Fairchild公司的FL7701是帶PFC功能的智能LED燈驅(qū)動器,內(nèi)置了高壓自偏置電路,輸入電壓范圍80VAC ~ 308VAC,帶自動重起模式的AOCP功能,內(nèi)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(yīng)用電路以及帶和不帶電解電容的應(yīng)用電路,2.4W LED鎮(zhèn)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(yīng)用:
LED Lamp for Decorative Lighting
LED Lamp for Low-Power Lighting
圖1.FL7701方框圖
圖2.FL7701典型應(yīng)用電路圖
圖3.FL7701高壓應(yīng)用電路圖
圖4.FL7701無電解電容的應(yīng)用電路
圖5.FL7701帶電解電容的應(yīng)用電路
采用FL7701的2.4W LED鎮(zhèn)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(zhèn)流器外形圖
圖7.2.4W LED鎮(zhèn)流器電路圖
2.4W LED鎮(zhèn)流器材料清單:
圖8.2.4W LED鎮(zhèn)流器PCB布局圖 |
