
Linear Technology
DESCRIPTION
The LT®3513 5-output adjustable switching regulator provides power for large TFT-LCD panels. The 38-pin 5mm × 7mm QFN device can generate a 3.3V or 5V logic supply along with the triple output supply required for the TFT-LCD panel. A lower voltage secondary logic supply may also be generated with the addition of an external NPN driven by the internal linear regulator. A step-down regulator provides a low voltage output, VLOGIC, with up to 1.2A of current while capable of operating from a wide input range of 4.5V to 30V. A high power step-up converter, a lower power 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 VON is disabled if any of the four outputs are more than 10% below the programmed voltage.
FEATURES
■ 4.5V to 30V Input Voltage Range
■ Four Integrated Switches: 2.2A Buck, 1.5A Boost, 0.25A Boost, 0.25A Inverter (Guaranteed Minimum Current Limit)
■ External NPN LDO Driver
■ Fixed Frequency, Low Noise Outputs
■ Inductor Current Sense for Buck
■ Soft-Start for All Outputs
■ Externally Programmable VON Delay
■ Three Integrated Schottky Diodes
■ PGOOD Pin for AVDD Output Disconnect
■ PanelProtectTM Circuitry Disables VON Upon Fault
■ Thermally Enhanced 38-Lead 5mm × 7mm QFN Package
APPLICATIONS
■ Automotive TFT-LCD Displays
■ Large TFT-LCD Desktop Monitors
■ Flat Panel Televisions