原标题：Fairchild FL7733A通用电压输入50W LED驱动解决方案

　　Fairchild公司的FL7733A是采用先进的初级边调整(PSR)的高度集成PWM控制器,最大限度地降低中低功率LED照明转换器的元件数量.所有条件下的总电流误差小于±3%,通用输入电压80 VAC-308 VAC变化小于±1%,从50%到100%的负载变化小于±1%,磁性电感变化±20%输出变化小于±1%.本文介绍了FL7733A主要特性,框图,50W LED驱动器主要指标,电路图,材料清单和PCB设计图.

　　The fl7733a is a highly-integrated PWM controller with advanced Primary-Side Regulation (PSR) technique to minimize components in low-to-mid-power LED lighting converters.

　　Using an innovative TRUECURRENT® technology to provide tight tolerance constant-current output, this LED driver enables designs with constant current (CC) tolerance of less than ±1% over the universal line voltage range to meet stringent LED brightness requirements.

　　By minimizing turn-on time fluctuation, high power factor and low THD over the universal line range are obtained in the FL7733A. An integrated high-voltage startup circuit implements fast startup and high system efficiency. During startup, adaptive feedback loop control anticipates the steady-state condition and sets initial feedback condition close to the steady state to ensure no overshoot or undershoot of LED current.The FL7733A also provides powerful protections, such as LED short / open, output diode short, sensing resistor short / open, and over-temperature for high system reliability.

　　The FL7733A controller is available in an 8-pin Small-Outline Package (SOP).

　　FL7733A主要特性:

　　Performance

　　< ±3% Total Constant Current Tolerance Over All Conditions

　　< ±1% Over Universal Line Voltage Variation

　　< ±1% from 50% to 100% Load Voltage Variation

　　< ±1% with ±20% Magnetizing Inductance Variation

　　Primary-Side Regulation (PSR) Control for Cost-Effective Solution without Requiring Input Bulk Capacitor and Secondary Feedback Circuitry

　　Application Input Voltage Range: 80 VAC-308 VAC

　　High PF of > 0.9, and Low THD of < 10% Over Universal Line Input Range

　　Fast < 200 ms Start-up (at 85 VAC) using Internal High-Voltage Start-up with VDD Regulation

　　Adaptive Feedback Loop Control for Startup without Overshoot

　　System Protection

　　LED Short / Open Protection

　　Output Diode Short Protection

　　Sensing Resistor Short / Open Protection

　　VDD Over-Voltage Protection (OVP)

　　VDD Under-Voltage Lockout (UVLO)

　　Over-Temperature Protection (OTP)

　　All Protections are Auto Restart (AR)

　　Cycle-by-Cycle Current Limit

　　图1.FL7733A框图

　　通用输入电压50W LED驱动器

　　50 W LED Driver with Ultra-Wide OutputVoltage Range at Universal Line

　　This user guide supports the evaluation kit for the FL7733A. It should be used in conjunction with the FL7733A datasheet as well as Fairchild’s application notes and technical support team.

　　This document describes a solution for an universal AC input voltage LED driver using the FL7733A Primary-Side Regulation (PSR) single-stage controller. The input voltage range is 90 VRMS ~ 277 VRMS and there is one DC output with a constant current of 1.0 A at 50 V. This document contains a general description of the FL7733A, the power supply solution specification, schematic, bill of materials, and typical operating characteristics.

　　图2.通用输入电压50W LED驱动器外形图

　　50W LED驱动器主要指标:

　　通用输入电压50W LED驱动器材料清单: