Design and Implementation of a Band-Pass SD Modulator Model with Non-Idealities using Simplorer VHDL

Abstract

This paper describes an implementation of a band-pass sigma-delta modulator behavioral model in Simplorer VHDL AMS. The model includes most of the non-idealities which affect the performance of the component, such as sampling jitter, kT/C noise and operational amplifier parameters. A comparison with another model, implemented in MATLAB SIMULINK by Brigati et al., is made to highlight and validate the proposed model. The spectrum plot and the Power Spectral Density of the output signal are also presented to evaluate the characteristics of the modulator model. Simulation results obtained using a second-order band-pass sigma-delta modulator demonstrate the validity of the model by the mean of estimating signal-to-noise and distortion ratios and some non-linearity errors such as differential non-linearity and integral non-linearity.