New Rail-to-Rail Column Driver for 8-bit Large TFT LCD Applications

In this paper, a high-speed low-power column driver using a new rail-to-rail scheme is proposed, designed and evaluated for large TFT LCD applications. The proposed output driver is composed of a differential amplifier stage, second amplifier stage, driver selector, dual push-pull output driver stage for rail-to-rail output driving and feedback path selector. The output driver amplifier achieves a very large driving capability by eliminating the RON of the output switches used for polarity control. This increases the output driving speed while retaining low quiescent current consumption and can minimize the area of the output driving transistors and switches used for output polarity inversion. The quiescent current consumptions for the PMOS input driver and NMOS input driver are 10uA/channel on average.