High-temperature (HT) applications have witnessed real growth during the last years. Several instrumentation and measurement applications require electronic circuits functioning reliably in HT. The analog-to-digital converter (ADC) and the operational amplifier (op-amp) are essential parts of measurement systems and circuits. They are the major parts of the analog front end of a conditioning signal circuit. Modeling HT electronic (HTE) components is a challenging task. The motivation of this paper is to describe an appropriate choice of the ADC and op-amp modeling approaches for HT ranges. The context of HTE systems is briefly described here and allows us to understand the challenges of such modeling. Comparing most known techniques enables us to make a suitable modeling choice for the HT. An appropriate methodology for modeling is presented. Some temperature-dependent models of ideal and nonideal ADC and op-amp are developed. The comparison of the simulation and experimental results is described to validate our approach choice.