PowerInt公司的LYTSwitch?-7系列是相切(Phase-Cut)可調光單級LED驅動器,具有PFC和恒流電流輸出.器件集成了帶有可變開態CrM控制器的725V高壓MOSFET.功率因素大于0.9,效率大于85%,線路輸入電壓±3% CC穩壓,輸入電壓90 VAC–308 VAC,主要用在LED照明.本文介紹了LYTSwitch?-7系列產品亮點,框圖和7.5 W,60 V,125 mA調光非隔離A19 LED驅動器電路圖,以及用于BR-30調光LED燈的采用LYTSwitch-7系列10W 88%效率TRIAC調光LED驅動器參考設計DER586主要特性和指標,電路圖,材料清單和PCB設計圖.

The LYTSwitch?-7 family is ideal for single-stage, high PF, constant current LED dimmable applications.

The family incorporates a high-voltage MOSFET with a variable on-time CrM controller. Extensive protection features with minimum external components provide industry leading power density and functionality.

The CrM operation results in low turn-on losses and reduces cost of output diode (slower reverse-recovery type can be used).

LYTSwitch-7 devices are suitable for applications from 4 W to 22 W. For more information, see Application section. LYTSwitch-7 peak current mode operation is suitable for TRIAC applications without the need for an active bleeder.

LYTSwitch?-7系列產品亮點:

Single-Stage PFC + Accurate CC Output
±3% CC regulation in single line input voltage applications
Power factor >0.9
High efficiency >85%
Robust 725 V MOSFET for increased line voltage surge resistance
Critical Conduction Mode (CrM) buck
Low EMI
Excellent line noise and transient rejection
Dimming Highlights
Fast turn-on (<500 ms)
Low pop-on
Better than 10:1 dimming ratio
Simple passive R-C damper
Monotonic dimming profile
Design Flexibility
Wide input (90 VAC – 308 VAC) and output voltage range operation
2 family members cover power range for optimum device selection
Requires no inductor bias winding
Small form factor package – SO-8
Highest Reliability
Industry’s lowest component count dimming solution
Comprehensive protection features with auto-restart Input and output overvoltage protection (OVP)
Output short-circuit protection
Open-loop protection
Advanced thermal control Thermal foldback ensures that light continues to be delivered at elevated temperatures
Over-temperature shutdown provides protection during fault

圖1.LYTSwitch?-7系列框圖

圖2.采用LYT7503D的7.5 W, 60 V, 125 mA調光非隔離A19 LED驅動器

用于BR-30調光LED燈的采用LYTSwitch-7系列10W 88%效率TRIAC調光LED驅動器參考設計DER586

This engineering report describes a low component count, TRIAC dimmable, non-isolated buck LED driver, designed to drive a nominal LED voltage string of 60 V at 170 mA from an input voltage range of 90 VAC to 132 VAC. This LED driver utilizes the LYT7503D from the LYTSwitch-7 family of devices.

The LYTSwitch-7 device is an SO-8 package LED driver controller IC designed for non-isolated buck topology applications. The LYTSwitch-7 ICs provide high efficiency, high power factor, accurate LED current regulation, and inherent dimming capability. LYTSwitch-7 ICs incorporate a high-voltage power MOSFET and variable frequency / variable on-time, critical conduction mode control engine for accurate current regulation, high power factor and proprietary power MOSFET utilization for high efficiency. The controller also integrates protection features such as input and output overvoltage protection, thermal fold-back, over temperature shutdown, output short-circuit and overcurrent protection.

DER-586 is a single stage 10 W TRIAC dimmable LED driver with constant current output. The key design goals were design simplicity, high efficiency, low component count, accurate constant current regulation, compact PCB and acceptable dimming compatibility. The design is intended for BR-30 dimmable LED bulb applications.

This document contains the power supply specification, schematic diagram, bill of materials, printed circuit layout, and performance data.

參考設計DER586主要特性:

? Single-stage power factor corrected, PF >0.9
? Accurate constant LED current (CC) regulation, ±5%
? High efficiency, > 88% at 120 VAC
? Low cost and low component count for compact PCB solution
? TRIAC dimmable
? Works with a wide selection of TRIAC dimmers
? Fast start-up time (<500 ms) – no perceptible delay
? Minimum dead-band or visible pop-on effect.
? Integrated protection features
? Open load and output short-circuit protection
? Thermal fold-back protection
? No damage during line brown-out or brown-in conditions
? Meets IEC 2.5 kV ring wave, 1 kV differential surge and EN55015 conducted EMI

圖3.參考設計DER586外形圖(正面)

圖4.參考設計DER586外形圖(背面)
參考設計DER586主要指標:

圖5.參考設計DER586電路圖
參考設計DER586材料清單:

圖6.參考設計DER586 PCB設計圖(正面)

圖7.參考設計DER586 PCB設計圖(背面)