Something that I noticed was that the SPDIF coax input circuit is converted to logic levels through an inverter... so the SPDIF signal is getting inverted? The circuit obviously seems to work, but it does surprise me a little; does it matter at all whether the signal is inverted or not?
Searching a little wider, and I found a SPDIF coax input schematic from Analog Devices, which uses a different topology, but also seems to invert the signal (+ve pin -> -ve terminal of U43 on page 9 of the attached datasheet).
To what extent do I need to account for inverting/not inverting the coax input signal when designing my own board?
XK-AUDIO-316-MC SPDIF input circuitry - the signal is inverted Topic is solved
-
- Member++
- Posts: 23
- Joined: Thu Mar 14, 2024 7:44 pm
XK-AUDIO-316-MC SPDIF input circuitry - the signal is inverted
You do not have the required permissions to view the files attached to this post.
View Solution
-
Verified
- XCore Addict
- Posts: 134
- Joined: Sun Dec 13, 2009 1:12 am
S/PDIF uses biphase mark encoding so is insensitive to inversion.
Only the presence of transitions is important, whether they are low to high or high to low makes no difference.
Cheers,
Joe
Only the presence of transitions is important, whether they are low to high or high to low makes no difference.
Cheers,
Joe
XMOS hardware grey beard.
-
- Member++
- Posts: 23
- Joined: Thu Mar 14, 2024 7:44 pm
Thanks for the quick reply.