P0012-02

DRBPackage

(TopView)

1

2

3

4

5

6

7

8

OUT

VDD

CD

VC4

VC1

VC2

VC3

GND

bq29440, bq2944L0

bq29449, bq2944L9

www.ti.com

SLUSA15B – MARCH 2010 – REVISED JUNE 2010

Voltage Protection for 2-Series, 3-Series, or 4-Series Cell Li-Ion Batteries

(Second-Level Protection)

Check for Samples: bq29440, bq2944L0, bq29449, bq2944L9

1

FEATURES

APPLICATIONS

•

Second-Level Protection in Li-Ion Battery

•

2-Series, 3-Series, or 4-Series Cell Secondary

Packs

Protection

–

Notebook Computers

•

External Capacitor-Controlled Delay Timer

–

Power Tools

•

–

Portable Equipment and Instrumentation

•

High-Accuracy Overvoltage Protection:

•

Fixed Overvoltage Protection Thresholds:

4.30 V, 4.35 V

•

Small 8L QFN Package

DESCRIPTION

The bq2944x is a secondary overvoltage protection IC for 2-series, 3-series, or 4-series cell lithium-ion battery

packs that incorporates a high-accuracy precision overvoltage detection circuit.

FUNCTION

The voltage of each cell in a battery pack is compared to an internal reference voltage. If any cells reach an

overvoltage condition, the bq2944x device starts a timer that provides a delay proportional to the capacitance on

the CD pin. Upon expiration of the internal timer, the OUT pin changes from a low state to a high state. An

optional latch configuration is available that holds the OUT pin in a high state indefinitely after an overvoltage

condition has satisfied the specified delay timer period. The latch is released when the CD pin is shorted to GND.

T

T

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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.

Copyright © 2010, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.