Fairchild FL7733A宽输入电压50W LED驱动方案

Fairchild公司的FL7733A是用在单级反激拓扑或降压-升压拓扑的有源功率因素修正(PFC)控制器,由于降低外接元件数量和次级反馈电路而最大限度降低成本,并提供了LED开路,短路和超温保护功能,输入电压80 VAC ~ 308 VAC.本文介绍了FL7733A主要特性, 框图和宽输入电压90 VRMS ~ 277 VRMS  50W LED驱动器主要指标,电路图,材料清单和PCB设计文件.
The FL7733A is an active Power Factor Correction (PFC) controller for use in singlestage flyback topology or buck-boost topology. Primary-side regulation and single-stage topology minimize cost by reducing external components such as the input bulk capacitor and secondary side feedback circuitry. To improve power factor and Total Harmonic Distortion (THD), constant on-time control is utilized with an internal error amplifier and a low bandwidth compensator. Precise constant-current control provides accurate output current, independent of input voltage and output voltage. Operating frequency is proportionally changed by the output voltage to guarantee Discontinuous Current Mode (DCM) operation, resulting in high efficiency and simple designs. The FL7733A also provides open-LED, short-LED, and over-temperature protection functions.
FL7733A主要特性:
High Performance
 Cost Effective Solution without requiring the use of an Input Bulk Capacitor and Secondary-Side Feedback Circuitry
 Power Factor Correction
 THD <10% over Universal Line Range
 CC Tolerance:
o < ±1% by Universal Line Voltage Variation
o < ±1% by 50% ~ 100% Load Voltage Variation
o < ±1% by ±20% Magnetizing Inductance Variation
 High-Voltage Startup with VDD Regulation
 Adaptive Feedback Loop Control for Startup without Overshoot
High Reliability
 LED Short / Open Protection
 Output Diode Short Protection
 Sensing Resistor Short / Open Protection
 VDD Over-Voltage Protection (OVP)
 VDD Under-Voltage Lockout (UVLO)
 Over-Temperatur...