LP8545_14 Datasheet, PDF (1/44 Pages) Texas Instruments – High-Efficiency LED Backlight Driver for Notebooks

LP8545
www.ti.com
SNVS635D – APRIL 2010 – REVISED DECEMBER 2013
High-Efficiency LED Backlight Driver for Notebooks
Check for Samples: LP8545
FEATURES
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•2 High-Voltage DC/DC Boost Converter with
Integrated FET with Four Switching Frequency
Options: 156/312/625/1250 kHz
• Configurable for Use with External FET for
Applications Needing Higher Output Voltage
• 2.7V – 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
• PWM Output Frequency and LED Current Set
Through Resistors
• Optional Synchronization to Display V_SYNC
Signal
• 6 LED Outputs with LED fault (Short/Open)
Detection
• Low Input Voltage, Over-Temperature, Over-
Current Detection and Shutdown
• Minimum Number of External Components
• WQFN 24-Pin Package, 4 x 4 x 0.8 mm
APPLICATIONS
• Notebook and Netbook LCD Display LED
Backlight
• LED Lighting
DESCRIPTION
The LP8545 is a white LED driver with integrated
boost converter. It has six 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.
Internal EEPROM is used for storing the configuration
data. This makes it possible to have minimum
external component count and make the solution very
small.
LP8545 has safety features which make it possible to
detect LED outputs with open or short fault. As well
low input voltage and boost over-current conditions
are monitored and chip is turned off in case of these
events. Thermal de-rating function prevents
overheating of the device by reducing backlight
brightness when set temperature has been reached.
LP8545 is available in TI's 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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