bq24230
bq24232
www.ti.com .......................................................................................................................................... SLUS821A–OCTOBER 2008–REVISED DECEMBER 2008
USB-FRIENDLY LITHIUM-ION BATTERY CHARGER AND POWER-PATH MANAGEMENT IC
1
FEATURES
2
•
Fully Compliant USB Charger
•
•
•
Proprietary Start-Up Sequence Limits Inrush
Current
–
–
–
Selectable 100-mA and 500-mA Maximum
Input Current
Status Indication – Charging/Done, Power
Good
100-mA Maximum Current Limit Ensures
Compliance to USB-IF Standard
Small 3 mm × 3 mm 16-Lead QFN Package
Input-based Dynamic Power Management
(VIN-DPM) for Protection Against Poor USB
Sources
APPLICATIONS
•
Bluetooth™ Devices
•
Low-Power Handheld Devices
•
•
28-V Input Rating With Overvoltage Protection
Integrated Dynamic Power-Path Management
(DPPM) Function Simultaneously and
Independently Powers the System and
Charges the Battery
TYPICAL APPLICATION CIRCUIT
1 kΩ
1
kΩ
•
•
Supports up to 500-mA Charge Current With
Current Monitoring Output (ISET)
SYSTEM
Programmable Input Current Limit up to
500 mA for Wall Adapters
Adaptor
DC
IN
OUT 10
11
13
1mF
GND
4.7mF
•
•
Programmable Termination Current (bq24232)
bq24230
5
8
EN2
VSS
Programmable Precharge and Fast-Charge
Safety Timers
BAT
2
3
4.7mF
15
TD
•
•
Reverse Current, Short-Circuit, and Thermal
Protection
PACK+
TEMP
1
TS
NTC Thermistor Input
PACK-
2.94 kΩ 4.32 kΩ
DESCRIPTION
The bq2423x series of devices are highly integrated Li-ion linear chargers and system power-path management
devices targeted at space-limited portable applications. The devices operate from either a USB port or ac
adapter and support charge currents between 25 mA and 500 mA. The high-input-voltage range with input
overvoltage protection supports low-cost, unregulated adapters. The USB input current limit accuracy and
start-up sequence allow the bq2423x to meet USB-IF inrush current specification. Additionally, the input dynamic
power management (VIN-DPM) prevents the charger from crashing poorly designed or incorrectly configured USB
sources.
The bq2423x features dynamic power-path management (DPPM) that powers the system while simultaneously
and independently charging the battery. The DPPM circuit reduces the charge current when the input current
limit causes the system output to fall to the DPPM threshold, thus supplying the system load at all times while
monitoring the charge current separately. This feature reduces the number of charge and discharge cycles on
the battery, allows for proper charge termination, and enables the system to run with a defective or absent
battery pack. Additionally, this enables instant system turn-on even with a totally discharged battery. The
power-path management architecture also permits the battery to supplement the system current requirements
when the adapter cannot deliver the peak system currents, enabling the use of a smaller adapter.
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
Bluetooth is a trademark of Bluetooth SIG, Inc..
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 © 2008, Texas Instruments Incorporated