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Microchip Technology ATSAMR21G16A-MU
- Part No.:
- ATSAMR21G16A-MU
- Manufacturer:
- Microchip Technology
- Category:
- RF Transceiver ICs
- Package:
- 48-VFQFN Exposed Pad
- Datasheet:
-
ATSAMR21G16A-MU.pdf
- Description:
- IC RF TXRX+MCU ISM>1GHZ 48QFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,795
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Product details
Overview
ATSAMR21G16A-MU from Microchip Technology (formerly Atmel) is a 48-pin QFN ARM Cortex-M0+ microcontroller with integrated 2.4GHz ISM band transceiver, 64KB Flash, 8KB SRAM, and USB 2.0 interface. It operates at up to 48MHz, supports SleepWalking peripherals, and delivers -99dBm RX sensitivity with +4dBm TX output for low-power wireless sensor node applications.
For engineers reviewing the ATSAMR21G16A-MU datasheet, ATSAMR21G16A-MU pinout, ATSAMR21G16A-MU application, or ATSAMR21G16A-MU equivalent, key selection criteria include RF transceiver integration, SERCOM-configurable serial interfaces, capacitive touch support, ultra-low-power sleep modes, and hardware AES acceleration for secure IoT edge devices.
Technical Context
The ATSAMR21G16A-MU integrates an ARM Cortex-M0+ CPU with a dedicated 2.4GHz transceiver (AT86RF233) via internal SERCOM4, supporting O-QPSK modulation, hardware MAC, and 250kb/s data rate. Its clock system combines DFLL48M and FDPLL96M for flexible domain-specific frequency scaling.
Peripherals include three 16-bit Timer/Counters (TC), three 16-bit Timer/Counters for Control (TCC), eight-channel 12-bit ADC with oversampling, two analog comparators, and Peripheral Touch Controller supporting up to 48 sensing channels - all coordinated by a 12-channel Event System enabling autonomous peripheral interaction in standby mode.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| CPU Core | ARM Cortex-M0+ running at up to 48MHz; enables deterministic real-time control with 2.46 CoreMark/MHz efficiency. |
| Memory | 64KB Flash / 8KB SRAM; sufficient for Zigbee/Thread stack + application firmware in compact wireless nodes. |
| RF Transceiver | Integrated AT86RF233: -99dBm RX sensitivity, +4dBm TX output, 250kb/s O-QPSK data rate, hardware AES-128 encryption. |
| ADC | 8-channel 12-bit ADC sampling at 350ksps with programmable gain (1×–16×) and hardware oversampling to 16-bit resolution. |
| USB Interface | Full-speed (12Mbps) USB 2.0 with embedded host/device capability and eight endpoints; supports firmware updates and HID-class peripherals. |
| Operating Range | 1.8V–3.6V supply voltage; industrial temperature range of -40°C to +85°C; qualified for battery-powered outdoor deployments. |
| Sleep Modes | Idle and standby modes with SleepWalking; peripherals wake autonomously without CPU intervention, reducing average current to µA-level. |
Pinout & Package
ATSAMR21G16A-MU uses a 48-pin QFN package (7mm × 7mm, 0.5mm pitch) with exposed thermal pad connected to GND. Pin functions are multiplexed across PORT A/B/C; RF pins RFP/RFN (pins 18/19) require differential 100Ω layout and AC coupling per RF design guidelines.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PA14 / PA15 | XTAL1 / XTAL2 | 16MHz crystal oscillator inputs for RF transceiver; require external 16MHz crystal and load capacitors. |
| PA12 / PA13 | FECTRL[2] / FECTRL[3] | Digital control outputs for antenna diversity switching or external PA enable in RF front-end designs. |
| PA24 / PA25 | USB_DP / USB_DM | Full-speed USB 2.0 differential pair; require 90Ω controlled impedance routing and ESD protection. |
| PA30 / PA31 | SWCLK / SWDIO | Two-pin Serial Wire Debug interface; supports non-intrusive on-chip programming and real-time debugging. |
| RFP / RFN | RF Differential Port | Bidirectional 100Ω differential RF interface; no external switch needed; DC-coupled to internal LNA/PA. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated RF Transceiver | AT86RF233 co-integrated with MCU core and SERCOM4; eliminates external SPI bus routing and reduces BOM count. |
| SleepWalking Peripherals | ADC, TC, and RTC can execute predefined tasks (e.g., periodic sampling, timer expiry) while CPU remains powered down - cuts active duty cycle. |
| Hardware Security Engine | Dedicated AES-128 accelerator and true random number generator (TRNG); enables secure over-the-air (OTA) firmware updates without CPU overhead. |
| Configurable SERCOMs | Five SERCOM modules each configurable as USART, UART, SPI, I²C (up to 3.4MHz), or LIN slave; simplifies interface consolidation in multi-sensor systems. |
| Peripheral Touch Controller | Supports 48-channel capacitive touch (buttons/sliders/wheels) with proximity sensing; replaces mechanical buttons and reduces system power vs. polling-based solutions. |
Applications
| Smart Home Sensor Node | Industrial Wireless Monitor |
|---|---|
Use Scenario: Battery-powered temperature/humidity/motion sensor reporting to gateway via IEEE 802.15.4 mesh network. IC Role / Device Role / Timing Role: Primary SoC handling sensor acquisition, RF packet assembly, MAC layer processing, and secure OTA update handling. Use Value: Integrated AT86RF233 and SleepWalking reduce average current to <15µA in deep sleep with periodic wake-up - extending 2xAA battery life beyond 5 years. | Use Scenario: DIN-rail mounted vibration/temperature monitor in factory automation, transmitting alerts via LoRaWAN-compatible 2.4GHz protocol. IC Role / Device Role / Timing Role: Real-time edge controller executing deterministic timing for ADC sampling, FFT preprocessing, and RF transmission scheduling. Use Value: TCC peripherals generate synchronized PWM waveforms for LED status indicators and precise timing for sensor sampling intervals - eliminating external timing ICs. |
| Medical Wearable Tracker | Asset Tracking Tag |
Use Scenario: Compact wearable device measuring heart rate variability and motion using capacitive touch and accelerometer interface. IC Role / Device Role / Timing Role: Central controller managing PTC-based touch UI, low-noise ADC for analog biosignals, and encrypted BLE-like advertising packets. Use Value: On-chip PTC supports up to 48 electrodes with automatic calibration - enabling high-resolution biometric sensing without external touch controller IC. | Use Scenario: GPS-denied indoor asset tag using RSSI-based localization and periodic beaconing in warehouse environments. IC Role / Device Role / Timing Role: Low-power location engine performing periodic RF scans, frame buffering, and timestamped event logging to Flash. Use Value: Hardware CRC-16 and auto-acknowledge in transceiver MAC layer ensure reliable packet delivery with zero software overhead - critical for loss-sensitive tracking logs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar wireless microcontroller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ATSAMR21G18A-MU | 256KB Flash / 32KB SRAM; identical pinout and peripheral set; higher memory for larger protocol stacks. | Required for full Thread/Zigbee 3.0 stack deployment with OTA storage; not suitable for cost-sensitive minimal firmware. | Select when firmware size exceeds 64KB or dual-bank OTA update capability is required. |
| NRF52840-QIAA | ARM Cortex-M4F core; Bluetooth 5.0/802.15.4/Thread support; no integrated USB; different pinout and package (QFN48 vs QFN73). | Optimized for BLE-centric applications; lacks native USB device/host and capacitive touch controller. | Choose for Bluetooth LE priority or when leveraging Nordic's SoftDevice ecosystem; requires PCB redesign. |
Compared with ATSAMR21G16A-MU, ATSAMR21G18A-MU offers scalable memory without layout change, while NRF52840-QIAA provides superior RF protocol breadth at the cost of USB functionality and touch integration - making ATSAMR21G16A-MU optimal for USB-enabled, touch-capable, cost-constrained 2.4GHz IoT nodes.
Availability
ATSAMR21G16A-MU is available at Aetrix Electronics and suitable for smart home sensor nodes, industrial wireless monitors, medical wearables, and asset tracking tags requiring stable component supply and long-term production continuity.
Supply support for ATSAMR21G16A-MU includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Microchip Technology acquired Atmel in 2016 and maintains the SMART ARM-based microcontroller portfolio with full technical documentation and toolchain support.
The SAM R21 product line was designed specifically for ultra-low-power, integrated wireless applications in constrained-edge IoT devices - combining RF, security, and intelligent peripherals in a single die.
FAQ
What is the maximum operating frequency and core type of the ATSAMR21G16A-MU?
The ATSAMR21G16A-MU features an ARM Cortex-M0+ processor core rated for operation up to 48MHz. This frequency is supported across its full industrial temperature range (-40°C to +85°C) and supply voltage range (1.8V–3.6V). The core delivers 2.46 CoreMark/MHz performance and includes a single-cycle hardware multiplier and Micro Trace Buffer for efficient real-time debugging. ATSAMR21G16A-MU achieves deterministic timing for time-critical wireless protocol stacks and sensor fusion algorithms.
Does the ATSAMR21G16A-MU include an integrated radio transceiver, and what are its key RF specifications?
Yes, the ATSAMR21G16A-MU integrates the AT86RF233 2.4GHz ISM band transceiver. Key RF specifications include -99dBm receiver sensitivity at 250kb/s O-QPSK, +4dBm maximum transmit output power, hardware-assisted MAC (auto-acknowledge, auto-retry), and 128-byte TX/RX frame buffer. It supports antenna diversity control via FECTRL[0..5] signals and includes a dedicated 16MHz crystal oscillator interface (XTAL1/XTAL2). ATSAMR21G16A-MU does not require external RF front-end components for basic operation.
What debug interface does the ATSAMR21G16A-MU support, and how is it implemented physically?
The ATSAMR21G16A-MU supports two-pin Serial Wire Debug (SWD) via PA30 (SWCLK) and PA31 (SWDIO). These pins are dedicated to debug functionality and automatically switch from GPIO mode upon debugger connection detection. The interface enables non-intrusive on-chip programming, real-time code execution tracing, and full memory/register access without halting peripheral operation. ATSAMR21G16A-MU does not require JTAG; SWD reduces PCB footprint and simplifies debug connector design compared to four-pin JTAG.
Can the ATSAMR21G16A-MU support capacitive touch interfaces, and how many channels are available?
Yes, the ATSAMR21G16A-MU includes a dedicated Peripheral Touch Controller (PTC) supporting up to 48 channels for capacitive touch buttons, sliders, wheels, and proximity sensing. It uses mutual capacitance measurement with automatic calibration and noise suppression. The PTC connects directly to PORT pins configured as X[0..7] and Y[0..5] lines - enabling matrix layouts without external touch ICs. ATSAMR21G16A-MU's PTC operates independently during SleepWalking, allowing touch wake-up events while the CPU remains in standby mode.
What USB capabilities does the ATSAMR21G16A-MU provide, and are both host and device modes supported?
The ATSAMR21G16A-MU features a full-speed (12Mbps) USB 2.0 interface with embedded host and device functionality. It supports eight endpoints and complies with USB 2.0 specification. Both modes operate concurrently - for example, acting as a USB device for PC communication while functioning as an embedded host for USB HID peripherals like keyboards or sensors. The interface uses dedicated DP/DM pins (PA24/PA25) and requires standard USB ESD protection and 90Ω differential routing. ATSAMR21G16A-MU's USB stack is supported by Microchip's ASF framework and compatible with common CDC, HID, and MSC class drivers.
ATSAMR21G16A-MU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- SMART™ SAM R21
- Package/Case:
- 48-VFQFN Exposed Pad
- Packaging:
- Tray
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- TxRx + MCU
- RF Family/Standard:
- General ISM > 1GHz
- Protocol:
- -
- Modulation:
- O-QPSK
- Frequency:
- 2.4GHz
- Data Rate (Max):
- 250kbps
- Power - Output:
- 4dBm
- Sensitivity:
- -99dBm
- Memory Size:
- 64kB Flash, 8kB SRAM
- Serial Interfaces:
- I2C, SPI, UART, USART, USB
- GPIO:
- 28
- Voltage - Supply:
- 1.8V ~ 3.6V
- Current - Receiving:
- 11.3mA ~ 11.8mA
- Current - Transmitting:
- 7.2mA ~ 13.8mA
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 48-QFN (7x7)
ATSAMR21G16A-MU FAQ
1.How can I place an order for ATSAMR21G16A-MU through Aetrix?
Please submit a Request for Quotation (RFQ) for ATSAMR21G16A-MU on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for ATSAMR21G16A-MU reliable?
The price and inventory of ATSAMR21G16A-MU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ATSAMR21G16A-MU is usually 5 days.
3.What payment methods are accepted for ATSAMR21G16A-MU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ATSAMR21G16A-MU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ATSAMR21G16A-MU?
ATSAMR21G16A-MU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ATSAMR21G16A-MU order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for ATSAMR21G16A-MU?
For technical support, including ATSAMR21G16A-MU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ATSAMR21G16A-MU requirements.
6.How does Aetrix verify that ATSAMR21G16A-MU is sourced from the original manufacturer or authorized distributors?
All ATSAMR21G16A-MU products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that ATSAMR21G16A-MU meets industry standards.
7.What is the process for return or replacement of ATSAMR21G16A-MU?
All ATSAMR21G16A-MU units undergo pre-shipment inspection (PSI). If there is an issue with ATSAMR21G16A-MU, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The ATSAMR21G16A-MU part is unused and in its original packaging.
Return procedure for ATSAMR21G16A-MU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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