LP8553 Series

Four channel high-efficiency LED backlight driver for notebooks with 3.3V PWM logic level

Catalog

Four channel high-efficiency LED backlight driver for notebooks with 3.3V PWM logic level

Part	Applications	Operating Temperature [Min]	Operating Temperature [Max]	Package / Case	Number of Outputs	Internal Switch(s)	Mounting Type	Type	Topology	Voltage - Supply (Max) [Max]	Supplier Device Package	Voltage - Output	Dimming
Texas Instruments LP8553TLE/NOPB	Backlight	-30 °C	85 °C	25-WFBGA DSBGA	4		Surface Mount	DC DC Regulator	Step-Up (Boost)	22 V	25-DSBGA	40 V	PWM

Catalog

Four channel high-efficiency LED backlight driver for notebooks with 3.3V PWM logic level

Key Features

• High-Voltage DC/DC Boost Converter with Integrated FETwith Four Switching Frequency Options: 156/312/625/1250 kHz2.7V to 22V Input Voltage Range to Support 1x…5x CellLi-Ion BatteriesProgrammable PWM Resolution8 to 13 True Bit (Steady State)Additional 1 to 3 Bits Using Dithering During BrightnessChangesI2C and PWM Brightness ControlAutomatic PWM & Current Dimming for ImprovedEfficiencyPWM Output Frequency and LED Current Set ThroughResistorsOptional Synchronization to Display VSYNCSignal4 LED Outputs with LED Fault (Short/Open) DetectionLow Input Voltage, Over-Temperature, Over-Current Detectionand ShutdownMinimum Number of External ComponentsDSBGA 25-Bump Package, 2.466 × 2.466 × 0.6 mmHigh-Voltage DC/DC Boost Converter with Integrated FETwith Four Switching Frequency Options: 156/312/625/1250 kHz2.7V to 22V Input Voltage Range to Support 1x…5x CellLi-Ion BatteriesProgrammable PWM Resolution8 to 13 True Bit (Steady State)Additional 1 to 3 Bits Using Dithering During BrightnessChangesI2C and PWM Brightness ControlAutomatic PWM & Current Dimming for ImprovedEfficiencyPWM Output Frequency and LED Current Set ThroughResistorsOptional Synchronization to Display VSYNCSignal4 LED Outputs with LED Fault (Short/Open) DetectionLow Input Voltage, Over-Temperature, Over-Current Detectionand ShutdownMinimum Number of External ComponentsDSBGA 25-Bump Package, 2.466 × 2.466 × 0.6 mm

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. 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.