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.