Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

3.3V VCCIO for Emulated LVDS (Max V)

I understand how the three resistor termination works to emulate LVDS with the MAX V and other devices that do not have true LVDS. All of the examples seem to imply that the IO supply needs to ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

The common mode voltage of 3.3V supplied LVDS_E_3R is oustside the LVDS specification, but it would be tolerated by most LVDS receivers. Ultimately you'll add bias resistors to achieve the specified 1.125 V to 1.375 V output common mode voltage.

20 ohm is a good guess for driver output resistance. For an exact specification of output characteristic and expectable type variation, refer to to MAX V Ibis files.