Integration of a Novel Folded Cascode Operational Amplifier with Class AB Output Stage Featuring Enhanced Performance in 0.18\ μ m CMOS

This paper introduces a meticulously crafted folded cascode operational amplifier (FC OpAmp) designed for diverse applications, implemented using TSMC <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.18\ μ m</tex> technology. The OpAmp exhibits effective performance characteristics, including minimal input bias current, a 4.28 MHz unity gain-bandwidth (UGB), and operation with a 5V supply at low power consumption (9.9 mW). With a DC gain of 130 dB, a generous input common-mode voltage range (-1.9 V to 3.94 V), and a low output resistance <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(1.17\ mΩ)</tex> , the amplifier excels in precision analog circuits. Additionally, the FC OpAmp serves as a low-pass filter, significantly reducing the high output resistance in folded cascode circuits through the incorporation of a Class AB output stage. This feature transforms the amplifier into an excellent low-impedance buffer for the precise driving of resistive loads. The design showcases advanced techniques and outstanding performance, offering adaptability for a spectrum of analog circuit applications within a unified amplifier design.