Qi Low Power Specifications

Free download of the specification

The Qi low power specification is available as free public download from this website. See http://www.wirelesspowerconsortium.com/downloads/wireless-power-specification-part-1.html

This document defines the interface for contactless power transfer between a power transmitter and a power receiver, based on near field magnetic induction between coils.

Test specification for members only

The Wireless Power Consortium created two additional documents

• Performance Requirements Specification. This document defines performance requirements for power transmitters and power receivers.
• Compliance Test Specification. This document defines the compliance test procedure for power transmitters and power receivers.

The  Performance Requirements Specification and the Compliance Test Specification are available for members only. To join the WPC see: http://www.wirelesspowerconsortium.com/about/how-to-join.html

Versions of the Qi specification

Version 1.0

• Qi transmitter delivers 5 Watt power into a Qi phone.
• Choice of transmitter designs include single coil transmitter, coil array transmitter, and moving coil transmitter.
• High flexibility in design of Qi receivers
• Limited flexibility in the design of Qi transmitters

Version 1.1

• Increased design freedom for transmitters. You can now choose between 12 different transmitter specifications.
• Increased sensitivity of "Foreign Object Detection". This prevents heating of metal objects in the neighborhood of an active transmitter.
• The possibility to power a Qi transmitter with a USB charger.