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.