</a>LED" title="LED">LED" title="LED">LED驱动器" title="LED驱动器">LED驱动器和半桥控制器,是全集成全保护的600V LED或开关电源" title="开关电源">开关电源(SMPS)控制集成电路,把PFC,系统控制和半桥驱动器集成在一起,可编程PFC过流保护,微功耗250uA起动,可变频率振荡器,主要用在隔离的LED驱动器和开关电源.本文介绍了IRS2548D主要特性,方框图, PFC控制电路框图和典型应用电路图以及40V/1.4A低压LED驱动器参考设计电路图,电感元件指标和材料清单.

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典型应用:

Isolated LED Drivers

Power Supplies



图1.IRS2548D方框图



图2.IRS2548D PFC控制电路框图



图3.IRS2548D典型应用电路图

采用IRS2548D 40V/1.4A低压LED驱动器

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.



图4.40V/1.4A低压LED驱动器外形图



图5. IRPLLED5(40V/1.4A低压LED驱动器)方框图



图6.IRPLLED5电路图(1)



图7.IRPLLED5电路图(2)



图8.IRPLLED5电路图(3)



图9.IRPLLED5电路图(4)



图10.IRPLLED5 PFC电感指标图



图11.IRPLLED5 变压器指标图



图12.IRPLLED5 反激电感指标图

材料清单(BOM):





详情请见:
http://www.irf.com/product-info/datasheets/data/irs2548dspbf.pdf
和
http://www.irf.com/technical-info/refdesigns/irplled5.pdf