CIRCUIT FEATURES OF HIGH-TEMPERATURE ANALOG MICROCIRCUITS ON GAN AND GAAS TRANSISTORS
Abstract
High-temperature integrated circuits, which remain operational at temperatures above 150°C, are required in many areas of industry: aerospace, aviation and automotive instrumentation, the petrochemical industry, electric power, and military electronics. Currently, foreign enterprises are mass-producing several high-temperature analog and analog-to-digital microcircuits based on silicon CMOS SOI structures – ADS1278-HT, ADS1282-HT, ADS8320-HT, INA129-HT, INA333-HT, OPA2333-HT, etc. Hightemperature silicon operational amplifiers and ADCs have also been developed in the Russian Federation. However, the maximum operating temperature of such products does not exceed 200°C due to the limitations of silicon technologies. For this reason, wide-bandgap semiconductors such as silicon carbide (SiC), gallium nitride (GaN) and gallium arsenide (GaAs) are most often considered as semiconductors intended for high-temperature microcircuits, which provide a number of characteristics necessary for hightemperature applications: wide bandgap, high carrier saturation velocity and low concentration of intrinsic charge carriers. An overview of the problems of developing high-temperature analog microcircuits based on GaN and GaAs transistors is presented. The features of the current-voltage characteristics of GaN and GaAs field-effect transistors operating in depletion and enhancement modes, electrical circuits of typical analog devices (charge-sensitive and operational amplifiers, comparators, current followers) and logical gates are considered. It is concluded that it is advisable to carry out the circuit synthesis of GaAs analog microcircuits using field-effect transistors with an n-type channel operating in depletion mode and p-n-p heterostructure bipolar transistors. Examples of such schemes are given. The relevance of the above research is related to the problems of import substitution of microcircuits based on widebandgap semiconductors (GaN, GaAs), providing a wide range of operating temperatures (over +150°C).
