A High Value, Linear and Tunable CMOS Pseudo-Resistor for Biomedical Applications

Abstract

A subthreshold MOS-based pseudo-resistor featuring a very high value and ultra-low distortion is proposed. A bandpass neural amplifier with a very low high-pass cutoff frequency is designed, to demonstrate the linearity of the proposed resistor. A BJT less CTAT current generator has been introduced to minimize the temperature drift of the resistor and make tuning easier. The standalone resistor has achieved 0.5% better linearity and a 12% improved temperature coefficient over the existing architectures. A neural amplifier has been designed with the proposed resistor as a feedback element. It demonstrated 31[Formula: see text]dB mid-band gain and a low-pass cutoff frequency of 0.85[Formula: see text]Hz. The circuit operates from a 1[Formula: see text]V supply and draws 950[Formula: see text]nA current at room temperature.

Wide‐range current‐controlled grounded resistor realization: A new application of the CMOS translinear elements

“…Tajalli et al 27 Nagulapalli et al 28 Guglielmi et al 29 This work exhibits a linear relationship in subthreshold, moderate and strong inversion regions, a characteristic unique to the proposed circuit only.…”

“…16,17 In view of the realizability of high-valued resistance (up to 1.3 GΩ), the proposed circuit can also be used in biomedical applications like the other high-valued pseudo-resistors reported in the literature. [27][28][29] A comparison of the proposed circuit with these quoted circuits has been carried out and is shown in Table 4.…”

Implementation of Analog Perceptron as an Essential Element of Configurable Neural Networks

“…For the summator block inside an analog perceptron, it can be implemented with lower anlog circuitry using OTAs instead of voltage amplifiers, thus reducing silicon area and power dissipation [ 40 ]. Furthermore, aiming at low-power applications, the active resistor comprised of MOS transistors operating in sub-threshold region can achieve high resistance and good tuning capability [ 41 , 42 , 43 ]. It is suitable for large value resistor implementation for the analog-based MLP.…”