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TI to team with Fulton on developing wireless-power-transfer-control ICs

By Margery Conner, Technical Editor -- EDN, 12/8/2008

Texas Instruments has announced that it is working with Fulton Innovation, developer of the eCoupled wireless-power-transfer technology, to accelerate development of efficient wireless-power technologies that can charge portable devices without traditional power cords. TI’s interest in eCoupled is to provide ICs for eCoupled-powered battery-charging systems for low-, medium-, and high-power applications ranging from cell phones to notebook computers to power tools and other rechargeable systems.

According to a Frost & Sullivan interview with eCoupled, the technology analyzes the charge profile of the battery and efficiently transfers the correct amount of energy. It accomplishes this task by constantly changing the operating frequency to seek resonance and adjusts the power transfer accordingly. Tightly coupled primary and secondary coils maximize the amount of power that is transferred.

The eCoupled technology works over distances of inches, not feet. It’s probably safe to say that efficiency decreases as distance increases, but Fulton does not confirm the technology’s efficiency. However, Masoud Beheshti, director of battery-charge solutions in TI’s battery-management-solutions group, says that, based on prototypes that incorporate the wireless-power receivers into handheld devices, the technology can achieve 90 to 95% efficiency, compared with nearly 100% efficiency for an electric power cord. On the other hand, it’s difficult to overestimate the importance of the coolness factor in sales of upper-end cell phones and handhelds. If enough customers are willing to pay a premium to be able to toss their cell phone onto a charging pad at home, office, car, or hotel, then the decrease in efficiency will not be a stumbling block.

And how much of a premium will wireless charging add to a portable device’s cost? Beheshti estimates that the parts will add 20 to 25% to the cost of the power components and 25 to 30% to the cost of the charger. It’s more difficult to come up with an estimate of the additional space that a portable device’s power “antenna” will require; Beheshti believes that figuring how to incorporate the most efficient antenna configuration in the least amount of space—perhaps the PCB (printed-circuit board)—would become part of a device manufacturer’s differentiating intellectual property.

Beheshti says that reference designs should emerge from TI in the next four to six weeks, with parts becoming available in eight to 12 months.