Fairchild公司的FL7701是带PFC功能的智能LED灯驱动器,内置了高压自偏置电路,输入电压范围80VAC ~ 308VAC,带自动重起模式的AOCP功能,内置超温保护功能,主要用于装饰LED灯和低功率LED灯.本文介绍了FL7701主要特性,方框图,典型和高压应用电路以及带和不带电解电容的应用电路,2.4W LED镇流器电路图,材料清单和PCB布局图.
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应用:
 LED Lamp for Decorative Lighting
 LED Lamp for Low-Power Lighting

图1.FL7701方框图

图2.FL7701典型应用电路图

图3.FL7701高压应用电路图

图4.FL7701无电解电容的应用电路

图5.FL7701带电解电容的应用电路

采用FL7701的2.4W LED镇流器

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.



图6.2.4W LED镇流器外形图

图7.2.4W LED镇流器电路图
2.4W LED镇流器材料清单:




图8.2.4W LED镇流器PCB布局图