The IUP Journal of Electrical and Electronics Engineering
Output Stages of Operational Amplifiers Based on Gallium Arsenide NJFET and Bipolar PNP Transistors

Article Details
Pub. Date : April, 2023
Product Name : The IUP Journal of Electrical and Electronics Engineering
Product Type : Article
Product Code : IJEEE020423
Author Name : Zhuk A A, Prokopenko N N, Chumakov V E and Kunts A V
Availability : YES
Subject/Domain : Engineering
Download Format : PDF Format
No. of Pages : 21



The paper considers schematics of low-power Output Stages (OS) and class AB Buffer Amplifiers (BA) for analog microcircuits realized on arsenide gallium n-channel field-effect transistors with control p-n junction and arsenide gallium bipolar p-n transistors within combined processes. The developed output stages are characterized by a relatively small static current consumption (about 100-200 Ω A), provide operation at load resistances greater than 1-2 k Ω, and have, as a rule, an increased input resistance. The maximum values of BA output currents for the positive polarity of the output voltage (vout) are determined by the width of the JFET channel, and for the negative vout half-wave, by the base current amplification factor of the BJT. In this connection, it is recommended to use compound Darlington p-n-p transistors in BA circuits. The results of computer simulation of the amplitude characteristics of pushpull BAs in LTspice at different load resistances show that the proposed circuit solutions provide the maximum amplitudes of positive and negative output voltages, close to the supply voltages. The circuit solutions considered are recommended for use in low-power operational amplifiers, including those operating under harsh operating conditions. The novelty of the paper lies in the investigation of a family of new pushpull class AB output stages for operational amplifiers, protected by 4 Russian patents and implemented under severe circuit restrictions on the types of GaAs transistors used (nJFET and nBJT).


A significant number of output stage circuits used in analog microelectronic products, including operational amplifiers, which are implemented on bipolar (BJT) and field (JFet, CMOS, CNI, CNS, etc.) transistors, and in their joint connection, are known (Liu et al., 1992; and Peatman et al., 2007; Fresina, 2011; Zampardi et al., 2012; Horowitz


Output stage, Buffer Amplifier (BA), Operational amplifier, Arsenide-gallium field-effect transistors, Arsenide-gallium bipolar transistors, Combined GaAs processes