Dual-mode module helps Bluetooth Classic audio and LE Audio product developers


FSC-BT631D module employs a Nordic nRF5340 SoC to deliver latest LE Audio connectivity solution for headphones and audio equipment

The advanced wireless audio module from Shenzhen Feasycom uses Nordic Semiconductor's nRF5340 multiprotocol SoC for dual-mode Bluetooth® Classic audio and LE Audio product designs. Described as the world's first Bluetooth module that can simultaneously support LE Audio and Bluetooth Classic audio, the 'FSC-BT631D' module measures only 12 by 15 by 2.2 mm. In addition to a high-end nRF5340 SoC, the module integrates a Bluetooth Classic transceiver chipset for enabling legacy Bluetooth audio applications.

The next generation of wireless audio

"LE Audio is the next generation of Bluetooth audio," says Nan Ouyang, CEO at Shenzhen Feasycom. "As the industry transitions from Bluetooth Classic Audio to LE Audio, wireless audio product developers ask for solutions that support both versions. We developed the FSC-BT631D module for these product developers, making audio streaming over Bluetooth LE possible with enhanced sound quality, power consumption, latency, and bandwidth performance."

For example, audio equipment solutions employing the Feasycom module can connect to audio source devices such as a smartphone, laptop or TV using Bluetooth Classic, then transmit audio to an unlimited number of other LE Audio devices using Auracast™ broadcast audio.

The nRF Connect SDK was also invaluable throughout the LE Audio development process
Nan Ouyang, Shenzhen Feasycom

The module employs the nRF5340 SoC’s dual Arm® Cortex®-M33 processors – providing a high performance application processor capable of DSP and Floating Point (FP) alongside a fully programmable, ultra low power network processor. The application core manages both the LE Audio codec and the codec for classic Bluetooth audio, while the Bluetooth LE protocol is supervised by the network processor.

Support for multiple protocols

The LE Audio connectivity is made possible through the nRF5340 SoC’s 2.4 GHz multiprotocol radio featuring 3 dBm output power and -98 dBm RX sensitivity for a link budget of 101 dBm. This radio also supports other major RF protocols including Bluetooth 5.3, Bluetooth Direction Finding, Long Range, Bluetooth mesh, Thread, Zigbee, and ANT™.

“We selected the nRF5340 SoC because it achieved a stable coexistence of LE Audio and Bluetooth Classic which was key to this application,” says Ouyang. “The performance of the dual-core CPUs, excellent power efficiency, and RF performance were other factors in the decision.”

The ultra-low power consumption is made possible due to the nRF5340’s new, power-optimized multiprotocol radio, which offers a TX current of 3.4 mA (0 dBm TX power, 3 V, DC/DC) and RX current of 2.7 mA (3 V, DC/DC). The sleep current is as low as 0.9 µA. Additionally, because the cores can operate independently, developers have the flexibility to optimize performance for power consumption, throughput, and low latency response.

“The nRF Connect SDK was also invaluable throughout the LE Audio development process, alongside the excellent technical information and application engineers provided by Nordic,” says Ouyang.