Area-Efficient Fully R-DAC Based TFT-LCD Column Driver Architectures With DAC Sharing Techniques

Abstract

This study proposes two types of area-efficient fully resistor digital-to-analog converter (R-DAC)-based thin-film transistor liquid crystal display (TFT-LCD) column drivers. In the first type of the column driver, two level shifters and two R-DACs are shared by four channels for die area saving. Two full resolution R-DACs and two less resolution R-DACs are used in four channels of the second column driver. Two experimental prototype 8-bit column drivers were implemented using 0.35- $\mu\hbox{m}$ CMOS technology to verify the proposed driving schemes. The maximum DNL and INL are 0.68 LSB and 0.68 LSB, respectively, for Type-I column driver, and are 0.81 LSB and 1.11 LSB, respectively, for Type-II column driver. Compared with a conventional fully R-DAC based TFT-LCD column driver, the proposed Type-I and Type-II column drivers have an area saving of 29.6% and 24.9%.