BQ29312A Datasheet, PDF (1/35 Pages) Texas Instruments – TWO-CELL, THREE-CELL, AND FOUR-CELL LITHIUM-ION OR LITHIUM-POLYMER BATTERY PROTECTION AFE

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bq29312A
SLUS629A – JANUARY 2005 – REVISED AUGUST 2005
TWO-CELL, THREE-CELL, AND FOUR-CELL LITHIUM-ION OR
LITHIUM-POLYMER BATTERY PROTECTION AFE
FEATURES
• 2-, 3-, or 4-Cell Series Protection Control
• Can Directly Interface With the bq2084 Gas
Gauges
• Provides Individual Cell Voltages and Battery
Voltage to Battery Management Host
• Integrated Cell Balancing Drive
• I²C Compatible User Interface Allows Access
to Battery Information
• Programmable Threshold and Delay for
Overload and Short Circuit During Charge and
Discharge
• System Alert Interrupt Output
• Host Control Can Initiate Sleep Power Mode
and Ship Mode
• Integrated 3.3-V, 25-mA LDO
• Supply Voltage Range From 4.5 V to 25 V
• Low Supply Current of 60-µA Typical
• bq29312A is 100% specification compatible
with the bq29312
APPLICATIONS
• Notebook PCs
• Medical and Test Equipment
• Portable Instrumentation
DESCRIPTION
The bq29312A is a 2-, 3-, or 4-cell lithium-ion battery
pack protection analog front end (AFE) IC that
incorporates a 3.3-V, 25-mA low-dropout regulator
(LDO). The bq29312A also integrates an I²C compat-
ible interface to extract battery parameters such as
cell voltages and control output status. Other par-
ameters such as current protection thresholds and
delays can be programmed into the bq29312A to
increase the flexibility of the battery management
system.
The bq29312A provides safety protection for over-
charge, overload, short-circuit, overvoltage, and
undervoltage conditions with the battery management
host. In overload and short-circuit conditions, the
bq29312A turns the FET drive off autonomously
dependant on the internal configuration setting.
SYSTEM PARTITIONING DIAGRAM
Fuse
Pack +
bq2084
Precharge Control
Fail-Safe Protection
PF Input
Power Management
LDO, TOUT, and Power Mode control
Supply V oltage
Temperature Measurement
<1% Error
T_INT
768 Bytes of
User Flash
32-kHz Clock
Generator
T1
32 kHz
SMBus
Cell Balancing Algorithm and Control
SBS v1.1 Data
System Interface
I²C
bq29312 RAM/Comms Validation
1^st Level OC
Protection
1^stLevel OV and
UV Protection
XAlert
Sleep
Pack Undervoltage
Power Mode
Control
Cell and Pack
Voltage
Measurement
Capacity Prediction <1% Error
Discharge / Charge /
Precharge FETs
bq29312A
PCH FET Drive
Precharge
FET Drive
Cell Balancing
Drive
LDO, Therm Output Drive & UVLO
System Watchdog Delay Counters
System Interface RAM Registers
Power Mode Control
2-Tier Overcurrent Protection
Voltage Level Translator
Pack -
Sense Resistor
(10 - 30 m W)
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 © 2005, Texas Instruments Incorporated