bq2010

The bq2010 Gas Gauge IC is intended for battery-pack or in-system installa-tion to maintain an accurate record of a battery's available charge. The C
monitors a voltage drop across a sense resistor connected in series between the negative battery terminal and ground to determine charge and dischargeactivityofthebattery.


NiMH and NiCd battery self-dis-charge of bq2010 is estimated based on an internal timer and temperature sensor.Compensations for battery tempera-ture and rate of charge or discharge are applied to the charge, discharge, and self-discharge calculations to provide available charge information across a wide range of operating conditions. Battery capacity of bq2010 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 segments are used to indicate graphi-callythenominalavailablecharge.


The bq2010 supports a simple single-line bidirectional serial link to an external processor (common ground). The bq2010 outputs battery information in response to external commandsovertheseriallink.


The bq2010 may operate directly from 3 or 4 cells. With the REF out-put and an external transistor, a simple,inexpensive regulator can be built to provide VCC across a greater numberofcells.


Internal registers of bq2010 include available charge, temperature, capacity, battery ID, battery status, and programming pin settings. To support subassembly testing, the outputs may also be controlled. The external processor may also overwrite some of the bq2010 gasgaugedataregisters.