Broadcast Like Never Before with LE Audio

May 29, 2025

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Bluetooth Low Energy (LE) is a variation of the Bluetooth wireless standard that’s designed for short-range data exchange with minimal power consumption. Introduced as part of the Bluetooth 4.0 specification, it enables devices like wearables, sensors, and smart home products to operate efficiently on small batteries. Bluetooth LE supports features like quick device discovery, secure connections, and in newer versions (5.0+), extended range, and higher data rates. 

Another welcome addition to the Bluetooth LE spec is the inclusion of LE Audio, which targets efficient wireless audio transmission. Bluetooth LE Audio is actually part of the Bluetooth 5.2 specification as a next-generation audio streaming technology. 

A Spec You Can Trust 

Bluetooth LE Audio is engineered to be a next-generation wireless audio standard built on Bluetooth LE technology, now that’s been time tested. It introduces the Low Complexity Communication (LC3) codec for higher audio quality at lower bit rates, significantly improving power efficiency and extending battery life in tiny devices like earbuds and hearing aids. The standard supports multi-stream audio for better synchronization between earbuds and Auracast broadcast audio, enabling one audio source to be shared with multiple listeners. 

From its inception, Bluetooth LE Audio was designed to deliver high-quality audio with significantly reduced power consumption compared to Bluetooth Classic Audio. Specifically, the LC3 codec improves audio quality, enabling more efficient use of power and better performance, even in challenging radio conditions and environments. The multi-stream audio feature permits multiple synchronized audio streams from a single source to multiple devices. This feature is aimed at smaller true wireless stereo (TWS) devices. In fact, LE Audio includes native support for hearing aids, improving accessibility and battery life for users with hearing loss. 

Auracast broadcast audio enables one-to-many audio streaming, allowing an audio source to broadcast to unlimited nearby receivers, a feature that can be deployed in public venues like airports or theaters. To be clear, Auracast is a specific feature within the broader context of multi-stream audio. While multi-stream audio enables a source device to transmit different audio streams to multiple devices, Auracast focuses on broadcasting the same audio stream to an unlimited number of receivers.  

Engineering Challenges 

Now that we’ve discussed all the great features of LE Audio, let’s look at some of the technical challenges it presents to the design engineer. One major hurdle is optimizing audio quality while maintaining ultra-low power consumption, especially in the tiniest devices, like earbuds and hearing aids. Implementing the LC3 codec efficiently requires balancing processing power and memory constraints without compromising latency or sound fidelity.  

Ensuring reliable multi-stream audio also demands precise synchronization between devices, which can be difficult in environments with wireless interference or a high number of users. And supporting Auracast broadcast audio introduces additional complexity, as devices must manage scalable connection management and latency control for the multiple listeners. 

The Right Device for LE Audio 

One MCU that can showcase some of the benefits of LE Audio is Infineon’s AIROC CYW20829. It offers unmatched reliability and range thanks to its integrated power amplifier which results in 10 dBm of transmit output power and a receive sensitivity of -98 dBm when handling Bluetooth LE at 1 Mbit/s. The part is fully compliant with Bluetooth LE 5.4, and requires very few external components. 

It’s important to note that the features of the AIROC CYW20829 MCU go beyond Bluetooth; integration is a clear hallmark for the device. With a 96-MHz Arm Cortex-M33 core handling application duties and a second Cortex-M33 dedicated to the Bluetooth 5.4 features, you get serious processing muscle in a single package. That tight integration means a leaner BOM and more design flexibility. Designers can also choose between the SoC or a pre-certified module. 

That integration consists of 256 kbytes of SRAM for applications, a Quad SPI interface for executing code from external flash memory, and a generous selection of interfaces including CAN FD, PDM, I2S, and ADCs. 

At the same time, security needn’t come with a performance penalty. Features like secure boot, hardware crypto acceleration, a true random number generator, and eFuse for key storage are all on board. 

The CYW20829 is backed by Infineon’s ModusToolbox, a comprehensive development ecosystem, and Zephyr RTOS support, giving engineers a mature development environment loaded with code examples. ModusToolbox can simplify embedded application development, as it provides a suite of tools, libraries, and runtime assets, offering a flexible and efficient development experience. The result is a Bluetooth LE Audio platform that’s built to scale, based on the needs and requirements of the application. 

An evaluation kit, the CYW920829M2EVK-02, is available to further speed development. The kit’s bevy of on-board peripherals enables evaluation, prototyping, and development of an array of Bluetooth LE applications. Those peripherals include a six-axis inertial measurement unit (IMU), a thermistor, an analog microphone, two user programmable buttons, and a series of LEDs. GPIO support with extended headers and Arduino Uno R3 compatibility allow for third-party shields. 

Take this solution for a test drive. You won’t be disappointed. Reach out and Infineon will be happy to provide you with a variety of tools to assist in your design.