< /a>LED" title="LED">LED" title="LED"> LED驱动器是采用LinkSwitchTM-PL系列的 LNK460KG器件,所用元件数量最少,效率大于87%,功率因素大于0.98,A-THD小于10%,输出功率20W,可替代T8管灯.本文介绍了LNK460KG主要特性,框图,典型应用电路,替代A19白炽灯的5W/15V LED驱动器电路图,以及采用LNK460KG的T8 20W/85V LED驱动器主要特性和技术指标,电路图,材料清单和PCB布局图.

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.

LinkSwitch-PL系列产品亮点:

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.LinkSwitch-PL系列框图

图2.LinkSwitch-PL系列典型应用电路图

图2.采用LNK457DG的5W/15V LED驱动器,替代A19白炽灯

采用LNK460KG的T8 20W/85V LED驱动器(DER-345)

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 235 mA from an input voltage range of 85 VAC to 135 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 boost 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.

T8 20W/85V LED驱动器主要特性:

 Low cost, low component count (parts), small size (height <8 mm)

 PF >0.98, % ATHD <6% at nominal input

 Highly energy efficient, >87% at nominal input

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

 Integrated protection and reliability features

 Output short-circuit and open load protected

 Auto recovery thermal shutdown with hysteresis

 No damage during brown-out conditions

 Meets 1 kV differential line surge

 IEC 61000-4-5 ring wave, IEC 61000-3-2 C harmonics and EN55015 B conducted EMI compliant

图3.T8 20W/85V LED驱动器外形图(180 mm x 16.4 mm x 8 mm).
T8 20W/85V LED驱动器主要指标:




图4.T8 20W/85V LED驱动器电路图

T8 20W/85V LED驱动器材料清单:



图5.T8 20W/85V LED驱动器PCB布局图
详情请见:
http://www.powerint.com/sites/default/files/product-docs/linkswitch-pl_family_datasheet.pdf
和
http://www.powerint.com/sites/default/files/PDFFiles/der345.pdf