1 PF

ISEL

MODE

EN

SCL

SDA

TS

VT

RS

RT

VBSense

BATT

10 PF

Li-Ion

CHG

EOC

GND

CHG-IN

LP3947

To

System

Supply

Diff-Amp

USB Power Source

4.3V to 5.5V

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

1

FEATURES

DESCRIPTION

The LP3947 is a complete charge management

23

•

Supports USB Charging Scheme

system that safely charges and maintains a Li-Ion

•

Integrated Pass Transistor

battery from either USB power source or AC adaptor.

•

Near-Depleted Battery Preconditioning

In USB mode, the LP3947 supports charging in low

power or high power mode. Alternatively, the LP3947

•

Monitors Battery Temperature

can take charge from AC adaptor. In both USB and

•

Built-In 5.6 Hour Timer

AC adaptor modes, charge current, battery regulation

•

Under Voltage and Over Voltage Lockout

voltage, and End of Charge (EOC) point can be

selected via I2C™ interface. The LP3947 can also

•

Charge Status Indicators

operate on default values that are pre-programmed in

•

Charge Current Monitor Analog Output

the factory. The battery temperature is monitored

•

LDO Mode Operation can source 1 Amp

continuously at the Ts pin to safeguard against

hazardous charging conditions. The charger also has

•

Continuous Over Current/Temperature

under-voltage and over-voltage protection as well as

Protection

an internal 5.6 hr timer to protect the battery. The

pass transistor and charge current sensing resistor

APPLICATIONS

are all integrated inside the LP3947.

•

Cellular Phones

The LP3947 operates in four modes: pre-qualification,

•

PDAs

constant current, constant voltage and maintenance

•

Digital Cameras

modes. There are two open drain outputs for status

indication. An internal amplifier readily converts the

•

USB Powered Devices

charge current into a voltage. Also, the charger can

•

Programmable Current Sources

operate in an LDO mode providing a maximum of 1.2

Amp to the load.

KEY SPECIFICATIONS

•

1% Charger Voltage Accuracy Over

0°C

≤ TJ ≤ 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 TA = 25°C

TYPICAL APPLICATION CIRCUIT

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.

2

I2C is a trademark of Philips Semiconductor Corporation.

3

All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2004–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.