【摘要】：隨著白光LED在1998年開發(fā)成功,白光LED給顯示照明領(lǐng)域更帶來了革命性的變化。白光LED具有無污染,長壽命,抗沖擊,耐震動,節(jié)電和維護(hù)成本低等優(yōu)點(diǎn)。在所有的LED應(yīng)用設(shè)備中,便攜式LED照明與顯示裝置是應(yīng)用最為廣泛的一類。因此LED背光驅(qū)動電路的研究成為一個越來越重要的課題。與傳統(tǒng)的LED背光驅(qū)動不同,本文采用了恒流源驅(qū)動電路,使得芯片尺寸減小,成本下降。另外,本文設(shè)計的低壓電流鏡電路,實(shí)現(xiàn)了非常小的壓降設(shè)計指標(biāo),大大降低了驅(qū)動電路的能量損耗,延長了應(yīng)用裝置的鋰電池使用時間。本文首先介紹了系統(tǒng)的工作原理,給出了PWM控制方式實(shí)現(xiàn)的系統(tǒng)結(jié)構(gòu)框圖。然后本文一一闡述了各分模塊的工作原理和電路設(shè)計,重點(diǎn)闡述了模擬電路部分的理論研究和設(shè)計實(shí)現(xiàn),即基準(zhǔn)電流源模塊和電流鏡電路模塊。在基準(zhǔn)電流源模塊,論文介紹了幾種典型的基準(zhǔn)電壓源電路,最后選擇了Sub Bandgap結(jié)構(gòu)的帶隙基準(zhǔn)電壓源電路結(jié)構(gòu)加以改進(jìn),作為為芯片的基準(zhǔn)電流源。在電流鏡電路模塊中,論文設(shè)計的超低壓降電流鏡電路,相比較傳統(tǒng)電流鏡電路,具有更簡單的電路結(jié)構(gòu)和更小的壓降。最后對整個芯片進(jìn)行了前仿真和版圖后仿真,仿真結(jié)果均達(dá)到或優(yōu)于設(shè)計指標(biāo)。
[Abstract]:With the successful development of white LED in 1998, white light LED has brought revolutionary changes to the field of display lighting. White LED has the advantages of no pollution, long life, shock resistance, vibration resistance, electricity saving and low maintenance cost. Among all LED applications, portable LED lighting and display devices are the most widely used. Therefore, the research of LED backlight drive circuit becomes more and more important. Different from the traditional LED backlight drive, the constant current source drive circuit is used in this paper, which reduces the chip size and reduces the cost. In addition, the low voltage current mirror circuit designed in this paper realizes the very small voltage drop design index, greatly reduces the energy loss of the drive circuit, and prolongs the life time of the lithium battery in the application device. In this paper, the working principle of the system is introduced, and the structure diagram of the PWM control mode is given. Then this paper describes the working principle and circuit design of each sub-module, focusing on the theoretical research and design of the analog circuit, that is, the reference current source module and the current mirror circuit module. In the reference current source module, several typical reference voltage source circuits are introduced in this paper. Finally, the bandgap voltage reference circuit with Sub Bandgap structure is selected to be the reference current source for the chip. In the current mirror circuit module, the design of ultra-low voltage drop current mirror circuit, compared with the traditional current mirror circuit, has a simpler circuit structure and smaller voltage drop. Finally, the whole chip is simulated before and after layout, and the simulation results reach or exceed the design target.
【學(xué)位授予單位】：復(fù)旦大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TM923.34

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本文編號：2245448