How to verify LVDS level compactibility between two ICS

[dssurya]

Hi,

I have got two LVDS support ICs , attached the voltage level specification. One IC LVDS supply voltage is 2.5V and other IC LVDS supply voltage is 1.8V. They mentioned differential voltage and input voltage range instead of common mode input for 1.8V supply LVDS IC. How to verify whether the mentioned voltage level supports other IC ?
 

[langwadt]

LVDS is LVDS

[dssurya]

Hi langwadt,
         I am asking about the voltage levels whether 1.8V IC specification meets the 2.5V IC? Refer the attachment

[ataradov]

LVDS is a well defined standard. It does not matter what is the supply voltage of the ICs. They will output and accept the same voltage levels on the LVDS lines.

And in your case 1.8 V one seems to be adjustable for some reason, so you will need to configure it to output standard LVDS levels.

The first IC is pretty much the standard LVDS, so you just need to adjust the 1.8 V one to be the same as the first one.

[xvr]

Maximum output voltage from 2.5V LVDS is 1.375+0.450/2 = 1.6V. Maximum allowed input for 1.8 LVDS is 1.575V. This is 25mV of excess 
It could work if you will be lucky enough 

[ataradov]

Where does 0.405 come from? 1375 mV is the maximum output voltage. The output is 1200 mV +/- 175 mV, so differential voltage is 350 mV, so it is just a standard LVDS.

LVDS is LVDS no vendor will design it to be incompatible.

[xvr]

Where does 0.405 come from?

From picture #1 of OP.

1375 mV is the maximum output voltage.

It's a maximum common voltage, not output (from picture #1)

The output is 1200 mV +/- 175 mV, so differential voltage is 350 mV,

This is 'typical' value from picture #1, not 'maximum'

[ataradov]

Ok, similar numbers are present in two different places.  So, if things go absolutely wrong on the 2.5 V side, it is technically would not be compatible with 1.8 side. I personally would not think about that twice for any volume project.