【摘要】 本文利用电容器的吸附效应模型,对吸附效应在四斜A/D 转换中的影响作了深入地分析,从中找到了A/D 转换的线性度、零点漂移、灵敏度与吸附参数之间的关系,并给出了补偿方法。在DO—13型高准确度、高灵敏度和高位数数字电压表研制中,利用这种方法实现了整机误差3.5ppm,转换灵敏度3μV,达到八十年代初期国际水平。更多还原

【Abstract】 Although the daul slope integrating A/D converter of the lowand medium level accuracy and sensitivity has the advantages of high CMRR(Common Mode Rejection Ratio),good linearity and low cost,which make itbe used widely,it has two serious disadvantages,the senselessness in the re-gion of zero and the absorption-effect of the integrating capacitor Hence to so-lve the problem of the absorption-effect theoretically is very important and itis quite necessary to find a compensation method for constructingthe four slopeA/D converter and finally the digital voltmeter of high quality.In the paper the influence of the capacitor’s absorption-effect on four slopeintegrating A/D converter is deeply analysed using the capacitor’s absorption-effect model.from the analysis we find the relationship between the absorptionparameter τ_n and the linearity,the zero drift and the sensitivity of theA/D conversion,and at last the compensating method is given.In the DO-13Type Digital Valtmeter,which is one of high accuracy,high sensitivity andlarge digital number,this method is utilized successfully with the result of3.5ppm whole device error and 3μV conversion sensitivity,which are at theworld level at the beginning of the eightys of the twentyth century.更多还原