RTT
DBT
SLUS732 – SEPTEMBER 2006
www.ti.com
SBS v1.1-COMPLIANT GAS GAUGE FOR
USE WITH THE bq29312
FEATURES
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Provides Accurate Measurement of Available
Charge in Li-Ion and Li-Polymer Batteries
Supports the Smart Battery Specification
(SBS) V1.1
Integrated Time Base Removes Need for
External Crystal with Optional Crystal input
Works With the TI bq29312 Analog Front-End
(AFE) Protection IC to Provide Complete Pack
Electronics for 7.2-V, 10.8-V or 14.4-V Battery
Packs With Few External Components
Based on a Powerful Low-Power RISC CPU
Core With High-Performance Peripherals
Integrated Flash Memory Eliminates the Need
for External Configuration EEPROM
Uses 16-Bit Delta Sigma Converter for
Accurate Voltage and Temperature
Measurements
Measures Charge Flow Using a High
Resolution 16-Bit Integrating Converter
– Better Than 0.65-nVh of Resolution
– Self-Calibrating
– Offset Error Less Than 1-µV
Programmable Cell Modeling for Maximum
Battery Fuel Gauge Accuracy
Drives 3-, 4-, or 5-Segment LED Display for
Remaining Capacity Indication
Available in a 38-Pin TSSOP (DBT) Package
DESCRIPTION
The bq2084-V143 SBS-compliant gas gauge IC for
battery pack or in-system installation maintains an
accurate record of available charge in Li-ion or
Li-polymer batteries. The bq2084-V143 monitors
capacity and other critical parameters of the battery
pack and reports the information to the system host
controller over a serial communication bus. It is
designed to work with the bq29312 AFE protection
IC to maximize functionality and safety and minimize
component count and cost in smart battery circuits.
Using information from the bq2084-V143, the host
controller can manage remaining battery power to
extend the system run time as much as possible.
The bq2084-V143 uses an integrating converter with
continuous sampling for the measurement of battery
charge and discharge currents. Optimized for
coulomb counting in portable applications, the
self-calibrating integrating converter has a resolution
better than 0.65-nVh and an offset measurement
error of less than 1-µV (typical). For voltage and
temperature reporting, the bq2084-V143 uses a
16-bit A-to-D converter. With the bq29312, the
onboard ADC also monitors the pack and individual
cell voltages in a battery pack and allows the
bq2084-V143 to generate the control signals
necessary to implement the cell balancing and the
required safety protection for Li-ion and Li-polymer
battery chemistries.
The bq2084-V143 supports the Smart Battery Data
(SBData) commands and charge-control functions. It
communicates data using the System Management
Bus (SMBus) 2-wire protocol. The data available
include
the
battery's
remaining
capacity,
temperature, voltage, current, and remaining
run-time predictions.
The bq2084-V143 provides LED drivers and a
pushbutton input to depict remaining battery capacity
from full to empty in 20%, 25%, or 33% increments
with a 3-, 4-, or 5-segment display.
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APPLICATIONS
Notebook PCs
Medical and Test Equipment
Portable Instrumentation
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2006, Texas Instruments Incorporated
TI [ TEXAS INSTRUMENTS ]
