GENERAL DESCRIPTION
Up to four backlight LEDs can be driven at up to 30mA each and keypad LEDs can be driven using lower currents set by the S2Cwire interface. In addition, up to four flash LEDs can be driven with up to 600mA total. Two separate S2Cwire™ (Simple Serial Control™) serial digital interfaces are used to enable, disable, and set the current to one of 16 levels for both backlight and flash LEDs. Backlight/keypad and flash current settings are also controlled through external resistors for increased versatility with reduced accuracy and matching. Backlight/keypad current matching is 1% for uniform display brightness, and flash current matching is 4% for uniform power dissipation. An integral flash timer set by an external capacitor protects the flash LED should a fault occur. A single enable input controls both regulators and each supplies up to 200mA to the load. Both LDOs consume only 85µA quiescent current, making them ideal for battery-operated applications. The AAT2842 is equipped with built-in short-circuit and over-temperature protection.
ANALOGICTECH
