Chipset Monitors And Protects Lithium Batteries

Designed for integration into lithium-type battery packs, the bq2081 and bq29311 chipset is said to accurately monitor battery capacity and to provide the primary safety control and voltage balancing functions of the battery cells. The two-chip set is designed for use in portable products powered by three or four series-connected Li-Ion or Li-Polymer battery packs. The bq2081 Smart Battery System (SBS) gas gauge IC and bq29311 Li-Ion protector IC together fit into less than one square inch of board space and reduce the number of components required to monitor and protect the battery packs by as much as 40%. The bq2081 employs, among other things, a continuous self-calibrating ADC and communicates to the bq29311 over a two-wire serial bus. Serving as an analog front-end to the bq2081 and accepting an input voltage of up to 25V, the bq29311 runs directly off the battery stack voltage and delivers a regulated 3.3V to the bq2081. The gas gauge IC comes in a 38-pin TSSOP and costs $4.05 each/1,000 and the protector IC is housed in a 24-pin TSSOP priced at $1.20. TEXAS INSTRUMENTS INC., Dallas, TX. (800) 477-8924, ext. 4500.