ADI’s WLED Charge-Pump Backlight Driver

Aug 27, 2010 Analog Devices, Inc. (ADI) of Norwood, Massachusetts USA, a producer of semiconductors for signal-processing applications, has introduced its new white LED charge-pump backlight driver - ADP8870.

ADI notes that the ADP8870 can lowers the power consumption of battery-operated handheld devices by up to 45 percent without compromising viewing quality.
The ADP8870 combines three key functions: a programmable backlight LED charge-pump driver with inputs for a photo transistor to automatically control the LED brightness and a PWM (pulse-width modulation) input to manage the scale of the output current.

ADI points out that this combination of features significantly reduces power use by automatically changing the current intensity based on the ambient lighting levels and the white content of the displayed image. By performing this function automatically, the ADP8870 eliminates the need for a processor to monitor the phototransistor, further reducing power requirements and simplifying the portable backlight design.

The ADP8870 controls up to seven LEDs either grouped together for backlight control or used independently for keypad illumination, indicator lighting or fun lighting1. The fading of each LED is programmable allowing the designer to customize the fade-in, fade-out, dim and off times.

www.analog.com
Author:  BIO T&T