基于XFAB工艺参数,设计了一种不受电容电压系数影响的高速高精度SAR ADC.在理论上定性分析了电容电压系数对高速高精度SAR ADC的影响,并使用Matlab进行定量分析.分析结果表明,1阶与2阶电容电压系数对ADC性能的影响具有不同的特点.针对1阶电容电压系数,使用改进的分裂电容结构进行消除;针对2阶电容电压系数,使用分段数字补偿来进行校正.校正完成以后,电容电压系数引起的非线性误差可以从±11.7 LSB降到±0.5 LSB以下,无杂散动态范围可以提高10 dB以上.“,”Based on the XFAB process parameters,a high speed and high resolution successive approximation register (SAR) ADC structure which was not affected by capacitor voltage coefficient had been proposed.At first,the influences of capacitor voltage coefficient on the characteristics of high speed and high resolution SAR ADC were analyzed qualitatively.Then numerical analysis was carried out by Matlab.The results showed that the first and second order capacitor voltage coefficients had different influences on the SAR ADC.The influence of the first order capacitor voltage coefficient could be eliminated by the improved split structure,and the influence of the second order capacitor voltage coefficient could be diminished by the segmentation digital compensation.After correction,the nonlinear errors caused by capacitor voltage coefficient could be reduced to-4-0.5 LSB from ± 11.7 LSB,and the SFDR could be increased by 10 dB.