LP8552 High-Efficiency LED Backlight Driver for Notebooks | TI.com

LP8552 (ACTIVE)

High-Efficiency LED Backlight Driver for Notebooks

 

Recommended alternative parts

  • TPS61177  - The device has the SAME FUNCTIONALITY as the compared device, but is not pin-for-pin equivalent and may not be parametrically equivalent.   TPS61177 is recommned if 24V Vin and/or QFN package is required
  • LP8557  - The device has the SAME FUNCTIONALITY as the compared device, but is not pin-for-pin equivalent and may not be parametrically equivalent.   LP8557 is optimised for 1-Cell Tablet architecture designs
  • LP8553  - The device has the SAME FUNCTIONALITY as the compared device, but is not pin-for-pin equivalent and may not be parametrically equivalent.   Supports 4 channel (instead of 6)

Description

The LP8552 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.

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.

The LP8552 has safety features which make it possible to detect LED outputs with open or short fault. As well low input voltage and boost overcurrent 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.

Features

  • High-Voltage DC/DC Boost Converter with Integrated FET
    with Four Switching Frequency Options: 156/312/625/1250 kHz
  • 2.7-V to 22-V 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-Compatible 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
  • 6 LED Outputs with LED Fault (Short/Open) Detection
  • Low Input Voltage, Over-temperature, Overcurrent Detection,
    and Shutdown
  • Minimum Number of External Components

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Parametrics Compare all products in Backlight LED drivers

 
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
Features
Operating temperature range (C)
Package Group
Package size: mm2:W x L (PKG)
LP8552
6    
2.7    
22    
10    
40    
1250    
Inductive    
50    
66    
Boost    
1    
93    
6 LED channels
Parallel    
Adjustable Switch Frequency
Enable/Shutdown
I2C Control
PWM Control    
-40 to 85    
DSBGA | 25    
See datasheet (DSBGA)