Nonlinear Quantization Technique for Multibit Sigma-Delta Modulators

This paper presents a nonlinear quantization technique applied in a multibit sigma-delta $\Sigma\triangle$ modulator. The technique is based on the unscented transform and utilizes a flash topology to modeling the quantizer of the modulator. To verify the proposed methodology a 4-bit, first-order and second-order $\Sigma\triangle$ modulators were modeled and simulated. Simulation results confirm the validity of the technique and in this case has been shown that significant improvements can be achieved on SINAD compared with the linear multibit modulators.