LP8553 High-Efficiency LED Backlight Driver for Notebooks | TI.com

LP8553 (ACTIVE) High-Efficiency LED Backlight Driver for Notebooks

 

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.

Automatic PWM dimming at lower brightness values and current dimming at higher brightness values can be used to improve the optical efficiency.

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.

LP8553 has safety features which make it possible to detect LED outputs with open or short fault. Low input voltage and boost over-current conditions are also monitored, and the chip is turned off when these events occur. Thermal de-rating function prevents overheating of the device by reducing backlight brightness when set temperature has been reached.

LP8553 is available in TI’s DSBGA 25-bump package.

Features

  • 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 VSYNC
    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 × 2.466 × 0.6 mm

Parametrics

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Part number Order Channels (#) Vin (Min) (V) Vin (Max) (V) Vout (Min) (V) Vout (Max) (V) Switching frequency (Max) (kHz) Type LED current per channel (mA) LED (#) Topology Shutdown current (Typ) (uA) Peak efficiency (%) LED configuration Function Features Operating temperature range (C) Package Group Package size: mm2:W x L (PKG)
LP8553 Order now 4     2.7     22     10     40     1250     Inductive     50     40     Boost     1     93         PWM Control     -30 to 85     DSBGA | 25     See datasheet (DSBGA)    
LP8555 Order now 12     2.7     20     7     28     1000     Inductive     50     96     Boost     3     93     6 LED channels
Dual
Parallel    
Backlight     Adjustable Switch Frequency
Analog/PWM Mixed Dimming
CABC
Edge Rate Control
I2C Control
Integrated Switch
OVP
PWM Control
Thermal Shutdown    
-40 to 85     DSBGA | 36     See datasheet (DSBGA)    
LP8556 Order now 6     2.7     20     7     48     1250     Inductive     50     60     Boost     0.1     95     Parallel       I2C Control     -30 to 85     DSBGA | 20
WQFN | 24    
See datasheet (DSBGA)
24WQFN: 16 mm2: 4 x 4 (WQFN | 24)    
LP8557 Order now 6     2.7     5.5     7     28     1000     Inductive     25     48     Boost     0.001     93     6 LED channels
Parallel    
  CABC
Edge Rate Control    
-30 to 85     DSBGA | 16     See datasheet (DSBGA)    
TPS61177A Order now 6     2.5     24     4.5     39     1200     Inductive     30     60     Boost     5     95     Dual
Parallel
Series    
  Analog Dimming