bq24200, bq24201, bq24202

bq24203, bq24204, bq24205

SLUS501A – OCTOBER 2001

SINGLECHIP LIION AND LIPOL CHARGE MANAGEMENT IC

FOR CURRENT LIMITED APPLICATIONS

1

www.ti.com

FEATURES

Current-Limited Wall Supplies

Single-Cell Li-Ion Packs With Coke or

Graphite Anodes

Accuracy

Time

Processor Interface Indicates

Charge-in-Progress, Charge Completion, and

Fault Conditions

During Charge

TYPICAL APPLICATION

DESCRIPTION

The bq2420x series are simple Li-Ion linear

charge management devices targeted at low-cost

and space limited charger applications. The

bq2420x

series

offer

integrated

powerFET,

high-accuracy voltage regulation, temperature

monitoring,

charge

status,

and

charge

termination, in a single monolithic device.

The bq2420x is designed to work with a

current-limited

wall-mount

transformer

and

therefore does not provide any current regulation.

However, these devices offer a fixed internal

current limit to prevent damage to the internal

powerFET. A time-limited pre-conditioning phase

is provided to condition deeply discharged cells.

Once the battery reaches the charge voltage, the

high accuracy voltage regulation loop takes over

and completes the charge cycle. Charge is

terminated based on minimum current. An internal

charge timer provides a backup safety for charge

termination.

Other standard features include an automatic

battery voltage and a recharge feature activated

threshold.

In addition to the standard features, the core

product provides two additional enhancements:

temperature monitoring and status display. The

temperature-sense circuit continuously measures

battery temperature using an external thermistor

and inhibits charge until the battery temperature is

within the user–defined thresholds. The STAT pin

indicates three conditions of operation of the

charger.

These

conditions

are

charge-

in-progress, charge complete, and fault. This

output can be used to drive an LED or an interface

to a microcontroller.

Copyright

 2001, Texas Instruments Incorporated

1

4

2

8

IN

VCC

VSS

OUT

7

BAT

6

CE

5

N/C

C1

bq24202DGN

3STAT

DC+

DC–

R1

C1

+

BATTERY PACK

UDG–01111

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.