bq2050H

The bq2050H Lithium Ion Power Gauge(TM) IC is intended for battery-pack or in-system installation to maintain an accurate record of available battery capacity. The IC monitors a voltage drop across a sense resistor connected in series between the negative battery terminal and ground to determine charge and discharge activity of the battery. Compensations for bat-tery temperature, self discharge, and rate of discharge of bq2050H are applied to the charge counter to provide available capacity information across a wide range of operating conditions.Battery capacity is automatically re-calibrated, or "learned," in the course of a discharge cycle from full toempty.


Nominal available capacity may be directly indicated using a five-segment LED display. These seg-ments are used to graphically indicate available capacity. The bq2050H also supports a simple single-line bidirectional serial link to an external processor (common ground). The 5kb HDQ bus interface reduces communications overhead intheexternalmicrocontroller.


Internal registers include available capacity, temperature, scaled available energy, battery ID, battery status, and Li-Ion charge FET status. The external processor may also overwrite some of the bq2050H powergaugedataregisters.


The bq2050H can operate from the batteries in the pack. The REF out-put and an external transistor allow a simple, inexpensive voltage regulator to supply power to the circuit fromthecells.