Altera_Forum
Honored Contributor
Honored ContributorLVDS output High Z or both to '0'
Hi,
I have LVDS output. Is there a any way to put both LVDS outputs to High-'Z' or either both driving '0' ? -TeroForum Discussion
5 Replies
Altera_ForumTo my knowledge, no. If you have an output set in LVDS mode it always operates as a differential pair.
- Altera_Forum--- Quote Start --- Hi, I have LVDS output. Is there a any way to put both LVDS outputs to High-'Z' or either both driving '0' ? -Tero --- Quote End --- Yes, you can disable (tri-state) LVDS outputs. You should be able to infer this in your HDL code or you could instantiate an Altera I/O buffer primitive (ALTIOBUF I think). You will need an output enable signal to enable/disable the output buffer. But as Galfonz said, you can't make an LVDS output buffer drive both sides low.
- Altera_Forum
Tristateable Bus LVDS drivers are always emulated LVDS. There should be no basic problem (besides some timing drawbacks) to connect it trough logic gates.
--- Quote Start --- Bus LVDS (BLVDS) output uses two single-ended outputs with the second output programmed as inverted. --- Quote End --- - Altera_Forum
Thanks, FvM, I didn't know that. To the OP, sorry for the misinformation (I was going from memory - always a mistake).
If you are able to add external components I've used M-LVDS transceivers from TI. Analog Devices also makes them I believe. They also provide some protection if the LVDS signals are going off-board. - Altera_Forum
That should work, but you won't be able to operate as fast as real hardware differential drivers (if that matters to you).
