Uncompensated Robust Rail-to-Rail New Amplifier Structure Compatible with Drivers of LCD Panels

Abstract

A new rail-to-rail amplifier structure that requires no compensation for the use as a channel buffer in column driver ICs of liquid crystal display (LCD) panels is introduced. The proposed amplifier utilizes current splitting technique applied on a rail-to-rail differential pair. Simulation results for 90 nm CMOS technology on LTSPICE under 1 V supply voltage is provided. Open loop simulations show that the proposed amplifier is capable of achieving high DC gain of 75.5 dB, high transconductance of 350μA/V, high output resistance of 22.2 MΩ with a phase margin of 80° and power consumption of 4.7 μWatt. When configured as a buffer, the amplifier exhibits rail-to-rail operation with low total harmonic distortion (THD) ranging from −66 to −53 dB only corresponding to an input voltage ranging from 0.2 to 1 Vp-p at 10 kHz frequency. For a step input, the output has a fast response with a rise and fall time of 1.56μs and 1.5μs respectively.