I'm using a development kit which is made a camera board and a FPGA board. So far, in this kit, the camera board is directly plugged onto the FPGA board.
I have tested a new code for my FPGA. However, this new design requires a specific hardware where the camera board should be connected using a flexible "cable" to the FPGA board. The length of this cable should be about 150-200 mm. It must carry the following signals:
- 6 differential pairs (LVDS 720 Mbps)
- 9 single wires (1 MHz - 72 MHz).
On the PCB, I used the following specifications for the traces (based on the development kit I'm using):
- differential pairs: 100 Ohms (+- 5 %)
- single ended signals: 50 Ohms (+- 10 %)
So far, I was considering using a cable such as this one. That's the first time I read about micro-coax for LVDS differential pairs but this solution seems appealing to me (also because of the tiny connector they use). Are this type of cables used for LVDS signals around 720 Mbps or are they designed for much lower speed? Are there any other proper solutions to make the connection between the two boards (flex-PCB, ribbon cables,... maybe)?
My last question is more about the PCB layout. If I'm using a cable instead of a direct board-to-board connection between my board, are there any specific points I must take care of in my PCB layout?
I have checked different commercial type cables (comments of MadHatter). The ones I have seen so far do not have enough wires: SATA (2 pairs), HDMI (4 pairs and 7 single wires), USB 3.0 (3 pairs), RJ45 (4 pairs). Even though I could have multiple cables going between the boards, I would like to have the smallest camera board as possible (40x40 mm2). Ideally, I would be happy with one cable for signals, one cable for power (but I did not talk about this one in my initial post since there is no problem with it).