GENERAL DESCRIPTION
Regulated internal current sources deliver excellent current and brightness matching in all LEDs. The primary group (4 LEDs) can be used to backlight the main phone display. The second group (3 LEDs) can be used to backlight a secondary display or to provide other lighting features (keypad LEDs, for example). Brightness of the two groups can be adjusted independently with pulsewidth modulated (PWM) digital signals. The LM2796 works off an extended Li-Ion input voltage range (2.7V to 5.5V). Voltage boost is achieved with a highefficiency 3/2x-gain charge pump. The LM2796 is available in National’s chip-scale 18-bump micro SMD package. FEATURES
n Drives up to 7 LEDs with up to 20mA each n LEDs controlled in 2 Distinct Groups, for Backlighting 2 Displays (main LCD and sub-LCD) n Excellent Current and Brightness Matching n High-Efficiency 3/2x Charge Pump n Extended Li-Ion Input: 2.7V to 5.5V n PWM Brightness Control: 100Hz - 1kHz n 18-bump Thin Micro SMD Package: (2.1m...
National Semiconductor
