Design fundamentals of high temperature silicon carbide operational amplifiers in the freely related environments MicroCap and LTspice

To simulate analog circuits in the freely available MicroCap and LTspice environments at temperatures up to 452 °C, template models of SiC transistors have been developed using the template modeling technique, in which the constant parameters of the model are replaced by fractional-rational functions, allowing a more accurate description of the physical processes in the JFET without violating the character their changes. Instructions have been developed for testing SiC JFet transistor models in LTspice and MicroCap environments. The purpose of the work is to study circuit solutions for high-temperature basic analog functional units, implemented on the basis of silicon carbide field-effect transistors using developed template models. The parameters of SiC two-terminal reference current circuits and dynamic loads of amplification stages of operational amplifiers with different numbers of series-connected SiC JFets, which can be used in high-temperature analog circuitry, are presented. The main characteristics of SiC differential stages and the simplest SiC operational amplifiers with paraphase output based on them were studied at temperatures of 25 °C and 452 °C. The results obtained are recommended for use in the design of high-temperature operational and instrumental amplifiers used in space instrumentation, deep well drilling equipment, automotive industry, nuclear reactors, etc. for processing signals from sensors of physical quantities and converting radio signals.