Power Efficient High Gain/CMRR and Low Noise ElectroOculogram for Human-Computer Interaction and Wearable IOT Devices

In this paper, we introduce a low noise biopotential amplifier in which a two-stage OPAMP is the central element of the circuit. For every circuit in the current technology, enhancement of power efficiency, area and reduced noise are the critical specifications. Capturing bio-signals is pivotal, given their minute amplitude (typically within a few millivolts) and low frequency (ranging between 0.1 Hz and 10 kHz). Developing electronic medical devices for health monitoring involves employing operational transconductance amplifiers. Yet, achieving accurate bio-signal measurement demands a high CMRR and precision amplification to mitigate input noise and enhance signal strength. The desired performance metrics are gain, power, and noise margin, CMRR, and so on. For this, our design of biopotential amplifiers is implemented in 90nm technology with a supply voltage of 500mV. The CADENCE SPECTRE simulation of the designed circuit dissipates power in the order of 195.28nW with 86.41dB gain at 180 phase, 217.51dB CMRR and 225.02aV/√Hz Noise. These simulated results show a satisfactory amplification of the signals.