3 STRINGS

OF 4 LEDS

FOR

KEYPAD

LP3958

SW

MAIN

SUB

KEY1

KEY2

KEY3

Li-Ion Battery

or Charger

= 70 mA

= 8...18 V

FB

VDD2

10 F

L1

10 PH

P

MCU

SCL

SDA

SUB

BACKLIGHT

0...25 mA/LED

MAIN

BACKLIGHT

0...25 mA/LED

NRST

VDDIO

IKEY

IRT

VDDA

100 nF

VREF

D1

VDD1

100 nF

GND 1-5

100 nF

1 PF

GPIO[0]/PWM

GPIO[1]

GPIO[2]

2 x 4.7 éF

COUT

IMAX

VOUT

CVDDA

CIN

CVDD

CVREF

RKEY

RRT

RSDA

VDDIO

CVDDIO

LP3958

www.ti.com

SNVS423C – JANUARY 2006 – REVISED MARCH 2013

Lighting Management Unit with High Voltage Boost Converter

Check for Samples: LP3958

1

FEATURES

DESCRIPTION

LP3958 is a Lighting Management Unit for portable

2

•

High-Efficiency Boost Converter With

applications. It is used to drive display backlight and

Programmable Output Voltage

keypad LEDs. The device can drive 5 separately

•

Two Individual Drivers for Serial Display

connected strings of LEDs with high voltage boost

Backlight LEDs

converter.

•

Three Drivers for Serial Keypad LEDs

The keypad LED driver allows driving LEDs from high

•

Automatic Dimming Controller

voltage

boost

converter

or

separate

supply

voltage.The

MAIN

and

SUB

outputs

are

high

•

Stand Alone Serial Leypad LEDs Controller

resolution current mode drivers. Keypad LED outputs

•

Three General-Purpose IO Pins

can be used in switch mode and current mode.

•

25-Bump DSBGA Package: 2.54mm x 2.54mm

External PWM control can be used for any selected

x 0.6mm

outputs.

The device is controlled through 2-wire low voltage

APPLICATIONS

I2C compatible interface that reduces the number of

•

Cellular Phones and PDAs

required connections.

•

MP3 Players

LP3958 is offered in a tiny 25-bump DSBGA

package.

•

Digital Cameras

Typical Application

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

All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2006–2013, 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.