Release of USB Power Delivery specification Revision 3.1

The USB Promoter Group, composed of Apple, Hewlett-Packard, Intel, Microsoft, Renesas Electronics, STMicroelectronics and Texas Instruments, has announced the release of the USB Power Delivery (USB PD) Revision 3.1 specification — a major update to enable the delivery of up to 240 W of power over the USB Type-C cable and connector. Prior to this update, USB PD was limited to 100 W via a solution based on 20 V using USB Type-C cables rated at 5 A.

The USB Type-C specification has also been updated with Release 2.1 to define 240 W cable requirements; with the updated USB PD protocol and power supply definition, this extends the applicability of USB PD to a large number of applications where 100 W wasn’t adequate.

The new USB PD architecture defines a much more stringent power negotiation protocol that helps to ensure that access to and use of this higher power capability can be done safely. It should be noted that safety requirements for products that use power in the range of 100–240 W are also more stringent than lower power products and are defined by the applicable safety specifications dictated by the regulations for each country where the products will be sold.

“With the new capabilities of USB Power Delivery 3.1, we now enable higher power products such as larger notebook PCs to shift from traditional power connectors to USB Type-C,” said Brad Saunders, USB Promoter Group Chairman. “We also anticipate a wider range of product application developers outside of the traditional USB ecosystem to now consider standardising on USB Type-C with USB PD.”

Key characteristics of the USB PD 3.1 specification include:

• A choice of three new fixed voltages: 28 V (above 100 W), 36 V (above 140 W) and 48 V (above 180 W) joining previously defined 5, 9, 15 and 20 V fixed voltages.
• A new adjustable voltage mode enabling a range from 15 V to one of three maximum voltages (28, 36 or 48 V) depending on the available power allowing the device being powered to request specific voltages to a 100 mV resolution.
   

This update is part of the USB performance roadmap and is specifically targeted to developers at this time. Branding and marketing guidelines are being established and will include a new cable labelling solution to inform users of the power capability supported by Certified USB Type-C cables.

“Always responsive to the market’s need for a higher-power, truly universal bus connector, the USB Promoter Group has again been quick to recognise and adapt its specifications for charging capability to anticipate customer requirements, potentially creating new markets for USB Power Delivery,” said Matteo Lo-Presti, Executive Vice President, Analog, Sub-Group General Manager, Analog MEMS, and Sensors Group, STMicroelectronics.

“The 3.1 revision to the USB Power Delivery specification, which includes the capability to provide up to 48 V and 240 W of power, will help enable additional design opportunities for current and new users of USB Type-C technology,” added Deric Waters, senior member of technical staff at Texas Instruments.

Image credit: ©stock.adobe.com/au/Talaj

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