Advanced Analogic Technologies, Inc. (Santa Clara, CA) introduced its AAT1409/7/5 family of multi-string LED backlight drivers with integrated boost converters and precision current sinks that can support up to 88 LEDs at 360mA total LED current. The drivers reduce the number of backlight PCBs and cost.
TheAAT1409/7/5 drivers from AnalogicTech™ operate from DC inputs, cigarette lighter adapters, or multi-cell Li-ion batteries over the 4.5V to 26V range. The family is available in 8, 6, and 4 channels making them ideal for driving white LED (WLED) edge backlighting for LCD panels ranging from 10 to 22 inches in size. The drivers also support up to 100 kHz PWM dimming frequency to ensure silent operation.
An additional consideration is that many portable LCD devices are battery-powered and operate under low ambient lighting conditions or in power saving modes, so require low level backlight dimming to extend battery run time. The AAT1409/7/5 addresses this with a design that maintains high efficiency during low PWM duty cycles to reduce wasted energy during light load conditions. The driver’s high-resolution 1000:1 PWM dimming range delivers precise control of backlight brightness, equivalent to a 10-bit resolution.