Simulation model of delta-sigma modulator

The segment of precision ADC is filed by the converters based on delta-sigma modulator (DSM). Such ADC are in the line of leading companies and are very popular on the market. These ADC have highest parameters but there are many applications which demand more precision converters. The example of this task is precision resistance measurement using replacement method. There the main signed component of instrumental error is proportional to integral nonlinearity of ADC´s transfer function (TF). This paper investigates the character of TF´s nonlnearity of ADC based on DSM for providing adequate forming the interpolation curve. A simulation model is developed which consists of DSM as the linear combination of nonlinear components and provides access to parameters of these components.