BALFLB-WL-09D3

Balun Overview

The BALFLB-WL-09D3 is an ultra-miniature balun from STMicroelectronics designed for STM32WL sub-GHz wireless microcontrollers. It integrates a matching network, balun, and harmonics filter within a QFN package suitable for two-layer PCBs. The device operates in the 470 MHz to 510 MHz frequency range with a nominal input impedance of 50 ohms. It features a low insertion loss of 1.9 dB and provides deep Tx rejection harmonic filtering. Optimized for high power mode operation at 17 dBm, this component utilizes IPD technology on a nonconductive glass substrate to ensure high RF performance and minimal footprint.

Balun Feature Summary

• Integrates matching network, balun, and harmonics filter for simplified design
• Customized impedance matching specifically for STM32WL sub-GHz wireless microcontrollers
• Provides deep Tx rejection harmonic filtering to ensure signal integrity
• Utilizes IPD technology on a nonconductive glass substrate for optimized RF performance

Balun Applications

• STM32WL sub-GHz wireless module integration
• High power mode RF front-end design
• Low profile antenna interface circuits

Balun Procurement Notes

Verify that the specific suffix D3 corresponds to the QFN-2L package variant intended for two-layer PCB applications. Confirm compatibility with the STM32WL microcontroller's high power mode requirements. Ensure the ordering documentation explicitly references the 470 MHz to 510 MHz operational range. Cross-reference the part number against official STMicroelectronics datasheets to validate the integrated harmonic filter specifications. Check for any specific handling instructions related to the ultra-miniature form factor during assembly.

Balun Selection Notes

Select this component when designing for STM32WL sub-GHz applications requiring a compact solution. It is appropriate for systems needing integrated balancing and filtering without external discrete components. Consider its suitability for two-layer PCB layouts due to its specific impedance matching customization. Evaluate its performance in high power modes where deep Tx rejection is critical. Ensure the physical dimensions align with the strict space constraints of the target module design.

Balun Part Context

This balun belongs to STMicroelectronics' family of ultra-miniature RF components tailored for the STM32WL series. Unlike general-purpose baluns, it is uniquely engineered with customized impedance matching for these specific microcontrollers. The product line emphasizes area reduction and BOM simplification by combining multiple RF functions into a single small footprint package.

Balun Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.