From: llc@fonz.dk   
      
   On 11/12/25 18:24, john larkin wrote:   
   > On 12 Nov 2025 16:15:27 GMT, Uwe Bonnes   
   >  wrote:   
   >   
   >> john larkin  wrote:   
   >>> On 12 Nov 2025 12:55:41 GMT, Uwe Bonnes   
   >>>  wrote:   
   >>>   
   >>>> Hello,   
   >>>>   
   >>>> the usual suspects (Digikey, Mouser, Farnell, etc) and a lot of web   
   >>>> browsing  did not bring up an accessible sources for 0.635 mm twisted   
   >>>> pair Ribbon Flat Cable sold by length beside some Alibaba seller   
   >>>> offering confectionated units.   
   >>>>   
   >>>> Has anybody some hint for a sensible source?   
   >>>>   
   >>>> Thanks   
   >>>   
   >>> Do you need twisted pair?   
   >>>   
   >> The transmitted signals are LVDS going to many Time to digital   
   >> channels. For LVDS signals on a non-twisted pair beside much more   
   >> radiated EMC I only expect double the crosstalk. So probably only near   
   >> coincident events on neighbouring will be affected. Do I miss   
   >> some effect to consider?   
   >>   
   >> But the physics event we want investigate will trigger neighbouring   
   >> channels and their timing relation is important. So fine pitch TP   
   >> would be nice...   
   >>   
   >> Thanks   
   >   
   > If you are concerned about picosecond jitter, TPs may be worth it.   
   >   
   > I'm planning a motherboard-babyboard system with flat fine-pitch   
   > ribbon cables. I plan to use pair-ground-pair-ground in the cables.   
   >   
      
   you can also get, or get made, two layer FFC so you can have a ground   
   plane, and example is the MIPI display cable for a raspberry pi 5   
      
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