TI Wi-Fi Chip Conserves Battery Power

Texas Instruments has unveiled a low-power chip designed to support power-hungry Wi-Fi adapters while still providing the fast, untethered Internet access that the wireless spec promises.

Power-hungry WiFi adapters can take a big bite out of battery life, especially for smaller portable devices such as PDAs. The new WiFi chip, the TNETW1100B, is said to consume a tenth or less of the standby power of competing chips. Since most Wi-Fi-enabled devices spend the vast majority of time in standby or other non-operational modes (TI estimates most devices spend 95 percent of their time in such "rest periods"), the new chip should substantially prolong battery life.

The savings will be most pronounced for PDAs and other small portable devices for which a wireless LAN adapter accounts for a larger proportion of overall power consumption than it does in, say, a notebook PC. TI expects to ship the TNETW1100B in volume by year-end. Products using the new chip should be available late this year or early in 2003, says Dan Nemits, TI product manager.

A Quarter Savings

Nemits points to the company's tests of the chip's efficiency. A PDA equipped with the new chip that receives 8MB of data and transmits 3.2MB over an eight-hour period will consume an average of 178.7 milliamp-hours of energy per hour, Nemits says. Of that, 3.7 mAh will power the wireless adapter. In contrast, the same PDA outfitted with a competing WiFi chip will consume an average of 239 mAh per hour, including 64 mAh for the wireless LAN adapter, Nemits says.

The result is a 26 percent decrease in battery life when using the competing chip, he adds. With notebooks, the battery life was only about 7 percent less with the competing chip, according to TI's tests.

For New, Existing Devices

The TNETW1100B comes in two form factors: a new 12-by-12mm package specifically designed for small portables with integrated WiFi capability, and a more traditional 16-by-16mm package (so vendors can use it to in existing devices). The new chip is also cheaper than its predecessors, so vendors now only have to spend about $20 on the materials for a WiFi adapter, compared to "the high 20s" only six months ago, Nemits adds.

"We're whittling down the barrier to getting this technology into different things," Nemits says.

The new chip also supports the 22-mbps technology TI introduced earlier this year in a WiFi chip now being used by D-Link and US Robotics, among others.