原标题：Diodes AL9910通用高压高亮LED驱动方案

　　Diodes 公司的AL9910/A是PWM高效高压高亮LED驱动器控制集成电路.源电压从85VAC到256VAC,输入电压高达500V. AL9910能以固定频率高达300kHz驱动外接MOSFET,输出电流从几毫安到大于1.0A,效率高于90%,主要应用在DC/DC或AC/DC LED驱动器,RGB背光LED驱动器,平板显示器背光,通用恒流源以及装饰LED照明.本文介绍了AL9910/A主要特性,功能方框图, 典型应用电路图和带与不带无源PFC的典型应用电路图.

　　UNIVERSAL HIGH VOLTAGE HIGH BRIGHTNESS LED DRIVER、

　　The AL9910/A is a PWM high-efficiency LED driver control IC. It allows efficient operation of High Brightness (HB) LEDs from voltage sources ranging from 85VAC up to 265VAC. The AL9910 controls an external MOSFET at fixed switching frequency up to 300kHz. The frequency can be programmed using a single resistor. The LED string is driven at constant current and provides constant light output and enhanced reliability. The output current can be programmed between a few milliamps and up to more than 1.0A.

　　The AL9910 uses a rugged high voltage junction isolated process that can withstand an input voltage surge of up to 500V. Output current to an LED string can be programmed to any value between zero and its maximum value by applying an external control voltage at the linear dimming control input of the AL9910. The AL9910 provides a low-frequency PWM dimming input that can accept an external control signal with a duty ratio of 0-100% and a frequency of up to a few kHz.

　　As well as standard SO-8 package the AL9910 is available in the thermally enhanced SO-8EP package.

　　AL9910/A主要特性:

　　• >90% Efficiency

　　• Universal rectified 85 to 265VAC input range

　　• Input voltage surge ratings up to 500V

　　• Internal voltage regulator removes start-up resistor

　　o 7.5V MOSFET drive – AL9910

　　o 10V MOSFET drive – AL9910A

　　• Drives LED Lamps from a few mA to more than 1A

　　• PWM Low-Frequency Dimming via Enable pin

　　• Internal Thermal Protection (OTP)

　　• SO-8 and SO-8EP in “Green” Molding Compound (No Br, Sb)

　　• Lead Free Finish/ RoHS Compliant

　　AL9910/A应用:

　　• DC/DC or AC/DC LED Driver application

　　• RGB Backlighting LED Driver

　　• Back Lighting of Flat Panel Displays

　　• General purpose constant current source

　　• Signage and Decorative LED Lighting

　　图1.AL9910/A功能方框图

　　图2.AL9910/A典型应用电路图

　　图3.AL9910/A典型应用电路图(无PFC)

　　图4.AL9910/A带无源PFC的典型应用电路图