Design and Simulation of an OTA for ECG Signals with High PSRR and CMRR

This paper presents the design and simulation of a high-gain, two-stage OTA. Using a 180 nm standard CMOS technology and resistive approximation techniques. The proposed symmetrical OTA, designed to function in the strong inversion region, achieves a gain of 72.06 dB, PSRR⁺, PSRR^- of 108 dB and 114 dB respectively, CMRR of 95 dB and a bandwidth of 22.9 kHz. Additionally, an IRN of 0.93 µVrms is obtained. Simulation results indicate that the designed OTA is a highly suitable candidate for biomedical applications, particularly for the detection and monitoring of electrocardiographic (ECG) signals.