electronic design and production

USB Audio interface


The Edel USB to I2S/SPDIF interface is an easy to integrate OEM solution for High End USB audio playback systems, supporting both USB Audio Class 1.0 and 2.0.

USB streaming is based on an asynchronous protocol, clocked by low jitter on board oscillators. Using this concept, the design benefits of a local high quality master clock to achieve jitter-free playback and bit-perfect data transfer.


External master clock synchronization is provided for enhanced flexibility and optimal clock distribution.

Full galvanic isolation avoids any interference issues between the audio device and the USB host. Critical components are powered by an external source to ensure optimal performances. The interface can also be configured to use bus power only, useful for using the board as a simple USB to S/PDIF mobile interface.

USB interface bloc diagram


  • USB 2.0 High Speed compliant & USB Audio Class 1.0 or 2.0 supported (user selectable)
  • 2-channel asynchronous endpoint for stereo jitter-free playback
  • On board low jitter oscillators
  • External master clock input
  • Resolution up to 24-bits, sampling rate up to 192kHz (96kHz for USB Audio Class 1.0) I2S and S/PDIF output
  • Full galvanic isolation
  • Based on XMOS XS1-L1 controller/DSP in 128TQFP package and SMSC USB3318 USB PHY.
  • Windows USB Audio Class 2.0 driver available




  • USB Audio Class 2.0 driver for MS Windows available here for download