ADAU1466 SPDIF (Fiber audio output ) distance question

Hello terryyuan,

It will depend some on the quality of the cable. This part was originally a Toshiba part. That part mentioned 10M max length in the datasheet. The newer part we use now is made by Everlight and it does not mention distance in that datasheet. Both mentions that it is an all plastic optical fiber (980/1000um).

10M seems reasonable to me but it will require good cables. These connectors were not meant to run over long distances. It was meant to connect to something that is located in the same rack or nearby.

Dave T

10m would be very long for an optical cable as the jitter is likely to be a problem. I would recommend a maximum of more like 3m for plastic optical fiber, though glass fiber is OK for longer runs. If you need a cable that long, I would strongly recommend using coaxial cable with RCA connectors. There is a fair amount of information about these cables on the Internet, and converter boxes are available (e.g. on Amazon) for less than US$20.

Hello Ken,

The spec max was stated as 10M but I did say it would require good cables. It is also stretching the performance to the edge so certainly capping this off to 3M would help. The difference between the signal being valid and "working" to having too much jitter is subjective and for some applications might be acceptable. So certainly "designer beware" when pushing any specification.

In the professional world, as you know, the SPDIF or AES/EBU runs that have to go a distance like between rooms, they all go to a 75-ohm coax then back to either optical or electrical levels for the original SPDIF or AES/EBU standard.

In my experience, I never saw these used to run more than 3M as well in a nearby rack so you made a valid point.

Dave T

thank you very much，It should be enough within 3M 。