应用于可携式产品液晶显示器之低静态电流与晶片面积的源极驱动电路架构

One Quiescent Current and Chip Area Efficient Architecture of TFT-LCD Source Driver for Portable Applications

在这篇论文中,我们提出一种适用于QCIF+解析度、262千色的薄膜电晶体液晶显示器,具有低靜态电流和晶片面积的源极驱动电路架构。此类驱动晶片可以实际被应用于行动电话或其他高阶可攜式电子产品上。传统A、B、C等三种形式的源极驱动电路,需使用大量的运算放大器来驱动面板中的画素,和较大阻值的电阻式数位类比转?电路来产生珈玛电压,以保有最低的靜态消耗电流。而我们提出的第四种源极驱动电路架构,仅使用二个运算放大器和较低电阻的电阻式数位类比转換电路,而且并不会增加靜态消耗电流。因此,这颗源极驱动晶片,不仅可省下晶片面积、增加产品竞<力,更可以降低靜态功率的消耗以延长电池的续航力。我们所提出的运算放大器和源极驱动电路之原型晶片,是利用3.3 V、0.35μmCMOS的制程技术来实现的.运算放大器电路的核心尺寸大小为100μm×50μm,源极驱动电路为400μm×650μm。由我们所提出的第四种驱动电路架构,晶片面积约可減少54.25 %,而靜态消耗电流仅需2.6 %。

One architecture of 262 K-colors TFT-LCD source driver efficient in chip dimension and static current, which is suitable for QCIF＋ （176RGB×240） resolutions, is propose＆ And it can be used in the mobile phone or the high-end portable in practicle. The conventional three type source drivers demand larger numbers of OPAMP buffers to drive the panel＇s pixels, and involve higher resistance value of R-DAC to generate gamma voltages for keeping the lowest static current. In this fourth type source driver, it only uses two OPAMPs and the lower resistance value of R-DAC without increasing the quiescent current. Thus, the source driver can save more area to increase the chip competitive advantages and reduce static power dissipation for extending the battery lifetime. The proposed prototype chip of the OPAMP and the 262K-colors TFT-LCD source driver were implemented by 3. 3 V 0. 35 μm CMOS fabrication technology. The circuit core size of the OPAMP is about 100 μm × 50 μm and the source driver is around 400 μm × 650 μm. The reduced chip area is approximately 54. 25 % and the wasted static current is around 2. 6 % by this forth architecture.