LT1942

U U FEATURES ■ Triple Output TFT Supply with Built-In Power Sequencing ■ Integrated White LED Backlight Driver ■ Integrated Schottky Diodes ■ Active Ballast Circuitry Ensures Precise Current Matching in White LEDs ■ Low Noise 1MHz Fixed Frequency Operation ■ 2.6V to 16V Input Voltage Range ■ Soft-Start Limits Inrush Current ■ TFT Supply Output Voltages Independently Set (Not Charge Pump Derived) ■ Power Good and Output Disconnect for TFT Supply ■ Built-In LED Dimming Capability ■ Open LED Protection for LED Driver ■ 24-Lead QFN Package (4mm × 4mm) U APPLICATIO S ■ Poly-Silicon TFT Displays ■ Amorphous Silicon TFT Displays , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. LT1942 Quad DC/DC Converter for Triple Output TFT Supply Plus LED Driver DESCRIPTIO The LT®1942 is a highly integrated quad switching regulator designed to provide all necessary power supply functions for TFT displays, including the white LED backlight driver. The TFT supply incorporates two boost and one inverting DC/DC converters. The TFT supply output voltages are independently set, unlike charge pump solutions which have many limitations. Power sequencing for the TFT supply is built into the part and is user programmable. The LED driver is a boost DC/DC converter that can be independently controlled. The LED driver has built-in dimming control for precise control of LED current. An 8:1 dimming range is achieved...