HIGH LINEARITY BALANCED PUSH-PULL DC AMPLIFIER WITH LOW ERROR OF ZERO OFFSET

Abstract

In various analog-to-digital and digital-to-analog systems, current scalers-converters (CSC) are widely used. It is important to note that since a large purely parasitic parameters of integrated circuits are capacitances, the application of the principles of amplification and conversion of currents has an advantage over the principle of conversion and amplification of voltages. It should be noted that different approaches to the structural and schematic implementation can be used to construct the CSC. Particularly specific is the construction of an CSC with a grounded load. Also, various options for constructing stable current generators based on operational amplifiers are widely used, however, the complexity of this approach is the need to use precision resistors. The authors propose a different approach to the construction of highly linear CSC. It consists in the use of high-linear high-resistance current mirrors with one or two outputs. However, this approach is not well known, so the topic of the article devoted to the principles of constructing high-linear push-pull scalers-current converters based on high-linear current mirrors is relevant. The article proposed a method for constructing scalers-current converters with high output supports and high linearity of the transmitted characteristics. The static and dynamic characteristics of the CSC, such as the bandwidth of the input signal in the frequency range, the linearity error of the transfer characteristic, and the small-signal output impedance, have been analyzed using computer simulation. The authors have proved that an CSC with a series connection of CM has a higher output impedance at the same time, as the use of CM with two parallel outputs has a smaller error in the linearity of the transfer characteristic.