Project Lighting - April 2008 - (Page 15)

FeAtURe sponsoR ADveRtIsement Cypress Semiconductor’s Evaluation Board for EZ-Color™ LED Controller The CY3261A-RGB board is a preprogrammed LED color mix board with seven pre-set colors using the CY8CLED16 EZ-Color HB LED Controller. The board is accompanied by a CD containing the color selector software application, PSoC Express 3.0 Beta 2, PSoC Programmer, and a suite of documents, schematics, and firmware examples. The color selector software application can be installed on a host PC and is used to control the EZ-Color HB LED controller using the included USB cable. The application enables you to select colors via a CIE 1931 chart or by entering coordinates. Click here for more information must be considered. Large copper lands on the PCB, directly under the LED slug, improve thermal spreading. The copper’s thickness and area, the thickness and thermal conductivity of the PCB material, and the use of an MCPCB are key to decreasing thermal resistance. intEgraL anaLysis will be sufficient for first-order analysis of the thermal problem. The MCPCB is mounted onto the base of a round heat sink using a double-sided, thermally conductive tape. This interface adds a theoretical thermal resistance of 0.3 K/W to the network. The spreading resistance within the base of the heat sink is expected to be zero, since the respective areas are the same. Heat is removed from the sink’s base and fins by natural convection and radiation. With the total thermal network in place, the junction temperature can be calculated for a specified ambient. When the LEDs are operating on 1.1 W, the junctions are within spec. In this setup, radiation heat transfer contributes 23% and must be included in the analysis. For natural convection cooling, the performance of the heat sink will differ based on the power supplied to the LED. Contents Viewpoint Selecting HBLED Drivers for Lighting Apps Simulation Technique for Optimizing White-LED Design An Analytical Approach to Cooling HBLEDs Lighting News Cypress Semiconductors 1530 E. Dundee Road - Suite 190 Palatine, Il 60074 USA Phone: 847-934-3144 Fax: 847-934-7364 http://www.cypress.com/ For a first-order solution, integral analysis identifies the problem areas (components and system layout) and the magnitude of the thermal issue (device junction temperature and required level of cooling). Some analyses can be performed quickly to get the scope of the problem—the so-called “what if” scenario. The action of the four LEDs mounted on the PCB is best described using an electrical analog (see Figure 3). Although this is a two-dimensional representation, in most cases it Home Page Product Training Module Online Ordering Suppliers Catalog for SucceSSful cooling, the thermal reSiStance of the PcB muSt Be conSiDereD 15 | Project lighting | aPr 08 http://digikey.com/ http://www.cypress.com/ http://digikey.com/ http://ad.doubleclick.net/clk;195096841;25485866;a http://dkc1.digikey.com/us/en/PTM/Modules.html http://sales.digikey.com/scripts/sales.dll?site=US;source=search http://suppliers.digikey.com/manufacturerlist.aspx?site=us&lang=en http://dkc1.digikey.com/us/en/pdf/Current.html

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Project Lighting - April 2008 Contents Viewpoint About Project Lighting Sponsor Simulation Technique for Optimizing White-LED Design An Analytical Approach to Cooling HBLEDs LED Lighting Needs Smarts to be Competitive Lighting News Enter to Win an iPhone Refernce Materials Lighting Quick Links

Project Lighting - April 2008

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