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USB-C: An Evolution in Power Standards for Portable Smart Devices

June 11, 2020 by Emily Gray-Fow

The EU is in the process of finalising a law that will force all portable smart devices to use USB-C as the standard for power and data connection.

While this has Apple up in arms (with their favoured Lightning connector and life-long issue with using standard, sensible connectors), many other people have become more and more accustomed to USB-C since its implementation in 2017. For those of us who only recently upgraded to USB-C from its predecessor, Micro-USB (the one with the right way up at the big and small ends of the cable), we might feel mildly vexed.

However, in a world where even the cheapest 'dumb-phones' now come with a Micro-USB connector, it's not so far cry back to the bad old days of having a different connector for every device.

In fact, common sense dictates that a single move by everyone to USB-C is a good idea. There's no 'wrong way up' for the small end of the cable that goes into the device, and it's faster and more secure than the old micro-USB' curved one side and flat the other' cable that could also end up causing damage to devices where it was forced in upside down. 


Common charging components.

OMTP Common Charging Protocol. Image Credit: Pugetbill / CC BY-SA 3.0


Differences for Difference's Sake?

A friend of mine is currently using a phone they found in a kitchen drawer after their smartphone needed repairs. It's a 2007 Sony CyberShot, and the connector on the charger has two flimsy sprung bits of plastic that are 100% essential if the prongs are to work. Due to age, it needs to be held in place with an elastic band, and of course, it's from that era when no mobile charger matched another. 

Another friend of mine, admittedly an extreme Luddite, had to be guided through the fact that the USB cable that came in their new phone box was the charger, and it was up to them to find their USB port or plug to make up the rest of the charger. While this is an extreme example, I feel it's important to point out to the designers and engineers reading this article just how little some people know about technology. This incident took place in 2017!

One Extreme to the Other

On the other extreme, rumours abound that the new EU law may go so far as to ban the bundling of a free charger in with new mobile phones. Even though we're accustomed to getting a charger with a phone, be it new or used, often, the 'free' charger that comes with a new handset is a place for the manufacturer to showcase some new technology such as fast charging. 

Maybe the people who are coming up with these ideas have nightmares about the bad old days when every phone had a different charger. How often have you ended up with a USB charging cable that's worn out, making you move on to the next cable in the drawer? Please, EU, if you ban charger sales, let them still include a new charging cable with every phone!


A close up image of a phone charging port.

A close-up of a smartphone's charging port. 


Once Upon a Time in Charger Land...

Of course, all of this stems from the dawn of mobile phones. Initially, many of these phones really were 'carphones' (thus the store name), with a battery at least the size of a modern laptop (but weighing in at eight times as much or more). My mother had one, and I'm pretty sure the phone end of it ended in a curly cable designed to look like a landline phone (with the 'guts' of the phone and battery stored in the 'suitcase' bit). 

The history of mobile phones is nothing if not complex; almost every new model has its own charger and plug design and essentially, mobile phone companies want consumers to have to buy a charger for any new handsets they purchase, even the latest of a company's own product line could easily feature a unique connector shape.

Frequently there were bits of plastic that might break off, springs that lost their springiness, delicate connections that served to tell the handset that it was connected to a 'genuine' branded charger that would quickly become damaged, among other issues. 

Add to this the number of after-market phone chargers made by assorted 3rd-party manufacturers and you had a recipe for disaster (and a recipe for filling at least one drawer with cables and old handsets in every house). 

It's Not Just About Legacy Phone Handsets

The driving force behind all the different chargers was greed to some extent⁠—especially when a manufacturer changed their charger form every other year. However, the biggest reason for these different chargers was the 'legacy' attitude towards intellectual property surrounding mobile devices at the time. 

In an era where mobile phones and digital devices were on the rise, we were faced with one case after the other in the patent courts. Some of you may remember Apple and Samsung's drawn-out battles against oblong touchscreens, or 'slide to open' smartphones. It's important to make sure the younger engineers of today know about this era, so they can avoid going down a similar path in the future. 


USB Type C cable.

A USB-C type cable.


The First Attempt at Consolidation

In 2009 the EU made the first significant attempt at harmonising charging specifications for mobile devices. The USB standard was chosen, along with the familiar micro-USB connector for the phone end of things.

Known as the OMTP Common Charging Protocol (CCP), the USB2 standard of 5V DC output from a 100V/240V AC source with a standby power of ≤ 0.15 W has been used for almost all mobile devices since then. 

The GSM Association and six of the biggest mobile phone manufacturers at the time signed the 2009 agreement, and up until a couple of years ago, this was the usual standard for mobile devices.  However, USB-C is superior to Micro-USB in many ways, and for the last couple of years, new devices have almost all come with USB-C rather than Micro-USB. 

Surely the Move to USB-C Will Go Smoothly Then?

  • Apple first revealed the USB-C connector to the world in 2015 on the 12-inch MacBook, and since then, it's gone from strength to strength. USB-C has a lot of appealing benefits over Micro-USB:

  • It can pump up to 18W, fast-charging mobile phones from 0%-80% in an hour

  • Its maximum capacity is 100W, and it can charge laptops 

  • It can transfer power both ways⁠—so your phone can charge your tablet or laptop 

  • Data speeds of up to 10Gbps from USB 3.1 cables, double that of USB-C connectors running the USB 3.0 protocol (both are still very fast though compared to Micro-USB's 480 Mbps), fast enough to support video


So, what's all the fuss? For one thing, Apple is still trying to push its in-house Lightning cable for iPhones. You have to stump up for a special charger and cable to use USB-C fast charging with your iPhone. Essentially, they're still stuck in the last decade as far as IP rights and common sense go. 



Whether or not they get a charger with their new devices, consumers will be getting USB-C with everything from now on, so as designers and engineers, we can assume that people will have both the charging plugs and the cables in their homes. Therefore, we should look at some of USB-C's exciting capabilities and start building them into our designs. 

Some of the things we haven't seen much of yet:

  • In-car USB-C or car audio USB-C connectors

  • Hi-Fi with built-in USB-C

  • Video applications for USB-C, especially USB 3.1

  • Device to device transfer cables⁠—these went out of fashion with Bluetooth and NFC, but the speeds available from USB-C make a case for their comeback

  • Applications for charging things with your phone or another portable device

Since we're going to have these connectors everywhere for some time to come, it would be great to see them used to their full potential, so get out there and design something interesting. 

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