February 25, 2013, 2:10 PM — Texas Instruments (TI) announced today it will begin shipping wireless charging chips this year that support multiple protocols, allowing a wider range of mobile devices to be charged using competing standards.
The first multi-mode chips are expected later this year, TI said, noting that it would support the Power 2.0 specification being worked on by the Power Matters Alliance, but which has yet to be published.
TI already ships integrated circuits that support the Wireless Power Consortium's Qi (pronounced "chee") standard, but it said its next-generation of chips would additionally support the Alliance For Wireless Power's (A4WP) "flexible wireless power" specification.
The Qi specification is by far the most widely adopted by the mobile industry to date. More than 120 companies already support the standard. TI's current bq500410A Chip allows a Qi-compliant smartphone or other portable devices to charge in a surface area of at least 70mm by 20mm.
The A4WP specification is supported by more than 30 members, including Samsung Electronics, Broadcom, IDT and Qualcomm.
A4WP's specification uses magnetic resonance, while the Qi standard uses magnetic induction. A4WP's specification allows for multiple mobile devices, from tablets to smart phones, to be charged at the same time when placed in a specified are of a charging pad.
The Alliance For Wireless Power shows how magnetic resonance works to wirelessly charge devices.
In contrast, magnetic induction charging techniques require that the mobile device be in contact with a charging surface within a very confined area. Magnetic resonance charging allows a mobile device to be placed in close proximity to the power source for charging, offering more freedom of device placement.
Both magnetic induction and magnetic resonance use two coils -- a transmitter coil and a receiver coil - to transmit power.
Alternating current in the transmitter coil generates a magnetic field, which induces a voltage in the receiver coil. In contrast, resonance charging offers wireless AC transmission to a device at a distance ranging from 5mm to 40 millimeters (about 1.5-in) from the power source.
Resonance charging transmits the power at a greater distance. So, for example, a mobile device could be charged when laid next to a laptop that has resonance charging capability.