Спеціалізовані двотактні підсилювачі струму для аналогової частини багатоканальних АЦП

Abstract

The article is devoted to the analysis of the construction of specialized push-pull direct current amplifiers with increased linearity of the transfer characteristic based on the method of balancing cascade currents, which are used to build converters of analog signals. The schemes of specialized push-pull direct current amplifiers with bidirectional paraphase outputs proposed by the authors are considered. The specificity of the current balancing method based on the bi-directional current reflector and the bi-directional phase-splitter of the input current, is analyzed. The circuits of the balancing and amplifying cascades with two and four outputs, which are used in the intermediate stages of push-pull direct current amplifiers, are also given and analyzed. Analytic expressions are derived for the calculation of low-signal current gain factors, both for individual components of the output currents and the through transmission factor in the balance mode. In addition, an expression is obtained for the through small-signal gain factor, and also the dependences showing a change in the overall through transmission factor within the range of the output signal are also given. Linearity errors resulting from these changes are analyzed.