Gallium Arsenide Op-Amp's Output Stage for High Temperature Operation

The features of the operational amplifier's output stage, which is adapted to gallium arsenide technological processes that allow the use of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{p - n - p}$</tex> bipolar transistors and junction field-effect transistors with an <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$n$</tex> channel, are considered. The basic scheme of the output stage, protected as an intellectual property object, was investigated in the LTspice environment. In this scheme, the adjustment of the deadband on the amplitude response is provided using special sub-schemes for the displacement of the transistor's static mode at different load resistances, namely by adjusting the resistance and connecting the reference current source in the load sub-scheme. Three examples of incorporation of the proposed gallium arsenide output stage into operational amplifier structures are presented. The use of gallium arsenide transistors makes it possible to expand the operational amplifier's operating temperature range to the level of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$+200 \ldots+250^{\circ} \mathrm{C}$</tex>. The presented circuitry solutions are promising for further research on technological processes that include other wide-band semiconductors, for example, silicon carbide, gallium nitride, etc.