Hi guys,
does anyone know which pins are in arduino Vidor MKR 4000 “LVDS”
Hi guys,
does anyone know which pins are in arduino Vidor MKR 4000 “LVDS”
Only LVDS lines are in camera connector.
Some more differential pairs are in PCIe connector.
these have 3.3v vccio. LVDS need 2.5V vccio
LVDS is differential, what matters it the signal common mode range and voltage swing.
Can I directly connect (DC couple) a 3.3V LVDS buffer to a 2.5V LVDS buffer?
Quartus require 2v5 vccio for LVDS in Cyclone 10. You can connect device that use 3v3 lvds to that camera connector. mini-PCIe connector has 3v3 iobanks so no LVDS funtionality to there.
Well, Quartus didn't complain about vccio at all.

Unfortunately, the bank that has most of the PCIe lines (bank 4) has no true LVDS transmitters, but can receive.
The bank 6 has dedicated transmitters, but the pairs' p/n lines are splitted up between PCIe and SAMD ports, so of no use.
Cyclone 10 datasheet indeed say that LVDS standard needs 2.5v vccio, but Quartus really doesn't report an error if I assign LVDS inputs on 3.3v bank 4, or input+output pairs in bank 6. And it allows using emulated LVDS with external resistors network on bank 4.
Didn't check if it can really communicate though ![]()
Reading stuff further.
Even if LVDS in 3.3v bank might appear to work, its outputs will be out of specs, not really recommended, and "might damage the buffer".
Inputs should be safe and likely will work as is just fine, but output is totally different beast, and really can fry if vccio is higher than 2.5v
So yeah, either use MIPI connector, or consider using dedicated LVDS transceivers connected with single-ended LVTTL lines.
You can use 2.5 VCCIO for 3v3 LVTTL input if pci clamp diode is disabled or 3v3 LVTTL (4mA) is used as transmitter. Try with 3v3 LVTTL output and LVDS output in same bank.
I think you can verity it from reports what VCCIO it selects there.