Besides the related quantization error of ADC the actual conversion digit,the acquisition accuracy is also affected by the noise and channel signal crosstalk. In order to improve the acquisition system precision,oversampling the input signal by controlling ADC and realizing the extraction filtering and averaging algorithm for improving ADC conversion resolution within FPGA is proposed. The method is realized by using the cheap chip to achieve the preci-sion index instead of the expensive chip,and the method is easy to implement. The histogram analysis was used to compare the collected data under different working modes. The results show that this method can reduce the measurement error of the system effectively and improve the measurement accuracy of the system.%采集精度除了与ADC的实际转换位数相关的量化误差有关外,还会受到一些噪声和通道间信号串扰的影响.为提高采集精度,提出通过FPGA控制ADC对输入信号进行过采样,然后在FPGA内部实现抽取滤波和求平均值算法提高ADC转换分辨率.该方法用廉价的芯片实现了只有昂贵芯片才能得到的精度指标,并且易于实现.最后利用了直方图分析法对不同工作方式下所采集的数据进行了分析比较,结果显示该方法能够有效的减小系统的测量误差,提高了系统测量精度.
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