TECHNOLOGY NEWS: ELECTRONICS
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Suited for powering mobile medical devices, a dc/dc boost convertor can draw power from solar and micro fuel cells.
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Portable equipment designers, including those in the medical product field, have been looking at applying solar and fuel cell technology to their devices to extend battery life and differentiate their products, says Uwe Mengelkamp, director of the dc/dc convertor product line at Texas Instruments (TI, Munich, Germany). To this end, TI has introduced a low-input-voltage dc/dc boost convertor that enables portable electronic equipment to draw power from alternative power sources such as solar and micro fuel cells.
Capable of charging a lithium battery using a single solar cell, the TPS61200 boost convertor could be used to charge portable devices with ambient lighting. “Assuming the solar cell on a portable device is big enough to supply power to the application during the day, enough energy can be stored in the device’s rechargeable battery during the day to supply the application during the night,” explains TI spokesperson Matt McKinney.
Although micro fuel cells have yet to find their way to the marketplace, they are predicted to become mainstream by around 2010, according to Paul Zimmerman, CEO of micro fuel cell developer Angstrom Power Inc. (North Vancouver, BC, Canada). Possible medical applications of micro fuel cells include point-of-care testing equipment and other portable medical devices. “Several companies around the world are currently working on micro fuel cell products,” says McKinney. “If you consider standard development cycles, this would imply that the design start for consumer applications is now, or has already happened.”
The convertor’s support of alternative power sources is the result of its ability to operate with high efficiency at input voltages less than 0.3 V. “Before the TPS61200, there was not a dc/dc convertor on the market that could support the low input voltages needed to convert power from a single solar cell or micro fuel cell,” McKinney says.
Housed in a 10-pin 3 × 3-mm QFN package, the TPS61200 is suitable for a variety of general-purpose medical devices powered by alkaline, nickel-cadmium, nickel–metal hydride, or one-cell lithium batteries. “We anticipate that it will be used in portable, battery-powered applications such as blood glucose meters, blood pressure monitors, and also digital thermometers.” In addition, the unit could be used in emergency mobile medical devices used outside of the hospital environment. “We see enormous potential for this type of device because of its capability to operate at very low input voltages, and open the door to innovation with low-power energy sources,” McKinney says.
