Fairchild FL7730 8.4W调光LED驱动方案.docx

Fairchild FL7730 8.4W调光LED驱动方案关键词：/search/?q=%B5%E7%D4%B4%B9%DC%C0%ED电源管理,/search/?q=LED%C7%FD%B6%AF%C6%F7LED驱动器,/search/?q=+PWM?PWM,/search/?q=AC%2FDC%D7%AA%BB%BB%C6%F7AC/DC转换器Fairchild公司的FL7730是高度集成的PWM控制器,为单级反激转换器提供增强的性能,其有所有权的TRUECURRENT?拓扑简化了LED照明的电路设计.应用电压80VAC ~ 308VAC,起动电流20uA,工作电流5mA,采用跳频有更好的EMI性能,主要用在LED照明系统.本文介绍了FL7730主要特性,方框图,典型应用电路以及采用FL7730的TRIAC调光180V-265VAC和90-140VAC 的LED驱动器参考设计电路图.FL7730MY: Single-Stage Primary-Side-Regulation PWM Controller for PFC and LED Dimmable DrivingThis highly integrated PWM controller, FL7730MY, provides several features to enhance the performance of single-stage flyback converters. The proprietary topology, TRUECURRENT?, enables the simplified circuit design for LED lighting applications.TRIAC dimming is smoothly managed by dimming brightness control without flicker. By using single-stage topology with primary-side regulation, an LED lighting board can be implemented with few external components and minimized cost. It does not require an input bulk capacitor or feedback circuitry. To implement good power factor and low total harmonic distortion, constant on-time control is utilized with an external capacitor connected to the COMI pin.Precise constant-current control regulates accurate output current versus changes in input voltage and output voltage. The operating frequency is proportionally changed by the output voltage to guarantee Discontinuous Conduction Mode (DCM) operation with higher efficiency and simpler design. The FL7730MY provides protections such as open-LED, short-LED, and over-temperature protections. Current-limit level is automatically reduced to minimize output current and protect external components in a short-LED condition.The FL7730MY frequency-hopping function in the oscillator improves EMI performance. The FL7730MY controller is available in an 8-pin SOP package.FL7730主要特性: Compatible with Traditional TRIAC Control (No need to change existing lamp infrastructure: wall switch wire) Compatible with No