一种提高测量分辨率和信噪比的方法  

A Method to Increase the Resolution and SNR of Measurement

作　　者：李锂[1] 高丽[1] 

机构地区：[1]西安工业大学电子信息工程学院,西安710032

出　　处：《西安工业大学学报》2006年第4期333-335,共3页Journal of Xi’an Technological University

摘　　要：在测量精度要求较高的地方(如直流电压测量到小数点后4位;温度的1/100℃变化的测量等),通常采用高分辨率的片外ADC来实现,增加了产品的成本.但采用过采样求均值的方法,既可以不采用片外ADC,又能提高ADC测量的分辨率和信噪比,很好地控制了产品成本,又提高了产品的性能.在对过采样和求均值的理论分析的基础上,得出了“对噪声源的特性为白噪声的信号,每增加一位分辨率可以通过用4倍的过采样频率进行采样来达到,而分辨率每增加一位将使信噪比增加6dB”的结论.In case of high accuracy measurement （for example.measuring the voltage of direct to the 4th decimal place;measuring the temperature to the 2nd decimal place etc. ）,extra ADC of high resolution is usually adpoted. Therefor the product cost is increased. With the method of over sampling and averaging, the resolution and signal noise rate（SNR）can he raised without extra ADC. The product cost is controlled and its function is achieved. By analyzing the theory of over sampling and averaging, the conclusion is educed that for white noise signal,the addition of each hit of resolution can he achieved via fourfold sampling frequency. And the addition of each bit will approximately increase SNR to 6bB.

关 键 词：过采样 求均值 A/D转换 分辨率 噪声 

分 类 号：TM935[电气工程—电力电子与电力传动]