Source for 0.635 mm Pitch Twisted Pair Flat ribbon needed

.050in doesn't seem to be a problem,

standard Digikey stuff.

Maybe get units straightened out with AliBaba seller?

RL

So you are not old enough to know SCSI U320 internal wiring.

Otherwise Samtec has confectionated FFTP cable but not wide and long enough.

Do you need twisted pair?

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

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.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

. . . . twisted at .025in pitch? Are you sure flat is needed?

If it was common at one time, look to scrap or preasembled stuff.

I see Samtec and 3M both with 0.05in pitch, and have used it.

RL

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

This is a physic experiment with 16 signals per cable, so mostly 34 wire cable is used. Source is perhaps 3 meters away from receiving crate. A first test needs some cables, later more than 1000 signals will be read.

Does anybody know when Hitachi Cable America dropped producing those cables?

Otherwise designing with unobtainium is not good.

Thanks

What did you use the last time you went looking (2022)?

As Don Y suggests, MQT micro quick-twist gets better results.

RL

micro quick-twist was produced by Hitachi Cable Manchester, Inc and is now known as Proterial Cable America, Inc (Wikipedia). I found no trace for something similar to micro quick-twist on their website.

For the 2022 project in the end I had control of everything and could go to 0.05 TP flat ribbon.

For the project now, I am not in control and was only asked to provide cabling. Maybe I can talk to the people providing the other hardware...

So maybe the ebay reel is a stop-gap solution. It's ~ commercially priced at US$5/ft. Old catalogs wanted ~$4.50/ft.

RL

Maybe multiple CAT6s ?

RL