STUDY OF FAST FLOAT POINT 10-12 BIT AD CONVERTER

摘要

Discretisation error is responsible for one of major metrological problems concerning digital instruments such as AD converters. Designing the device of stable relative error would provide the ideal solution. The aim of this work is to introduce the problem and propose the float point AD converter with variable gain amplifier (VGA) as a solution. The proposed fast setting gain with flash AD converter as a coarse one is the new approach. The conversion consists of two stages coarse and fine one. The VGA works as pre-processing circuit for fine conversion. The VGA gives the stable signal value according to the coarse conversion. In result the relative error of conversion is stable. Programmable correction of the gain will be presented. The results of simulation confirm the measurement error stabilisation and high frequency operation.