A Low Noise Front-end Amplifier for Pyroelectric Transducer Based Respiration Monitoring System

摘要

This paper reports a low-power low-noise folded-cascode OTA based charge amplifier designed to be used as the front-end amplifier (FEA) for a pyroelectric transducer based respiration monitoring system. The amplifier is designed in 0.5μm standard CMOS process and consumes only 5.4 μW of power with 1.8V supply voltage. The operational transconductance amplifier (OTA) adopts a pseudo-resistor based diode-connected MOSFET in the feedback configuration to achieve a 1 mHz low corner frequency. Measurement results show an FEA input referred noise of only 5.017 μV_(RMS) over the frequency range of 125 mHz to 10 kHz. Test results also include the recording of the respiratory signal acquired by the pyroelectric transducer and the FEA.