Continuous Time Delta-Sigma Modulators with Arbitrary DAC Waveforms

In this paper a straight-forward approach to extract the equivalent loop-gain of a continuous time Delta-Sigma modulator with an arbitrary DAC waveform in z-domain is presented. In this approach the arbitrary DAC waveform is approximated by the infinite number of rectangular pulse shapes. Then simply using the transformations available in literature for a rectangular DAC pulse shape and applying superposition on each rectangular pulse shape, the loop-gain of the system is derived in z-domain.

Keywords:

Continuous time , Delta-Sigma modulator , Arbitrary DAC waveform