Low-offset Voltage Error and Low Noise Based CMOS Push-pull Operational Amplifier for Biomedical Applications in 180-nm CMOS Technology

This study illustrates an implementation of low-offset voltage error and low noise CMOS push-pull operational amplifier (op-amp) operating in weak inversion/subthreshold region. The op-amp shows different performance parameters such as DC gains, common-mode rejection ratios (CMRR), power supply rejection ratios (PSRR), DC offset voltage errors, input-referred-noise (IRN) and total harmonic distortions (THD). The performance parameters are varied with changing in W and L with same aspect ratio. The simulation results are drawn through UMC 0.18-µm CMOS technology with supply of 1.8 V. This circuit is to be useful in low frequency based biomedical analog signal processing applications.