The controlling body for USB – USB-IF has released its USB-C 3.1 Extended Power Range (EPR) standard that supports up to USB-C 240W upstream charging. That should spell the end to proprietary power bricks, plug packs and the detested Surface ribbon.
To be fair, this won’t happen overnight – the 100W upstream limit has been around for some time. It will need new chargers, new cables and new charging protocols. The most significant issue will be to ensure that the cable you use is designated Active and can handle the wattage. It will be backwards compatible with USB 2.0.
But with support from Intel, Microsoft, Apple, Foxconn, Samsung and most OEM laptop and PC makers, we should see it later in 2021.
USB-C 240W – how?
USB-C PS has traditionally used 5V/3A/15W as a base and then negotiates higher voltages like 20V/3A/60W.
The new standard supports up to 48V/5A/240W, so it will need new devices to accept more voltage than the 20V/5A/100W limit. A downside is these cables are likely to be around .5m, whereas USB-C 3.1 Gen 2 can be a metre to transmit 3A. And temperature control of the battery, device and cable will be critical. As a safeguard, cables will carry special markings.
The standard supports
Fixed voltage (SPR) 3A and 5A to 100W
Programmable power supply (PPS), and
Adjustable voltage supply (AVS).
Extended Power Range (EPR) 15V and 28V, 36V, 48V in 100mV steps to 240W
USB-C 240W – Why?
240W is not necessarily an invitation to up thermal design power in CPU/GPU but to make more power available for docks to ensure all ports support maximum downstream power. 240W is already common or high-end gaming notebooks to support discrete GPUs. It will help power printers, monitors, task lighting as well. ERP adoption into the tool, robot and domestic goods markets will enable faster, larger battery packs and even a USB-C kettle.
We will also see more multi-function chargers with more output ports covering QC, OPPO/vivo/realme VOOC, and other types of power. A 240W can support 48 USB-A 5V/1A/5W ports.
And it opens the way for smaller Gallium Nitride (GaN) chargers over the traditional transformer/capacitor bricks.
You can read our guide to USB here. And you can read the 419 page USB-IF document here (it is a PDF, so check downloads).