bq24007

bq24008

SLUS479D − JANUARY 2001 − REVISED NOVEMBER 2004

SINGLECELL LiION CHARGE MANAGEMENT IC WITH

TIMERENABLE FOR PDAs AND INTERNET APPLIANCES

FEATURES

Transistor and Reverse-Blocking Schottky

and Thermal Protection

Disable Charge Timer and Termination When

Charge Current Is Shared With a Load or

When Battery Is Absent

With Programmable Charge Current

Designs for Single-Cell Li-Ion Packs With

Coke or Graphite Anodes

and Fast Charge

Deeply Discharged Cells and Minimizing Heat

Dissipation During Initial Stage of Charge

Monitoring Before and During Charge

Driving Single, Double, or Bicolor LEDs or

Host-Processor Interface

Time

20-Lead TSSOP PowerPAD



APPLICATIONS

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 bq24007 and bq24008 provide the timer-enable

function, allowing the host to disable the charge timer

when charge current is shared with a load or when the

battery is absent. This feature is ideal for applications

such

as

cellular

phones,

PDAs,

and

internet

appliances.

The bq2400x measures battery temperature using an

external thermistor. For safety reasons, 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.

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.

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.

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Copyright

 2002 − 2004, Texas Instruments Incorporated