FEATURES
Reports Accurate State-of-Charge in Li-Ion
and Li-Pol Cells, No System Processor
Calculations Needed
Communicates Directly With the Integrated
HDQ Engine in TI OMAP
Processors
Reports Cell Temperature and Voltage
High-Accuracy Coulometric Charge and
Discharge Current Integration with
Automatic Offset Cancellation
Requires No Offset Calibration
Programmable Input/Output Port
Internal Time-Base Eliminates External
Crystal Oscillator
Four Automatic Low-Power Operating Modes
− Active: < 100 μA
− Sleep: < 2.5 μA
− Ship: < 1.7 μA
− Hibernate: < 1.5 μA
Small 8-Pin TSSOP Package

APPLICATIONS
PDAs
Smart Phones
MP3 Players
Digital Cameras
Internet Appliances
Handheld Devices

DESCRIPTION
The bq26501, the first in the bqJUNIOR family
of advanced gas gauge device for handhald
applications, is a highly accurate standalone
single-cell Li-Ion and Li-Pol battery capacity
monitoring and reporting device targeted at space
limited portable applications. The device monitors
a voltage drop across a small current sense
resistor connected in series with the battery to
determine charge and discharge activity of the
battery. Compensations for battery temperature,
self-discharge, and rate of discharge are applied
to the charge counter to provide available capacity
across a wide range of operating conditions.
Battery capacity is automatically recalibrated, or
learned, in the course of a discharge cycle from full
to empty. Internal registers include available
capacity, cell temperature and voltage,
state-of-charge, and status and control registers.
The bq26501 can operate directly from single-cell
Li-Ion and Li-Pol batteries and communicates to
the system over a simple one-wire bi-directional
serial interface. The 5-kbits/s HDQ bus interface
reduces communication overhead in the external
microcontroller.