Abstract:

Sigma-delta ADC (AD Converter) is usually used in data acquisition system. It is necessary to research the process in which the power spectrum of quantization noise is shaped in ADC so that we can match the signal's bandwidth between the ADC's output and the next module's input. The higher-order sigma-delta modulator was modeled and the power spectrum shaping for quantization noise was analyzed. The theoretical analysis and the simulation result show that the quantization noise can be largely suppressed by over-sampling in higher-order sigma-delta ADC.

Key words: data acquisition, A/D converter, power spectrum, quantization noise, over-sampling