Texas Instruments BQ2010SN-D107

NiCd/NiMH gas gauge with 1-wire (DQ) interface and 5 LED drivers 16-SOIC 0 to 70

5mA 3V 6.5V Battery Monitor SOIC-16 9.9mm*3.91mm*1.58mm

The bq2010 Gas Gauge IC is intended for battery-pack or in-system installation to maintain an accurate record ofa battery's available charge. The IC monitors a voltage drop across asense resistor connected in series between the negative battery terminal and ground to determine charge and discharge activity of the battery. NiMH and Ni Cd battery self-dis-charge is estimated based on an internal timer and temperature sensor. Compensations for battery temperature and rate of charge or discharge are applied to the charge, discharge, and self-discharge calculations to pro-vide available charge information across a wide range of operating con-ditions. Battery capacity is automatically recalibrated, or "learned," in the course of a discharge cycle from full to empty. Nominal available charge may be directly indicated using a five- or six-segment LED display. These seg-ments are used to indicate graphically the nominal available charge. The bq2010 supports a simple single-line bidirectional serial link to an external processor (commonground). The bq2010 outputs battery information in response to external commands over the serial link. The bq2010 may operate directly from 3 or 4 cells. With the REF output and an external transistor, a sim-ple, inexpensive regulator can be built to provide VCC across a greater number of cells. Internal registers include available charge, temperature, capacity, battery ID, battery status, and programming pin settings. To support subassembly testing, the outputs may also be con-trolled. The external processor may also overwrite some of the bq2010gas gauge data registers.