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The wires count is suspect. USB 1.0-2.0 only use two wires for data (the other two are ground and power). USB 3.0 uses 4 for data (plus extra shield, 2 for USB
by gblargg 6mo ago
The wires count is suspect. USB 1.0-2.0 only use two wires for data (the other two are ground and power). USB 3.0 uses 4 for data (plus extra shield, 2 for USB 2.0 and 2 for power). I don't know well enough the others.
- Liftyee 6mo agoThe wires count seems to be the number of conductors in the cable (i.e. the number of wires you'll find if you cut a cable in half, including ground and power). It's true that the actual data is sent over a lower number of diffpairs. I suspect the shield is not included in the number of wires, since all USB cables have a shield (not sure if usb 3.0 has an extra return ground wire for high speed).
- crote 6mo agoIt still would't be right. Full-featured USB-C has 8x superspeed (tx1p, tx1n, rx1p, rx1n, tx2p, tx2n, rx2p, rx2n), 2x high-speed (dp, dn), 2x power (vbus, gnd), 2x SBU, 1x CC. That's 15 wires.
- adrian_b 6mo agoA full-featured USB-C connector has 24 pins, as shown in a diagram in the parent article. The "12-wire" count of the parent article refers only to the main wires, i.e. the 4 USB 2.0 wires + 4 differential pairs for USB 3 or 4. Similarly, the "8-wire" count for Type A connectors refers only to the main wires, i.e. 4 USB 2.0 wires + 2 differential pairs for USB 3.
- crote 6mo agoYes, but not all of those 24 pins are used, and some of them are duplicated. I also don't think you can make this "main wire" distinction: you shouldn't be counting the power wires if you only care about USB data in the Type A case, and you should arguably be counting the CC wire in the Type C case if you want to go for "strictly necessary to function", or the SBU wires if you want to go for "carries data at nontrivial speeds".