Powerint公司的LinkSwitch-PH系列大大地簡化了實現功率因素大于0.9,TRIAC調光和高效率的LED驅動器的設計.器件集成了725V功率MOSFET,連續模式PWM控制器,用于自偏壓的高壓開關電流源,頻率抖動,逐個周期限流和滯后熱關斷電路,最適合用于離線LED驅動器.本文介紹了LinkSwitch-PH系列產品亮點, 功能方框圖, 14W和7W LED驅動器電路圖,以及采用LNK417EG無電解電容高效率(≥90%) PFC大于0.9的15W LED驅動器參考設計電路圖,主要指標和材料清單與PCB布局圖.
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系列產品亮點:
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應用:
• Off-line LED driver
圖1. LinkSwitch-PH系列功能方框圖
圖2. LinkSwitch-PH系列絕緣TRIAC調光高功率因素通用輸入14W LED驅動器電路圖
圖3. LinkSwitch-PH系列絕緣無調光高功率因素通用輸入7W LED驅動器電路圖 采用LNK417EG無電解電容高效率(≥90%) PFC大于0.9的15W LED驅動器參考設計
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驅動器參考設計主要特性:
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No electrolytic capacitors
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Clean monotonic start-up – no output blinking
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Fast start-up (<100 ms) – no perceptible delay
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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
圖4.15W LED驅動器參考設計外形圖: 3.115” L x 1.525” W.
電源指標:
圖5.15W LED驅動器參考設計電路圖
圖6.變壓器電路圖
變壓器主要指標:
圖7. PCB布局圖(頂層)
詳情請見:
http://www.powerint.com/sites/default/files/product-docs/linkswitch-ph_family_datasheet.pdf
和
http://www.powerint.com/sites/default/files/PDFFiles/der284.pdf
