Date: 04/06/2010

Charge pump based LED backlight drivers with adaptive switching control enhance LED efficiency

Maxim has introduced the charge pump based LED backlight drivers for driving 6 or 7 white LEDs (WLEDs). MAX8847/MAX8848 backlight LED drivers use negative-charge-pump architecture to eliminate in-line resistance from the battery to WLEDs. As a result, mode switching from 1x to 1.5x is delayed during battery discharge, thereby minimizing dropout. These drivers use the adaptive-mode-switching technology to control each LED individually. The usage of this technology is said to increase LED efficiency by 12% and thus is suggested for cell phones, smartphones, digital still cameras, and other portableLCD fitted devices.

The MAX8847/MAX8848 is suggestest for replacing clumsy inductor-boost LED drivers to save the space on the PCB board. MAX8847/MAX8848 consists of a serial pulse/PWM interface to control each LED, which enables multizone light management and allows up to 32 brightness levels. These drivers consume quiescent current of 120µA and also facilitates "always-on" displays that require minimal power. MAX8847/MAX8848 provides high LED current accuracy (±2%, max) and is said to ensure even brightness and minimizes power dissipation. These driver ICs also features built-in temperature derating and overvoltage protection thus extending the life of the LEDs.

Package: 3mm x 3mm, 16-pin TQFN package.

Price: starts at US$1.95

For more information visit: www.maxim-ic.com