Teplytskyi M. Push-pull DC amplifiers with balancing feedback for multi-bit parallel DAC

The object of study - functioning process of the proposed high-speed push-pull dc amplifiers for multi-bit parallel DAC; the purpose is to improve static and dynamic characteristics of the push-pull dc amplifiers for multi-bit parallel DAC by applying the proposed methods of structural and functional organization using the balance feedback to improve their performance and linearity of transfer characteristic and to reduce additive error; methods of the theory of linear integrated circuits and amplifiers, theory of electrical and magnetic circuits, as well as theory of systems with feedback and computer modeling were used; theoretical results: method of adjusting the input bias current zero and reducing its temperature drift for push-pull high-linear high-speed current amplifiers by the use of structural redundancy with a bias zero current sensor, and the block that generates a compensation current was the first time proposed; mathematical models of the transfer characteristics for balanced feedback circuit, which is implemented on the basis of bidirectional current reflector was also the first time proposed; further development of the method of structural and functional organization of high-speed push-pull dc amplifier for multi-bit DAC, which differs from existing approaches by using the balance feedback and specialized push-pull current reflectors was given; further development of the method of specialized push-pull current mirrors construction, which differs from the existing by taking into account their requirements for input and output impedances and possibility to use these reflectors in pre-output or output stages, was also given. Practical results - developed a number of practical solutions that are protected by patents of Ukraine, in particular, the compensation current generator scheme for parametric adjustment of the bias zero current of DC amps; high-linear DC amps schemes with bandwidth close to the cutoff frequency amplification of bipolar transistors at 100 MHz-1 GHz; high-linear high-speed DC amps circuits with low input current and low temperature drift; improved characteristics of the sound channels settings analyzer, in particular, such as operating frequency band, THD level determination by using DAC, that includes developed high-speed precision DC amplifier. The degree of implementation - results are implemented by the State Company "National Radio Company of Ukraine" and in the educational process at the Department of Computer Science of Vinnytsia National Technical University. Sphere (industry) of use - systems of direct digital synthesis of analog signals and audio channels analyzers.