BQ24273 Datasheet, PDF (1/27 Pages) Texas Instruments – 2.5A, Single Input, Single Cell Switchmode Li-Ion Battery Charger with Integrated Current Sense

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bq24273
SLUSB08 – JUNE 2012
2.5A, Single Input, Single Cell Switchmode Li-Ion Battery Charger with
Integrated Current Sense
Check for Samples: bq24273
FEATURES
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• High-Efficiency Switch Mode Charger with
Integrated Current Sense Element
• Single Input Charger
– 20V input rating, with 10.5V Over-Voltage
Protection (OVP)
– Integrated FETs for Up to 2.5A Charge Rate
• Integrated Charge Current Sense Element for
Reduced BOM Count and Board Space
Savings
• Safe and accurate Battery Management
Functions
– 0.5% Battery Regulation Accuracy
– 10% Charge Current Accuracy
• Voltage-based, NTC Monitoring Input (TS)
– JEITA Compatible
• Thermal Regulation Protection for Output
Current Control
• BAT Short-Circuit Protection
• Soft-Start Feature to Reduce Inrush Current
• Thermal Shutdown and Protection
• Available in Small 49-ball WCSP or QFN-24
Packages
APPLICATIONS
• Handheld Prducts
• Portable Media Players
• Portable Equipment
• Tablets and Portable Internet Devices
APPLICATION SCHEMATIC
IN
SW
HOST
PMID
SDA
SCL
CD
INT
BOOT
CS+
`
BAT
BYP
PGND STAT
TS
DRV
TEMP ^PACK+
PACK-
System
Load
DESCRIPTION
The bq24273 is a highly integrated single cell Li-Ion battery charger with integrated charge current sense
element device targeted for space-limited, portable applications with high capacity batteries. The single cell
charger operates from a dedicated power source such as a wall adapter or wireless power supply for a versatile
solution. The integrated sense element eliminates the need for an external sense resistor reducing the total
solution size and external component count.
The battery is charged in three phases: precharge, fast charge constant current and constant voltage. In all
charge phases, an internal control loop monitors the IC junction temperature and reduces the charge current if
the internal temperature threshold is exceeded. Charge is terminated based on user-selectable minimum current
level. A software watchdog provides a safety backup for I2C interface while a safety timer prevents continuously
charging a damaged battery. During normal operation, bq24273 automatically restarts the charge cycle if the
battery voltage falls below an internal threshold and automatically enters sleep mode or high impedance mode
when the input supply is removed. The charge status is reported to the host using the I2C interface. Additionally,
a voltage-based battery pack thermistor monitoring input (TS) is included that monitors battery temperature for
safe charging. The TS function for bq24273 JEITA compatible.
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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 © 2012, Texas Instruments Incorporated