2017-06-16 9:33 GMT+02:00 mike.valk@gmail.com mike.valk@gmail.com:
2017-06-16 8:55 GMT+02:00 mike.valk@gmail.com mike.valk@gmail.com:
To the left I see that all HDMI tracks are routed trough some chips. What are those? Magnetics, impedance matchers? I mention that because on the blue tracks the'res a log of extra track for matching track length. maybe that should that be done before those chips.
Just a design thought on track length. Because of impedance matching HF tracks should be of equal length. And to minimize their EM emission the need to run parallel. But when changing direction you get an inner and outer track where the outer track becomes longer. To mitigate that you have those curly lines scattered around, usually at the end. Those cost a lot of room.
Since the schematics already show two layers with HF signal tracks why not place the Tx and Rx track on top of each other. Result: Parallel tracks. And very close to each other. Equal lengths on "curves". And minimize the curly tacks.
I know that this introduces issue when you need tracks crossing. But that could be solved by cross bridging... Hmm how am I going to visualize that in text....
T R x x | | Tx_____ / | | \ / | | o Tx/Rx---< | | >----Rx/Tx o | | / \Rx_____/ | | | |
ASCII art needs monospace font...
Tx/Rx on the left come in stacked. Before the bridge they split Rx passes a via to the Tx layer. leaving the Rx layer free for other tracks to pass on the Rx layer. After the bridge Tx passes the via the the previous Rx layer and Rx continues on the Tx layer, The swapped layers. Both Rx and Tx have passed a keeping a match via count for impedance matching.