bq2092 Datasheet | UNITRODE

Gas Gauge IC with SMBus-Like Interface Features - Provides accurate measurement of available charge in Ni Cd, Ni MH, and Li-Ion rechargeable batteries - Supports SBData charge control mands for Li-Ion, Ni MH, and Ni Cd chemistries - Designed for battery pack integration - 120µA typical operating current - Small size enables implementations in as little as 3 4 square inch of - Two-wire SMBus-like interface - Measurements pensated for current and temperature - Programmable self-discharge and charge pensation - 16-pin narrow SOIC General Description The bq2092 Gas Gauge IC With SMBus-Like Interface is intended for battery-pack or in-system installation to maintain an accurate record of available battery charge. The bq2092 directly supports capacity monitoring for Ni Cd, Ni MH, and Li-Ion battery chemistries. The bq2092 uses the SMBus protocol that supports many of the Smart Battery Data (SBData) mands. The bq2092 also supports SBData charge control. Battery state-ofcharge, capacity remaining, remaining time and chemistry are available over the serial link. Battery-charge state can be directly indicated using a four-segment LED display to graphically depict battery full-toempty in 25% increments. The bq2092 estimates battery selfdischarge based on an internal timer and temperature sensor and user-programmable rate information stored in external EEPROM. The bq2092 also automatically recalibrates or “learns” battery capacity in the full course of a discharge cycle from full to empty. The bq2092 may operate directly from three nickel chemistry cells. With the REF output and an external transistor, a simple, inexpensive regulator can be built to provide VCC for other battery cell configurations. An external EEPROM is used to program initial values into the bq2092 and is necessary for proper operation. Pin Connections SEG1 SEG2 SEG3 SEG4 VOUT...