A novel split capacitor array switching scheme with proportional coefficient for SAR ADC

Abstract

A novel switching scheme with proportional coefficient for successive approximation register analog-to-digital converter is presented in this work. The proposed switching scheme realize proportional coefficient by means of charge-sharing, which can achieve a high energy efficiency. Due to the split capacitor array structure is adopted here, the total capacitance can be reduced by 96.9% over the conventional structure. Moreover, the bridge capacitor is the unit capacitor, which is very convenient for layout design and capacitance matching. Furthermore, the proposed switching scheme reduces the energy by 99.9% compared with the conventional architecture through using the MSB-split switching structure and the single-side method. The proposed switching scheme also has a good performance in reset energy consumption and linearity. Based on the MATLAB simulation results, the maximum differential nonlinearity and maximum integral nonlinearity results of the proposed switching scheme are 0.626 LSB and 0.727 LSB, respectively.