LP8553_14 Datasheet, PDF (1/42 Pages) Texas Instruments – LP8553 High-Efficiency LED Backlight Driver for Notebooks

LP8553
www.ti.com
SNVS701B – SEPTEMBER 2011 – REVISED JANUARY 2014
LP8553 High-Efficiency LED Backlight Driver for Notebooks
Check for Samples: LP8553
FEATURES
1
•2 High-Voltage DC/DC Boost Converter with
Integrated FET with Four Switching Frequency
Options: 156/312/625/1250 kHz
• 2.7V to 22V Input Voltage Range to Support
1x…5x Cell Li-Ion Batteries
• Programmable PWM Resolution
– 8 to 13 True Bit (Steady State)
– Additional 1 to 3 Bits Using Dithering
During Brightness Changes
• I²C and PWM Brightness Control
• Automatic PWM & Current Dimming for
Improved Efficiency
• PWM Output Frequency and LED Current Set
Through Resistors
• Optional Synchronization to Display V_SYNC
Signal
• 4 LED Outputs with LED Fault (Short/Open)
Detection
• Low Input Voltage, Over-Temperature, Over-
Current Detection and Shutdown
• Minimum Number of External Components
• DSBGA 25-Bump Package, 2.466 x 2.466 x
0.6 mm
APPLICATIONS
• Notebook and Netbook LCD Display LED
Backlight
• LED Lighting
DESCRIPTION
The LP8553 is a white LED driver with integrated
boost converter. It has four adjustable current sinks
which can be controlled by PWM input or with I²C-
compatible serial interface.
The boost converter has adaptive output-voltage
control based on the LED driver voltages. This
feature minimizes the power consumption by
adjusting the voltage to lowest sufficient level in all
conditions.
LED outputs have 8-bit current resolution and up to
13-bit PWM resolution with additional 1-3 bit dithering
to achieve smooth and precise brightness control.
Proprietary Phase Shift PWM control is used for LED
outputs to reduce peak current from the boost
converter, thus making the boost capacitors smaller.
The Phase Shifting scheme also eliminates audible
noise.
Typical Application (1)
V_{BATT 5.5V ± 22V}
V_DDIO reference voltage
VSYNC signal
100 nF
C_{VLDO 5V}
1 éF
V_DDIO
V_LDO VIN
VSYNC
L1
D1
C_IN ^{15 éH}
10 éF
SW
FB
10V ± 40V
210 mA ± 400 mA
39 pF
C_OUT
4.7 éF
1 éF 120 k#
R_ISET
R_FSET
MCU
Can be left floating
if not used
FILTER
ISET
FSET
SCLK
SDA
PWM
EN
FAULT
LP8553
GNDs
OUT1
OUT2
OUT3
OUT4
1
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2
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 © 2011–2014, Texas Instruments Incorporated