Fine pitch twisted pair ribbon cable

It's usually mfred with a defined distance between 'flattened' sections - required for automated termination.

The 0.635mm pitch? That's 0.025in in 'merkin.

I see your problem.

Hitachi stopped producing it? Says who?

RL

Collegues at another institute that try to order.

Bye

There are 21 types of (0.025) micro-twist cable.

I see discontinued notices for only 5 of these types.

Effective Date March 1, 2022

Product - Micro Quick Twist Series

TPO MQT 20051-068,

TPO DLMQT 20095-068, 20096-068,

?? 20293-068,

MQT 20050-068, 23195-068

The -68 may refer to the conductor count.

There are other varieties of the same TPO MQT, TPO DLMQT and MQT cables in the catalog, not to mention conductor counts, but I see that MQT products are no longer linked in the general sales blurbs.

RL

Do you really need twisted pair? For differential data, likely not.

Yes, it is intended for differential data with LVDS level on many neighbouring pairs. Electrical coupling is probably not an issue with LVDS and the way the pairs are twisted does not decrease electrical coupling substantial. But magnetic coupling is nearly canceled out and I think has influence.

What is your reasoning that differential data does not profit from twisted pairs?

Thanks

How about 3M? Not sure about the fine pitch, though.

Just that the coupling between flat pairs may not trash the data enough to matter. It might be easy to try.

I generally use flat cable with a ground (or an AC ground, like a power supply) between pairs. That's more prudence than known necessity. It might have less crosstalk than between adjacent twisted pairs.

Not twisted.

RL

We have the Hitachi 20096-068 cable you've mentioned IN STOCK. Chris Schwartz CS Electronics

We have this cable in stock. Chris Schwartz

It looks like that cable has pairs with identical twist pitch but alternating twist sign. Unshielded ethernet cables usually have different pitches in the pairs to minimize crosstalk, at the price of different prop delay per pair.

The choice to go to twist vs flat cable depends heavily on cable length and data speeds. Flat is a lot cheaper and easier; just order your jumpers from Mouser.