Fairchild公司的FL7701是帶PFC功能的智能LED燈驅動(dòng)器,內置了高壓自偏置電路,輸入電壓范圍80VAC ~ 308VAC,帶自動(dòng)重起模式的AOCP功能,內置超溫保護功能,主要用于裝飾LED燈和低功率LED燈.本文介紹了FL7701主要特性,方框圖,典型和高壓應用電路以及帶和不帶電解電容的應用電路,2.4W LED鎮流器電路圖,材料清單和PCB布局圖.
The FL7701 LED lamp driver is a simple IC with PFC function. The special “adopted digital” technique of the IC can automatically detect input voltage condition and send an internal reference signal for achieving high power factor. When AC input is applied to the IC, PFC function is automatically enabled. Otherwise, when DC input is applied to the IC, PFC function is automatically disabled. The FL7701 does not need a bulk capacitor(electrolytic capacitor) for supply rail stability, which can significantly affect to LED lamp system.

FL7701主要特性:
 Digitally Implemented Active PFC Function (No Additional Circuit Necessary for High PF)
 Built-in HV Supplying Circuit: Self Biasing
 Application Input Range :80VAC ~ 308VAC
 AOCP Function with Auto-Restart Mode
 Built-in Over-Temperature Protection Function
 Cycle-by-Cycle Current Limit
 Current-Sense Pin Open Protection
 Low Operating Current: 0.85mA (Typical)
 Under-Voltage Lockout with 5V Hysteresis
 Programmable Oscillation Frequency
 Programmable LED Current
 Analog Dimming Function
 Soft-Start Function
 Precise Internal Reference: ±3%

FL7701應用:
 LED Lamp for Decorative Lighting
 LED Lamp for Low-Power Lighting

圖1.FL7701方框圖

圖2.FL7701典型應用電路圖

圖3.FL7701高壓應用電路圖

圖4.FL7701無(wú)電解電容的應用電路

圖5.FL7701帶電解電容的應用電路

采用FL7701的2.4W LED鎮流器

This document describes the proposed solution for a universal-input 2.4W LED ballast using the FL7701. The input voltage range is 90VRMS – 265VRMS and there is one DC output with a constant current of 85mA at 28VMAX. This document contains general description of FL7701, the power supply specification, schematic, bill of materials, and the typical operating characteristics.



圖6.2.4W LED鎮流器外形圖

圖7.2.4W LED鎮流器電路圖
2.4W LED鎮流器材料清單:




圖8.2.4W LED鎮流器PCB布局圖