The ADV7622/3 and ADV7511 have different ARC termination circuits. On the ADV7511, the coupling capacitors are in-line but on the ADV7622, the coupling capacitors are in parallel. Why is this?
The ADV7511 has a three pin ARC architecture – it has two dedicated HEAC pins and a dedicated HPD pin.
The ADV7622/2 has a two pin ARC architecture – the hot plug and one of the arc inputs share the same pin.
This is the reason that the termination circuits are different on both – it is not possible to use series coupling capacitors on the two pin ARC architecture as it would remove the 5V DC HPD level.
The circuits are required to set the correct voltage levels on the ARC inputs.