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Altera_Forum
Honored Contributor
Honored ContributorInternal LVDS for between-board communicatino
Hello, Suppose that I have two boards with Stratix II FPGAs. The boards sit close to each other, and lines from one FPGA reach the other, via a connector. The total length is circa 20 cm (8 inc...
Altera_ForumHonored Contributor
Honored Contributor --- Quote Start --- The two boards do share a common chassis, but their operating voltages and grounds are generated by separate isolated DC/DC converters. Their grounds are definitely close enough to not require AC coupling on the transmission lines. --- Quote End --- A problem may arise, when the LVDS signal ground is the only ground connection between the two systems or even the only existing ground connection at all. Then high intereference currents are attracted by this connection. An additional ground connection and a common mode choke including all data lines and the signal ground (e. g. a ferrite core around the cable) may be advisable.
