Catalog
High-efficiency LED backlight driver for Tablet PCs
Key Features
• Dual High-Efficiency DC/DC Boost Converters2.7-V to 20-V VDD Range12 50-mA High-Precision LED CurrentSinks With 12-Bit Brightness ControlAdaptive LED Current Sink HeadroomControls for Maximum System EfficiencyLED String Count Auto-DetectionPhase-Shifted PWM Mode for Reduced AudibleNoisePWM Input Duty-Cycle and/or I2C-RegisterBrightness ControlHybrid PWM and Current Dimming for Higher LEDDrive Optical EfficiencyFlexible CABC SupportEPROM, I2C-Register, or External Resistorsfor ConfigurationImproved Boost EMI Performance with Slew-Rate Control,Spread Spectrum, and Phase-Shifted SwitchingExtensive Fault Detection SchemesDual High-Efficiency DC/DC Boost Converters2.7-V to 20-V VDD Range12 50-mA High-Precision LED CurrentSinks With 12-Bit Brightness ControlAdaptive LED Current Sink HeadroomControls for Maximum System EfficiencyLED String Count Auto-DetectionPhase-Shifted PWM Mode for Reduced AudibleNoisePWM Input Duty-Cycle and/or I2C-RegisterBrightness ControlHybrid PWM and Current Dimming for Higher LEDDrive Optical EfficiencyFlexible CABC SupportEPROM, I2C-Register, or External Resistorsfor ConfigurationImproved Boost EMI Performance with Slew-Rate Control,Spread Spectrum, and Phase-Shifted SwitchingExtensive Fault Detection Schemes
Description
AI
The LP8555 is a high efficiency LED driver with integrated dual DC-DC boost converters. It has 12 high-precision current sinks that can be controlled by a PWM input signal, an I2C master, or both.
Dual-boost configuration of LP8555 shares the load to two inductors and allows thinner overall solution size and better efficiency compared to single-boost solutions. 12 LED strings allows driving high number of LEDs with optimal efficiency since boost conversion ratio can be kept low.
The boost converter has adaptive output voltage control based on the LED current sink headroom voltages. This feature minimizes the power consumption by adjusting the voltage to lowest sufficient level in all conditions.
The LED string auto-detect function enables use of the same device in systems with 2 to 12 LED strings for the maximum design flexibility. Proprietary Hybrid PWM and Current dimming mode enables additional system power savings. Phase-shift PWM allows reduced audible noise and smaller boost output capacitors. Flexible CABC support combines brightness level selections based on the PWM input and I2C commands.
The LP8555 is a high efficiency LED driver with integrated dual DC-DC boost converters. It has 12 high-precision current sinks that can be controlled by a PWM input signal, an I2C master, or both.
Dual-boost configuration of LP8555 shares the load to two inductors and allows thinner overall solution size and better efficiency compared to single-boost solutions. 12 LED strings allows driving high number of LEDs with optimal efficiency since boost conversion ratio can be kept low.
The boost converter has adaptive output voltage control based on the LED current sink headroom voltages. This feature minimizes the power consumption by adjusting the voltage to lowest sufficient level in all conditions.
The LED string auto-detect function enables use of the same device in systems with 2 to 12 LED strings for the maximum design flexibility. Proprietary Hybrid PWM and Current dimming mode enables additional system power savings. Phase-shift PWM allows reduced audible noise and smaller boost output capacitors. Flexible CABC support combines brightness level selections based on the PWM input and I2C commands.
