A Low- Power Low-Noise Current-Feedback Instrumentation Amplifier based on gm boosted OTA for ECG Acquisition

This paper presents a CMOS operational transconductance amplifier (OTA) based current-feedback instrumentation amplifier (CFIA) optimized for low-power and low-noise electrocardiogram (ECG) detection that is implemented as a fully differential difference amplifier (FDDA). The suggested CFIA consists of only a few MOS transistors and an R-C feedback loop. Simulation results in Cadence Virtuoso with SCL $0.18 \mu \mathrm{m}$ CMOS technology are used to assess the effectiveness of the proposed CFIA. The gain, common mode rejection ratio (CMRR), and $-3 \mathrm{~dB}$ bandwidth of the suggested CFIA were found to be $50.25 \mathrm{~dB}$, 99.15 dB, and $0.52 \mathrm{~Hz}-2.62 \mathrm{kHz}$, respectively. PVT analysis is also performed to see the effect on the proposed design’s performance parameters. It achieves input impedance that is high enough across the whole frequency range of an ECG. An input impedance of $796.7 \mathrm{M} \Omega$ at $50 \mathrm{~Hz}$ and input-referred noise (IRN) of $0.016 \mu V_{\text {rms}}$ over 0.1 to $300 \mathrm{~Hz}$ are measured. Power consumption for the proposed CFIA is 189 nW with a 1.8 V power supply. The robustness of the amplifier is verified by the Monte-Carlo mismatch simulation.