A structure of cascading multi-bit modulators without dynamic element matching or digital correction

A new structure of cascading multi-bit Sigma Delta modulators is proposed in this paper. Using a multi-bit quantizer in each stage, the modulator's performance is largely improved. Furthermore this structure does not require any dynamic element matching or digital correction circuit to attenuate the non-linearity error. This is because the modulator's first stage uses a multi-bit quantizer, but only the most significant bit is used to generate the feedback. By this way the non-linearity error is eliminated. Simulation results are demonstrated with circuit non-idealities considered.