Fairchild 公司的FL7701是帶PFC功能的智能LED燈驅動器，內置高壓自偏壓電路，數字實現有源PFC功能，帶自動重起模式的AOCP功能，內置超溫保護功能，典型的工作電流0.85mA，可編程振蕩器頻率和LED電流，主要用在LED裝飾照明和低功率LED照明。本文介紹了FL7701主要特性，方框圖，有和沒有電解電容的應用電路圖以及2.52W參考設計主要特性和指標，電路圖和PCB布局圖。

FL7701：Smart LED Lamp Driver IC with PFC function

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

? 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沒有電解電容的應用電路圖

圖3。FL7701有電解電容的應用電路圖

FL7701參考設計指標：

FL7701參考設計主要特性：

??Digital implemented active PFC function

??Built in HV supplying circuit: Self biasing

??AOCP function with auto restart mode

??Cycle-by-cycle current limit

??Current sense pin open protection

??Low operating current: 0.85mA (typ.)

??Programmable Oscillation Frequency

??Programmable LED Current

??Analog Dimming Function

圖4。FL7701參考設計電路圖

圖5。FL7701參考設計外形圖

圖6。FL7701參考設計PCB布局圖
詳情請見：
http://www.fairchildsemi.com/ds/FL/FL7701.pdf
和
http://www.fairchildsemi.com/support/referencedesign/docs/RD-L030.pdf