Analysis of the Instrumentation Amplifiers Errors by Simulation Modeling
Anton A. Gulko, Andrey Nikolayevich Serov · 2021 International Ural Conference on Electrical Power Engineering (UralCon) · 2021
Currently, instrumentation amplifiers are widely used to construct measurement channels of measurement and control equipment. This amplifiers are differential, which makes it possible to obtain an output signal proportional to the difference between the input voltages. The value of the voltage gain, depending on the design features, can be set by using an additional external resistance, external jumpers or by applying an external control digital code. Like any measuring transducer, an instrumentation amplifier is characterized by an additive, multiplicative, and nonlinear error component. Accounting for each of the listed error components in the total measurement error of the considered signal parameter is often a difficult task. For this reason, simulation modeling is widely applied. This paper discusses the principles of constructing a model of an instrumental amplifier, taking into account the imperfection of its transfer characteristic. The presence of additive and multiplicative components of the error, transfer function nonlinearity, magnitude response, finite input and output ranges are taken into account. An existing model obtained by using the Spice-model in Tina-TI program (developed by Texas Instruments company) is considered and a model was performed by using the Simulink software program. The resulting model makes it possible to simulate instrumental amplifiers of all known types, as well as decisive amplifiers, dividers and other analog and digital measurement converters.