What is USB-PD?

Here’s a new term you might not have heard about. You’ve noticed it in Solid Signal’s line of PD-enabled accessories. You might be asking yourself what’s so special there. PD is something you’ll really want to look for in the coming months.

PD stands for Power Delivery

We all hate power cords. At least it seems like we do. Not only that, we want to charge things quickly. This is a problem because your standard USB cord coming out of a computer delivers only about 2.5 watts of power. That’s not going to be enough to get that phone charged up as quickly as you want. A “cube” style charger will give you about 5 watts. Fast chargers using regular USB cords can up that ante to 12 watts, meaning you can charge twice as fast. Even regular USB-C cords can only charge your phone at 15 watts. That’s great but it’s not much of an improvement.

That’s where USB PD comes in. It’s a smart standard that lets a USB type C port supply up to 100 watts of power. Yes, 100 watts. That’s enough to power a non-gaming PC or even a large monitor. It’s also enough to fry a cell phone if it’s not used properly.

How a regular charger works

Regular phone chargers, just like all electrical devices, supply consistent voltage and variable amperage. In the case of a phone charger, it’s supplying 5 volts and however many amps the device can draw, up to its maximum rating. This is done fairly unintelligently. The device’s power supply simply pulls current as needed and if the charger can supply it, it does. That’s how pretty much every electrical appliance works.

How PD works

If a USB port is configured for PD, it will start by delivering a safe amount of power. The connected device will then communicate how much power it needs and that’s how much power will be supplied.  This allows for more efficiency, better power and cost management, and ensures that a connected device won’t get more current than it can handle.

If a connected device isn’t PD-compatible, it’s assumed that it can accept the 15 watts that is standard for USB-C. So, PD is a backward compatible standard.

An interesting feature is that PD can actually work either way. Your computer can charge your phone, but your phone could technically charge your computer if it had enough battery to do it. PD can switch intelligently between providing a lot of power and providing high-speed data, and in the case of something like a monitor, it could provide both at the same time.

PD takes the place of…

PD is a standard which should render two more Apple standards obsolete. Apple’s laptops use USB C for power, and use the Thunderbolt standard over USB-C to provide fast data to monitors and other devices. PD could bring Apple into compliance with other manufacturers. That would make it easier to provide Apple devices with more options for cables and charging.

If Apple finally ditches its proprietary Lightning standard for USB-C PD, you could finally see one charger that rules the cell phone world. After so many years of waiting, that would be… very nice.

What will PD do for you today?

Unless you have a fairly new phone, PD isn’t going to do a lot. According to Android Authority, these phones support PD in the winter of 2019-20:

  • Asus Zenfone 6
  • Doogee S90
  • Google Pixel 3
  • Google Pixel 3 XL
  • Google Pixel 3a
  • Google Pixel 3a XL
  • Google Pixel 4
  • Honor View 20
  • Huawei Mate 20
  • Huawei Mate 20 Pro
  • Huawei Mate 20 X
  • Huawei Mate 30 Pro
  • Huawei P20 Pro
  • Huawei P30
  • Huawei P30 Pro
  • LG G8X
  • LG V30
  • LG V40
  • Nokia 7.1
  • Nubia Red Magic Mars
  • OnePlus 6T
  • OnePlus 6T (McClaren)
  • OnePlus 7 Pro
  • Realme X
  • Realme XT
  • Samsung Galaxy Note 8
  • Samsung Galaxy S10 (Exynos)
  • Samsung Galaxy S10+ (Snap)
  • Samsung Galaxy S10e (Exynos)
  • Samsung Galaxy S9+
  • Xiaomi Mi 8 Lite
  • Xiaomi Mi 9

Most of these are pretty obscure phones. For regular folks it boils down to the latest Galaxy and Galaxy Note, plus the Google Pixel 3 and all other Pixels after that. The LG V30 and V40 are also fairly popular and you might have one of those.

However, expect that list to grow a lot over the next 12 months, and I project that most new phones will support PD by the end of ’20.

About the Author

Stuart Sweet
Stuart Sweet is the editor-in-chief of The Solid Signal Blog and a "master plumber" at Signal Group, LLC. He is the author of over 5,000 articles and longform tutorials including many posted here. Reach him by clicking on "Contact the Editor" at the bottom of this page.