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Microchip Technology ATSAMR21E16A-MF
- Part No.:
- ATSAMR21E16A-MF
- Manufacturer:
- Microchip Technology
- Category:
- RF Transceiver ICs
- Package:
- 32-VFQFN Exposed Pad
- Datasheet:
-
ATSAMR21E16A-MF.pdf
- Description:
- IC RF TXRX+MCU ISM>1GHZ 32QFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,520
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Product details
Overview
ATSAMR21E16A-MF from Microchip Technology (formerly Atmel) is a 32-bit ARM Cortex-M0+ wireless microcontroller integrating an ultra-low-power 2.4GHz ISM band transceiver, 64KB Flash, 8KB SRAM, and operating at up to 48MHz. It delivers 2.14 CoreMark/MHz performance and supports SleepWalking peripherals for autonomous low-power operation in battery-powered IoT sensor nodes.
For engineers reviewing the ATSAMR21E16A-MF datasheet, ATSAMR21E16A-MF pinout, ATSAMR21E16A-MF application, or ATSAMR21E16A-MF equivalent, this page provides verified technical context, validated pin functions, confirmed RF transceiver specs (-99dBm RX sensitivity, +4dBm TX), real-world use cases, and two rigorously cross-checked alternative parts.
Technical Context
The ATSAMR21E16A-MF implements a single-core ARM Cortex-M0+ processor with Thumb-2 ISA, 32-bit AHB-Lite bus, and Micro Trace Buffer (MTB). Its integrated 2.4GHz transceiver uses hardware-assisted MAC (Auto-Acknowledge, Auto-Retry), SFD-detection, and CRC-16 computation, with dedicated SERCOM4 interfacing to the AT86RF233 RF front-end.
It features three 16-bit Timer/Counters (TC), three 16-bit Timer/Counters for Control (TCC), a 12-channel Event System, and a 12-channel DMA controller. Clocking includes DFLL48M and FDPLL96M PLLs, dual oscillators (XOSC/XOSCRF), and independent clock domains enabling per-peripheral frequency optimization.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| CPU Core | ARM Cortex-M0+, 48MHz max - enables deterministic real-time control with Thumb-2 instruction efficiency and single-cycle multiplier. |
| Memory | 64KB Flash / 8KB SRAM - sufficient for Zigbee/Thread stack + application logic in compact edge-node firmware. |
| RF Transceiver | 2.4GHz ISM band, 250kbps data rate, -99dBm RX sensitivity, +4dBm TX output - meets IEEE 802.15.4 physical layer requirements for robust mesh networking. |
| Power Management | Idle & standby sleep modes; SleepWalking peripherals wake clocks autonomously - extends coin-cell battery life to multi-year operation in sensor endpoints. |
| Analog Peripherals | 4-channel 12-bit ADC (350ksps), 2 analog comparators, PTC supporting 12 capacitive touch channels - enables local sensing and UI without external components. |
| Package & Environment | 32-pin QFN, -40°C to +125°C industrial grade, MSL3 - suitable for harsh environments including smart metering and industrial monitoring. |
| Interface Flexibility | 4 SERCOM modules configurable as USART/I²C/SPI/LIN; USB 2.0 full-speed device/host - simplifies connectivity to gateways, debug tools, and legacy sensors. |
Pinout & Package
ATSAMR21E16A-MF is housed in a 32-pin QFN package (5mm × 5mm, 0.5mm pitch) with an exposed thermal pad internally connected to GND. The pad must be soldered to PCB ground for mechanical stability and thermal performance; it is not a functional signal pin.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| PA00 / PA01 | XIN32 / XOUT32 | 32.768kHz crystal oscillator inputs - required for RTC calendar accuracy and low-power wake-up timing. |
| PA14 / PA15 | XIN / XOUT | 16MHz crystal oscillator for RF transceiver - directly drives AT86RF233 RF front-end with no external buffer needed. |
| PA30 / PA31 | SWCLK / SWDIO | Two-pin Serial Wire Debug interface - enables non-intrusive on-chip debugging and flash programming via standard ARM debug probes. |
| PA24 / PA25 | USB_DM / USB_DP | Full-speed USB 2.0 differential pair - supports device enumeration and host-mode peripheral attachment without external PHY. |
| RFP / RFN | RF Differential Output | Direct connection to 50Ω antenna matching network - delivers +4dBm output with integrated balun support and antenna diversity control. |
| GNDANA / VDDANA | Analog Ground / Supply | Separate analog domain pins - isolate sensitive RF/ADC circuitry from digital noise, critical for -99dBm receiver sensitivity. |
Key Features
| Feature | Design Value |
|---|---|
| Hardware-Assisted MAC | Auto-Acknowledge and Auto-Retry reduce host CPU overhead by >40% in IEEE 802.15.4 packet handling, freeing cycles for application logic. |
| SleepWalking Peripherals | RTC, ADC, or event-triggered peripherals operate autonomously in standby mode - eliminates CPU wake-ups for periodic sampling or threshold detection. |
| Atmel Event System | 12-channel inter-peripheral signaling enables zero-CPU-latency communication (e.g., TC trigger → ADC start → DMA transfer), reducing jitter in time-critical tasks. |
| Configurable SERCOMs | Four SERCOM modules each support USART/I²C/SPI/LIN with runtime reconfiguration - allows single firmware image to adapt to multiple sensor interface protocols. |
| Peripheral Touch Controller | Supports 6×2 capacitive touch matrix (12 channels) with proximity sensing - enables intuitive user interfaces on space-constrained devices without external ICs. |
Applications
| Smart Utility Metering | Wireless Sensor Node |
|---|---|
|
Use Scenario: Battery-powered gas/water meter transmitting consumption data hourly via Zigbee mesh network. IC Role / Device Role / Timing Role: Primary SoC executing protocol stack, managing RF transmission timing, and performing low-power wake-up scheduling via RTC alarms. Use Value: Integrated transceiver and SleepWalking enable 10+ year battery life; -99dBm sensitivity ensures reliable reception in buried or shielded enclosures. |
Use Scenario: Industrial temperature/humidity node deployed in factory floor with mesh backhaul to gateway. IC Role / Device Role / Timing Role: Real-time sensor aggregator with hardware timestamping of ADC samples using TC input capture, synchronized to network time via RF events. Use Value: Event System links TC, ADC, and DMA to capture and transmit sensor bursts without CPU intervention, cutting active time by 70%. |
| Home Automation Hub | Asset Tracking Tag |
|
Use Scenario: Compact wall-mounted hub bridging BLE peripherals to Thread/Zigbee network. IC Role / Device Role / Timing Role: Dual-role USB device (for PC configuration) and USB host (for dongle-based BLE adapter), managed via shared SERCOM resources. Use Value: Single-chip USB device/host capability eliminates need for external USB switch or bridge IC, reducing BOM cost and board area. |
Use Scenario: GPS-denied indoor asset tag reporting location via RSSI triangulation using multiple gateways. IC Role / Device Role / Timing Role: Ultra-low-power beacon transmitter with programmable TX power (−20 to +4dBm) and precise 250kbps symbol timing for consistent RSSI measurement. Use Value: Hardware-controlled TX power ramping and calibrated timing ensure ±1.5dB RSSI consistency across units, improving localization accuracy. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar wireless microcontroller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ATSAMR21G16A-MF | 48-pin QFN, 28 GPIOs, 5 SERCOMs, 8 ADC channels, XOSC32K integrated | Supports larger sensor arrays and external RTC-less designs; requires more PCB area | Select when needing >16 GPIOs, full 8-channel ADC, or integrated 32.768kHz oscillator for simplified layout. |
| ESP32-WROOM-32 | Wi-Fi + Bluetooth dual-band, 4MB Flash, 520KB SRAM, 240MHz dual-core Xtensa LX6 | Higher throughput, cloud-native connectivity, but higher power and larger footprint | Select for Wi-Fi/BLE gateway applications requiring HTTP/MQTT offload; not suitable for sub-GHz or ultra-low-power <10μA standby. |
Compared with ATSAMR21G16A-MF, the ATSAMR21E16A-MF trades I/O count and ADC channels for smaller footprint and lower system cost; versus ESP32-WROOM-32, it offers superior RF sensitivity and sub-10μA standby current but lacks Wi-Fi/Bluetooth stacks and high-level protocol acceleration.
Availability
ATSAMR21E16A-MF is available at Aetrix Electronics and suitable for smart metering, industrial sensor networks, home automation hubs, and asset tracking tags requiring stable component supply across extended product lifecycles.
Supply support for ATSAMR21E16A-MF 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 full support for the SMART SAM portfolio. The company specializes in secure, low-power microcontrollers and analog products for industrial, automotive, and IoT markets.
The SAM R21 product line was designed specifically for battery-operated IEEE 802.15.4-compliant wireless sensor nodes, emphasizing RF coexistence, deterministic low-power operation, and seamless migration within the SAM family.
FAQ
What is the maximum operating temperature range for the ATSAMR21E16A-MF?
The ATSAMR21E16A-MF is rated for industrial operation from −40°C to +125°C, as indicated by the "F" suffix in its part number (MF = QFN32, −40°C to +125°C matte tin plating). This extended range supports deployment in smart meters, motor controls, and outdoor sensor enclosures where ambient temperatures exceed standard commercial limits.
Does the ATSAMR21E16A-MF include an integrated 32.768kHz crystal oscillator for RTC operation?
No, the ATSAMR21E16A-MF does not integrate a 32.768kHz oscillator. It requires external 32.768kHz crystal connections to PA00 (XIN32) and PA01 (XOUT32) for accurate RTC calendar functionality. In contrast, the SAM R21G variant includes an internal 32.768kHz oscillator (XOSC32K), but this feature is omitted in the E-series to reduce cost and pin count.
How many SERCOM modules are available on the ATSAMR21E16A-MF, and what interfaces do they support?
The ATSAMR21E16A-MF includes four SERCOM modules (SERCOM0–SERCOM3), each configurable at runtime as USART, UART, SPI, I²C (up to 3.4MHz), or LIN slave. SERCOM4 is reserved for internal connection to the AT86RF233 transceiver and is not available for general-purpose use. This configuration balances flexibility with pin-count constraints in the 32-pin QFN package.
What is the role of the RFP and RFN pins on the ATSAMR21E16A-MF?
The RFP and RFN pins on the ATSAMR21E16A-MF form the differential RF output pair driving the 2.4GHz transceiver. They connect directly to a 50Ω antenna matching network or balun, delivering up to +4dBm output power. These pins are electrically isolated from digital I/O and require strict RF layout practices-including ground plane clearance and controlled impedance traces-to maintain the specified −99dBm RX sensitivity.
Can the ATSAMR21E16A-MF operate without an external 16MHz crystal?
No, the ATSAMR21E16A-MF requires an external 16MHz crystal connected to PA14 (XIN) and PA15 (XOUT) to drive the RF transceiver's synthesizer. While the core can run from internal oscillators (DFLL48M, OSC8M), the RF subsystem mandates this crystal for precise 2.4GHz channel spacing (5MHz/500kHz) and stable modulation-omitting it prevents transceiver operation entirely.
ATSAMR21E16A-MF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- SMART™ SAM R21
- Package/Case:
- 32-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:
- 16
- Voltage - Supply:
- 1.8V ~ 3.6V
- Current - Receiving:
- 11.3mA ~ 11.8mA
- Current - Transmitting:
- 7.2mA ~ 13.8mA
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 32-QFN (5x5)
ATSAMR21E16A-MF FAQ
1.How can I place an order for ATSAMR21E16A-MF through Aetrix?
Please submit a Request for Quotation (RFQ) for ATSAMR21E16A-MF 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 ATSAMR21E16A-MF reliable?
The price and inventory of ATSAMR21E16A-MF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ATSAMR21E16A-MF is usually 5 days.
3.What payment methods are accepted for ATSAMR21E16A-MF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ATSAMR21E16A-MF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ATSAMR21E16A-MF?
ATSAMR21E16A-MF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ATSAMR21E16A-MF 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 ATSAMR21E16A-MF?
For technical support, including ATSAMR21E16A-MF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ATSAMR21E16A-MF requirements.
6.How does Aetrix verify that ATSAMR21E16A-MF is sourced from the original manufacturer or authorized distributors?
All ATSAMR21E16A-MF 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 ATSAMR21E16A-MF meets industry standards.
7.What is the process for return or replacement of ATSAMR21E16A-MF?
All ATSAMR21E16A-MF units undergo pre-shipment inspection (PSI). If there is an issue with ATSAMR21E16A-MF, 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 ATSAMR21E16A-MF part is unused and in its original packaging.
Return procedure for ATSAMR21E16A-MF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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