10-bit TFT-LCD源驱动电路的设计

Design of 10-bit TFT-LCD Source Driver Circuit

DAC和驱动Buffer是TFT-LCD源驱动电路芯片中的重要模块,决定着芯片的主要性能。文章讨论了传统的R-DAC结构及其用于10-bit TFT-LCD源驱动电路时的弊端,详细阐述了新型R-DAC+C-DAC的原理以及设计方法,并采用0.35μm 5VCMOS工艺设计和实现了该电路。Hspice仿真结果表明,所设计的DAC电路的DNL和INL分别小于0.4LSB和1.5LSB,输出电压的建立时间小于3.5μs。该新型结构DAC的面积约是传统结构面积的1/8,且能够实现10亿色(210×210×210)的全真彩显示。

DAC and drive Buffer is a key module of TFT-LCD source driver IC,which determines the main properties of the chip.Firstly,the drawbacks of traditional R-DAC structure used for 10-bit TFT-LCD source driver circuit was discussed,then the new R-DAC ＋ C-DAC principles and design methods were described.The proposed DAC circuit was designed and realized using 0.35 μm 5 V CMOS process.The results of Hspice simulation show that the DNL and INL of DAC circuit are less than 0.4 LSB or 1.5 LSB,respectively,and the output voltage settling time is less than 3.5 μs.The chip area of new structure DAC is 1/8 of the traditional structure DAC,and can achieve the 10 billion colors（210×210×210） display.