</a>LED" title="LED">LED" title="LED">LED驅動器,包括PWM控制器和功率MOSFET,能增強低功率反激轉換器的性能,應用電壓范圍80VAC ~ 308VAC,提供LED開路,短路和超溫保護功能.主要用于LED照明系統.本文介紹了FLS3247主要特性,方框圖,通用輸入10W LED驅動器電路圖以及10W LED驅動器評估板主要指標,電路圖,材料清單和PCB布局圖.

This highly integrated PWM controller with power MOSFET, FLS3217 / FLS3247, provides several features to enhance the performance of low-power flyback converters. The proprietary topology enables simplified circuit design for LED lighting applications.

By using the single-stage topology with primary-side regulation, an LED lighting board can be implemented with the few external components and minimized cost; requiring no input bulk capacitor or feedback circuitry.

To implement good power factor and low THD, constant on-time control is utilized with an external capacitor connected to COMI. Precise constant-current control regulates accurate output current versus changes in input voltage and output voltage. The operating frequency is proportionally changed by the output voltage to guarantee DCM operation with higher efficiency and simple design.

FLS3217 and FLS3247 provide protection features such as open-LED, short-LED, and over-temperature protection. The current-limit level is automatically reduced to minimize the output current and protect external components in short-LED condition.

FLS3247主要特性:

? Cost-Effective Solution without Input Bulk Capacitor and Feedback Circuitry

? Power-Factor Correction (PFC)

? Integrated Power MOSFET

? Accurate Constant-Current (CC) Control Independent Online Voltage, Output Voltage, and Magnetizing Inductance Variation

? Linear Frequency Control for Increased Efficiency

? Open / Short-LED Protection

? Cycle-by-Cycle Current Limiting

? Over-Temperature Protection with Auto Restart

? Low Startup Current: 20μA

? Low Operating Current: 5mA

? VDD Over-Voltage Protection (OVP)

? VDD Under-Voltage Lockout (UVLO)

? Application Voltage Range: 80VAC ~ 308VAC

FLS3247應用:

? LED Lighting System

圖1.FLS3247方框圖

圖2.FLS3247通用輸入10W LED驅動器電路圖

10W LED驅動器評估板

This document describes the proposed solution for a universal line voltage LED ballast using the FLS3247N Primary-Side Regulator (PSR) single-stage controller. The input voltage range is 90VRMS – 265VRMS and there is one DC output with a constant current of 400mA at 25VMAX. This document contains a general description of the FLS3247N, the power supply specification, schematic, bill of materials, and typical operating Characteristics.

10W LED驅動器評估板主要指標:



圖3.10W LED驅動器評估板外形圖(59mm (L) ×25.5mm (W) × 20.0mm (H))

10W LED驅動器評估板主要特性:

? Cost effective solution without input bulk capacitor and feedback circuitry

? Power Factor Correction

? Accurate constant-current (CC) Control

? Linear frequency control for better efficiency and easy design

? Constant current regulation vs. output voltage change (11~28V) : <± 2.85%

? Constant current regulation vs. line voltage change (90~265VAC) : <± 2.85%

? Output open & short circuit protection with auto restart

? System efficiency up to 86.8%

? PF and THD: PF (> 0.9), THD(< 20%)

圖4.10W LED驅動器評估板電路圖

10W LED驅動器評估板材料清單:


圖5.10W LED驅動器評估板布局圖(頂層)

圖6.10W LED驅動器評估板布局圖(底層)
詳情請見:
http://www.fairchildsemi.com/ds/FL/FLS3247.pdf
和
http://www.fairchildsemi.com/an/AN/AN-FEBL042.pdf