STW4102_08 Datasheet, PDF (1/34 Pages) STMicroelectronics – Dual USB/wall adapter Li-ion battery charger with gas gauge

STw4102
Dual USB/wall adapter Li-ion battery charger with gas gauge
Features
■ Constant current constant voltage (CCCV)
linear charger
■ Common or separate USB/wall adapter inputs
■ Fast charge current control up to 1 A for wall
adapter and up to 500 mA for USB
■ Support for currents higher than 1 A using
external components
■ Programmable charge voltage (4.1 V, 4.2 V,
4.3 V, 4.35 V) with 1% accuracy
■ Thermal regulation
■ Trickle charge mode at low battery voltage
■ Wall adapter voltage up to 16 V
■ Battery overvoltage protection at 4.7 V
■ Gas gauge with 13-bit AD converter
■ Battery voltage monitor with 7-12 bit AD
converter
■ I²C interface for device monitoring and control
■ Charge status output pin
■ Power detection output pin
■ Programmable watchdog security timer
■ 4.7 V LDO regulator (with external power
MOSFET)
Applications
■ Cellular phones (GSM, CDMA, WCDMA),
PDA, MP3 players, cordless phones
■ Digital camera, USB appliances, bluetooth
devices, portable navigation devices
Description
The STw4102 is a standalone constant current
constant voltage (CCCV) linear charger
specifically designed for Li-ion batteries.
QFN 24
(Plastic micropackage)
Pin connections
(top view)
MAIN
VOUT
USBPWR
DRIVER
LDODRV
LDOFB
24 23 22 21 20 19
1
18
2
17
3
16
4
15
5
14
6
13
7 8 9 10 11 12
VIO
SCL
SDA
RESETN
STDBY
C32KHZ
The STw4102 offers dual charging capability
using separate inputs for USB cable and wall
adapter, or a single input that accepts both.
The STw4102 also offers programmable fast
charge current using an external resistor. A
thermal regulation circuit limits the charge current
against the die high power dissipation or high
ambient temperature. An end of charge output pin
indicates the charge termination when the fast
charge current drops below 10% of the
programmed current value.
The STw4102 includes an accurate gas gauge
based on a 13-bit AD converter. An external
resistor is used between battery and ground to
sense a charge/discharge current. With a typical
30 mΩ resistor, current can be up to 2.5 A.
March 2008
Rev 2
1/34
www.st.com
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