Low-Power High-Linearity Switching Procedure for Charge-Redistribution SAR ADC

摘要

An energy-efficient capacitive switching scheme in successive approximation register (SAR) analogue-to-digital converter (ADC) is proposed for biomedical applications. With novel sequence initialization and by reducing the up-switching steps during the A/D conversion, the average switching energy of this proposed procedure is reduced by over 98.7% compared with the conventional architecture after taking the parasitic capacitance into consideration. The number of capacitors in the proposed capacitor array is just 1/4 of that in the conventional switching scheme. Moreover, behavioral simulation performed in MATLAB for the 10-bit SAR ADC shows that the linearity performance of this proposed switching scheme is much better than that of previous architectures.