MCU

LP8553

SW

FB

VLDO

GNDs

EN

ISET

VDDIO

PWM

SCLK

SDA

OUT1

OUT2

OUT3

OUT4

L1

D1

10V ± 40V

5.5V ± 22V

FILTER

5V

FSET

15 éH

VSYNC

210 mA ± 400 mA

COUT

CIN

10 éF

4.7 éF

CVLDO

1 éF

VDDIO reference voltage

VSYNC signal

120 k

#

100 nF

1 éF

FAULT

Can be left floating

if not used

39 pF

VIN

RISET

RFSET

VBATT

LP8553

www.ti.com

SNVS701B – SEPTEMBER 2011 – REVISED JANUARY 2014

LP8553 High-Efficiency LED Backlight Driver for Notebooks

Check for Samples: LP8553

1

FEATURES

APPLICATIONS

2

•

High-Voltage DC/DC Boost Converter with

•

Notebook and Netbook LCD Display LED

Integrated FET with Four Switching Frequency

Backlight

Options: 156/312/625/1250 kHz

•

LED Lighting

•

2.7V to 22V Input Voltage Range to Support

1x…5x Cell Li-Ion Batteries

DESCRIPTION

The LP8553 is a white LED driver with integrated

•

Programmable PWM Resolution

boost converter. It has four adjustable current sinks

–

8 to 13 True Bit (Steady State)

which can be controlled by PWM input or with I2C-

–

Additional 1 to 3 Bits Using Dithering

compatible serial interface.

During Brightness Changes

The boost converter has adaptive output-voltage

•

I2C and PWM Brightness Control

control based on the LED driver voltages. This

•

Automatic PWM & Current Dimming for

feature

minimizes

the

power

consumption

by

Improved Efficiency

adjusting the voltage to lowest sufficient level in all

conditions.

•

PWM Output Frequency and LED Current Set

Through Resistors

LED outputs have 8-bit current resolution and up to

13-bit PWM resolution with additional 1-3 bit dithering

•

Optional Synchronization to Display VSYNC

to achieve smooth and precise brightness control.

Signal

Proprietary Phase Shift PWM control is used for LED

•

4 LED Outputs with LED Fault (Short/Open)

outputs to reduce peak current from the boost

Detection

converter, thus making the boost capacitors smaller.

•

Low Input Voltage, Over-Temperature, Over-

The Phase Shifting scheme also eliminates audible

noise.

Current Detection and Shutdown

•

Minimum Number of External Components

•

DSBGA 25-Bump Package, 2.466 x 2.466 x

0.6 mm

Typical Application (1)

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 © 2011–2014, 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.