LT1943

U U LT1943 High Current Quad Output Regulator for TFT LCD Panels FEATURES ■ 4 Integrated Switches: 2.4A Buck, 2.6A Boost, 0.35A Boost, 0.35A Inverter (Guaranteed Minimum Current Limit) ■ Fixed Frequency, Low Noise Outputs ■ Soft-Start for all Outputs ■ Externally Programmable VON Delay ■ Integrated Schottky Diode for VON Output ■ PGOOD Pin for AVDD Output Disconnect ■ 4.5V to 22V Input Voltage Range ■ PanelProtectTM Circuitry Disables VON Upon Fault ■ Available in Thermally Enhanced 28-Lead TSSOP U APPLICATIO S ■ Large TFT-LCD Desktop Monitors ■ Flat Panel Televisions , LTC and LT are registered trademarks of Linear Technology Corporation. PanelProtect is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. DESCRIPTIO The LT®1943 quad output adjustable switching regulator provides power for large TFT LCD panels. The device, housed in a low profile 28 pin thermally enhanced TSSOP package, can generate a 3.3V or 5V logic supply along with the triple output supply required for the TFT LCD panel. Operating from an input range of 4.5V to 22V, a step-down regulator provides a low voltage output VLOGIC with up to 2A current. A high-power step-up converter, a lowerpower step-up converter and an inverting converter provide the three independent output voltages AVDD, VON and VOFF required by the LCD panel. A high-side PNP provides delayed turn-on of the VON signal and can handle up to 30mA. Protection circuitry ensures that ...