Flashback: USB-C, the one cable to rule all of them

The battle for the smartphone wired connector is over and USB-C is the best way ahead. This multi-function port can do nearly all the pieces – it might probably cost gadgets, switch knowledge, deal with audio and video output, it even permits you to plug in equipment.

How did we get right here? Effectively, for years now the European Union has been attempting to coax electronics producers into selecting a standard commonplace to keep away from the mess (and waste) that proprietary connectors create. Early on microUSB was the connector of alternative, however with the arrival of USB Kind C, or USB-C for brief, the business shifted over to the brand new commonplace.

And due to some EU regulation that comes into impact on the finish of 2024, USB-C is mandatory for mainly all moveable electronics (with some exceptions for the smallest gadgets like smartwatches).

Flashback: USB-C, the one cable to rule them all

Most smartphone makers readily adopted USB-C, similar to they did microUSB earlier than that. The one massive holdout is Apple, which nonetheless makes use of Lightning on its iPhones, AirPods and EarPods – that’s it, all the pieces else has moved on to USB-C, together with the distant for the new Apple TV.

We expect Apple’s lineup is an efficient illustration of why USB-C is so good. Lighting is actually a USB 2.0 port. This implies sluggish knowledge transfers when syncing recordsdata between an iPhone and a pc or when transferring RAW pictures from a reminiscence card to an iPad.

Do you know that there’s really a Lightning-based card reader that runs at USB 3.0 speeds? So sooner transfers are potential, however apparently it’s a troublesome feat to tug off and solely iPad Professionals assist it. And even then Apple by no means launched a video adapter than can go above 1080p.

Lightning can be restricted in how a lot energy it might probably carry. The charger for iPhones high out at 30W, whereas Apple’s USB-C charger for the brand new MacBooks can output 140W. Okay, that’s not fully commonplace, but it surely’s not even the utmost that USB-C can carry.

Let’s attempt to hold issues organized and break down the foremost features of USB-C one after the other.


USB began life as a knowledge port. USB 1.0 and 1.1 are canine sluggish and barely remembered now, USB 2.0 remains to be very a lot alive. USB-C has a complete of 24 pins, 12 on either side (properly, 22 pins, however let’s not get slowed down in particulars). Proper within the center is a single D+/D- pair, that’s the info connection of your typical USB 2.0 cable and is necessary for USB-C. This ensures that each one cables can have no less than some connectivity.

The pinout of a USB Type C cable
The pinout of a USB Kind C cable

USB 3 added extra pairs of cables for knowledge switch – there are 4 further pairs in a USB-C plug. Whereas USB 2 is restricted to 480MBps, the additional cabling of a USB-C cable permits 10, 20, 40 and even 80GBps switch speeds.

A fast be aware: the USB-C connector is utilized by USB, in fact, but additionally by Thunderbolt. This distinction is about to vanish as USB 4 is predicated on Thunderbolt 3 and the brand new USB 4 version 2 is predicated on Thunderbolt 4.

One other fascinating utility is carrying PCI-Specific alerts – that is mainly a wired model of the PCIe slots on a pc motherboard. This has enabled exterior GPUs to be related to laptops utilizing a single cable.


One other common use of USB-C is video output. DisplayPort might be the commonest use and USB-C has largely changed the previous, giant DP port. Extra importantly, it’s not knowledge OR video, it’s knowledge AND video AND energy.

This permits a single machine to hook up with a hub that provides a normal HDMI port, a number of USB Kind A and Kind C ports, perhaps a card reader, audio and mic jacks, and many others. Such hubs are constructed into some displays, permitting you as well up a full desktop expertise by plugging in a single cable.

Flashback: USB-C, the one cable to rule them all

That’s fairly helpful for laptops, in fact, however a number of smartphone makers provide desktop modes – Samsung’s DeX, Motorola’s Prepared For, Huawei has one too. Even Apple has one, Stage Manager for the iPad Professionals (which use USB-C, in fact).

There are different choices moreover DisplayPort, MHL and HDMI adapters can be found too. A few of these are lively adapters that convert from one commonplace to a different, however there are easy passive adapters too.


We are going to shortly point out audio right here. USB can energy an exterior DAC which you can plug headphones into. Nevertheless, like with video out there’s a passive choice too – Audio Adapter Accent mode.

USB-C has loads of pins to work with and some of these might be remapped to the cabling wanted for a typical TRRS jack, so a easy passive adapter can join a headset with a microphone. Word that that is purely an analog mode and digital circuits are disconnected to keep away from noise.


The bottom USB commonplace has fairly low energy limits (500mAh for USB 2.0), though most producer’s don’t comply with the usual to the letter so 10W adapters are fairly frequent.

After all, producers need their merchandise to face out and quick charging is a technique to do this, particularly now that smartphone batteries are a number of 3-6,000mAh in capability. This led to many proprietary options like Qualcomm’s Fast Cost and Oppo’s VOOC.

The usual technique, nevertheless, is USB Energy Supply (USB-PD for brief). The preliminary model prescribed a number of voltages and present ranges that might be supported – 2A at 5V, plus 3A or 5A at both 12V or 20V. This gave Energy Supply fairly a variety of 10W to 100W.

Nevertheless, these mounted voltages require DC to DC conversion contained in the cellphone to carry them right down to one thing extra appropriate to the lithium battery inside. USB-PD Revision 2 launched a few extra voltages – 9V and 15V – however that wasn’t sufficient.

Revision 3 permits gadgets to speak to their chargers and request a selected voltage. It could actually vary from as little as 3.3V to as excessive as 21V and it may be dialed in exactly with 20mV steps. Chargers that assist this are marked “Programmable Energy Provide”. This manner the charger is the one coping with the additional warmth, not the cellphone (lithium batteries are don’t prefer it when issues get scorching).

FacetMounted SupplyProgrammable Energy Supply
Fixed Voltage mode5V
5V Prog (3.3 V to five.9 V)
9V Prog (3.3V to 11.0V)
15V Prog (3.3V to 16.0V)
20V Prog (3.3V to 21.0V)
PresentSpherical (PDP/Voltage) to nearest 10mARoundDown (PDP/Prog Voltage) to nearest 50mA
Step DimensionNoneNominal 20 mV
Present Restrict mode NoneSure, nominal 50 mA steps
Periodic RDOs throughout operation No – doesn’t applySure, wanted for PPS operation
Requires Strong Port DesignSureSure

The most recent USB-PD Extended Power Range commonplace add extra mounted voltages – 28V, 36V and 48V. This made the brand new most 240W of energy (48V at 5A), which is sufficient for even beefy laptops (although telephones are already near the 240W restrict). There’s a new Adjustable Voltage Provide choice too, which permits the machine to progressively modify the voltage between 15V and 48V in 100mV steps.

Flashback: USB-C, the one cable to rule them all

Word that for security causes such highly effective cables require a chip referred to as an “e-marker”. This chip alerts to the charger and cellphone (or laptop computer or no matter) that the cable is able to carrying the additional energy.

Some criticism

As a lot as we like USB-C, we are able to’t fake it’s excellent. Our one main grievance is that whereas it has so, so many capabilities, not all gadgets and never all cables assist all the pieces. Loads of the options we talked about above are optionally available.

The worst a part of it’s that it may be very troublesome to determine which gadgets and which cables assist what. The USB-IF is attempting to straighten issues out with new labels that clearly point out how a lot knowledge and energy a given cable can carry.

This also needs to repair our different grievance, the naming scheme grew to be an absolute monster. Do you know that there isn’t a USB 3.0 anymore? That received relabled USB 3.1 Gen 1. However that doesn’t exist anymore both, it’s USB 3.2 Gen 1 now.

Issues received even clunkier with titles reminiscent of USB 3.2 Gen 2×2. Ugh. Fortunately, all that might be changed with the a lot clearer labels: USB 5Gbps, USB 10Gbps, USB 20Gbps and USB 40Gbps (and, presumably, USB 80Gbps quickly). Significantly better.

Flashback: USB-C, the one cable to rule them all

As for energy, there might be two ranges – USB 60W and USB 240W. There received’t be a 100W label since apparently the distinction between 100W cables and 240W cables is sufficiently small that by the point the brand new labels come into play, it received’t make sense to promote 100W cables anymore.

Flashback: USB-C, the one cable to rule them all


USB-C has been nice – we use it to cost our telephones, laptops, headphones, shavers, flashlights and absolutely anything else that has a battery inside and suits in a backpack.

It has allowed us to create comfortable workplaces at our desks with displays, keyboards, mice and so forth all coming to life by plugging in a single cable. And contemplating that the most recent requirements permit it to hold many occasions extra knowledge and energy than the unique specification, USB-C might be not executed evolving but.

Will there ever be a USB-D? Presumably, however not any time quickly. Will the world drop cables and go wi-fi? Most likely not – it’s not an environment friendly method to cost. It’s not nice for knowledge both, 2.4GHz Wi-Fi is already painfully congested in residence buildings and 5GHz is getting fairly crowded too, which has pushed the Wi-Fi Alliance to maneuver into the 6GHz band.

For the foreseeable future USB-C is the one cable to rule all of them.


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