Noise-cancelling sturdy MASH delta-sigma modulator

A noise-cancelling sturdy multi-stage noise-shaping (NC-SMASH) structure that cancels first stage quantization error is proposed. Without any modification to existing analog blocks in the traditional sturdy MASH (SMASH) structure, adding digital noise-cancelling filters (NCFs) will cancel the first stage quantization error. This quantization error cancellation, unlike the traditional MASH structure, is less sensitive to analog loop filter matching and digital filters. This is because the leakage of the first stage quantization error is shaped by the overall noise transfer function (NTF) of the proposed NC-SMASH structure. Therefore, this technique allows using low gain opamps without signal-to-noise ratio degradation and reducing the number of the first stage quantization levels. Detailed Matlab simulation results are provided to prove the efficiency of the proposed modulator.