bq24730
www.ti.com
SLUS695–MARCH 2006
ADVANCED MULTI-CHEMISTRY AND MULTI-CELL SYNCHRONOUS SWITCH-MODE
CHARGER AND SYSTEM POWER SELECTOR
FEATURES
APPLICATIONS
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•
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Portable Notebook Computers
Portable DVD Players
Webpads, PC Tablets
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High Efficiency:
– NMOS-NMOS Synchronous Buck Converter
With Fixed 300 kHz Frequency
– Enhanced 6-V Drive Supply Voltage and
99.5% Max Duty Cycle
DESCRIPTION
The bq24730 is a high efficiency synchronous battery
pack charger with high level of integration for portable
•
High Voltage and Current Regulation
Accuracy (0°C-85°C):
applications. This device implements
a
high
– 0.4% Charge Voltage Regulation Accuracy
– 4% Charge Current Regulation Accuracy
performance analog front-end that interfaces to the
system power management micro-controller through
a hardware interface.
– 4% Adapter Current Regulation Accuracy
Dynamic Power Management (DPM)
The dynamic power management (DPM) function
modifies the charge current depending on system
load conditions, avoiding ac adapter overload.
•
•
3-Cell or 4-Cell Li-Ion Battery Voltage Select
Programmable Battery Charge Current, and
AC Adapter Current via Resistor
High accuracy current sense amplifiers enable
accurate measurement of either the charge current or
the ac adapter current, allowing termination of
nonsmart packs and monitoring of overall system
power. The input current sense amplifier can be
enabled with no adapter to sense battery discharge
current.
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•
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2% Accurate Current Sense Amplifiers for
Both Input Current and Charge Current
(0°C-125°C)
Input Current Sense Amplifier Can Be Enabled
with No Adapter to Sense Battery Discharge
Current
Integrated features such as charger soft start, charge
overcurrent protection, and IC temperature monitoring
provide a second level of protection, in addition to
pack and system protection functions.
Regulates Charge Current Down to 0-V
Battery Voltage
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AC Adapter Operating Range 8 V–24 V
Internal Soft Start
Status Indicators:
– AC Adapter Present
1
2
32
31
30
29
28
27
26
25
CHGEN
CELLS
BATDRV
SYS
– Low Battery Indicator
ACDRV
– DPM Regulation Loop Active Indicator
3
ACN
4
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Reverse Battery to Adapter Discharge
Protection
ACP
SYNP
SYNN
5
ACDET
bq24730
(Top View)
6
ACSET
AIRDET
BYPASS
DPMDET
LBSET
EAO
SRP
SRN
BAT
Battery/Adapter to System Power Selector
Function
7
8
9
24 SRSET
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Charge Overcurrent Protection
10
11
12
23
IBAT
Available in 40-Pin 5x7mm QFN Package
22
IADAPT
21
LOWBAT
EAI
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.
PowerPAD is a trademark of Texas Instruments.
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 © 2006, Texas Instruments Incorporated