[原创] Fairchild FL7794 PWM调光大功率LED AC直接驱动方案

Fairchild公司的FL7794是直接从AC线驱动的LED驱动器,从而最小化外接RC无源元件的数量,输入电压90~305 VAC.正常配置下一个电阻可调整LED功率,一个电容提供稳定电压来偏置内部并联稳压器.器件提供模拟/PWM可调光特性,采用高PF和低的THD可获得高效率,主要用于高稳定的大功率LED照明系统.本文介绍了FL77944主要特性,框图,以及12W评估板FEBFL77944A4测试条件,电路图和材料清单.

The FL77944 is a direct AC line LED driver with a minimal number of external RC passive components. In normal configuration, one resistor is to adjust LED power, and one capacitor is to provide a stable voltage to an internal biasing shunt regulator.

The FL77944 provides phase-cut dimming with wide dimming range, smooth dimming control and good dimmer compatibility. It achieves high efficiency with high PF and low THD, which makes the FL77944 suitable for high-efficiency LED lighting systems. The FL77944 has a dedicated DIM pin which can be used with analog or digital PWM dimming. The FL77944 can also be used with a rheostat dimmer switch which is suitable for desktop or indoor lamps.

Operation of FL77944 admits driving higher-wattage systems, such as street lights and down lights, by simply parallel connecting the driver ICs.

FL77944主要特性:

The simplest Direct AC LED Driver with Only Two External RC Passive Component..

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