LP3947ISD-51 Datasheet, PDF (1/20 Pages) Texas Instruments – LP3947 USB/AC Adaptor, Single Cell Li-Ion Battery Charger IC

LP3947
www.ti.com
SNVS298B – NOVEMBER 2004 – REVISED APRIL 2013
LP3947 USB/AC Adaptor, Single Cell Li-Ion Battery Charger IC
Check for Samples: LP3947
FEATURES
1
•23 Supports USB Charging Scheme
• Integrated Pass Transistor
• Near-Depleted Battery Preconditioning
• Monitors Battery Temperature
• Built-In 5.6 Hour Timer
• Under Voltage and Over Voltage Lockout
• Charge Status Indicators
• Charge Current Monitor Analog Output
• LDO Mode Operation can source 1 Amp
• Continuous Over Current/Temperature
Protection
APPLICATIONS
• Cellular Phones
• PDAs
• Digital Cameras
• USB Powered Devices
• Programmable Current Sources
KEY SPECIFICATIONS
• 1% Charger Voltage Accuracy Over
0°C ≤ T_J ≤ 85°C
• 4.3V to 6V Input Voltage Range
• 100 mA to 750 mA Charge Current Range, in
Charger Mode
• 100 mA to 500 mA Charge Current Range, in
USB Mode
• WSON Package Power Dissipation:
2.7W at T_A = 25°C
DESCRIPTION
The LP3947 is a complete charge management
system that safely charges and maintains a Li-Ion
battery from either USB power source or AC adaptor.
In USB mode, the LP3947 supports charging in low
power or high power mode. Alternatively, the LP3947
can take charge from AC adaptor. In both USB and
AC adaptor modes, charge current, battery regulation
voltage, and End of Charge (EOC) point can be
selected via I²C™ interface. The LP3947 can also
operate on default values that are pre-programmed in
the factory. The battery temperature is monitored
continuously at the Ts pin to safeguard against
hazardous charging conditions. The charger also has
under-voltage and over-voltage protection as well as
an internal 5.6 hr timer to protect the battery. The
pass transistor and charge current sensing resistor
are all integrated inside the LP3947.
The LP3947 operates in four modes: pre-qualification,
constant current, constant voltage and maintenance
modes. There are two open drain outputs for status
indication. An internal amplifier readily converts the
charge current into a voltage. Also, the charger can
operate in an LDO mode providing a maximum of 1.2
Amp to the load.
TYPICAL APPLICATION CIRCUIT
USB Power Source
4.3V to 5.5V
CHG-IN
1 PF
ISEL
MODE
CHG
EOC
EN
LP3947
GND
BATT
VBSense
RT
TS
VT
RS
Li-Ion
To
System
Supply
10 PF
Diff-Amp
SCL
SDA
More Application Circuit can be found in APPLICATION NOTES.
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.
I²C is a trademark of Philips Semiconductor Corporation.
2
All other trademarks are the property of their respective owners.
3
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 © 2004–2013, Texas Instruments Incorporated