原标题：Powerint LYTSwitch-4大功率LED驱动电源解决方案

　　powerint公司的LYTSwitch-4大功率LED驱动器系列产品LYT4221-4228/4321-4328集成了控制器和高压功率FET,控制器提供高功率因素和恒流输出,包括了振荡器,反馈电路,5.9V稳压器,滞后的超温保护,频率抖动,逐个周期限流,自动重起,电感修正,功率因素和恒流控制.本文介绍了LYTSwitch-4系列产品亮点,框图,典型应用电路以及20W/36V TRIAC调光高功率因素LED驱动器设计电路和用于PAR30灯的采用LYTSwitchTM-4 LYT4322E的14.35W高效(>86%)高功率因素(>0.95)TRIAC调光LED驱动器主要指标,电路图,材料清单和PCB布局图.

　　A LYTSwitch-4 device monolithically combines a controller and high-voltage power FET into one package. The controller provides both high power factor and constant current output in a single-stage. The LYTSwitch-4 controller consists of an oscillator, feedback (sense and logic) circuit, 5.9 V regulator, hysteretic over-temperature protection, frequency jittering, cycle-by-cycle current limit, auto-restart, inductance correction, power factor and constant current control.

　　LYTSwitch-4系列产品亮点:

　　Better than ±5% CC regulation

　　TRIAC dimmable to less than 5% output

　　Fast start-up <250 ms at full brightness

　　<1s at 10% brightness

　　High power factor >0.9 Easily meets EN61000-3-2 Less than 10% THD in optimized designs

　　Up to 92% efficient

　　132 kHz switching frequency for small magnetics

　　High Performance, Combined Driver, Controller, Switch

　　The LYTSwitch family enables off-line LED drivers with high power factor which easily meet international requirements for THD and harmonics. Output current is tightly regulated with better than ±5% CC tolerance1. Efficiency of up to 92% is easily achieved in typical applications.

　　Supports a Wide Selection of TRIAC Dimmers

　　The LYTSwitch family provides excellent turn-on characteristics for leading-edge and trailing-edge TRIAC dimming applications. This results in drivers with a wide dimming range and fast start-up, even when turning on from a low conduction angle – large dimming ratio and low “pop-on” current.

　　Low Solution Cost and Long Lifetime

　　LYTSwitch ICs are highly integrated and employ a primary-side control technique that eliminates the optoisolator and reduces component count. This allows the use of low-cost single-sided printed circuit boards. Combining PFC and CC functions into a single-stage also helps reduce cost and increase efficiency. The 132 kHz switching frequency permits the use of small, low-cost magnetics.

　　LED drivers using the LYTSwitch family do not use primary-side aluminum electrolytic bulk capacitors. This means greatly extended driver lifetime, especially in bulb and other high temperature applications.

　　图1. LYTSwitch-4系列框图

　　图2. LYTSwitch-4系列典型应用电路

　　图3. 20W/36V TRIAC调光高功率因素LED驱动器设计电路

　　用于PAR30灯的采用LYTSwitchTM-4 LYT4322E的14.35W高效(>86%)高功率因素(>0.95)TRIAC调光LED驱动器

　　The document describes a non-isolated, high power factor (PF), high efficiency, TRIAC dimmable LED driver designed to drive a nominal LED string voltage of 41 V at 350 mA from an input voltage range of 195 VAC to 265 VAC (50 Hz typical). The topology used is a single-stage non-isolated tapped buck that meets high power factor, constant current regulation, and dimming requirements for this design.

　　This document contains the LED driver specification, schematic, PCB details, bill of materials, transformer documentation and typical performance characteristics.

　　图4. 14.35W PAR30灯LED驱动器外形图

　　14.35W PAR30灯LED驱动器主要指标:

　　图5. 14.35W PAR30灯LED驱动器电路图

　　14.35W PAR30灯LED驱动器材料清单: