IDC connector vs ribbon pitch

Which drawing? A quick Digikey search turns up, e.g., 10150-8000EE which is a .050" IDC Wiremount Plug which Mass terminates to .025" pitch flat ribbon cable. The drawing shows .025 contact spacing on the wire side. Still, people do make mistakes on drawings every day so there certainly could be one out there with incorrect dimensions.

tch. 3M advertises their MDR series of connectors as being 0.050" pitch, w hich is the horizontal pitch between connector contacts. However, these Ce ntronics style connectors have two rows (an upper and a lower row).

don't understand how an IDC connector with two rows of 0.050" pitch contact s (effective pitch of 0.025") can use a 0.050" pitch ribbon cable. Do MDR connectors take two 0.050" ribbon cables, on one top of another?

Hi Rich,

Thanks for your response. I'm interested in the 3M 10236-0210EC (Digikey # MRB36A-ND), which is a 36-contact, 0.050" IDC Wiremount Receptacle. The dr awing on page 2 of their datasheet shows a 0.050" contact spacing, but I do n't see how this can be. A 36-wire, 0.05" pitch cable should be (36-1)*0.0

5" = 1.75" wide. But the table in the datasheet says that the connector dimension "D" for this part is only 1.05". I don't see how a 1.05" wide co nnector can accommodate a 1.75" wide cable.

Doug

There's a top row and bottom row of the connector; so, the connector width A (from center of first to center of last contact) is (18-1)* 0.05"= 0.850 just as the drawing shows. The pitch of the WIRES is 0.025", the even wires mate with a bottom-row and the odd ones with a top-row connector pin.

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Thank you, that's what I was afraid of. A 0.025" ribbon cable is a pretty fine pitch. I used a vise to attach some IDC connectors to one once and en ded up misaligning them and connecting the wrong wires. Is it possible to use two 0.050" ribbon cables, one for the top row and one for the bottom ro w?

pin.

y fine pitch. I used a vise to attach some IDC connectors to one once and ended up misaligning them and connecting the wrong wires. Is it possible t o use two 0.050" ribbon cables, one for the top row and one for the bottom row?

I suspect not. Both SCSI cables and 80-wire parallel ATA cables use this fine-pitch ribbon, so the problem has been around for a decade or two now. It helps to have a stereo microscope (or at least a jeweler's loupe) and a strong light. It also helps to buy prebuilt cables...

r pin.

tty fine pitch. I used a vise to attach some IDC connectors to one once an d ended up misaligning them and connecting the wrong wires. Is it possible to use two 0.050" ribbon cables, one for the top row and one for the botto m row?

.

That's getting pretty fine for me to work with. I might have to look at a larger connector that can accept a 0.050" pitch ribbon cable. Thanks very much for your help. Doug

ch. 3M advertises their MDR series of connectors as being 0.050" pitch, wh ich is the horizontal pitch between connector contacts. However, these Cen tronics style connectors have two rows (an upper and a lower row).

on't understand how an IDC connector with two rows of 0.050" pitch contacts (effective pitch of 0.025") can use a 0.050" pitch ribbon cable. Do MDR c onnectors take two 0.050" ribbon cables, on one top of another?