Energy-efficient Sub-DAC merging with charge-sharing switching scheme for SAR ADC

A novel energy-efficient sub-DAC merging with charge-sharing switching scheme for successive approximation register (SAR) analogue-to-digital converter (ADC) is presented. The proposed switching scheme can achieve no switching energy consumption in the first comparison cycle by using the top-plate sampling technique. Furthermore, sub-DAC merging with charge-sharing technique is performed for the rest of the comparison cycles. Compared to the conventional scheme, the proposed switching scheme achieves 99.18% less switching energy and 93.75% less number of capacitors.