1

2

3

4

5

6

7

8

9

10

15

14

13

12

11

20

19

18

17

16

ACN

ACP

CMSRC

ACDRV

ACOK

BATDRV

SRN

SRP

GND

LODRV

bq24735

bq24735

www.ti.com

SLUSAK9

– SEPTEMBER 2011

1-4 Cell Li+ Battery SMBus Charge Controller for Supporting Turbo Boost Mode with

N-Channel Power MOSFET Selector

Check for Samples: bq24735

1

FEATURES

DESCRIPTION

The

bq24735

is

a

high-efficiency,

synchronous

2

•

Adapter and Battery Provides Power to

battery charger, offering low component count for

space-constraint, multi-chemistry battery charging

Boost Mode

applications.

•

SMBus Host-Controlled NMOS-NMOS

The bq24735 supports Turbo Boost by allowing

Synchronous Buck Converter with

battery discharge energy to system when system

Programmable 615kHz, 750kHz, and 885kHz

power demand is temporarily higher than adapter

Switching Frequencies

maximum power level so that adapter will not crash.

•

Automatic N-channel MOSFET Selection of

The bq24735 utilizes two charge pumps to separately

System Power Source from Adapter or Battery

drive n-channel MOSFETs (ACFET, RBFET and

Driven by Internal Charge Pumps

BATFET)

for

automatic

system

power

source

•

Enhanced Safety Features for Over Voltage

selection.

Protection, Over Current Protection, Battery,

SMBus controlled input current, charge current, and

Inductor and MOSFET Short Circuit Protection

charge voltage DACs allow for very high regulation

•

Programmable Input Current, Charge Voltage,

accuracies that can be easily programmed by the

Charge Current Limits

system power management micro-controller.

– ±0.5% Charge Voltage Accuracy up to 19.2V

The bq24735 uses internal input current register or

– ±3% Charge Current Accuracy up to 8.128A

external ILIM pin to throttle down PWM modulation to

reduce the charge current.

– ±3% Input Current Accuracy up to 8.064A

– ±2% 20x Adapter Current or Charge Current

The bq24735 charges one, two, three or four series

Amplifier Output Accuracy

QFN package.

•

Programmable Battery Depletion Threshold,

and Battery LEARN Function

PIN CONFIGURATION

•

Programmable Adapter Detection and

Indicator

•

Integrated Soft Start

•

Integrated Loop Compensation

•

Real Time System Control on ILIM pin to Limit

Charge Current

•

AC Adapter Operating Range 4.5V-24V

•

5

µA Off-State Battery Discharge Current

•

0.65mA (0.8mA max) Adapter Standby

Quiescent Current

•

APPLICATIONS

•

Portable Notebook Computers, UMPC,

Ultra-Thin Notebook, and Netbook

•

Handheld Terminal

•

Industrial and Medical Equipment

•

Portable Equipment

1

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.

2

Intel is a registered trademark of Intel.

PRODUCTION DATA information is current as of publication date.

Copyright

© 2011, 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.