PowerintLNK417EG15W离线LED驱动电源方案(DER284)
LinkSwitch-PH dramatically simplifies implementation of LED drivers requiring Power Factors greater than 0.9, TRIAC dimming, and high efficiency. This highly integrated controller introduces a new control technique that provides very high power factor and accurate output current control, and eliminates passive circuitry required for power factor correction, optocoupler and secondary current control circuitry.
Each device incorporates a 725V power MOSFET, a continuous-mode PWM controller, a high voltage switched current source for self biasing, frequency jittering, cycle-by-cycle current limit and hysteretic thermal shutdown circuitry into a monolithic IC.
LinkSwitch-PH系列产品亮点:
Dramatically Simplifies Off-line LED Drivers
Single-stage power factor correction and accurate constant current (CC) output
Flicker-free, phase-controlled TRIAC dimming
Eliminates optocoupler and all secondary current control circuitry
Eliminates all control loop compensation circuitry
Simple primary-side PWM dimming interface
Universal input voltage range
Enables designs that are electrolytic-free
Accurate and Consistent Performance
Fast start-up time
Compensates for transformer inductance tolerances
Compensates for line input voltage variations
Frequency jittering greatly reduces EMI filter size and costs
Advanced Protection and Safety Features
Auto-restart for short circuit protection
Open circuit fault detection mode
Automatic thermal shutdown or restart with hysteresis
Meets high voltage creepage requirement between DRAIN and all other signal pins both on PCB and at package
EcoSmart - Energy-Efficiency Technology
Low standby power remote ON/OFF feature ( 50 mW at 230 VAC)
No current sense resistors - maximizes efficiency
High efficiency operation, >85% achievable
Green Package
Halogen free and RoHS compliant package
LinkSwitch-PH应用:
• Off-line LED driver
图1. LinkSwitch-PH系列功能方框图
图2. LinkSwitch-PH系列绝缘TRIAC调光高功率因素通用输入14W LED驱动器电路图
图3. LinkSwitch-PH系列绝缘无调光高功率因素通用输入7W LED驱动器电路图 采用LNK417EG无电解电容高效率(≥90%) PFC大于0.9的15W LED驱动器参考设计
This document describes an isolated, power factor corrected, very high efficiency LED driver designed to drive a 30 V LED string at a current of 500 mA (nominal). The input voltage range is 90 VAC to 265 VAC.
The LED driver uses a LNK417EG device from the LinkSwitch-PH family of ICs. This integrated controller and 725 V MOSFET dramatically reduces the complexity and component count of the solution.
The key design goals were to achieve the highest possible efficiency and eliminate electrolytic capacitors. Both are key factors for increasing the lifetime and reliability of LED drivers making this solution ideal for industrial and commercial applications.
15W LED驱动器参考设计主要特性:
No electrolytic capacitors
Clean monotonic start-up – no output blinking
Fast start-up (100 ms) – no perceptible delay
Highly energy efficient
o ≥90% at 115 VAC and 230 VAC input Low cost, low component count and small printed circuit board footprint solution
o No current sensing required
o Frequency jitter for smaller, lower cost EMI filter components Integrated protection and reliability features
o Output open-circuit / output short-circuit protected with auto-recovery
o Line input overvoltage shutdown extends voltage withstand during line faults.
o Auto-recovering thermal shutdown with large hysteresis protects both components and printed circuit board
o No damage during brown-out or brown-in conditions
Meets IEC 61000-4-5 ring wave, IEC 61000-3-2 Class C harmonics and EN55015 B conducted EMI
图4.15W LED驱动器参考设计外形图: 3.115” L x 1.525” W.
电源指标:
图5.15W LED驱动器参考设计电路图
图6.变压器电路图
变压器主要指标:
图7. PCB布局图(顶层)
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