Linearity analysis on a series-split capacitor array for high-speed SAR ADCs

A novel capacitor array structure for successive approximation register (SAR) ADC is proposed. This circuit efficiently utilizes charge recycling to achieve high-speed of operation and it can be applied to high-speed and low-to-medium-resolution SAR ADC. The static linearity performance, namely the INL and DNL, of the proposed structure is theoretically analyzed and behavioral simulations are performed to demonstrate its effectiveness. Simulation results show that to achieve the same conversion performance the proposed capacitor array structure can reduce the average power consumed from the reference ladder by 90%, as compared to the binary-weighted splitting capacitor array structure.