驅(qū)動(dòng)led陣列的電源及拓?fù)浣鉀Q方案

　　大量的LED，特別是高亮度LED（HB LED），越來越多地被用于各種陣列配置，用于顯示背光照明、區(qū)域照明和數(shù)字標(biāo)牌。當(dāng)驅(qū)動(dòng)一個(gè)或幾個(gè)發(fā)光二極管是相當(dāng)簡單的，這樣做對(duì)這些較大的陣列帶來的問題，整個(gè)LED互連拓?fù)浣Y(jié)構(gòu)，以及選項(xiàng)供電，甚至控制陣列。

　　一個(gè)單一的LED需要20和60毫安之間的驅(qū)動(dòng)電流，并有一個(gè)電壓下降1.8至4 V（名義上1.8 V的紅色LED，移動(dòng)到2 V的琥珀，2.2 V為黃色，3.5伏為綠色，3.6 V為藍(lán)色，高達(dá)4 V為白色）。驅(qū)動(dòng)發(fā)光二極管意味著設(shè)計(jì)者必須把他們的想法從更常見的電壓源供應(yīng)轉(zhuǎn)移到不常見的，但同樣可行的電流源（恒流）供應(yīng)或驅(qū)動(dòng)，他們往往不熟悉這種供電模式及其含義。

　　The LED power-supply （see the TechZone article “How to Choose the Right Power Supply for Your LED Lighting Project”） and driver chain is conceptually simple （Figure 1）。 Driving the LEDs themselves is both easy and difficult. It is easy because they individually are a low/moderate current and voltage load， and the driver can operate at an efficient DC/DC conversion frequency， usually between 100 kHz and 1.5 MHz. However， it is difficult because the driver must act as a current source， not the more conventional voltage source， and this places new and sometimes difficult demands on its circuitry （and designers of the circuitry）。