EFR32BG21 Common Specs
Bluetooth Low Energy Radio
- Compatible with Bluetooth 5, Bluetooth 5.1 and Bluetooth mesh specification
- Excellent receive sensitivity:
- 104.9 dBm @125 kbps GFSK
- -97.5 dBm @1 Mbps GFSK
- -94.4 dBm @2 Mbps GFSK
- 104.9 dBm @125 kbps GFSK
- Programmable output power: Up to +20 dBm
- Active mode RX: 8.8 mA
- Active mode TX: 9.3 mA @ 0 dBm
- Active mode TX: 33.8 mA @ 10 dBm
Rich Analog and Digital Peripherals
- 12-bit 1 Msps SAR Analog to Digital Converter (ADC)
- Analog Comparators (ACMP)
- 8 Channel DMA Controller
- Peripheral Reflex System (PRS)
- PTA (Packet Traffic Arbitration) for Wi-Fi Coexistence
- 16-bit Timer/Counters
- 3 Compare/Capture/PWM channels per Timer
- 32-bit Timer/Counter
- 3 Compare/Capture/PWM channels per Timer
- 24-bit Low Energy Timer for waveform generation
- Watchdog Timers
- Universal Synchronous/Asynchronous Receiver/Transmitter (UART/SPI/SmartCard(ISO 7816)/IrDA/I2S)
- I2C interface with SMBus support
- Up to 20 General Purpose I/O pins
- Output state retention and asynchronous interrupts
Powerful MCU & Memory Options
- ARM® Cortex®-M33
- Floating-Point Unit
- Up to 80 MHz Clock Speed
- Low Active Mode Current: 50.9 µA/MHz
- Up to 1024 kB of Programmable Flash
- Up to 96 kB SRAM
Package Options
- QFN32 (4 mm x 4 mm)
Securing Your IoT Product
IoT security is key to protecting company brands, end user privacy and commercial viability of products. Vulnerabilities can be exploited through both remote Internet attacks and physical hands-on-attacks.
Developers using the Silicon Labs EFR32BG21 family have access to the highest level of IoT security provided by Secure Vault.
BG21 Security Features
Whitepaper: Preparing for Next-Gen Cyber Attacks on IoT

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Part Number | MCU Core | Core Frequency (MHz) | Flash | RAM | Bluetooth 5.1 | Bluetooth 5 | Bluetooth Mesh | Secure Vault | Cryptography | Output Power Range (dBm) | Receive Sensitivity | GPIO | RX Current (mA) | UART | USART | I²C | SPI | I²S | ADC | Comparators | Timers (16-bit) | Temperature Range ºC | Package Type | Package Size (mm) |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ARM Cortex-M33 | 80 | 1024 | 96 | Yes | AES-128 AES-256 ECC SHA-1 SHA-2 | -20 10.5 | -97 (1 Mbit/s GFSK) | 20 | 8.7 | 0 | 3 | 2 | 0 | 3 | 12-bit, SAR, 1 Msps | 2 | 2 | -40 125 | QFN32 | 4x4 | ||||
ARM Cortex-M33 | 80 | 512 | 64 | Yes | AES-128 AES-256 ECC SHA-1 SHA-2 | -20 10.5 | -97 (1 Mbit/s GFSK) | 17 | 8.7 | 0 | 3 | 2 | 0 | 3 | 12-bit, SAR, 1 Msps | 2 | 2 | -40 125 | QFN32 | 4x4 | ||||
ARM Cortex-M33 | 80 | 768 | 64 | Yes | AES-128 AES-256 ECC SHA-1 SHA-2 | -20 10.5 | -97 (1 Mbit/s GFSK) | 20 | 8.7 | 0 | 3 | 2 | 0 | 3 | 12-bit, SAR, 1 Msps | 2 | 2 | -40 125 | QFN32 | 4x4 | ||||
ARM Cortex-M33 | 80 | 1024 | 96 | Yes | AES-128 AES-256 ECC SHA-1 SHA-2 | -20 20 | -97 (1 Mbit/s GFSK) | 20 | 8.7 | 0 | 3 | 2 | 0 | 3 | 12-bit, SAR, 1 Msps | 2 | 2 | -40 125 | QFN32 | 4x4 | ||||
ARM Cortex-M33 | 80 | 512 | 64 | Yes | AES-128 AES-256 ECC SHA-1 SHA-2 | -20 20 | -97 (1 Mbit/s GFSK) | 20 | 8.7 | 0 | 3 | 2 | 0 | 3 | 12-bit, SAR, 1 Msps | 2 | 2 | -40 125 | QFN32 | 4x4 | ||||
ARM Cortex-M33 | 80 | 768 | 64 | Yes | AES-128 AES-256 ECC SHA-1 SHA-2 | -20 20 | -97 (1 Mbit/s GFSK) | 20 | 8.7 | 0 | 3 | 2 | 0 | 3 | 12-bit, SAR, 1 Msps | 2 | 2 | -40 125 | QFN32 | 4x4 | ||||
ARM Cortex-M33 | 80 | 1024 | 96 | — | AES-256 ECC SHA-1 SHA-2 | -20 10 | -97 (1 Mbit/s GFSK) | 20 | 8.7 | 3 | 3 | 2 | 3 | 3 | 12-bit, SAR, 1 Msps | 2 | 7 | -40 125 | QFN32 | 4x4 | ||||
ARM Cortex-M33 | 80 | 512 | 64 | — | AES-256 ECC SHA-1 SHA-2 | -20 10 | -97 (1 Mbit/s GFSK) | 20 | 8.7 | 3 | 3 | 2 | 3 | 3 | 12-bit, SAR, 1 Msps | 2 | 7 | -40 125 | QFN32 | 4x4 | ||||
ARM Cortex-M33 | 80 | 768 | 64 | — | AES-256 ECC SHA-1 SHA-2 | -20 10 | -97 (1 Mbit/s GFSK) | 20 | 8.7 | 3 | 3 | 2 | 3 | 3 | 12-bit, SAR, 1 Msps | 2 | 7 | -40 125 | QFN32 | 4x4 | ||||
ARM Cortex-M33 | 80 | 1024 | 96 | — | AES-256 ECC SHA-1 SHA-2 | -20 20 | -97 (1 Mbit/s GFSK) | 20 | 8.7 | 3 | 3 | 2 | 3 | 2 | 12-bit, SAR, 1 Msps | 2 | 7 | -40 125 | QFN32 | 4x4 | ||||
ARM Cortex-M33 | 80 | 512 | 64 | — | AES-256 ECC SHA-1 SHA-2 | -20 20 | -97 (1 Mbit/s GFSK) | 20 | 8.7 | 3 | 3 | 2 | 3 | 3 | 12-bit, SAR, 1 Msps | 2 | 7 | -40 125 | QFN32 | 4x4 | ||||
ARM Cortex-M33 | 80 | 768 | 64 | — | AES-256 ECC SHA-1 SHA-2 | -20 20 | -97 (1 Mbit/s GFSK) | 20 | 8.7 | 3 | 3 | 2 | 3 | 3 | 12-bit, SAR, 1 Msps | 2 | 7 | -40 125 | QFN32 | 4x4 |
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EFR32xG21 Wireless Gecko Starter Kit
The EFR32xG21 Wireless Gecko Starter Kit (SLWSTK6006A) includes everything needed to enable developers to create a mesh network and evaluate the EFR32xG21A with Secure Element and the EFR32xG21B with Secure Vault Series 2 Wireless Gecko SoCs. This kit provides the common baseboard and comes with 6 xG21A modules (SLWRB418xA). If you want to evaluate the EFR32xG21B you must buy the xG21B modules (SLWRB4181C +10 dBm) separately.

EFR32xG21 Wireless Gecko Starter Kit
The EFR32xG21 Wireless Gecko Starter Kit (SLWSTK6006A) includes everything needed to enable developers to create a mesh network and evaluate the EFR32xG21A with Secure Element and the EFR32xG21B with Secure Vault Series 2 Wireless Gecko SoCs. This kit provides the common baseboard and comes with 6 xG21A modules (SLWRB418xA). If you want to evaluate the EFR32xG21B you must buy the xG21B modules (SLWRB4181C +10 dBm) separately.