C-JFET OpAmp on “Folded” Cascode with Compensation Channel for the Systematic Component of the Zero Bias Voltage

Abstract

The article considers the original operational amplifier (OpAmp) circuits. The OpAmps is made on complementary FETs, which have a control pn-junction (C-JFET) manufactured by JSC “Integral”. The novelty of this OpAmp circuits is the introduction of identical uncontrolled JFET dynamic loads. This circuit technique minimizes the systematic component of the zero bias voltage in a wide temperature range ($-197\div 27^{\circ}$C) and increases the gain (up to 92 dB) of the OpAmp. Mathematical calculations of the proposed OpAmps are given. The authors of the article recommend the developed C-JFET OpAmps for low-noise, low-temperature and radiation-resistant A/D and analog interfaces (for example, comparators, signal converters, active RC/RLC filters).