帰還係数可変化によるΔΣ型A/D変換器の広ダイナミックレンジ化

抄録

In this paper, we propose the expanding technique of the ΔΣ ADC dynamic range by changing a feedback coefficient. The feedback coefficient is switched from 1 to 0.5 according to the input signal voltage value. It can improve the SNR at the small amplitude input reducing the quantization noise by the small feedback coefficient. We confirmed by the circuit simulation that the proposed circuit archives a dynamic range of 102 dB, and improves SNR of 6 dB from the conventional circuit.