High-voltage broadband amplifier for a frequency range of up to 30 MHz and a maximum output voltage of up to 30 V

The main application area of the high-voltage signal amplifier (HVSA) is to amplify the output voltage of measuring calibrators to a level sufficient for metrological certification of the most commonly used thermoelectric converters within their frequency range. A characteristic feature of existing operational amplifiers is that their maximum output voltage decreases as the frequency range in which they operate increases. To address the shortcomings of the existing design, a prototype with an increased number of amplifier stages was developed and implemented. The integration of modern amplifiers enabled an expansion of the operating voltage and frequency range. The HVSA comprises a series of amplifiers operating with supply voltages lower than the output voltage range. This paper proposes the development of HVSAs through multi-stage integration of low-voltage operational amplifiers with virtual power supplies and independent parallel current feedback. The study presents circuit diagrams for HVSAs, matrix equations for analytical and numerical determination of the gain coefficient, and equations for errors as functions of the component base. A prototype amplifier was developed on an aluminium nitride ceramic board, which serves both as a printed circuit board and as a heat sink for heat diffusion due to the high thermal conductivity of aluminium nitride. The experimental data, derived from a comparison of dynamic characteristics of the existing device and the newly developed prototype, confirm the usability and effectiveness of adopting this approach. Metrological studies were conducted, confirming the suitability of the developed prototype for use in a military secondary measurement standard for the unit of electric voltage in the range of 0.1 V to 1000 V AC and frequencies from 10 Hz to 30 MHz, according to the ВВЕТУ 08-07-01-09 measurement standard.