Why are modern USB cables able to put through more data in the same form factor? Why are some micro USB cables power only, while others can carry data? How is USB-C able to transfer such a large amount of both power and data?
How are we able to do this now, but we weren’t in the past? What’s changed?
In: Technology
The original USB standard only included a single twisted pair of wire for data, with two conductors on each end of the cable. This was fine for 480 megabits per second one direction at a time, but couldn’t scale up much more with the existing standards for cable
The USB 3.0 standard supplemented that with an extra pair for each direction, allowing speeds of 5/10gigabits per second biditectionally. The downside is that for the Micro-usb, this required a different plug, which never gained widespread adoption outside a few devices like the Galaxy S5.
The USB-c connector throws in an (optional) extra set of bidirectional lanes (two pairs in each direction total), allowing a total of 10/20 gigabits per second in the USB protocol standards, but also allows for alternate protocols such as Displayport for video to use one or more of those pairs instead.
>Why are some micro USB cables power only, while others can carry data?
Cost. It’s annoying for the end user, but some manufactures will order cables without data pins if they’re being bundled in with a device that just needs a small amount of power over USB.
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