原标题：Powerint LNK419EG 18W T8管灯LED驱动设计方案(DER298)

　　powerint公司的18W替代T8荧光管灯的LED驱动器采用LinkSwitchTM-PH系列LNK419EG,输入电压90VAC到265VAC,输出电压200V/90mA.拓扑采用单级非隔离降压-升压,具有紧凑和低元件数的特点,线路和负载调整有于2%,110VAC的效率大于89.5%, THD小于20%,而230VAC时的效率大于90%,THD小于28%.本文介绍了设计方案DER298的主要特性,优势和指标,电路图和材料清单.

　　Constant Current (<2% Regulation), Non-Isolated Buck-Boost, Power Factor Corrected,18 W LED Driver Using LinkSwitchTM-PH LNK419EGT8 Tube Retrofit LED Driver

　　The document describes a universal, non-isolated, high efficiency, high power factor (PF) LED driver designed to drive a nominal LED string voltage of 200 V at 90 mA from an input voltage range of 90 VAC to 265 VAC. The LED driver utilizes the LNK419EG from the LinkSwitch-PH family of ICs.

　　The topology used is a single-stage non-isolated buck-boost that meets the stringent space requirements for this design. Enhanced line and load output current regulation requirement is achieved by directly sensing and regulating the output current. High power factor and low THD is achieved by employing the LinkSwitch-PH IC which also provides a sophisticated range of protection features including auto-restart for open control loop and output short-circuit conditions. Line overvoltage provides extended line fault and surge withstand, and accurate hysteretic thermal shutdown ensures safe average PCB temperatures under all conditions.

　　图1.EMI板和降压-升压板外形图

　　18W T8管灯LED驱动器(DER298)主要特性:

　　 Designed for linear fluorescent LED tube retro fit applications

　　 Compact, low component count design – fits into ends of tube enclosure

　　 Frequency jitter for smaller, lower cost EMI filter components

　　 Excellent line and load regulation, <2% typical

　　 Highly energy efficient

　　 ≥89.5% at 110 VAC

　　 ≥90% at 230 VAC

　　 Power factor corrected

　　 PF >0.93 across line and load, EN61000-3-2(c) compliant

　　 A-THD <28% (230 VAC), <20% (115 VAC)

　　 Integrated protection and reliability features

　　 Output short-circuit protected with auto-recovery

　　 Line input overvoltage shutdown extends voltage withstand during line faults.

　　 Auto-recovering thermal shutdown with large hysteresis protects both components and

　　printed circuit board

　　 IEC 61000-4-5 ring wave and surge and EN55015 B conducted EMI compliant 18W T8管灯LED驱动器主要指标:

　　图2.18W T8管灯LED驱动器电路图

　　18W T8管灯LED驱动器材料清单: