Approaches to the implementation of noise-coupling in continuous-time Delta-Sigma modulators

In this paper, two novel approaches to the implementation of noise-coupling in continuous-time Delta-Sigma modulators are presented. The first approach is based on an enhanced split architecture while the second approach on noise-coupling between two stages. The latter yields a very robust architecture as the requirements on the accuracy of coefficient matching between the paths are quite low. Compared to the stand-alone modulator, the performance is thus significantly improved while the stability of the system is still determined by the single-stage modulator. High-level simulations performed on a dual-path noise-coupled second-order continuous-time Delta-Sigma modulator implemented as a Verilog-A model prove the feasibility of the approach.