You have entered a value in the highlighted fields below that contain invalid characters. Please revise your selection using valid characters only.

Product may not be an exact match for your search

You previously purchased this product. View in Order History



Radio Board, EFR32 Flex Gecko, 2.4 GHz/915 MHz, +19.5dBm


Image is for illustrative purposes only. Please refer to product description.

Manufacturer Part No:
Order Code:
Technical Datasheet:
SLWRB4253A   Datasheet
See all Technical Docs

Product Information

Want to see similar products? Simply select your required attributes below and hit the button ×

Silicon Laboratories






EFR32FG12 Radio Board & Main Board


Find similar products Choose and modify the attributes above to find similar products.

Technical Documents (1)

CAD Downloads


Terms and Conditions

CAD Models - Notice
CAD Models and drawings are provided to you on a revocable limited licence for your internal use only but remain the property of the manufacturer who retain all intellectual property rights and ownership. They are provided to assist you in decision making and as design guide but are not guaranteed to be error free, accurate or up to date and is not intended to be taken as advice.
Use of these CAD models and other options provided are downloaded and used entirely at your own risk and by continuing you confirm acceptance of the above.

Accept Cancel

Product Overview

The SLWRB4253A from Silicon Labs is an EFR32 Flex Gecko 2.4GHz and 915MHz dual band radio board. The Flex Gecko SLWRB4253A radio board plugs into the wireless starter kit main board provided with the Flex Gecko starter kits to get access to display, buttons and additional features from expansion boards. With the supporting Simplicity Studio suite of tools, developers can take advantage of graphical wireless application development and visual energy profiling and optimization. The radio board can also be used as a reference design for matching networks of the RF interfaces. The board contains a Flex Gecko wireless system on chip 2.4GHz and 915MHz dual band and optimized for operation with 19dBm output power. For the 2.4GHz band with the on-board printed antenna and RF connector enables radiated and conducted testing. For the 915MHz band the on-board SMA connector enables conducted testing and attachment of external whip antenna for radiated tests.
  • Wireless SoC EFR32FG12P433F1024GL125 ARM cortex M4 with FPU, 1024KB flash, 256KBRAM
  • Touch slider
  • Crystals for LFXO and HFXO is 32.768KHz and 38.4MHz
  • Radio board supports dual-band operation with its integrated sub-GHz ISM & 2.4GHz band transceivers


Embedded Design & Development

Available for back order

More stock available to supplier lead times which is approximately 7/4/22

Due to market conditions delivery times are for general guidance only and may be subject to change at short notice

Notify me when back in stock


Pricing is unavailable. Please contact customer services.

Price for:
Multiple: 1 Minimum: 1
Quantity Price Your Price
1+ HK$473.42
Promotional price
Contract Price
Web only price
Web only contract price

Pricing is unavailable. Please contact customer services.

No longer stocked:: No Longer Manufactured::
Add to Basket Add to Basket Pre-Order
Restricted Item
Add Part No. / Line Note
Total Price:
Total Price: ( )
Total Price: --