A High-bandwidth, Low-noise Rail-To-Rail Operational Amplifier

In order to accommodate lower operating voltages while ensuring that data can be transmitted stably and continuously, the op-amp designed in this paper is a dual-channel rail-to-rail op-amp that features high bandwidth and low noise. Rail-to-rail inputs and outputs are realized using complementary differential input pairs of NMOS and PMOS in parallel and Class AB output stages. The common-mode input range is $+2.5 \mathrm{~V} \sim+5.5 \mathrm{~V}$ and is fabricated using a $0.18 \mu \mathrm{~m}$ CMOS process. Post-simulation results show an input offset voltage of $2.72 \mu \mathrm{~V}$, an open-loop gain of 104 dB, a gain bandwidth product of 11 MHz, an equivalent input noise of 21 nV at 10 KHz, and a quiescent current of 1 mA at a single op-amp supply voltage of 5 V.