Date: 19/08/2010

LED backlight driver IC from AnalogicTech can drive string of 88 LEDs

Advanced Analogic Technologies has unveiled the AAT1409/7/5 family of multi-string LED backlight drivers. AAT1409/7/5 integrates boost converters and precision current sinks to drive 88 LEDs at 360mA total LED current.

“As LCD displays continue to gain traction in the computing, consumer and industrial markets, features like power, efficiency, accuracy and flexibility of the backlight drivers are all critical differentiators,” said Ray Chan, technical marketing manager at AnalogicTech. “By offering a product family designed for a specific range of LCD panels – 10-inch to 22-inch in this case – we are able to offer a very powerful and effective approach to LCD power management.”

The AAT1409/7/5 LED driver chips operate from DC voltage in 4.5V to 26V range. The family is available in 8, 6 and 4 channels for driving backlights of LCD display panels in the sizes of 10 to 22 inches. The drivers also support up to 100 kHz PWM dimming frequency to ensure silent operation.

The AAT1409/7/5 supports backlight dimming to extend battery run time in portable tablets and smartphones. . These drivers offer 1000:1 PWM dimming range to precisely control of backlight brightness, equivalent to a 10-bit resolution.

Other features and benefits:
High-efficiency light load mode achieves up to 88 percent conversion efficiency at a 5 percent dimming duty cycle
100kHz PWM dimming frequency and optionally synchronized switching frequency to system clock reduces audible noise
+/- 2 percent LED current accuracy and matching between strings
Selectable switching frequency accommodates various inductor and capacitor sizes
Up to 92 percent efficiency over wide input voltage (VIN) range of 4.5V to 26.0V
LX rated to 50V
Up to eight LED current sinks at 45mA each
Flexible configurations with disable or parallel channels
Open/shorted LEDs enable fault tolerance
Current limit protection, over-voltage protection and over-temperature protection
Soft-start to minimize inrush current

Package: TQFN34-24 low profile package

Operating temperature range: -40 C to +85C

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