Modeling and Simulation of a Pressure Sensing Solution Based on Silicon Carbide for Harsh Environment Applications

Harsh conditions of high temperature and pressure typically present in industrial applications of pressure sensing pose unique challenges to system design, modeling and simulation. Capacitive sensor structures, operating in touch mode at high pressures, present a complicated problem for closed form modeling and numerical simulation. Furthermore, a material such as silicon carbide (SiC) that is able to withstand high temperatures and pressures needs to be used instead of the more conventional silicon. The absence of standard circuit models for simulation of SiC devices makes circuit design challenging. This paper presents the processes of modeling, design and simulation of a capacitive pressure sensor structure based on SiC as well as the extraction of SPICE models for the simulation of SiC MOSFETs and the use of these models for the design of a sensor interface circuit. Finally, the functionality of the whole system is simulated using commercial electronic design automation (EDA) software.