LP8553
高效率LED背光驱动器的笔记本电脑 High-Efficiency LED Backlight Driver for Notebooks
The 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 s DSBGA 25-bump package.
- .
- 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