A Second-Order Sigma-Delta Modulator with Built-in VGA to Improve SNR and Harmonic Distortion

@inproceedings{Li1999ASS,
  title={A Second-Order Sigma-Delta Modulator with Built-in VGA to Improve SNR and Harmonic Distortion},
  author={Xiaopeng Li and Mohammed Ismail},
  booktitle={Great Lakes Symposium on VLSI},
  year={1999}
}
A modified architecture of the second-order switchedcapacitor modulator is proposed. A simple four-transistor variable gain attenuator is included in the architecture which continuously adjusts the reference voltage of the quantizer feedback. This improves the output SNR for small signal input and reduces the harmonic distortion for large signal input… CONTINUE READING