Quasilinear analytical methods for /spl Sigma//spl Delta/ modulation

A quasilinear model is utilized to represent the nonlinear component, one-bit quantizer, within a second order lowpass sigma-delta (/spl Sigma//spl Delta/) modulator such that the theoretical shaped noise spectra with respect to diverse sinusoidal inputs can be obtained. A highly important contribution of exploring the theoretical shaped noise spectra is to confidently design the required complementary decimation stage/filter in lieu of trial and error approaches as well as overstrained conditions. A complete sigma-delta modulation (/spl Sigma//spl Delta/M) system is constructed and well controlled. The consistency of the theoretical and simulation results demonstrates the robustness of our analytical strategy. This analytical approach can also be applied to bandpass and MASH architectures.