eli5 Why is USB-c a better connector than micro-usb, or even regular usb?


Besides the obvious reasons (it’s smaller than usb and can work both angles of insertion unlike micro-usb), why is usb-c considered superior? I understand it’s more able to handle fast charging and better data transfer, but what are the mechanics behind that?

In: 3

It’s better because it doesn’t use a latching mechanism for one to secure the cable. That was the number one killer of ports on devices that used them, it was a terrible design.

Next there’s the bandwidth and power capabilities, a new spec can dictate standards that can be added, ergo higher charge rates with device and charger negotiation was born.

Best of all, do finally a reversible plug. Can go in any orientation and if it’s USB-C on both ends, either end works (there are those novelty cables where it does but those aren’t following spec).

It’s small, it’s reversible, and it’s designed for a long connector life (the part that wears out most, the retention springs, are on the cable side)

It also has enough pins for USB 3 data use, unlike the 2.0 micro-b connector, and includes additional contacts that can be used for features such as dual high speed lanes (up to 20gbps with Gen2x2), Thunderbolt, VirtualLink, Displayport, or other protocols. (The usb-c connector can use up to 4 superspeed pairs, instead of the 0 on the 2.0 micro b connector)

It’s smart.

Notice how old cables have USB A on one side and some version of USB B on the other, but now cables just have USB C on both sides? That’s because old USB was dumb. If the port is wired up to send power, it *will* send power regardless of how the other side is wired up. If you aren’t careful, you’ll send power to something that is also trying to send power and something ends up fried.

So industry standard was: USB A to send power, USB B to receive power. That way ordinary people physically cannot accidentally fry something.

But with the new USB standard, the two sides negotiate with each other. They figure out which way to send power first before actually fully sending it. So now you can have the same connector on both ends.

The old USB connectors have four electrical contacts. Data positive and negative, ground and power. With the latest USB 2 standard we were at the limit of what was possible with this and still be backwards compatible. For high speed data transfers we needed a new type of data cables based on AC technology rather then the old DC technology. The equipment at either end would not be backwards compatible. So for USB 3 there are separate high speed data contacts, one in each direction. That means a minimum of four extra contacts. The old data contacts were kept for backwards compatibility. For high power delivery it is important that the device and charger is able to be in constant communication so they can negotiate the voltage and current at any time as well as test if there are any issues with the cable or connectors. In the older standards this was added on to the existing wires but this was hard to implement. So when redesigning the connector and cables anyway they added a dedicated power communication connector as well.

The first thing they did was to cram these five contacts into the back of the USB-A connector. You can actually see this in USB-3 enabled USB-A connectors as they have four contacts in the front and then five more in the back. But for micro-USB there were not enough room. The first attempt was to make the connector wider with an USB-3 section to the side. But this made it longer then the USB-A connector and even more fragile. So they ended up redesigning the entire connector into the USB-C connector and fitted a lot more contacts into it. Not only for USB-3 but also future proofing it with more contacts which have enabled it to be used for things like thunderbolt and USB-4 as well.

When miniaturizing USB was first attempted, there were features that had to be sacrificed, so they would have slower data transfer, lower power, and latches that were more prone to breaking. Because of this we had to keep creating new USB types in order to accommodate new devices and their requirements

Now, technology has improved to the point where we can pack all the features we need into a small cable like USB C. To give some context, I had an external GPU for a laptop made in 2013. The data cable to connect the GPU to the laptop has a connector that is over an inch wide. Now, you would use thunderbolt, which uses a USB C socket.

Since there are no real downsides to using USB C in most situations, it makes sense to use it for as many cases as possible just for convenience. Every device I own uses USB C, so I can use the same chargers for anything from a laptop to game consoles, or even rechargable double A batteries, when before I would have had to spend several minutes hunting down some niche cable type. I can also use the same cables to plug in displays or transfer data if I need to