TI Presents Impedance Track Gas Gauge Technology

Texas Instruments Inc. (TI, Dallas, TX) announced a unique "gas gauge" technology that calculates remaining capacity in lithium-based battery packs with up to 99% accuracy throughout the entire life of a battery. The new Impedance Track™ technology allows designers and users of portable medical, industrial appliances and notebooks to prolong battery use and always know the exact amount of potential energy left inside the battery.

The Impedance Track technology precisely gauges changes in impedance, or resistance caused by battery age, temperature and cycle patterns, to accurately predict the run time of two-cell, three-cell and four-cell battery packs. The technology, which sits inside TI´s Flash-based bq20z8x gas gauge chipset, analyzes the precise state of charge when a battery pack is in a relaxed state by correlating between a battery pack´s open circuit voltage and the current state of charge and temperature.

The bq20z8x gas gauge chipset with Impedance Track is sampling now. Volume production is scheduled for the fourth quarter of 2004. The chipset is packaged in a 38-pin, thin-shrink small-outline package (TSSOP), and the bq29312 in a 24-pin TSSOP package. Pricing in 1,000-piece quantities is $4.35 each for the bq20z8x and $1.20 each for the bq29312. A second-level protection IC, the bq29400, is also available in an eight-pin DCT package priced at $0.42 each in quantities of 1,000 units.