Powerint LNK460KG 20W LED驱动方案

发布时间：2012-8-21 11:20 发布者：1770309616

Powerint公司的LinkSwitch-PL系列产品集成了725V功率MOSFET,间断模式可变频率可变开态时间控制器,频率抖动器,逐个周期的限流和滞后热关断等功能,具有高效率和高功率因素,它的控制算法提供无闪烁TRIAC调光,而外接元件最少.本文介绍了LNK460KG产品亮点,方框图,典型应用电路,替代A19白炽灯5W 15V LED驱动电路图以及20W LED驱动演示板主要特性和指标,电路图,材料清单和PCB元件布局图.

High Efficiency (>90%), High Power Factor (>0.97), Low A-THD (<15%), 20 W Output Non-Isolated Buck LED Driver Using LinkSwitchTMPL LNK460KGHigh Efficiency (>90%), High Power Factor (>0.97), Low A-THD (<15%), 20 W Output Non-Isolated Buck LED Driver Using LinkSwitchTMPL LNK460KG

The LinkSwitch-PL family enables a very small and low cost single-stage power factor corrected constant current driver for solid state lighting. Optimized for direct LED current sensing, the LinkSwitch-PL operates over a wide input voltage range delivering an output power of up to 16 W. The LinkSwitch-PL control algorithm provides flicker-free TRIAC dimming with minimal external components.

Each device incorporates a 725 V rated power MOSFET, a novel discontinuous mode variable frequency variable on-time controller, frequency jitter, cycle by cycle current limit and hysteretic thermal shutdown in a monolithic 4-pin IC, available in SO-8C, eSOP-12, and eDIP-12 packages.

LNK460KG产品亮点:

Dramatically Simplifies Off-line LED Drivers

• Flicker-free phase-controlled TRIAC dimming

• Single stage power factor correction and accurate constant current (CC) output

• Very low component count with small non-electrolytic bulk capacitor for compact replacement lamp designs

• Compact SO8, eSOP, and eDIP packages

• Completely eliminates control loop compensation

Advanced Performance Features

• Optimized for non-isolated flyback designs

• Frequency jitter greatly reduces EMI filter size and costs

• Low dissipation direct sensing of LED current

Advanced Protection and Safety Features

• Cycle skipping regulation for abnormally low output power to clamp peak output current delivered

• 725 V integrated power MOSFET allows small bulk capacitance and maximizes power capability

• Short-circuit, overload, open feedback and output overvoltage protection

• Hysteretic thermal shutdown

• Meets high-voltage creepage between DRAIN and all other pins both on PCB and at package

EcoSmart™ - Energy Efficient

• High power factor optimizes system lumen per input VA

• Control algorithm balances switching and conduction losses over line and load to maintain optimum efficiency

图1.LNK460KG方框图

图2.LNK460KG典型应用电路图

图2.替代A19白炽灯5W 15V LED驱动电路图

20W LED驱动演示板

The document describes a non-isolated, high efficiency, high power factor (PF) LED driver designed to drive a nominal LED string voltage of 85 V at 240 mA from an input voltage range of 195 VAC to 265 VAC (47 Hz – 63 Hz). The LED driver utilizes the LNK460KG from the LinkSwitch-PL family of ICs.

The topology used is a single-stage non-isolated buck that meets the stringent space and efficiency requirements for this design. LinkSwitch-PL based designs provide high power factor (>0.9) meeting international requirements.

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

20W LED驱动演示板主要特性:

 Low cost, low component count (29 parts), small size (height <8 mm), and single-sided PCB

 Single-stage power factor correction and constant current (CC) output

 Highly energy efficient, >90%

 Integrated protection and reliability features

 Output short-circuit protection with auto-recovery

 Auto-recovering thermal shutdown with hysteresis

 No damage during brown-out conditions

 PF >0.97, % ATHD <15% at nominal 230 VAC input

 Easily meets Class C harmonic requirement (>25 W) even with multiple tubes in parallel operation

 Meets 1 kV differential line surge and EN55015 conducted EMI