CDROM SPDIF question

[splus]

Hi,
I found my CDROM's SPDIF output is TTL level but come with +5V DC bias.
I directly plug it into CS8414 but it does not work.
how do I remove the 5V DC bias? Thanks!


😕

 

[pieris]

You can remove bias with a capacitor (perhaps 0.1uF) in series with the SPDIF output. Usually a transformer is used on the receiving end (in front of the CS8414) which effectively eliminates the DC bias.

See Appendix A of the CS8414 datasheet:
http://www.cirrus.com/en/pubs/proDatasheet/8413-4.pdf