Simplicity SDK Platform Version 5.2.3 (February 18, 2026) - Release Notes#

Simplicity SDK Version 2025.6.3

The Platform provides infrastructure support for applications developed with higher-level protocols, and it provides an interface with the underlying hardware.

Click here for earlier releases.

Silicon Labs Series 3: The Future of IoT is Here#

Our first Series 3 products are now supported with a comprehensive SDK, enabling faster, more secure, and more scalable IoT development.

With unmatched performance, power efficiency, and multi-radio flexibility, the Series 3 platform future-proofs your designs while ensuring backward compatibility with Series 2.

Learn more: Series 3 Wireless Platform | SiMG301 | SiBG301

Release Summary#

Release Item	Version	Release Date	Release Notes	Key Features	API Changes	Bug Fixes	Chip Enablement
Platform MCU	5.2.3	February 18, 2026	Release Notes	New Clock Manager PCLK divider auto-configuration. Clock Manager validation enhancements.	None.	IADC high-precision mode accuracy fixes. Power Manager clock restoration fixes during sleep. FreeRTOS tick power manager time-critical function classification.	SiXG301 family support (GCC only). EFR32BG22L and EFR32FG23L device families.
Bootloader	3.1.3	February 18, 2026	Release Notes	None.	None.	None.	None.
Security	5.2.3	February 18, 2026	Release Notes	Added support for SiXG301 device family ( Series-3 ). Fixed bug in PSA ITS driver. Fixed bug to enable CCM* No-Tag support in PSA Cipher driver on Series-3. Fixed bug in PSA SE MAC driver on Series-3 for algorithm AES-HMAC-MMO which caused psa_hmac_compute to fail. For TrustZone apps, by default, enabled countermeasure option for securing I/O buffers in PSA Crypto APIs. Minor code size improvements.	None.	None.	None.
Micrium OS	5.18.2	February 18, 2026	Release Notes	Restricted Micrium OS usage to Series 2 devices	None.	CMSIS-RTOS osMessageQueueGet osWaitForever wait fix.	None.
CPC	4.7.2	September 24, 2025	Release Notes	Improved SPI driver compatibility for Series 2 and 3 devices. Added preprocessor validation for UART RX buffer size without hardware flow control.	None.	None.	None.
MVP Math Library	5.2.3	February 18, 2026	Release Notes	None.	None.	None.	None.
RAIL Library	2.19.3	February 18, 2026	Release Notes	None.	None.	None.	None.

Impact of Release Changes#

Impact Statements | Migration Guide

Impact Statements#

None.

Migration Guide#

sl_main migration:
- See the sl_system to sl_main migration guide for detailed instructions.
- Learn more about using sl_system_compatibility in baremetal applications here.

Using This Release#

Installation and Use | Help and Feedback

Installation and Use#

To run your first demo, see our Getting Started Guides.

To kick start your development, see our Developer's Guide.

For information about Secure Vault Integration, see Secure Vault.

To review Security and Software Advisory notifications and manage your notification preferences:

Go to https://community.silabs.com/.
Log in with your account credentials.
Click your profile icon in the upper-right corner of the page.
Select Notifications from the dropdown menu.
In the Notifications section, go to the My Product Notifications tab to review historical Security and Software Advisory notifications
To manage your preferences, use the Manage Notifications tab to customize which product updates and advisories you receive.

To learn more about the software in this release, dive into our online documentation.

Help and Feedback#

Contact Silicon Labs Support.
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SDK Release and Maintenance Policy#

See our SDK Release and Maintenance Policy.