termination on I2S recommendable?

[weissi]

Wolfson recommends a 50Ohm resistor on the clock line of an I2S source. I haven´t seen this at other manufactors like BB, AD or Crystal....
What do you say? Only for longer trace distances? or generally?
But otherwise: What would be bad if I do so....

 

[yves]

resistor on I2S lines

I hv seen an article in the Hifi News and Record Rev
magazine (1989 I believe, off the top of my head)
that recommends this as a solution to high rf
(rising and falling edges) signals around the circuitry.
I hv tried this on my cd player and the sounds seems
to be a little bit smoother, but that was my impression
then without significant listening. I have left it in there
since. I used 1k ohm.

Yv

 

[Fred Dieckmann]

termination

Try series termination at the source (driver) end of the trace. Maybe 20 to 30 ohms.


http://www.dde-eda.com/ecadman/guide/hs.html#SeriesTermination

http://www.sigcon.com/pubsAlpha.htm

 

[jwb]

What's the rise time, logic level, and trace length? It isn't the format (I2S) that is important, but the signal parameters.

 

[Jocko Homo]

Just try it

You might learn something.

Jocko

 

[weissi]

I know that it has nothing to do with I2S as it......

Let´s try it, resistors don´t cost a world, or should I use audiophile resistors ;-)

 

[Fred Dieckmann]

termination resistors

Just use some 1% 1/4watt and it should be fine. SMTs would be fine too. the idea is to use some non inductive.

Fred


P.S.

"Music makes for a quiet mind." what about loud mindless music?

 

[weissi]

I think the tolerance has nothing to do with it.... but I hope I understand you, that you mean that lower tolerances mean also lower inductivity......

But another question: How Long (or short) should the traces at maximum be, I mean i could calculate it on my one, but has anyone practical experience with that? I plan to have split boards, one for the DIR, and one for the DAC. Should I buffer the lines with an 74HCT???? or is there a other method (despite the LVD one, seems to be an expensive one, isn´t it??)

Thanks