BQ24735 Datasheet, PDF (1/42 Pages) Texas Instruments – 1-4 Cell Li+ Battery SMBus Charge Controller for Supporting Turbo Boost Mode with N-Channel Power MOSFET Selector

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
FEATURES
1
•2 Adapter and Battery Provides Power to
System Together to Support Intel^® CPU Turbo
Boost Mode
• SMBus Host-Controlled NMOS-NMOS
Synchronous Buck Converter with
Programmable 615kHz, 750kHz, and 885kHz
Switching Frequencies
• Automatic N-channel MOSFET Selection of
System Power Source from Adapter or Battery
Driven by Internal Charge Pumps
• Enhanced Safety Features for Over Voltage
Protection, Over Current Protection, Battery,
Inductor and MOSFET Short Circuit Protection
• Programmable Input Current, Charge Voltage,
Charge Current Limits
– ±0.5% Charge Voltage Accuracy up to 19.2V
– ±3% Charge Current Accuracy up to 8.128A
– ±3% Input Current Accuracy up to 8.064A
– ±2% 20x Adapter Current or Charge Current
Amplifier Output Accuracy
• Programmable Battery Depletion Threshold,
and Battery LEARN Function
• 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
• 5µA Off-State Battery Discharge Current
• 0.65mA (0.8mA max) Adapter Standby
Quiescent Current
• 20-pin 3.5 x 3.5 mm² QFN Package
DESCRIPTION
The bq24735 is a high-efficiency, synchronous
battery charger, offering low component count for
space-constraint, multi-chemistry battery charging
applications.
The bq24735 supports Turbo Boost by allowing
battery discharge energy to system when system
power demand is temporarily higher than adapter
maximum power level so that adapter will not crash.
The bq24735 utilizes two charge pumps to separately
drive n-channel MOSFETs (ACFET, RBFET and
BATFET) for automatic system power source
selection.
SMBus controlled input current, charge current, and
charge voltage DACs allow for very high regulation
accuracies that can be easily programmed by the
system power management micro-controller.
The bq24735 uses internal input current register or
external ILIM pin to throttle down PWM modulation to
reduce the charge current.
The bq24735 charges one, two, three or four series
Li+ cells, and is available in a 20-pin, 3.5x3.5 mm²
QFN package.
PIN CONFIGURATION
20 19 18 17 16
ACN 1
ACP 2
CMSRC 3
ACDRV 4
ACOK 5
bq24735
15 LODRV
14 GND
13 SRP
12 SRN
11 BATDRV
6 7 8 9 10
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.
Intel is a registered trademark of Intel.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2011, Texas Instruments Incorporated