BQ24004 Datasheet, PDF (1/22 Pages) Texas Instruments – TWO-CELL Li-ION CHARGE MANAGEMENT IC FOR PDAs AND INTERNET APPLIANCES

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bq24004
bq24005
bq24006
SLUS476B – DECEMBER 2000 – REVISED MAY 2002
TWO-CELL Li-ION CHARGE MANAGEMENT IC FOR PDAs
AND INTERNET APPLIANCES
FEATURES
D Highly Integrated Solution With FET Pass
Transistor and Reverse-Blocking Schottky
and Thermal Protection
D Integrated Voltage and Current Regulation
With Programmable Charge Current
D High-Accuracy Voltage Regulation (±1%)
D Ideal for Low-Dropout Linear Charger
Designs for Two-Cell Li-Ion Packs With Coke
or Graphite Anodes
D Up to 1.2-A Continuous Charge Current
D Safety-Charge Timer During Preconditioning
and Fast Charge
D Integrated Cell Conditioning for Reviving
Deeply Discharged Cells and Minimizing Heat
Dissipation During Initial Stage of Charge
D Optional Temperature or Input-Power
Monitoring Before and During Charge
D Various Charge-Status Output Options for
Driving Single, Double, or Bicolor LEDs or
Host-Processor Interface
D Charge Termination by Minimum Current and
Time
D Low-Power Sleep Mode
D Packaging: 20-Lead TSSOP PowerPAD
APPLICATIONS
D PDAs
D Internet Appliances
D MP3 Players
D Digital Cameras
DESCRIPTION
The bq2400x series ICs are advanced Li-Ion linear
charge management devices for highly integrated and
space-limited applications. They combine high-
accuracy current and voltage regulation; FET pass-
transistor and reverse-blocking Schottky; battery
conditioning, temperature, or input-power monitoring;
charge termination; charge-status indication; and
charge timer in a small package.
The bq2400x measures battery temperature using an
external thermistor. For safety, the bq2400x inhibits
charge until the battery temperature is within the
user-defined thresholds. Alternatively, the user can
monitor the input voltage to qualify charge. The
bq2400x series then charge the battery in three phases:
preconditioning, constant current, and constant
voltage. If the battery voltage is below the internal
low-voltage threshold, the bq2400x uses low-current
precharge to condition the battery. A preconditioning
timer provides additional safety. Following pre-
conditioning, the bq2400x applies a constant-charge
current to the battery. An external sense-resistor sets
the magnitude of the current. The constant-current
phase is maintained until the battery reaches the
charge-regulation voltage. The bq2400x then
transitions to the constant voltage phase. The user can
configure the device for cells with either coke or
graphite anodes. The accuracy of the voltage regulation
is better than ±1% over the operating junction
temperature and supply voltage range.
Charge is terminated by maximum time or minimum
taper current detection
The bq2400x automatically restarts the charge if the
battery voltage falls below an internal recharge
threshold.
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.
PowerPAD is a trademark of Texas Instruments.
PRODUCTION DATA information is current as of publication date. Products
conform to specifications per the terms of Texas Instruments standard warranty.
Production processing does not necessarily include testing of all parameters.
Copyright  2002, Texas Instruments Incorporated