AAT1235

The AAT1235 is a highly integrated, high efficiency power solution for white LED backlight and keypad backlights in mobile/portable devices. It is based on a switching boost converter which steps up the single- cell lithium-ion/polymer battery voltage to drive 5 strings of series-connected white LEDs with preci- sion current regulation.

The AAT1235 is capable of driving a total of four LEDs per channel. The boost converter can produce an output drive of up to 24V at 100mA. The high switching frequency (up to 2MHz) provides fast response to load tran- sients and allows the use of small external compo- nents.

Afully integrated control circuit simplifies the design and reduces total solution size. AnalogicTech's Advanced Simple Serial Control? 2 (AS Cwire?) serial digital input is used to individual- ly turn each output sink on/off and adjust the LED current by group. Unlike conventional pulse width modulation (PWM) control of LED brightness, the AAT1235 drives the LEDs with constant, non-pulsat- ing current. 2 Asimilar device is also available with an I C two- wire interface; please see the AAT1236 datasheet.

The AAT1235 is available in a Pb-free, thermally- enhanced 16-pin 3x4mm TDFN package and is specified for operation over the -40!aC to +85!aC te perature range.