USB-C

What is USB-C Power Delivery?

USB Power Delivery, or USB PD, is how a USB-C charger and a device agree on power. They talk first, settle on a voltage and a current, and only then does the power rise above 5 V. It goes up to 240 W.

By Cords®Updated 3 November 20263 min read

Cords® Cylindric UX1 in Pale Pink under a globe lamp

5 Vwhere every charge starts

20 Vtop of the standard range, up to 100 W

48 Vtop of the extended range, up to 240 W

2012the first version

A conversation before the power

Plug in a USB-C cable and the charger offers 5 V, nothing more. Then the two ends talk over the cable.

The USB Power Delivery handshake: plugged in at 5 V; the charger lists 5, 9, 15 or 20 V; the device asks for 20 V up to 3 A; the charger agrees and switches; 20 V flows — The first moments of a charge, in plain words. The voltage rises only after the device has asked and the charger has agreed.

The charger lists what it can supply. The device picks the one it wants. The charger agrees, switches, and says when it is ready.

This is why a laptop charger is safe for a phone. The phone asks for what a phone needs, and gets no more.

The voltages

Power Delivery works in fixed steps. The standard range runs 5, 9, 15 and 20 V, at up to 3 A on any USB-C cable, and up to 5 A at 20 V on a cable built for it. The extended range, added in 2021, adds 28, 36 and 48 V at 5 A.

15 W

5 V × 3 A

27 W

9 V × 3 A

45 W

15 V × 3 A

100 W

20 V × 5 A

140 W

28 V × 5 A, extended range

180 W

36 V × 5 A, extended range

240 W

48 V × 5 A, extended range

The extended range is for devices that need more than 100 W.

The versions

2012: Revision 1.0, the first version, finalised in July.
2014: Revision 2.0, alongside the USB-C connector, with the fixed steps of 5, 9, 15 and 20 V.
2015: Revision 3.0. The Programmable Power Supply, PPS, was added to it in 2017.
2021: Revision 3.1, in May: the extended range, up to 240 W at 48 V.
2023: Revision 3.2, in October: the Adjustable Voltage Supply, AVS, across the standard range.

A newer charger still talks to an older device. The two settle on what both understand.

PPS and AVS: finer steps

Fixed steps suit most devices. Some phones prefer to set the voltage themselves as they charge. PPS lets them ask in steps of 20 mV. Samsung's Super Fast Charging is built on it.

AVS does the same in steps of 100 mV. Apple's newest Pro iPhones reach their top speed on an adapter with AVS and USB Power Delivery 3.2.

The cable has a say

Every USB-C cable carries 3 A: 60 W at 20 V. Above that, the cable needs a small chip, an e-marker, that tells the charger it can carry 5 A. Above 20 V, it needs to be an EPR cable, marked 240 W on both plugs. Without the right cable, the charger stays below it.

Cords® USB-C Cord A1 in Pale Pink coiled on a marble table — USB-C Cord A1 in Pale Pink and in Jet Black.

Cords® USB-C Cord A1 in Jet Black, coiled — USB-C Cord A1 in Pale Pink and in Jet Black.

USB-C Cord A1 carries 100 W with USB Power Delivery.

Cords® USB-C Cord A1 in Jet Black: its two USB-C plugs, seen from above — USB-C Cord A1100 W with USB Power DeliveryUSB 2.0 data, 480 MbpsBraided, 1 m or 2 mSee USB-C Cord A1

Power Delivery on Cords®

Cylindric UX1 and Cubical C1 use USB Power Delivery 3.1. Both work in the standard range: Cylindric UX1 gives up to 100 W from one port and 165 W across four; Cubical C1 gives up to 65 W.