The next generation of wireless audio projects is now getting on the bench, as developers get access to the first Bluetooth LE Audio evaluation platforms. Nordic Semiconductor has long been a reference in Bluetooth development platforms and has now released its nRF5340 Bluetooth LE Audio DK board, which includes everything required for developers to take advantage of the latest Bluetooth standard, including LC3 codec, low power consumption, and wireless stereo enhancements.
The new nRF5340 Audio Development Kit (DK) from Nordic Semiconductor, is a complete design platform for rapid development of Bluetooth LE Audio products, and is based on Nordic’s nRF5340 System-on-Chip (SoC), the world’s first wireless SoC with two Arm Cortex-M33 processors. The SoC is an ideal choice for LE Audio and other complex connected applications, the Norwegian company says.
When it was unveiled to the world, at CES 2020, LE Audio was described by the Bluetooth Special Interest Group (SIG) as “the future of wireless sound”. No one could have predicted then that two years of global pandemic would cool down those ambitions as it did, and that two years later we would be starting to actually have some tools to play with for the first developments.
The LE Audio technology essentially promotes the adoption of the Low Complexity Communications Codec (LC3), an enhanced replacement for the low complexity sub-band codec (SBC) used by Classic Audio – the default codec when users don’t have source and sink devices with AAC or aptX support (the standard quality codes of choice for audio-quality oriented designs). As an advanced codec, LC3 ensures that LE Audio features both improved audio quality and better battery life than Classic Audio in all use cases. Extensive listening tests have shown that at all sample rates, the audio quality of LC3 exceeds that of SBC at the same sample rate and provides equivalent or better audio quality at half the wireless data rate. This lower data rate is a key factor in minimizing the power consumption of LE Audio products. LE Audio also brings true wireless stereo (TWS) and other new functions to wireless audio including Audio Sharing. Since 2020, basically all key technology companies have already licensed LC3 from Fraunhofer, but its practical implementations are yet to appear on the market.
The new Nordic nRF5340 Audio DK now makes it easy to embark on LE Audio projects. It is highly configurable, allowing it to function as a USB dongle to send and receive high-quality audio data from a PC, a business headset, or a TWS earbud – most use cases require two or more nRF5340 Dk boards. The Audio DK includes two 3.5 mm audio jacks for analog “in” and headphones “out”; five user-programmable buttons and LEDs; an SD-Card holder for extra storage; a SEGGER J-Link debugger for programming and debugging, and connectors to access the analog/digital interfaces and GPIOs. The DK is typically powered via USB but also has a battery connector for a Li-ion/Li-Po battery. The current consumption can be measured on the board and by using the dedicated current measurement pins and Nordic’s Power Profiler Kit II or other current measuring equipment.
The nRF5340 SoC at the heart of the Audio DK combines a high-performance application processor with a fully programmable ultra low power network processor. The dual core architecture enables optimum power efficiency with high performance. The 128MHz Arm Cortex-M33 application processor (incorporating 1MB of Flash and 512KB of RAM) is ideal for handling custom applications and audio codecs such as LC3. The 64MHz Arm Cortex-M33 network processor (with 256KB Flash and 64KB RAM) is power optimized to run Nordic’s Bluetooth LE Audio RF protocol software. The nRF Connect SDK, the development platform for the nRF5340 SoC, features board support for the nRF5340 Audio DK and supports LE Audio, Bluetooth LE, Thread, and other applications.
In addition to the nRF5340 SoC, the Audio DK board features Nordic’s nPM1100 power management IC (PMIC), and Cirrus Logic’s CS47L63 Audio digital signal processor (DSP). The PMIC features a highly-efficient configurable buck regulator and an integrated battery charger with a charge current up to 400mA. The nPM1100’s extremely small form factor makes it an ideal PMIC for space-constrained applications like TWS Earbuds. The CS47L63’s high-performance DAC and differential output driver are optimized for direct connection to an external headphone load. It suits earbuds with mono-only and direct speaker output.
“LE Audio represents one of those rare occasions where there’s no technical trade-offs limiting what a designer can do. It brings better audio quality, including TWS, more robust wireless connectivity and vastly improved battery life,” says Vince Hagen, Business Development Manager for LE Audio with Nordic Semiconductor. “An engineer can, for example, design earbuds with incredible sound quality and extended battery life by replacing Classic Audio with LE Audio. Alternatively, they can use smaller batteries to shrink their product’s form factor and direct material costs, while still matching the original product’s playtime.”
The nRF5340 Audio DK is available now from Nordic’s distribution partners. It is priced at $169.
www.nordicsemi.com
