原标题：Powerint LNK302 150W LED街灯照明参考设计(RDR-292)

　　powerint公司的150W LED街灯照明参考设计(RDR-292) 采用LinkSwitch-TN系列的LNK302和HiperPFS与HiperLCS系列产品,组合了PFS功率系数级和LCS输出级,输入电压90 VAC - 265 VAC,100%负载和50%负载时的功率系数大于0.9.本文介绍了LNK302产品亮点,方框图以及150W LED街灯照明参考设计主要特性与指标,电路图,材料清单和PCB布局图.

　　Reference Design Report for a 150 W Power Factor Corrected LLC Power Supply for LED Street Lighting

　　LinkSwitch-TN is specifically designed to replace all linear and capacitor-fed (cap dropper) non-isolated power supplies in the under 360 mA output current range at equal system cost while offering much higher performance and energy efficiency.

　　LinkSwitch-TN devices integrate a 700 V power MOSFET, oscillator, simple On/Off control scheme, a high voltage switched current source, frequency jittering, cycle-by-cycle current limit and thermal shutdown circuitry onto a monolithic IC. The startup and operating power are derived directly from the voltage on the DRAIN pin, eliminating the need for a bias supply and associated circuitry in buck or fl yback converters. The fully integrated auto-restart circuit in the LNK304-306 safely limits output power during fault conditions such as short-circuit or open loop, reducing component count and system-level load protection cost. A local supply provided by the IC allows use of a non-safety graded optocoupler acting as a level shifter to further enhance line and load regulation performance in buck and buck-boost converters, if required.

　　LNK302产品亮点:

　　Cost Effective Linear/Cap Dropper Replacement

　　• Lowest cost and component count buck converter solution

　　• Fully integrated auto-restart for short-circuit and open loop fault protection – saves external component costs

　　• LNK302 uses a simplifi ed controller without auto-restart for very low system cost

　　• 66 kHz operation with accurate current limit – allows low cost off-the-shelf 1 mH inductor for up to 120 mA output current

　　• Tight tolerances and negligible temperature variation

　　• High breakdown voltage of 700 V provides excellent input surge withstand

　　• Frequency jittering dramatically reduces EMI (~10 dB) – minimizes EMI fi lter cost

　　• High thermal shutdown temperature (+135 °C minimum)

　　Much Higher Performance over Discrete Buck and Passive Solutions

　　• Supports buck, buck-boost and fl yback topologies

　　• System level thermal overload, output short-circuit and open control loop protection

　　• Excellent line and load regulation even with typical confi guration

　　• High bandwidth provides fast turn-on with no overshoot

　　• Current limit operation rejects line ripple

　　• Universal input voltage range (85 VAC to 265 VAC)

　　• Built-in current limit and hysteretic thermal protection

　　• Higher effi ciency than passive solutions

　　• Higher power factor than capacitor-fed solutions

　　• Entirely manufacturable in SMD

　　EcoSmart®– Extremely Energy Effi cient

　　• Consumes typically only 50/80 mW in self-powered buck topology at 115/230 VAC input with no load (opto feedback)

　　• Consumes typically only 7/12 mW in fl yback topology with external bias at 115/230 VAC input with no load

　　• Meets California Energy Commission (CEC), Energy Star, and EU requirements

　　LNK302应用:

　　• Appliances and timers

　　• LED drivers and industrial controls

　　图1.LNK302功能动框图

　　150W LED街灯照明参考设计

　　This engineering report describes a 48 V, 150 W reference design power supply for 90 VAC - 265 VAC LED street lights which can also serve as a general purpose evaluation board for the combination of a PFS power factor stage with an LCS output stage using devices from the Power Integration’s HiperPFS and HiperLCS device families.

　　The design is based on the PFS708EG IC and LQA05TC600 diode for the PFC front end, with a LNK302 utilized in a non-isolated flyback bias supply. An LCS702HG IC is used for the LLC output stage.

　　The circuit shown in this report is optimized for >0.9 power factor, over an input voltage range of 90 VAC - 230 VAC, at both 100% load and 50% load. If >0.9 power factor is not required at 50% load, the circuit can be cost reduced by downsizing common mode filter L1 and PFC input capacitor C6. Contact Power Integrations for more details.

　　This power supply is designed to be mounted inside a grounded enclosure for streetlight service, with the input AC safety ground connected to the chassis. EMI and line surge tests should be performed with the supply screwed down to a ground plane with the input AC safety ground connected to this plane.

　　150W LED街灯照明参考设计主要特性:

　　 Integrated PFC stage using

　　o PFS708EG from HiperPFS family of ICs

　　o LQA05TC600 ultrafast soft recovery QSpeed diode

　　 Integrated LLC stage using

　　o LCS702HG from HiperLCS family of ICs

　　 Simple snubberless bias supply using

　　o LNK302DG from LinkSwitch-TN family of ICs

　　 CAPZero (CAP002DG) IC used to discharge X capacitors for higher efficiency compared to resistive solution

　　 High frequency (250 kHz) LLC for small transformer size

　　 >95% full load PFC efficiency at 115 VAC

　　 >95% full load LLC efficiency

　　 System efficiency 91% / 93% at 115 VAC / 230 VAC

　　图2.150W LED街灯照明参考设计(RD-292)外形图

　　150W LED街灯照明参考设计主要指标:

　　图3.150W LED街灯照明参考设计(RDR-292)电路图:输入滤波器,PFC功率级和偏压电源

　　图4.150W LED街灯照明参考设计(RDR-292)电路图:LLC级

　　150W LED街灯照明参考设计(RDR-292)材料清单:

　　图5.150W LED街灯照明参考设计(RDR-292)PCB布局图:顶层

　　图6.150W LED街灯照明参考设计(RDR-292)PCB布局图:底层