This paper evaluates the prediction of stability of various symmetric cross coupled low-pass sigma delta(ΣΔ) modulators, by using the describing function theory. The symmetric cross coupled low pass ΣΔ modulator, enhances performance and stability when compared to conventional noise shaping sigma delta modulators and achieves up to 2Nth order noise shaping from N-path cross coupling with better in-band noise rejection without sacrificing conversion rate and bandwidth. Here, over-loading levels of symmetric cross coupled ΣΔ modulatorsare predicted and compared with time domain simulations for sinusoidal signals. The relationship between stability, NTF and quantizer levels has also been investigated.
Sabarinath, Prakash, J., Jose, B. R., & Mathew, J. (2015). Overloading prediction in symmetric cross coupled low-pass sigma delta modulators. In Procedia Computer Science (Vol. 46, pp. 1223–1229). Elsevier B.V. https://doi.org/10.1016/j.procs.2015.01.037