At 03:41 PM 8/26/02 -0400, Robert E. Griffith wrote: >I have an audio project that currently uses a CS4334 DAC to provide L/R >analog audio outputs from a digital I2S audio stream (from a STA013 mp3 >decoder). I am trying to research SPDIF digital audio to see if I could >support it as well. I have been googling for a while, but have not found >any information on the physical line driving for SPDIF. > >Does anyone know of any good links for SPDIF digital audio? > >Does anyone know if there are line driver chips for SPDIF? Or, is it simple >enough that it is done with discrete components? SPDIF is a single ended (1 wire + gnd) interface with 0.5V for HI and 0V for LO. I generally derive my SPDIF outputs from the RS-422 driver I use to get AES/EBU - all it needs is a 10:1 voltage divider from one of the RS-422 outputs. I generally use 680R & 82R for the divider resistors, assuming a non-terminated SPDIF input. My preferred RS-422 receiver and transmitter is the 26C31 and 26C32 quad parts: cheap, reliable and available from many sources. I suspect that if all that you want is a single SPDIF output, you just need to make sure that whatever output stage you are using swings all the way to the supply rail and then attenuate that down to 0.5V peak with a 75R source impedance. It *is* that simple! dwayne -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 18 years of Engineering Innovation (1984 - 2002) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics