How maximum FPC cable distance should I use for MIPI DSI LCD ?

[talel_hajsalem]

Hello,

I'm working on a custom IMX8MM board, and I have an LCD display.

when using a 5cm FPC cable and its working, but when using 10cm or 20cm it does not work.

If I decrement the pixel clock it sometimes work.

How maximum length should I don't pass?

Thanks,

Talel

[igorpadykov · Accepted solution]

Hi Talel

cable length depends on many factors, including cable material, signal losses in board/cable and

connectors, impedance matching, so I am afraid there is no simple formula to calculate. 

One can try to find it experimentally controlling signal quality by oscilloscope or try to perform ibis modelling.

Best regards
igor