A Low Power Low Noise Chopper-Stabilized Tow-stage Operational Amplifier for Portable Bio-potential Acquisition Systems Using 90 nm Technology

Abstract

This paper presents a high performance chopper-Stabilized Two-stage operational amplifier for biomedical applications. This Two-stage is designed for low noise, low power, high PSRR and high CMRR. The Miller compensation technique (Cc) is used with a nulling active resistance (Rz) implemented using Transmission gate (TG) transistors for stable operation in feedback mode. Chopper stabilization technique has been widely used in amplifiers for flicker (1/f) noise and offsets reduction purposes using the principles of modulation and demodulation. Thus, the functionality and performance of modulation and demodulation circuits determines the realization and attainment of chopper stabilization. The operational amplifier was manufactured in a SPECTRE using GPDK 90nm CMOS technology with threshold voltages of a 0.17 V and -0.14 V achieve a low power 2.6uW, Hz nV / 5 . 13at 10Hz high CMRR up to 130dB and PSRR up to 70dB at 1V power supply.

An Apparatus for Spectral Emissivity Measurements of Thermal Control Materials at Low Temperatures

“…During measurements, the beam passed the chopper wheel in periodicity and was modulated in a specific frequency. Meanwhile, the chopper controller sent the reference signal—having the same frequency as the beam—to the reference channel of the lock-in amplifier [12,13,14]. The beam of radiation then passed the potassium bromide interferometer and was transformed into an interference light with the Fourier transform frequency.…”