Energy efficient switching scheme based on MSB-split structure for SAR ADC

An energy efficient switching algorithm for low voltage SAR ADC is presented. By the combination of MSB-split and merge-and-split techniques, this switching method consumes negative energy in the MSB bit switching, which contributes to 99.76% switching energy reduction comparing to the conventional solution. Furthermore, without requiring for a third reference voltage makes it especially suitable for ADC design under low supply voltage. Additionally, LSB-down technique is employed, which reduces the total capacitor DAC area by 50%. The simulated differential-nonlinearity and integrated-nonlinearity are 0.27 and 0.21LSB, respectively, demonstrating that the proposed switching algorithm has a relatively good linearity.