I am implementing ESD protection for HDMI video input. The HDMI video goes through a custom cable of ours, into a connector board attached to our enclosure, through an edge card connector, into our main board and into the receiver chip.
I usually add the ESD protection circuit on our connector board because that's the first part where the high speed signals make contact from a cable to a board.
Would it be bad practice to add another ESD protection circuit on the main board since the signals will go from the connector board to the main board via edge card connector?
I'm worried that adding extra capacitance to the high speed signals will cause signal integrity issues and that it will be overkill.