White LED Driver Offers Dynamic Backlight Control
- Created on Tuesday, 01 September 2009
Portable media devices have increasingly larger displays and longer video playback, and require more power. The LM3530 from National Semiconductor Corp. (Santa Clara, CA) employs ambient light-sensing algorithms and content-adjustable backlighting to optimize displays, saving 55 percent of power.
The LM3530 LED driver has a 12-bump micro SMD package measuring only 1.615 mm × 1.215 mm × 0.425 mm. Logarithm and linear LED brightness mapping provides flicker-free dimming, and a fixed-frequency, 500 kHz boost converter provides high efficiency over the LED current range.
The LM3530 current-mode boost converter can supply up to 29.5 mA of power to 11 white LEDs from a single-cell lithium-ion battery. A I2C compatible interface allows the designer to adjust for lighting effects like fading, external ambient conditions and lighting level, as well as brightness and image performance.