4
Why do type A and B USB cables have 4 contacts and most mini and micro have 5?
Do the cables actually have 5 wires for mini and micro?
All the mini cables I have have 4 terminals on the A end and 5 on the B (mini) end, so is the 5th just a null connection or does it connect to one of the other 4 connections?
Thanks, I still scratch my head because one end (A) of the cable has 4 contacts and the mini end (B) has 5, is there any schematic of a mini usb cable? Since all standard USB female sockets on PCs are 4 pin, why the fifth on one end if cannot be used. – Moab – 2011-04-16T00:50:35.607
@MoabFollowing the links others provided would have lead you here http://www.maxim-ic.com/app-notes/index.mvp/id/1822 where there is a full explanation with drawings.
– BrianA – 2011-04-16T05:29:53.577Thanks, I did and it does not have a diagram with 4 on the A end and 5 on the B (mini) end. What does this 5th connections do on the mini end, is it null? or somehow connected to the other 4 wires? – Moab – 2011-04-16T14:36:45.010
@Moab The 5th pin is not connected to the other side. It's either shorted to GND (via a resistor) or left not connected. It signals the OTG host whether it should be in host / device mode. – fseto – 2011-04-18T03:19:54.317