一种高性能Σ-ηA/D转换器的设计

The Design of a High Performance Σ-Δ A/D Converter

对于传统的Σ-ΔA/D转换器(ADC),其信噪比(SNR)随输入信号强度的减小而降低。文章根据自适应理论提出了一种自适应Σ-ΔADC的解决方案及相应的电路实现。该电路设计充分考虑了在电路实现中误差的存在,给出了误差自校正电路。仿真结果表明,这种自适应Σ-ΔADC的SNR几乎与输入信号的强度无关。

For a conventional sigmadelta analogtodigital converter (ΣΔ ADC), the signaltonoise ratio (SNR) decreases with the reduction of input signal strength The existing concept of selfadaptive quantization is applied to the design of a ΣΔ ADC to improve its SNR An adaptive algorithm is proposed, and its circuit implementation is described in the paper Taking errors present in the implementation into consideration, an error selfcorrection circuit is designed Results from simulation indicate that, for this selfadapted ΣΔ ADC, the signaltonoise ratio (SNR) has little to do with the strength of signals