High-Speed and Low-Power Analog Source Driver for TFT-LCD Using Dynamic Current Biased Operational Amplifier

摘要

This paper describes high-speed and low-power analog source driver built with operational amplifier (OPAMP) for driving large resistive and capacitive load of TFT-LCD panel. To obtain large slew-rate without increasing quiescent current, dynamic current biasing scheme is developed. The dynamic current bias circuit operates as auxiliary current source and supplies or sinks large amount of current only when the OPAMP is slewing. The analog source driver is implemented in a 0.35μm CMOS process, and for 20KΩ and 200pF data-line loading of 30-inch TFT-LCD panel, the settling time is 7.2μs and 6.4μs respectively for rising and falling while the quiescent current is only 5～6.5μA.