基于低壓照明的可調光LED驅動器的設計

Cirrus公司的CS1680是低壓照明的可調光LED驅動器,具有最好的變壓器兼容性,調光特性以及高達83%的效率,最低調光量5%,輸出電壓12V/15V,主要用在MR16燈和所有的12VAC/DC低壓照明應用.本文介紹了CS1680主要特性,框圖和應用電路,以及CRD1680-7W 7 W參考設計主要特性,電路圖,材料清單和PCB設計圖.

The CS1680 is a cascade boost-buck dimmable LEDdriver for the 12V halogen lamp-replacement market.

The CS1680 uses a Cirrus Logic proprietary intelligentdigital control that provides exceptional single-lamp andmulti-lamp transformer compatibility for non-dimmer systemsand dimmer systems paired with electronic andmagnetic low-voltage transformers.

The CS1680 integrates a continuous conduction mode(CCM) boost converter that provides transformer compatibilityand dimmer compatibility. An adaptive digitalalgorithm controls the boost stage and dimmer compatibilityoperation mode to enable flicker-free operationdown to 5% output current with leading-edge and trailing-edge dimmers.

CS1680主要特性:

? Best-in-class Transformer Compatibility
- Magnetic Transformers
- Electronic Transformers
? Best-in-class Dimmer Compatibility
- Leading-edge (TRIAC) Dimmers
- Trailing-edge Dimmers
? High Efficiency
- Up to 80% for CS1680-00 Applications
- Up to 83% for CS1680-02 Applications
? Flicker-free Dimming
? 5% Minimum Dimming Level
? Cascade Boost-buck Topology with Constant-currentOutput
- CS1680-00 Output Voltage ?15V
- CS1680-02 Output Voltage ?21V
? Fast Startup
? Tight LED Current Regulation: Better than ±10%
? >0.9 Power Factor on Magnetic Transformers
? Soft Start
? Protections:
-Output Open/Short
- Boost Overvoltage
-Overcurrent Detection
- External Overtemperature Using NTC

CS1680應用:

? MR16 Lamps
? All 12VAC/VDC Low-voltage Lighting Applications

圖1.CS1680框圖

圖2.CS1680應用電路圖

CRD1680-7W 7 W參考設計

The CRD1680-7W reference design demonstrates theperformance of the CS1680 dimmable LED driver forlow-voltage lighting with a target output of 430mA driving4?LEDs in series. It provides exceptional single-lampand multi-lamp transformer compatibility for non-dimmersystems and dimmer systems paired with electronic andmagnetic low-voltage transformers. The form factor istargeted to fit into MR16 LED lamp applications.

The CRD1680-7W board is optimized to deliver low system cost in a high-efficiency, flicker-free, phase-dimmable,solid-state lighting (SSL) solution for incandescent lamp replacement applications. The feedback loop is closedthrough an integrated digital control system within the IC. Protection algorithms such as output open/short, overcurrentdetection, boost overvoltage, and overtemperature thermistors protect the system during abnormal conditions.

Details of these features are provided in the CS1680 Dimmable LED Driver IC for Low-voltage Lighting data sheet.

The CRD1680-7W board demonstrates the performance of the CS1680. This reference board has been designedfor an output load of 4?LEDs in series at a target output current of 430mA (12.0V typical).

This document provides the schematic for the board. It includes oscilloscope screen shots that indicate various operatingwaveforms. Graphs are also provided that document the performance of the board in terms of Efficiency vs.Line Voltage, Output Current vs. Line Voltage, and Output Current vs. Dim Angle for the CS1680 dimmable LEDcontroller IC.

CRD1680-7W 7 W參考設計特性:

? Constant-current Output
? Flicker-free Dimming
? Line Voltage 12VAC/VDC, ±10%
? Rated Input Power: 7.0W
? Rated Output Power: 5.6W
? Output Voltage: <15V
? High Efficiency with Magnetic and ElectronicTransformers
? Low Component Count
? Supports Cirrus Logic Product CS1680

圖3.CRD1680-7W 7 W參考設計外形圖

圖4.CRD1680-7W 7 W參考設計電路圖

CRD1680-7W 7 W參考設計材料清單:

圖5.CRD1680-7W 7 W參考設計PCB尺寸

圖6.CRD1680-7W 7 W參考設計PCB頂層絲印圖

圖7.CRD1680-7W 7 W參考設計PCB底層絲印圖

圖8.CRD1680-7W 7 W參考設計PCB走線圖(層1)

圖9.CRD1680-7W 7 W參考設計PCB走線圖(層2)

圖10.CRD1680-7W 7 W參考設計PCB走線圖(層3)

圖11.CRD1680-7W 7 W參考設計PCB走線圖(層4)