Sony/Philips Digital Interface

What Does Sony/Philips Digital Interface Mean?

The Sony/Philips Digital Interface (S/PDIF) is a protocol that uses an electrical or optical cable to carry digital audio signals between components and devices over short distances. S/PDIF allows data transfers of audio files between devices without the need for conversion to analog and vice versa. Depending on its purpose, it may use fiber optic cables via TOSLINK or a coaxial cable with RCA connectors.


Its formal name is Sony/Philips Digital Interface Format (S/PDIF)

Techopedia Explains Sony/Philips Digital Interface

S/PDIF is used for the following processes:

  • Interconnecting home theater components and digital audio equipment, such as those using DAT format
  • Interconnecting other audio processing devices to transmit audio data in various formats, with the 48 kHz sampling rate as the most common format used in DAT and the 44.1 KHz format used in audio CDs.

Because the S/PDIF format has no defined data rate standard that allows support of both or additional formats, it sends data using a biphase mark code, which has one-two transitions per bit and allows for direct extraction of the original word clock from the digital signal. A caveat to this interface format is that the receiver has no control over the data rate. Thus, it must synchronize its conversion with the source’s clock to prevent bit slip.


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Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.