A novel decoder for ΣΔ modulator providing both high resolution and low latency

Sigma delta modulators can be viewed as simple precise encoders for analog signals. While the oversampling technique has received wide attention, its full potential is not realized because of the lack of an optimum decoder. A new decoding method is proposed in this paper which uses the inherent signal flow structure of an encoder to achieve optimal decoding. The proposed decoding method can achieve the following advantages over other decoding methods: (A) high resolution, much lower mean square error; (B) consistent output (tested by DC inputs) compared to sine filtering or other linear decoding methods; (C) much shorter latency compared to FIR filters; and (D) input noise reduction right at the decoding stage (it will extract the signal from input noise) since it uses the correlation function of one-bit stream and the robustness characteristic (it will work for un-modeled noise)