interface stratixIV with an external ultrafast comparator

Hi OliB

Desole du retard...

Thanks for those explanation. They are very useful and interesant.

First, the choice of target Stx IV comes from others reasons, not necessarily technical.

1)We are interested on a 8Gbps operation transceiver, so from StxIV datasheet we need to use 0.82V for VCM at the receiver..

2)we would like to focus on the "coupling between comparator/FPGA": From stratixIV datasheet, we understand that the "Absolute VMIN for a receiver pin" (Transceiver input) is (-0.4V) and the "Absolute VMAX for a receiver pin" is 1.6V.

So we cannot directly drive the StxIV transceiver input by the comparator output, its rigth?

Using AC coupling cannot support 8Gbps operation, rigth ?

Shalom