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IR公司的IRS2548D是帶PFC LED驅動器和半橋控制器,是全集成全保護的600V LED或開關電源(SMPS)控制集成電路,把PFC,系統控制和半橋驅動器集成在一起,可編程PFC過流保護,微功耗250uA起動,可變頻率振蕩器,主要用在隔離的LED驅動器和開關電源.本文介紹了IRS2548D主要特性,方框圖, PFC控制電路框圖和典型應用電路圖以及40V/1.4A低壓LED驅動器參考設計電路圖,電感元件指標和材料清單. IRS2548D: SMPS/LED DRIVER PFC + HALF-BRIDGE CONTROL IC The IRS2548D is a fully integrated, fully protected 600V LED or switched mode power supply control IC with integrated PFC control for a Boost pre-regulator. The IRS2548D is based on the popular IRS2168D electronic ballast control IC re-designed for use in LED driver or half-bridge power supply applications. The PFC circuitry operates in critical conduction mode and provides high PF, low THD and DC bus regulation. The IRS2548D features include programmable minimum run frequency and adjustable oscillator frequency that can be driven by an opto isolator or other feedback circuit in a feedback loop for frequency modulation in resonant systems. The IRS2548D also includes PFC over-voltage and over-current protection, half bridge over current protection and a logic level enable input that can be used for PWM dimming in LED drivers or general burst mode operation. IRS2548D主要特性: PFC, system control and half-bridge driver in one IC Critical-conduction mode boost-type PFC Programmable PFC over-current protection Half Bridge Driver Half Bridge Over Current Protection Variable Frequency Oscillator Fixed internal 1.6us HO and LO deadtime Internal bootstrap MOSFET Internal 15.6V zener clamp diode on Vcc Micropower startup (250uA) Latch immunity and ESD protection IRS2548D典型應用: Isolated LED Drivers Power Supplies 
圖1.IRS2548D方框圖
圖2.IRS2548D PFC控制電路框圖
圖3.IRS2548D典型應用電路圖 采用IRS2548D 40V/1.4A低壓LED驅動器 Solid state light sources are now available that offer viable alternatives to Fluorescent and HID lamps and far surpass incandescent lamps. Luminous efficacy expressed in Lumens per Watt has now reached levels enabling LEDs to be used for general illumination. High brightness LEDs also possess the added advantages of longer operating life span up to 50000 hours and greater robustness than other less efficient light sources making them suitable for outside applications such as street lighting. High power LEDs are ideally driven with constant regulated DC current, requiring a "driver" or "converter" to provide the required current from an AC or DC power source. A two stage power converter based around the IRS2548D PFC plus half bridge LED driver IC provides a controlled current output over a wide AC line voltage input range with high power factor and low THD. The IRPLLED5 evaluation board is an off line isolated low voltage / high output current LED driver designed to supply a 1.4A regulated DC output current over a voltage range of 30V to 60V operating from an AC line input voltage between 90 and 305VAC 50/60Hz. It also includes 1-10V dimming capability from 0 to 100% of light output. The outputs of this LED driver are fully protected against short circuit and limit the open circuit voltage to below 60VDC for safety compliance.
圖4.40V/1.4A低壓LED驅動器外形圖
圖5. IRPLLED5(40V/1.4A低壓LED驅動器)方框圖
圖6.IRPLLED5電路圖(1)
圖7.IRPLLED5電路圖(2)
圖8.IRPLLED5電路圖(3)
圖9.IRPLLED5電路圖(4)
圖10.IRPLLED5 PFC電感指標圖
圖11.IRPLLED5 變壓器指標圖
圖12.IRPLLED5 反激電感指標圖 材料清單(BOM):
詳情請見: http://www.irf.com/product-info/datasheets/data/irs2548dspbf.pdf 和 http://www.irf.com/technical-info/refdesigns/irplled5.pdf |
