LOW-POWER HIGH-SPEED CLASS-AB BUFFER AMPLIFIERS FOR LIQUID-CRYSTAL DISPLAY SIGNAL DRIVER APPLICATION

Abstract

Two types of low-power, high-speed, but with a large input dynamic range and output swing class-AB output buffer amplifiers which are suitable for the liquid-crystal display signal driver application are proposed. The driving capabilities of the circuits are achieved by adding comparators which sense the rising and falling edges of the input waveform and then turn on an auxiliary driving transistor to help charging/discharging the output load. The auxiliary driving transistors stay at "off" in the stable state, thus drawing no static power. Hence, the buffers draw little current during static but have an improved driving capability during transients. They are demonstrated in a 0.6 μm CMOS technology. The measured data do show that the proposed output buffer circuits are very suitable for the application of liquid-crystal display signal driver.