Differential amplifier for biomedical signal acquisition applications based on stacked transistors

Prateek Jain; Vivekanand Mishra; Sandip A. Mehta

doi:10.3103/S0735272724020043

Authors

Prateek Jain Nirma University, Ahmedabad (Guj), India https://orcid.org/0000-0002-8191-9785
Vivekanand Mishra Alliance University, Bangalore, India https://orcid.org/0000-0001-8664-4699
Sandip A. Mehta Nirma University, Ahmedabad, India https://orcid.org/0000-0002-5453-2497

DOI:

https://doi.org/10.3103/S0735272724020043

Keywords:

ECG, electrocardiogram, signal conditioning, high CMRR, PSRR, Input noise

Abstract

This study presents a two-stage differential amplifier circuit that has been improved for use in a realistic biomedical signal conditioning system. CMOS technology serves as the foundation for the circuit. A MOS-based low-pass filter using stacked transistors creates a low-power differential amplifier with low noise and high common-mode rejection ratio (CMRR) for portable electrocardiogram (ECG) signal conditioning. Stack transistors with MOS connected at the output terminal are used to improve the design for electrocardiogram (ECG) signal conditioning and other types of signal conditioning for biomedical devices. Standard 45nm CMOS process technology was used in the construction of the amplifier that is being discussed. The amplifier runs at a supply voltage of 0.85 V. The simulation findings are produced using the Cadence Analogue Virtuoso Spectre Simulator to generate the simulation. The differential amplifier described demonstrates a CMRR = 140 dB at frequency of 80 Hz, a power supply rejection ratio (PSRR) of 68 decibels, and a power dissipation of 1.3 mW. These characteristics conform to the simulation results. While the slew rate is 11 V/s, the input-referred noise is 2.62 mV/Hz1/2. Compared to the conventional differential amplifier, the performance characteristics generated by this approach are better and more efficient than those created by the standard circuit. The proposed design improves the noise performance of the differential amplifier developed in the past, which enhances noise performance.

Author Biographies

Prateek Jain, Nirma University, Ahmedabad (Guj)

E&I Department

Sandip A. Mehta, Nirma University, Ahmedabad

Institute of Technology

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