C2000 MCU的控制多個LED串的方法

　　隨著LED技術(shù)的不斷發(fā)展，電源效率的提高和成本的節(jié)省使得LED的使用方式越來越多。同時，系統(tǒng)使用更多種類的LED，每種LED都需要不同的驅(qū)動，以達(dá)到最佳的性能、效率和顏色精度。汽車系統(tǒng)，例如，使用LED的各種功能，包括頭燈，遠(yuǎn)光燈，霧燈，轉(zhuǎn)彎燈等-每一個需要不同類型的LED和/或不同數(shù)量的LED。

　　開發(fā)人員可以使用不同的功率級拓?fù)浜涂刂品椒?qū)動多個LED字符串。每個拓?fù)浜涂刂品椒ǘ加懈髯缘膬?yōu)點(diǎn)，這取決于應(yīng)用程序。兩種常見的演示實(shí)現(xiàn)LED照明設(shè)計的實(shí)現(xiàn)，提供了兩個LED照明開發(fā)套件基于實(shí)時控制C2000 Piccolo?建筑–DC/DC LED照明開發(fā)套件和多直流/直流彩色LED開發(fā)套件。結(jié)合TI公司的業(yè)界領(lǐng)先的開發(fā)軟件和工具，工程師們可以使用這些工具包來加速各種照明應(yīng)用的發(fā)展。

　　Power stage topologies and control methods

　　There are several common power stage design topologies and digital control methods used in the LED lighting industry. Each design implementation and control method offers its unique advantages and considerations. TI showcases two of these power stage design topologies and two accompanying control methods with its C2000 LED lighting developer’s kits.

　　Figure 1 shows the power topology for a single， shared power stage as used in the DC/DC LED Lighting Developer’s Kit. This topology utilizes a Piccolo F28035 MCU to control a single， flexible SEPIC DC/DC power stage and eight separate LED dimming stages for control of same type and same length LED strings. SEPIC is a dynamic topology which can run off a high voltage （up to 48 volts） and step up or step down the drive voltage appropriately. With this control topology， developers can precisely and independently control luminosity and color temperature of same-type/same-length LED strings. A single power stage topology is well-suited for applications such as industrial lighting where consistent output is required.