Design of MOS based Tera-? Resistance for Biomedical Signal (mHz) Applications

Authors

  • Bellamkonda Saidulu, Santosh Kumar Sahoo

Abstract

The proposed method for implementation of resistance amplifier is consisting of telescopic Operational Transconductance Amplifier (OTA) combined with source degeneration to achieve bandwidth range from millihertz (mHz) to KHz. The challenging issue is that to implement a larger time constant (sec), having the value of R and C components are to be in the range of Tera Ohm (T?) and picofarad (pF) respectively as per system-on-chip (SoC) designs. The implementation of high-value resistance is preferred than keeping larger capacitance to avoid on-chip issues like area, speed, and power consumption. To mitigate this problem, active (MOS based) resistor is proposed to have Tera Ohm (T?) resistance with low noise and low operating voltage (Vgs) it leads to low power consumption which plays a vital role in bio amplifier applications. This amplifier allows amplifying the neuro signals from 0.35 Hz to 7.5 kHz along with the rejection of input DC offset generated at the electrode-tissue interface. This bandwidth range can be tunable by selecting the proper value for MOS Depletion Pseudo-Resistor (MDPR) and feedback capacitor (Cf). The MDPR reduces the attenuation of the signal amplitude from the sensor to the input of OTA. This proposed design is carried out with simulation results in the cadence environment. Noise Efficiency Factor (NEF) is one of the limitations of noise and power. This limit approaches by operating the MOS transistors in either weak or strong inversion.

Published

2020-12-01

Issue

Section

Articles