Linear LT3513 5输出LCD电源方案

Linear 公司的LT3513是 5输出的可调开关稳压电源,可用作大型TFT-LCD屏电源. LT3513能产生3.3V或5.0V逻辑电源,而输入电压为4.5V到30V,并集成了四个开关:2.5A降压开关,1.6A升压开关,0.25A升压开关和0.25A的反向开关.所有的输出具有软起动功能,主要应用在汽车电子TFT-LCD显示屏,大型TFT-LCD台式监视器和平板电视机.本文介绍了LT3513的主要特性,方框图以及典型应用电路.

The LT3513 5-output adjustable switching regulator provides power for large TFT-LCD panels. The 38-pin 5mmx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.

LT3513主要特性:
4.5V to 30V Input Voltage Range
Four Integrated Switches: 2.5A Buck, 1.6A 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 5mmx7mm QFN Package
LT3513应用:
Automotive TFT-LCD Displays
Large TFT-LCD Desktop Monitors
Flat Panel Televisions




图1. LT3513方框图



图2.LT3513典型应用电路