LP8543 Datasheet, PDF (1/40 Pages) Texas Instruments – SMBus/I2C Controlled WLED Driver for Medium-Sized LCD Backlight

LP8543
www.ti.com
SNVS604D – AUGUST 2009 – REVISED MARCH 2013
SMBus/I2C Controlled WLED Driver for Medium-Sized LCD Backlight
Check for Samples: LP8543
FEATURES
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•2 High-Voltage DC/DC Boost Converter with
Integrated FET
• 5.5V to 22V Input Voltage Range to Support 2x,
3x and 4x Li-Ion Batteries.
• PWM Phase Shift Control with Adaptive Boost
Output to Increase Efficiency Compared to
Conventional Boost Converters Topologies
• PWM Brightness Control for Single Wire
Control and Stand-Alone Use
• Digital Ambient Light Sensor Interface with
User-Programmed Ambient Light to Backlight
Brightness Curve
• Easy-to-Use EEPROM Calibration for Current,
Intensity and Ambient Light Response Setting
• Seven LED Drivers with LED Fault
(Short/open) Detection
• Eight-Bit LED Current Control
• Internal Thermal Protection and Backlight
Safety Dimming Feature
• Two Wire, SMBus/ I²C-Compatible Control
Interface
• Low-Input Voltage Detection and Shutdown
• Minimum Number of External Components
• WQFN 24-Pin Package, 4 x 4 x 0.8 mm
APPLICATIONS
• Medium Sized (>10 inches) LCD Display
Backlight
• LED Lighting
DESCRIPTION
The LP8543 is a white LED driver with integrated
boost converter. It has 7 adjustable current sinks
which can be controlled by SMBus or I²C-compatible
serial interface, PWM input and Ambient Light Sensor
(ALS).
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. Phase Shift PWM dimming offers further
power saving especially when there is poor matching
in the forward voltages of the LED strings. Boost
voltage can also be controlled through the
SMBus/I²C.
Internal EEPROM stores the data for backlight
brightness and ambient light sensor calibration.
Brightness can be calibrated during the backlight unit
production so that all units produce the same
brightness. EEPROM also stores the coefficients for
the LED control equations and the default LED
current value. LED current has 8–bit adjustment from
0 to 60 mA.
The LP8543 has several safety and diagnostic
features. Low-input voltage detection turns the chip
off if the system gets stuck and battery fully
discharges. Input voltage detection threshold is
adjustable for different battery configurations.
Thermal regulation reduces backlight brightness
above a set temperature. LED fault detection reports
open or LED short fault. Boost over-current fault
detection protects the chip in case of over-current
event.
LP8543 is available in the WQFN 24-pin package.
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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.
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