原标题：Powerint LNK605DG 4.2W LED驱动方案

　　powerint 公司的4.2W LED驱动方案是采用LNK605DG器件,输入电压为85–265VAC,输出电压为12V/350mA. 4.2W LED驱动方案初级采用恒压/恒流(CV/CC)控制器,从而省略了次级控制和光耦.输出电压精度±5%,输出电流精度±10%,包括火线电压,负载和温度补偿和元件误差.主要应用手机,无绳电话,PDA,MP3的充电器,适配器,LED驱动器等.本文介绍了LNK605DG的主要特性,应用案例和4.2W LED驱动方案设计电路图, PCB布局(61mm x 24mm)与材料清单.

　　Energy-Efficient, Accurate CV/CC Switcher 4.2W LED驱动器指标: 85–265 VAC Input; 12 V, 350 mA Output This engineering report describes the design for a universal input, 12 V, 350 mA CV/CC power supply for LED driver applications. This power supply utilizes the LNK605DG device from the Power Integrations LinkSwitch-II family.

　　This document contains the power supply and transformer specifications, schematics, bill of materials, and typical performance characteristics pertaining to this power supply.

　　4.2W LED驱动器特性:

　　Summary and Features

　　Accurate primary-side constant voltage/constant current (CV/CC) controller eliminates secondary side control and optocoupler

　　±5% output voltage and ±10% output current accuracy including line, load,temperature and component tolerance

　　No current-sense resistors for maximized efficiency

　　Low part-count solution for lower cost

　　Over-temperature protection–tight tolerance (±5%) with hysteretic recovery for safe PCB temperatures under all conditions

　　Auto-restart output short circuit and open-loop protection

　　EcoSmart–Easily meets all existing and proposed international energy efficiency standards–China (CECP) / CEC / EPA / European Commission

　　ON/OFF control provides constant efficiency to very light loads

　　No-load consumption<200 mW at 265 VAC

　　Ultra-low leakage current:<5 μA at 265 VAC input (no Y capacitor required)

　　Easy compliance to EN55015 and CISPR-22 Class B EMI

　　Green package: halogen free and RoHS compliant

　　LNK603-606/613-616 LinkSwitch-II 系列特性:

　　Energy-Efficient, Accurate CV/CC Switcher for Adapters and Chargers The LinkSwitch-II dramatically simplifies low power CV/CC charger designs by eliminating an optocoupler and secondary control circuitry. The device introduces a revolutionary control technique to provide very tight output voltage and current regulation, compensating for transformer and internal parameter tolerances along with input voltage variations.

　　The device incorporates a 700 V power MOSFET, a novel On/Off control state machine, a high voltage switched current source for self biasing, frequency jittering, cycle-by-cycle current limit and hysteretic thermal shutdown circuitry onto a monolithic IC.

　　LNK603-606/613-616 LinkSwitch-II 系列产品亮点:

　　Dramatically Simplifies CV/CC Converters

　　Eliminates Optocoupler and all secondary CV/CC control circuitry

　　Eliminates all control loop compensation circuitry

　　Advanced Performance Features

　　Compensates for transformer inductance tolerances

　　Compensates for input line voltage variations

　　Compensates for cable voltage drop (LNK61X series)

　　Compensates for external component temperature variations

　　Very tight IC parameter tolerances using proprietary trimming technology

　　Frequency jittering greatly reduces EMI filter cost

　　Even tighter output tolerances achievable with external resistor selection/trimming

　　Advanced Protection/Safety Features

　　Auto-restart protection reduces power delivered by >95% for output short circuit and control loop faults (open and shorted components)

　　Hysteretic thermal shutdown – automatic recovery reduces power supply returns from the field Meets HV creepage requirements between Drain and all other pins both on the PCB and at the package

　　EcoSmart  – Energy Efficient

　　Easily meets all global energy efficiency regulations No-load consumption<200 mW at 230 VAC and down to below 30 mW with optional external bias On/Off control provides constant efficiency down to very light loads – ideal for CEC and ENERGY STAR 2.0 regulations No current sense resistors – maximizes efficiency

　　Green Package

　　Halogen free and RoHS compliant package

　　Applications

　　Chargers for cell/cordless phones, PDAs, MP3/portable audio devices, adapters, LED drivers, etc.

　　图1.LNK603-606/613-616 LinkSwitch-II 系列方框图

图2.4.2W LED驱动器电路图

　　材料清单(BOM):