说明：  高精度、低功耗模数转换器是当今集成电路设计模拟领域的研究热点之一，采用sigma-delta调制原理和过釆样原理的模数转换器广泛使用在音频、数字网络、电子测量等系统中。此类模数转换器，为降低信号带内的量化噪声功率，而釆用噪声整形技术，为提高模数转换器的信噪比，使用过采样技术，将基带中的量化噪声调制到了高频区域，这样就增加了基带中的信噪比，也就是增加了转换器的有效量化位数，由于采用较高的过采样率，Sigma-Delta ADC的转换速率相对较低，高精度和较低转换速率的特点，使得Sigma-Delta ADC特别适用于测量。
(High precision, low power analog to digital converter is in today s integrated circuit design simulation has become one of the hot research field, the principle of sigma-delta modulation and ADC sampling principle is widely used in audio, digital network, electronic measurement system. This type of analog-to-digital converter, in order to reduce the quantization noise power signal in the band, and the use of noise shaping technique, in order to improve the SNR of the analog-to-digital converter, using the oversampling technique, modulate the quantization noise in the baseband to the high frequency region, which increases in the baseband signal to noise ratio, that is to increase the effective number of quantization bits converter, due to the sampling rate is high, the Sigma-Delta ADC conversion rate is relatively low, the characteristics of high accuracy and low conversion rate, so that Sigma-Delta ADC is especially suitable for measuring)