Pin 9 | PA05 — GPIO / AIN5 |
| Pin 10 | PA06 — GPIO / AIN6 |
| Pin 11 | PA07 — GPIO / AIN7 |
| Pin 12 | PA08 — GPIO / AIN8 / SERCOM0 PAD0 |
| Pin 13 | PA09 — GPIO / AIN9 / SERCOM0 PAD1 |
| Pin 14 | PA10 — GPIO / AIN10 / SERCOM0 PAD2 |
| Pin 15 | PA11 — GPIO / AIN11 / SERCOM0 PAD3 |
| Pin 16 | PA12 — GPIO / SERCOM2 PAD0 |
| Pin 17 | PA13 — GPIO / SERCOM2 PAD1 |
| Pin 18 | PA14 — GPIO / SERCOM2 PAD2 |
| Pin 19 | PA15 — GPIO / SERCOM2 PAD3 |
| Pin 20 | GND — Ground |
| Pin 21 | VDDIO — Digital I/O supply |
| Pin 22 | PA16 — GPIO / SERCOM1 PAD0 / I2S FS |
| Pin 23 | PA17 — GPIO / SERCOM1 PAD1 / I2S SCK |
| Pin 24 | PA18 — GPIO / SERCOM1 PAD2 / I2S MCK |
| Pin 25 | PA19 — GPIO / SERCOM1 PAD3 / I2S SD |
| Pin 26 | PA20 — GPIO / SERCOM3 PAD0 |
| Pin 27 | PA21 — GPIO / SERCOM3 PAD1 |
| Pin 28 | PA22 — GPIO / SERCOM3 PAD2 |
| Pin 29 | PA23 — GPIO / SERCOM3 PAD3 |
| Pin 30 | PA24 — GPIO / USB DM |
| Pin 31 | PA25 — GPIO / USB DP |
| Pin 32 | PA26 — GPIO / SERCOM5 PAD0 |
| Pin 33 | PA27 — GPIO / SERCOM5 PAD1 |
| Pin 34 | PA28 — GPIO / SERCOM5 PAD2 |
| Pin 35 | PA29 — GPIO / SERCOM5 PAD3 |
| Pin 36 | PA30 — GPIO / SWCLK (programming debug clock) |
| Pin 37 | PA31 — GPIO / SWDIO (programming debug data) |
| Pin 38 | RESET — Active-low reset, internal pull-up |
| Pin 39 | GND — Ground |
| Pin 40 | VDDOUT — Internal regulator output (decouple 1uF) |
| Pin 41 | VDDCORE — Core voltage (decouple 1uF) |
| Pin 42 | PB02 — GPIO / SERCOM5 PAD0 / ADC AIN14 |
| Pin 43 | PB03 — GPIO / SERCOM5 PAD1 / ADC AIN15 |
| Pin 44 | PB04 — GPIO / SERCOM3 PAD0 / ADC AIN6 (alt) |
| Pin 45 | PB05 — GPIO / SERCOM3 PAD1 / ADC AIN7 (alt) |
| Pin 46 | PB06 — GPIO / SERCOM3 PAD2 |
| Pin 47 | PB07 — GPIO / SERCOM3 PAD3 |
| Pin 48 | PB08 — GPIO / SERCOM4 PAD0 |
Typical Applications
ATSAMD20G18A-ANT is suitable for 6 applications: USB HID / CDC Devices, Home Automation Hubs, Smart Metering and Energy Monitoring, Industrial Control and HMI Panels, Consumer Electronics and Wearables, IoT Sensor Nodes with USB Diagnostics.
USB HID / CDC Devices
The ATSAMD20G18A-ANT integrates a full-speed USB 2.0 device controller with on-chip transceiver, making it ideal for USB HID keyboards, mice, CDC virtual COM ports, and custom USB peripherals without an external PHY. The 256 KB Flash accommodates USB stacks plus application code, and 32 KB SRAM handles descriptor buffers and CDC line-coding buffers. Placed as the only MCU on the board with DP/DM traces routed as a 90-ohm differential pair and a 4.7 uF bulk capacitor on VBUS, it delivers low BOM cost and single-IC USB connectivity. The Cortex-M0+ 48 MHz core sustains the 12 Mbps USB traffic with CPU headroom remaining for the application layer.
Recommended
Home Automation Hubs
The 6 SERCOM modules (UART/SPI/I2C-configurable) and 12-bit ADC of the ATSAMD20G18A-ANT allow a single MCU to interface with multiple wireless modules (LoRa, Zigbee, BLE bridges), sensors, and legacy RS-485 buses used in home-automation gateways. The wide 1.62-3.63V supply tolerance accommodates both battery and mains-powered variants, and the -40C to +105C industrial temperature range covers outdoor and boiler-room installations. The Cortex-M0+ SleepWalking peripheral-event system reduces power by waking the CPU only when a peripheral needs service, extending battery life in wireless sensor nodes that share the same PCB.
Recommended
Smart Metering and Energy Monitoring
The 12-bit 1 MSPS ADC of the ATSAMD20G18A-ANT with up to 20 channels is well matched to current-sense amplifiers and voltage-divider networks in single-phase and three-phase smart-meter designs. Combined with the 32 KB SRAM, the device can implement IEC 62053-21/22 class 1 metering algorithms while keeping real-time calibration tables. The wide -40C to +105C range supports outdoor meter enclosures, and the low-power SleepWalking features reduce average consumption to support battery-augmented metering deployments. Drop-in alternative ATSAMD20E18A-AU adds enhanced timers for power-line communication timing.
Recommended
Industrial Control and HMI Panels
The 48-pin TQFP ATSAMD20G18A-ANT offers up to 38 GPIO lines plus SERCOM flexibility to drive segment LCDs, keypads, rotary encoders, and Modbus RTU links in industrial HMI panels. The 256 KB Flash supports localized Chinese/English UI strings and Modbus register maps; 32 KB SRAM allows reasonable screen buffers for 4-inch monochrome displays. The extended -40C to +105C operating temperature range and Microchip's industrial-quality pedigree make this part a good fit for factory-floor equipment with strict long-term availability commitments (Microchip typically provides 10+ year longevity for SAM D devices).
Recommended
Consumer Electronics and Wearables
The low-power SleepWalking peripheral-event system and 1.62-3.63V supply range of the ATSAMD20G18A-ANT support coin-cell operated wearables and consumer devices where idle current is critical. The Cortex-M0+ running at 48 MHz delivers enough headroom for BLE stack preprocessing when paired with an external BT module, and the integrated USB supports charging-port firmware updates. The 48-TQFP package is hand-solderable for prototype runs and matches the form factor of typical wearable PCBs. The same silicon (ATSAMD20G18A-AU, tray variant) is available for higher-volume assembly lines.
Recommended
IoT Sensor Nodes with USB Diagnostics
The integrated USB 2.0 full-speed controller of the ATSAMD20G18A-ANT enables USB-based firmware update, sensor-data logging to a host PC, and in-field diagnostics without external bridge chips. The 12-bit ADC and 6 SERCOM interfaces support multi-sensor fusion nodes (temperature, humidity, motion, light), and the SERCOM-based I2C bus connects to common sensors like the Bosch BMI270 IMU or Sensirion SHT40. The industrial -40C to +105C rating covers outdoor IoT deployments, and Microchip's longevity program guarantees long-term supply for IIoT gateway integrators.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD20G18A-ANT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD20G18A-AU | ATSAMD20E18A-AU | ATSAMD20G17A-AUT | ATSAMD21G18A-AU |
|---|---|---|---|---|---|
| Package | 48-TQFP (7x7 mm) | 48-TQFP (7x7 mm) - same | 48-TQFP (7x7 mm) - same | 48-TQFP (7x7 mm) - same | 48-TQFP (7x7 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core | ARM Cortex-M0+ 48 MHz | ARM Cortex-M0+ 48 MHz | ARM Cortex-M0+ 48 MHz | ARM Cortex-M0+ 48 MHz | ARM Cortex-M0+ 48 MHz |
| Flash | 256 KB | 256 KB | 256 KB | 128 KB (-50%) | 256 KB |
| SRAM | 32 KB | 32 KB | 32 KB | 16 KB (-50%) | 32 KB |
| Operating Voltage | 1.62 V to 3.63 V | 1.62 V to 3.63 V | 1.62 V to 3.63 V | 1.62 V to 3.63 V | 1.62 V to 3.63 V |
| USB Controller | USB 2.0 Full-Speed Device + transceiver | USB 2.0 Full-Speed Device | USB 2.0 Full-Speed Device | USB 2.0 Full-Speed Device | USB 2.0 Full-Speed Host/Device/OTG |
| Operating Temperature | -40 C to +105 C | -40 C to +105 C | -40 C to +105 C | -40 C to +105 C | -40 C to +85 C |
Key Differentiators
- Industrial 105 C operating temperature (vs ATSAMD21G18A-AU)
- Full 256 KB Flash / 32 KB SRAM on a 48 MHz Cortex-M0+ (vs ATSAMD20G17A-AUT)
- On-chip USB 2.0 Full-Speed transceiver eliminates external PHY (vs Generic Cortex-M0+ MCUs requiring external PHY)
Design Notes
Place a 100 nF X7R decoupling capacitor within 3 mm of every VDDIO/VDDIN pin pair, plus a single 4.7 uF bulk capacitor near the USB VBUS or main supply. The internal 1.2V regulator output (VDDOUT) and core rail (VDDCORE) each require a dedicated 1 uF X7R capacitor with traces shorter than 5 mm to suppress load-transient ringing. Estimated: based on 48-pin TQFP layout from the SAM D20 datasheet (40001806D) reference schematic, not a measured value.
Route the USB DP/DM pair on PA24/PA25 as a 90-ohm differential with intra-pair length matching better than 150 mils. Keep the pair reference to a continuous ground plane on the layer immediately below, and avoid routing any digital signal across the DP/DM pair. The 48-TQFP exposed pad (where present) must be soldered to a 4 mm x 4 mm thermal pad tied to GND to keep junction temperature below 100 C at full 48 MHz operation with USB active.
Do not enable the brown-out detector (BOD) thresholds below 1.6V if the application draws high inrush current from the supply, because BOD at 1.5V can reset the MCU during bulk-capacitor charge-up. Configure the DFLL48M closed-loop reference to either a 32.768 kHz crystal (best accuracy) or the internal 32 kHz RC (lowest BOM cost). Estimated: typical application startup inrush of 200 mA from a 3.3V/100 mA source can take ~2 ms to settle the bulk capacitor, which is within the BOD hold time.
Reserve the SWD pins (PA30 = SWCLK, PA31 = SWDIO) for programming/debug; route them to a 10-pin Cortex-Debug header with 100-ohm series termination near the MCU. If the application needs both SWD and GPIO, multiplex the pins via the PORT group multiplexing register but provide a 4-layer PCB break-out option to reach the debug header without rework. Estimated: typical debug trace length 25-50 mm requires no termination beyond the on-chip weak pull-downs.
Compliance Information
RoHS compliant and lead-free per Mouser GREEN marking (105C, GREEN, 1.6-3.6V designation). AEC-Q100 is not applicable (industrial grade, not automotive qualified).
