Low Noise Low Power CMOS Telescopic-OTA for Bio-Medical Applications

Bellamkonda Saidulu,Kumaravel Sundaram,Arun Manoharan

doi:10.3390/computers5040025

Bellamkonda Saidulu, Kumaravel Sundaram + Show 1 more

Open Access

https://doi.org/10.3390/computers5040025

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Abstract

The preamplifier block is crucial in bio-medical signal processing. The power intensive Operational Transconductance Amplifier (OTA) is considered, and the performance of preamplifier is studied. A low noise and low power telescopic OTA is proposed in this work. To reduce the noise contribution in the active load transistors, source degeneration technique is incorporated in the current stealing branch of the OTA. The OTA design optimization is achieved by g m / I d methodology, which helps to determine the device geometrical parameters (W/L ratio). The proposed design was implemented in CMOS 90 nm with bias current and supply voltage of 1.6 µA and 1.2 V, respectively. The post layout simulation results of the proposed amplifier gave a gain of 62 dB with phase margin 57°, CMRR 78 dB, input referred noise 3.2 µVrms, Noise Efficiency Factor (NEF) 1.86 and power consumption of 1.92 µW.

Highlights

The recent advancement in health monitoring system with NEMS/MEMS technology has opened up the opportunity for integrating a greater number of sensors on a chip which in its turn allows for better disease diagnosis and treatment of patients
This work will focuses on the frequency range of Epilepsy seizure diagnoses using EEG signal which is limited to 100 Hz
This paper proposed a noise reduction technique by introducing source degeneration in the current stealing branch [2,11], which has more impact on noise reduction

Summary

Introduction

The recent advancement in health monitoring system with NEMS/MEMS technology has opened up the opportunity for integrating a greater number of sensors on a chip (high density) which in its turn allows for better disease diagnosis and treatment of patients. Some of the bio-signal recording systems are constructed such that they are implantable, and are placed beneath the skin to record for a fairly long period (7–12 weeks) to diagnose the disorders These recording systems demand low power consumption, small size [2] and low noise for faithful signal detection. MDPR is used for the rejection of DC offset at the electrode-tissue interface, which emulates high resistance values (Tera ohm) with smaller swing. Due to bio-compatibility, the existing circuitry still requires improvement in terms of: area, noise level, heat and power dissipation [3]

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