The LP8543 is a white LED driver with integrated boost converter. It has 7 adjustable
current sinks which can be controlled by SMBus or I2C-compatible serial
interface, PWM input and Ambient Light Sensor (ALS).
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. Phase Shift PWM dimming offers further power saving especially when there is poor
matching in the forward voltages of the LED strings. Boost voltage can also be controlled through
the SMBus/I2C.
Internal EEPROM stores the data for backlight brightness and ambient light sensor
calibration. Brightness can be calibrated during the backlight unit production so that all units
produce the same brightness. EEPROM also stores the coefficients for the LED control equations and
the default LED current value. LED current has 8–bit adjustment from 0 to 60 mA.
The LP8543 has several safety and diagnostic features. Low-input voltage detection turns
the chip off if the system gets stuck and battery fully discharges. Input voltage detection
threshold is adjustable for different battery configurations. Thermal regulation reduces backlight
brightness above a set temperature. LED fault detection reports open or LED short fault. Boost
over-current fault detection protects the chip in case of over-current event.
LP8543 is available in the WQFN 24-pin package.
The LP8543 is a white LED driver with integrated boost converter. It has 7 adjustable
current sinks which can be controlled by SMBus or I2C-compatible serial
interface, PWM input and Ambient Light Sensor (ALS).
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. Phase Shift PWM dimming offers further power saving especially when there is poor
matching in the forward voltages of the LED strings. Boost voltage can also be controlled through
the SMBus/I2C.
Internal EEPROM stores the data for backlight brightness and ambient light sensor
calibration. Brightness can be calibrated during the backlight unit production so that all units
produce the same brightness. EEPROM also stores the coefficients for the LED control equations and
the default LED current value. LED current has 8–bit adjustment from 0 to 60 mA.
The LP8543 has several safety and diagnostic features. Low-input voltage detection turns
the chip off if the system gets stuck and battery fully discharges. Input voltage detection
threshold is adjustable for different battery configurations. Thermal regulation reduces backlight
brightness above a set temperature. LED fault detection reports open or LED short fault. Boost
over-current fault detection protects the chip in case of over-current event.
LP8543 is available in the WQFN 24-pin package.