Development of low power Dynamic threshold PCS System

Abstract

Real-time reception of sensor signals is one of the most significant operations in analog signal processing. Driven by low-power and low-voltage requirements for integrated mixed signal portable applications, this paper propose a novel low power Dynamic Threshold Photo Catalytic Sensor (DTMOS)system to work efficiently below lower bound of power supply independent of substrate bias effect. Another important feature of DTMOS is that the fabrication of circuits based on DTPCS is less complex and more economical. The SPICE simulations were performed with 120 nm technology parameters and results verify the performance of the circuit. The proposed system has high linearity and simple structure hence it is suitable for high-performance and low-power analog VLSI applications. The main reason of employing a readout circuit to PCS circuitry, is the fact that the fluctuation of O2 influences the threshold voltage, which is internal parameter of the FET and can manifest itself as a voltage signal at output but as a function of the trans-conductance gain. The trans- conductance is a passive parameter and in order to derive voltage or current signal from its fluctuations the sensor has to be attached to readout circuit. This circuit provides high sensitivity to the changes in percentage of O2 in the solution.