Low-noise CMOS amplifier for readout electronic of resistive NEMS audio sensor

Investigation of readout electronic dedicated to electromechanical audio sensor is presented. The circuit is able of reading piezoresistive gauge implemented with silicon nanowire (NEMS) and bring electromechanical signal to high-resolution digital output. Low-noise low-power CMOS operational transconductance amplifier (OTA) is presented. The low-noise amplifier (LNA) has been designed in a 0.28 μm CMOS process with a 2.5 V supply voltage and occupies an area of 120 × 160 μm². For the Post-layout Simulation, the OTA achieves a 65 dB DC gain. It achieves a noise floor of 6 nV/√Hz within the frequency range from 1 Hz to 10 kHz. The total power consumption including the common mode feedback circuit (CMFB) and the biasing circuit is 150 μW.