High Performance Two-Stage Operational Transconductance Amplifier (OTA) for Biomedical Applications: Design, Simulation & Performance Analysis

This paper elucidates the design, simulation, and performance analysis of a CMOS operational transconductance amplifier (OTA) for biomedical applications. High performance OTA modules are critical for developing biomedical systems as OTA determines the gain, signal to noise ratio (SNR) of measurand physiological signals along with other specifics. The proposed OTA design is a high gain and power constraint design critical for various real-time applications, especially for biomedical amplifiers, active filters, and sensor interfaces. In this work, we report on a high performance two-stage CMOS OTA implemented with UMC PDK 180 nm technology. Further, we compare the proposed design with reported OTAs in the literature. From simulations it is found that compared to other designs reported in the literature, the OTA depicts a gain, GainBandwidthProduct (GBW) and stable phase margin of 51.4dB, 18.93 MHz and 65.96° respectively with low power consumption of 1.23mW. Further, investigation of Process, Voltage, and Temperature (PVT) impact is reported across all corners (TT, FF, and SS) with temperature variations from -40 °C to 125 °C, and for supply voltages of 1.78 V, 1.8 V, and 1.82 V to ensure the robustness of the OTA. Monte Carlo analysis with 400 mismatch samples depict that the proposed OTA is reliable, showing minimum deviation in the key performance metrics.